nist-gov/www.nist.gov/topic-terms/optical-physics-and-communications
2025-03-05 18:59:57 +00:00

1508 lines
100 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# ">
<head>
<meta charset="utf-8" /><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.283.2.min.js.LICENSE.txt */
(()=>{var e,t,r={122:(e,t,r)=>{"use strict";r.d(t,{a:()=>i});var n=r(944);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.R)(3);if(!t||"object"!=typeof t)return(0,n.R)(4);const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{if(null===e[a]){r[a]=null;continue}Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.R)(1,e)}return r}catch(e){(0,n.R)(2,e)}}},555:(e,t,r)=>{"use strict";r.d(t,{Vp:()=>c,fn:()=>s,x1:()=>u});var n=r(384),i=r(122);const o={beacon:n.NT.beacon,errorBeacon:n.NT.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){try{const t=c(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}function c(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function u(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.a)(t,o);const r=(0,n.nY)(e);r&&(r.info=a[e])}},217:(e,t,r)=>{"use strict";r.d(t,{D0:()=>m,gD:()=>v,xN:()=>h});r(860).K7.genericEvents;const n="experimental.marks",i="experimental.measures",o="experimental.resources",a=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var s=r(614),c=r(944),u=r(384),l=r(122);const d="[data-nr-mask]",f=()=>{const e={feature_flags:[],experimental:{marks:!1,measures:!1,resources:!1},mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{ajax:{deny_list:void 0,block_internal:!0,enabled:!0,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},get feature_flags(){return e.feature_flags},set feature_flags(t){e.feature_flags=t},generic_events:{enabled:!0,autoStart:!0},harvest:{interval:30},jserrors:{enabled:!0,autoStart:!0},logging:{enabled:!0,autoStart:!0},metrics:{enabled:!0,autoStart:!0},obfuscate:void 0,page_action:{enabled:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,autoStart:!0},performance:{get capture_marks(){return e.feature_flags.includes(n)||e.experimental.marks},set capture_marks(t){e.experimental.marks=t},get capture_measures(){return e.feature_flags.includes(i)||e.experimental.measures},set capture_measures(t){e.experimental.measures=t},capture_detail:!0,resources:{get enabled(){return e.feature_flags.includes(o)||e.experimental.resources},set enabled(t){e.experimental.resources=t},asset_types:[],first_party_domains:[],ignore_newrelic:!0}},privacy:{cookies_enabled:!0},proxy:{assets:void 0,beacon:void 0},session:{expiresMs:s.wk,inactiveMs:s.BB},session_replay:{autoStart:!0,enabled:!1,preload:!1,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,fix_stylesheets:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){a(t)?e.mask_selector="".concat(t,",").concat(d):""===t||null===t?e.mask_selector=d:(0,c.R)(5,t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){a(t)?e.block_selector+=",".concat(t):""!==t&&(0,c.R)(6,t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,c.R)(7,t)}},session_trace:{enabled:!0,autoStart:!0},soft_navigations:{enabled:!0,autoStart:!0},spa:{enabled:!0,autoStart:!0},ssl:void 0,user_actions:{enabled:!0,elementAttributes:["id","className","tagName","type"]}}},g={},p="All configuration objects require an agent identifier!";function m(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function h(e,t){if(!e)throw new Error(p);g[e]=(0,l.a)(t,f());const r=(0,u.nY)(e);r&&(r.init=g[e])}function v(e,t){if(!e)throw new Error(p);var r=m(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}},371:(e,t,r)=>{"use strict";r.d(t,{V:()=>f,f:()=>d});var n=r(122),i=r(384),o=r(154),a=r(324);let s=0;const c={buildEnv:a.F3,distMethod:a.Xs,version:a.xv,originTime:o.WN},u={customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,onerror:void 0,ptid:void 0,releaseIds:{},appMetadata:{},session:void 0,denyList:void 0,timeKeeper:void 0,obfuscator:void 0,harvester:void 0},l={};function d(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!l[e])throw new Error("Runtime for ".concat(e," was never set"));return l[e]}function f(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");l[e]={...(0,n.a)(t,u),...c},Object.hasOwnProperty.call(l[e],"harvestCount")||Object.defineProperty(l[e],"harvestCount",{get:()=>++s});const r=(0,i.nY)(e);r&&(r.runtime=l[e])}},324:(e,t,r)=>{"use strict";r.d(t,{F3:()=>i,Xs:()=>o,xv:()=>n});const n="1.283.2",i="PROD",o="CDN"},154:(e,t,r)=>{"use strict";r.d(t,{OF:()=>c,RI:()=>i,WN:()=>l,bv:()=>o,gm:()=>a,mw:()=>s,sb:()=>u});var n=r(863);const i="undefined"!=typeof window&&!!window.document,o="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=i?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),s=Boolean("hidden"===a?.document?.visibilityState),c=/iPad|iPhone|iPod/.test(a.navigator?.userAgent),u=c&&"undefined"==typeof SharedWorker,l=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Date.now()-(0,n.t)())},687:(e,t,r)=>{"use strict";r.d(t,{Ak:()=>c,Ze:()=>d,x3:()=>u});var n=r(836),i=r(606),o=r(860),a=r(646);const s={};function c(e,t){const r={staged:!1,priority:o.P3[t]||0};l(e),s[e].get(t)||s[e].set(t,r)}function u(e,t){e&&s[e]&&(s[e].get(t)&&s[e].delete(t),g(e,t,!1),s[e].size&&f(e))}function l(e){if(!e)throw new Error("agentIdentifier required");s[e]||(s[e]=new Map)}function d(e="",t="feature",r=!1){if(l(e),!e||!s[e].get(t)||r)return g(e,t);s[e].get(t).staged=!0,f(e)}function f(e){const t=Array.from(s[e]);t.every((([e,t])=>t.staged))&&(t.sort(((e,t)=>e[1].priority-t[1].priority)),t.forEach((([t])=>{s[e].delete(t),g(e,t)})))}function g(e,t,r=!0){const o=e?n.ee.get(e):n.ee,s=i.i.handlers;if(!o.aborted&&o.backlog&&s){if(r){const e=o.backlog[t],r=s[t];if(r){for(let t=0;e&&t<e.length;++t)p(e[t],r);Object.entries(r).forEach((([e,t])=>{Object.values(t||{}).forEach((t=>{t[0]?.on&&t[0]?.context()instanceof a.y&&t[0].on(e,t[1])}))}))}}o.isolatedBacklog||delete s[t],o.backlog[t]=null,o.emit("drain-"+t,[])}}function p(e,t){var r=e[1];Object.values(t[r]||{}).forEach((t=>{var r=e[0];if(t[0]===r){var n=t[1],i=e[3],o=e[2];n.apply(i,o)}}))}},836:(e,t,r)=>{"use strict";r.d(t,{P:()=>c,ee:()=>u});var n=r(384),i=r(990),o=r(371),a=r(646),s=r(607);const c="nr@context:".concat(s.W),u=function e(t,r){var n={},s={},l={},d=!1;try{d=16===r.length&&(0,o.f)(r).isolatedBacklog}catch(e){}var f={on:p,addEventListener:p,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=g(n),c=m(e),l=c.length,d=0;d<l;d++)c[d].apply(a,r);var p=v()[s[e]];p&&p.push([f,e,r,a]);return a},get:h,listeners:m,context:g,buffer:function(e,t){const r=v();if(t=t||"feature",f.aborted)return;Object.entries(e||{}).forEach((([e,n])=>{s[n]=t,t in r||(r[t]=[])}))},abort:function(){f._aborted=!0,Object.keys(f.backlog).forEach((e=>{delete f.backlog[e]}))},isBuffering:function(e){return!!v()[s[e]]},debugId:r,backlog:d?{}:t&&"object"==typeof t.backlog?t.backlog:{},isolatedBacklog:d};return Object.defineProperty(f,"aborted",{get:()=>{let e=f._aborted||!1;return e||(t&&(e=t.aborted),e)}}),f;function g(e){return e&&e instanceof a.y?e:e?(0,i.I)(e,c,(()=>new a.y(c))):new a.y(c)}function p(e,t){n[e]=m(e).concat(t)}function m(e){return n[e]||[]}function h(t){return l[t]=l[t]||e(f,t)}function v(){return f.backlog}}(void 0,"globalEE"),l=(0,n.Zm)();l.ee||(l.ee=u)},646:(e,t,r)=>{"use strict";r.d(t,{y:()=>n});class n{constructor(e){this.contextId=e}}},908:(e,t,r)=>{"use strict";r.d(t,{d:()=>n,p:()=>i});var n=r(836).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},606:(e,t,r)=>{"use strict";r.d(t,{i:()=>o});var n=r(908);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.d,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.d);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},878:(e,t,r)=>{"use strict";function n(e,t){return{capture:e,passive:!1,signal:t}}function i(e,t,r=!1,i){window.addEventListener(e,t,n(r,i))}function o(e,t,r=!1,i){document.addEventListener(e,t,n(r,i))}r.d(t,{DD:()=>o,jT:()=>n,sp:()=>i})},607:(e,t,r)=>{"use strict";r.d(t,{W:()=>n});const n=(0,r(566).bz)()},566:(e,t,r)=>{"use strict";r.d(t,{LA:()=>s,bz:()=>a});var n=r(154);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n.gm?.crypto||n.gm?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n.gm?.crypto||n.gm?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},614:(e,t,r)=>{"use strict";r.d(t,{BB:()=>a,H3:()=>n,g:()=>u,iL:()=>c,tS:()=>s,uh:()=>i,wk:()=>o});const n="NRBA",i="SESSION",o=144e5,a=18e5,s={STARTED:"session-started",PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},c={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},u={OFF:0,FULL:1,ERROR:2}},863:(e,t,r)=>{"use strict";function n(){return Math.floor(performance.now())}r.d(t,{t:()=>n})},944:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.debug&&console.debug("New Relic Warning: https://github.com/newrelic/newrelic-browser-agent/blob/main/docs/warning-codes.md#".concat(e),t)}r.d(t,{R:()=>n})},284:(e,t,r)=>{"use strict";r.d(t,{t:()=>c,B:()=>s});var n=r(836),i=r(154);const o="newrelic";const a=new Set,s={};function c(e,t){const r=n.ee.get(t);s[t]??={},e&&"object"==typeof e&&(a.has(t)||(r.emit("rumresp",[e]),s[t]=e,a.add(t),function(e={}){try{i.gm.dispatchEvent(new CustomEvent(o,{detail:e}))}catch(e){}}({loaded:!0})))}},990:(e,t,r)=>{"use strict";r.d(t,{I:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},389:(e,t,r)=>{"use strict";function n(e,t=500,r={}){const n=r?.leading||!1;let i;return(...r)=>{n&&void 0===i&&(e.apply(this,r),i=setTimeout((()=>{i=clearTimeout(i)}),t)),n||(clearTimeout(i),i=setTimeout((()=>{e.apply(this,r)}),t))}}function i(e){let t=!1;return(...r)=>{t||(t=!0,e.apply(this,r))}}r.d(t,{J:()=>i,s:()=>n})},289:(e,t,r)=>{"use strict";r.d(t,{GG:()=>o,sB:()=>a});var n=r(878);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.sp)("load",e,t)}function a(e){if(i())return e();(0,n.DD)("DOMContentLoaded",e)}},384:(e,t,r)=>{"use strict";r.d(t,{NT:()=>o,US:()=>l,Zm:()=>a,bQ:()=>c,dV:()=>s,nY:()=>u,pV:()=>d});var n=r(154),i=r(863);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return n.gm.NREUM||(n.gm.NREUM={}),void 0===n.gm.newrelic&&(n.gm.newrelic=n.gm.NREUM),n.gm.NREUM}function s(){let e=a();return e.o||(e.o={ST:n.gm.setTimeout,SI:n.gm.setImmediate,CT:n.gm.clearTimeout,XHR:n.gm.XMLHttpRequest,REQ:n.gm.Request,EV:n.gm.Event,PR:n.gm.Promise,MO:n.gm.MutationObserver,FETCH:n.gm.fetch,WS:n.gm.WebSocket}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,i.t)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function l(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},843:(e,t,r)=>{"use strict";r.d(t,{u:()=>i});var n=r(878);function i(e,t=!1,r,i){(0,n.DD)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},434:(e,t,r)=>{"use strict";r.d(t,{Jt:()=>o,YM:()=>c});var n=r(836),i=r(607);const o="nr@original:".concat(i.W);var a=Object.prototype.hasOwnProperty,s=!1;function c(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");const a="-"===n.charAt(0);for(let s=0;s<t.length;s++){const c=t[s],u=e[c];l(u)||(e[c]=r(u,a?c+n:n,i,c,o))}},r.flag=o,r;function r(t,r,n,s,c){return l(t)?t:(r||(r=""),nrWrapper[o]=t,function(e,t,r){if(Object.defineProperty&&Object.keys)try{return Object.keys(e).forEach((function(r){Object.defineProperty(t,r,{get:function(){return e[r]},set:function(t){return e[r]=t,t}})})),t}catch(e){u([e],r)}for(var n in e)a.call(e,n)&&(t[n]=e[n])}(t,nrWrapper,e),nrWrapper);function nrWrapper(){var o,a,l,d;try{a=this,o=[...arguments],l="function"==typeof n?n(o,a):n||{}}catch(t){u([t,"",[o,a,s],l],e)}i(r+"start",[o,a,s],l,c);try{return d=t.apply(a,o)}catch(e){throw i(r+"err",[o,a,e],l,c),e}finally{i(r+"end",[o,a,d],l,c)}}}function i(r,n,i,o){if(!s||t){var a=s;s=!0;try{e.emit(r,n,i,t,o)}catch(t){u([t,r,n,i],e)}s=a}}}function u(e,t){t||(t=n.ee);try{t.emit("internal-error",e)}catch(e){}}function l(e){return!(e&&"function"==typeof e&&e.apply&&!e[o])}},993:(e,t,r)=>{"use strict";r.d(t,{A$:()=>o,ET:()=>a,p_:()=>i});var n=r(860);const i={ERROR:"ERROR",WARN:"WARN",INFO:"INFO",DEBUG:"DEBUG",TRACE:"TRACE"},o={OFF:0,ERROR:1,WARN:2,INFO:3,DEBUG:4,TRACE:5},a="log";n.K7.logging},773:(e,t,r)=>{"use strict";r.d(t,{z_:()=>o,XG:()=>s,TZ:()=>n,rs:()=>i,xV:()=>a});r(154),r(566),r(384);const n=r(860).K7.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},630:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewEvent},782:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewTiming},344:(e,t,r)=>{"use strict";r.d(t,{G4:()=>i});var n=r(614);r(860).K7.sessionReplay;const i={RECORD:"recordReplay",PAUSE:"pauseReplay",REPLAY_RUNNING:"replayRunning",ERROR_DURING_REPLAY:"errorDuringReplay"};n.g.ERROR,n.g.FULL,n.g.OFF},234:(e,t,r)=>{"use strict";r.d(t,{W:()=>o});var n=r(836),i=r(687);class o{constructor(e,t){this.agentIdentifier=e,this.ee=n.ee.get(e),this.featureName=t,this.blocked=!1}deregisterDrain(){(0,i.x3)(this.agentIdentifier,this.featureName)}}},603:(e,t,r)=>{"use strict";r.d(t,{j:()=>K});var n=r(860),i=r(555),o=r(371),a=r(908),s=r(836),c=r(687),u=r(289),l=r(154),d=r(944),f=r(773),g=r(384),p=r(344);const m=["setErrorHandler","finished","addToTrace","addRelease","recordCustomEvent","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start",p.G4.RECORD,p.G4.PAUSE,"log","wrapLogger"],h=["setErrorHandler","finished","addToTrace","addRelease"];var v=r(863),b=r(614),y=r(993);var w=r(646),R=r(434);const A=new Map;function E(e,t,r,n){if("object"!=typeof t||!t||"string"!=typeof r||!r||"function"!=typeof t[r])return(0,d.R)(29);const i=function(e){return(e||s.ee).get("logger")}(e),o=(0,R.YM)(i),a=new w.y(s.P);a.level=n.level,a.customAttributes=n.customAttributes;const c=t[r]?.[R.Jt]||t[r];return A.set(c,a),o.inPlace(t,[r],"wrap-logger-",(()=>A.get(c))),i}function _(){const e=(0,g.pV)();m.forEach((t=>{e[t]=(...r)=>function(t,...r){let n=[];return Object.values(e.initializedAgents).forEach((e=>{e&&e.api?e.exposed&&e.api[t]&&n.push(e.api[t](...r)):(0,d.R)(38,t)})),n.length>1?n:n[0]}(t,...r)}))}const x={};function N(e,t,g=!1){t||(0,c.Ak)(e,"api");const m={};var w=s.ee.get(e),R=w.get("tracer");x[e]=b.g.OFF,w.on(p.G4.REPLAY_RUNNING,(t=>{x[e]=t}));var A="api-",_=A+"ixn-";function N(t,r,n,o){const a=(0,i.Vp)(e);return null===r?delete a.jsAttributes[t]:(0,i.x1)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),j(A,n,!0,o||null===r?"session":void 0)(t,r)}function k(){}m.log=function(e,{customAttributes:t={},level:r=y.p_.INFO}={}){(0,a.p)(f.xV,["API/log/called"],void 0,n.K7.metrics,w),function(e,t,r={},i=y.p_.INFO){(0,a.p)(f.xV,["API/logging/".concat(i.toLowerCase(),"/called")],void 0,n.K7.metrics,e),(0,a.p)(y.ET,[(0,v.t)(),t,r,i],void 0,n.K7.logging,e)}(w,e,t,r)},m.wrapLogger=(e,t,{customAttributes:r={},level:i=y.p_.INFO}={})=>{(0,a.p)(f.xV,["API/wrapLogger/called"],void 0,n.K7.metrics,w),E(w,e,t,{customAttributes:r,level:i})},h.forEach((e=>{m[e]=j(A,e,!0,"api")})),m.addPageAction=j(A,"addPageAction",!0,n.K7.genericEvents),m.recordCustomEvent=j(A,"recordCustomEvent",!0,n.K7.genericEvents),m.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,o.f)(e).customTransaction=(r||"http://custom.transaction")+t,j(A,"setPageViewName",!0)()},m.setCustomAttribute=function(e,t,r=!1){if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return N(e,t,"setCustomAttribute",r);(0,d.R)(40,typeof t)}else(0,d.R)(39,typeof e)},m.setUserId=function(e){if("string"==typeof e||null===e)return N("enduser.id",e,"setUserId",!0);(0,d.R)(41,typeof e)},m.setApplicationVersion=function(e){if("string"==typeof e||null===e)return N("application.version",e,"setApplicationVersion",!1);(0,d.R)(42,typeof e)},m.start=()=>{try{(0,a.p)(f.xV,["API/start/called"],void 0,n.K7.metrics,w),w.emit("manual-start-all")}catch(e){(0,d.R)(23,e)}},m[p.G4.RECORD]=function(){(0,a.p)(f.xV,["API/recordReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.RECORD,[],void 0,n.K7.sessionReplay,w)},m[p.G4.PAUSE]=function(){(0,a.p)(f.xV,["API/pauseReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.PAUSE,[],void 0,n.K7.sessionReplay,w)},m.interaction=function(e){return(new k).get("object"==typeof e?e:{})};const T=k.prototype={createTracer:function(e,t){var r={},i=this,o="function"==typeof t;return(0,a.p)(f.xV,["API/createTracer/called"],void 0,n.K7.metrics,w),g||(0,a.p)(_+"tracer",[(0,v.t)(),e,r],i,n.K7.spa,w),function(){if(R.emit((o?"":"no-")+"fn-start",[(0,v.t)(),i,o],r),o)try{return t.apply(this,arguments)}catch(e){const t="string"==typeof e?new Error(e):e;throw R.emit("fn-err",[arguments,this,t],r),t}finally{R.emit("fn-end",[(0,v.t)()],r)}}}};function j(e,t,r,i){return function(){return(0,a.p)(f.xV,["API/"+t+"/called"],void 0,n.K7.metrics,w),i&&(0,a.p)(e+t,[r?(0,v.t)():performance.now(),...arguments],r?null:this,i,w),r?void 0:this}}function I(){r.e(296).then(r.bind(r,778)).then((({setAPI:t})=>{t(e),(0,c.Ze)(e,"api")})).catch((e=>{(0,d.R)(27,e),w.abort()}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{T[e]=j(_,e,void 0,g?n.K7.softNav:n.K7.spa)})),m.setCurrentRouteName=g?j(_,"routeName",void 0,n.K7.softNav):j(A,"routeName",!0,n.K7.spa),m.noticeError=function(t,r){"string"==typeof t&&(t=new Error(t)),(0,a.p)(f.xV,["API/noticeError/called"],void 0,n.K7.metrics,w),(0,a.p)("err",[t,(0,v.t)(),!1,r,!!x[e]],void 0,n.K7.jserrors,w)},l.RI?(0,u.GG)((()=>I()),!0):I(),m}var k=r(217),T=r(122);const j={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},I={};var O=r(284);const S=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let P=!1;function K(e,t={},r,n){let{init:a,info:c,loader_config:u,runtime:d={},exposed:f=!0}=t;d.loaderType=r;const p=(0,g.pV)();c||(a=p.init,c=p.info,u=p.loader_config),(0,k.xN)(e.agentIdentifier,a||{}),function(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");I[e]=(0,T.a)(t,j);const r=(0,g.nY)(e);r&&(r.loader_config=I[e])}(e.agentIdentifier,u||{}),c.jsAttributes??={},l.bv&&(c.jsAttributes.isWorker=!0),(0,i.x1)(e.agentIdentifier,c);const m=(0,k.D0)(e.agentIdentifier),h=[c.beacon,c.errorBeacon];P||(m.proxy.assets&&(S(m.proxy.assets),h.push(m.proxy.assets)),m.proxy.beacon&&h.push(m.proxy.beacon),_(),(0,g.US)("activatedFeatures",O.B),e.runSoftNavOverSpa&&=!0===m.soft_navigations.enabled&&m.feature_flags.includes("soft_nav")),d.denyList=[...m.ajax.deny_list||[],...m.ajax.block_internal?h:[]],d.ptid=e.agentIdentifier,(0,o.V)(e.agentIdentifier,d),e.ee=s.ee.get(e.agentIdentifier),void 0===e.api&&(e.api=N(e.agentIdentifier,n,e.runSoftNavOverSpa)),void 0===e.exposed&&(e.exposed=f),P=!0}},374:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},860:(e,t,r)=>{"use strict";r.d(t,{$J:()=>u,K7:()=>s,P3:()=>c,XX:()=>i,qY:()=>n,v4:()=>a});const n="events",i="jserrors",o="browser/blobs",a="rum",s={ajax:"ajax",genericEvents:"generic_events",jserrors:i,logging:"logging",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",softNav:"soft_navigations",spa:"spa"},c={[s.pageViewEvent]:1,[s.pageViewTiming]:2,[s.metrics]:3,[s.jserrors]:4,[s.spa]:5,[s.ajax]:6,[s.sessionTrace]:7,[s.softNav]:8,[s.sessionReplay]:9,[s.logging]:10,[s.genericEvents]:11},u={[s.pageViewEvent]:a,[s.pageViewTiming]:n,[s.ajax]:n,[s.spa]:n,[s.softNav]:n,[s.metrics]:i,[s.jserrors]:i,[s.sessionTrace]:o,[s.sessionReplay]:o,[s.logging]:"browser/logs",[s.genericEvents]:"ins"}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.283.2.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.283.2.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),l=0;l<u.length;l++){var d=u[l];if(d.getAttribute("src")==r||d.getAttribute("data-webpack")==t+o){s=d;break}}if(!s){c=!0;var f={296:"sha512-2Y8GMAOGF658KnXzOZ/v+DlLch8TBFvV0tTNnOy9wrpvtDa1t5CdZMyX+LubTymBlzPp6NUjllBghMCZqXBPmg=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://js-agent.newrelic.com/",(()=>{var e={374:0,840:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.283.2.PROD"]=self["webpackChunk:NRBA-1.283.2.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(374);var e=i(944),t=i(344),r=i(566);class n{agentIdentifier;constructor(){this.agentIdentifier=(0,r.LA)(16)}#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}addPageAction(e,t){return this.#e("addPageAction",e,t)}recordCustomEvent(e,t){return this.#e("recordCustomEvent",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}addRelease(e,t){return this.#e("addRelease",e,t)}log(e,t){return this.#e("log",e,t)}}class o extends n{#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}start(){return this.#e("start")}finished(e){return this.#e("finished",e)}recordReplay(){return this.#e(t.G4.RECORD)}pauseReplay(){return this.#e(t.G4.PAUSE)}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}wrapLogger(e,t,r){return this.#e("wrapLogger",e,t,r)}}var a=i(860),s=i(217);const c=Object.values(a.K7);function u(e){const t={};return c.forEach((r=>{t[r]=function(e,t){return!0===(0,s.gD)(t,"".concat(e,".enabled"))}(r,e)})),t}var l=i(603);var d=i(687),f=i(234),g=i(289),p=i(154),m=i(384);const h=e=>p.RI&&!0===(0,s.gD)(e,"privacy.cookies_enabled");function v(e){return!!(0,m.dV)().o.MO&&h(e)&&!0===(0,s.gD)(e,"session_trace.enabled")}var b=i(389);class y extends f.W{constructor(e,t,r=!0){super(e.agentIdentifier,t),this.auto=r,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===e.init[this.featureName].autoStart&&(this.auto=!1),this.auto?(0,d.Ak)(e.agentIdentifier,t):this.ee.on("manual-start-all",(0,b.J)((()=>{(0,d.Ak)(e.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator(e)})))}importAggregator(t,r={}){if(this.featAggregate||!this.auto)return;let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let o;try{if(h(this.agentIdentifier)){const{setupAgentSession:e}=await i.e(296).then(i.bind(i,861));o=e(t)}}catch(t){(0,e.R)(20,t),this.ee.emit("internal-error",[t]),this.featureName===a.K7.sessionReplay&&this.abortHandler?.()}try{if(!this.#t(this.featureName,o))return(0,d.Ze)(this.agentIdentifier,this.featureName),void n(!1);const{lazyFeatureLoader:e}=await i.e(296).then(i.bind(i,103)),{Aggregate:a}=await e(this.featureName,"aggregate");this.featAggregate=new a(t,r),t.runtime.harvester.initializedAggregates.push(this.featAggregate),n(!0)}catch(t){(0,e.R)(34,t),this.abortHandler?.(),(0,d.Ze)(this.agentIdentifier,this.featureName,!0),n(!1),this.ee&&this.ee.abort()}};p.RI?(0,g.GG)((()=>o()),!0):o()}#t(e,t){switch(e){case a.K7.sessionReplay:return v(this.agentIdentifier)&&!!t;case a.K7.sessionTrace:return!!t;default:return!0}}}var w=i(630);class R extends y{static featureName=w.T;constructor(e,t=!0){super(e,w.T,t),this.importAggregator(e)}}var A=i(908),E=i(843),_=i(878),x=i(782),N=i(863);class k extends y{static featureName=x.T;constructor(e,t=!0){super(e,x.T,t),p.RI&&((0,E.u)((()=>(0,A.p)("docHidden",[(0,N.t)()],void 0,x.T,this.ee)),!0),(0,_.sp)("pagehide",(()=>(0,A.p)("winPagehide",[(0,N.t)()],void 0,x.T,this.ee))),this.importAggregator(e))}}var T=i(773);class j extends y{static featureName=T.TZ;constructor(e,t=!0){super(e,T.TZ,t),this.importAggregator(e)}}new class extends o{constructor(t){super(),p.gm?(this.features={},(0,m.bQ)(this.agentIdentifier,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(R),this.runSoftNavOverSpa=[...this.desiredFeatures].some((e=>e.featureName===a.K7.softNav)),(0,l.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.R)(21)}get config(){return{info:this.info,init:this.init,loader_config:this.loader_config,runtime:this.runtime}}run(){try{const t=u(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>a.P3[e.featureName]-a.P3[t.featureName])),r.forEach((r=>{if(!t[r.featureName]&&r.featureName!==a.K7.pageViewEvent)return;if(this.runSoftNavOverSpa&&r.featureName===a.K7.spa)return;if(!this.runSoftNavOverSpa&&r.featureName===a.K7.softNav)return;const n=function(e){switch(e){case a.K7.ajax:return[a.K7.jserrors];case a.K7.sessionTrace:return[a.K7.ajax,a.K7.pageViewEvent];case a.K7.sessionReplay:return[a.K7.sessionTrace];case a.K7.pageViewTiming:return[a.K7.pageViewEvent];default:return[]}}(r.featureName).filter((e=>!(e in this.features)));n.length>0&&(0,e.R)(36,{targetFeature:r.featureName,missingDependencies:n}),this.features[r.featureName]=new r(this)}))}catch(t){(0,e.R)(22,t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,m.Zm)();delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator;return r.ee.get(this.agentIdentifier).abort(),!1}}}({features:[R,k,j],loaderType:"lite"})})()})();</script>
<noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style>
</noscript><script async src="https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script>
<script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "G-CSLL4ZEK4L", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"Optical physics and communications","node_id":"1079971","content_type":"Topic Landing Page"});</script>
<link rel="canonical" href="https://www.nist.gov/optical-physics-and-communications" />
<link rel="shortlink" href="https://www.nist.gov/node/1079971" />
<meta name="citation_title" content="Optical physics and communications | NIST" />
<meta property="og:site_name" content="NIST" />
<meta property="og:type" content="Article" />
<meta property="og:url" content="https://www.nist.gov/optical-physics-and-communications" />
<meta property="og:title" content="Optical physics and communications" />
<meta property="og:image" content="https://www.nist.gov/themes/custom/nist_www/img/homepage/nist_mark.png" />
<meta property="article:published_time" content="2016-06-30T13:50-04:00" />
<meta property="article:modified_time" content="2025-01-14T12:08-05:00" />
<meta name="dcterms.title" content="Optical physics and communications" />
<meta name="dcterms.date" content="2016-06-30T13:50-04:00" />
<meta name="dcterms.type" content="text" />
<meta name="dcterms.format" content="text/html" />
<meta name="dcterms.identifier" content="https://www.nist.gov/optical-physics-and-communications" />
<meta name="dcterms.source" content="NIST" />
<meta name="dcterms.created" content="2016-06-30T13:50-04:00" />
<meta name="dcterms.modified" content="2025-01-14T12:08-05:00" />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:description" content="" />
<meta name="twitter:site" content="NIST" />
<meta name="twitter:title" content="Optical physics and communications" />
<meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA" />
<meta name="Generator" content="Drupal 10 (https://www.drupal.org)" />
<meta name="MobileOptimized" content="width" />
<meta name="HandheldFriendly" content="true" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="nist_search_modified" class="elastic" content="2025-01-14T12:08:00-05:00" />
<meta name="nist_search_bundle" class="elastic" content="topic_landing_page" />
<link rel="icon" href="/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon" />
<title>Optical physics and communications | NIST</title>
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_1cDzbmPH_r3TlmAWnZ1vNbRK2kKDlxEjRcXhk8Z4KyQ.css?delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxFTosKwyAM_KGufpJovbWh0YjRuv39XLdSCEfuBefdstsq47Lx929pkTQl0mrrhoihCXtXbJRgAqnzDMuU9knfWhFHV3HmzcriHf-6vfeL41W_eRNKy47nP52yK24tLm96Obcyt5SbZ9INYToIXc2J8xjRGEMKEIvoEeyTwMEUaJakdOBxmveKSEsRpYoP86pfLw" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_kGS0ApDpFo-_3JI4Ijxg4RCWlTqsImK3lqH7bCv5v2U.css?delta=1&amp;language=en&amp;theme=nist_www&amp;include=eJxFTosKwyAM_KGufpJovbWh0YjRuv39XLdSCEfuBefdstsq47Lx929pkTQl0mrrhoihCXtXbJRgAqnzDMuU9knfWhFHV3HmzcriHf-6vfeL41W_eRNKy47nP52yK24tLm96Obcyt5SbZ9INYToIXc2J8xjRGEMKEIvoEeyTwMEUaJakdOBxmveKSEsRpYoP86pfLw" />
<link rel="stylesheet" media="print" href="/sites/default/files/css/css_-IXwLuTUdm8IGHxib8GX8wWKw3LjKsNWSYYskZ5fEGg.css?delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxFTosKwyAM_KGufpJovbWh0YjRuv39XLdSCEfuBefdstsq47Lx929pkTQl0mrrhoihCXtXbJRgAqnzDMuU9knfWhFHV3HmzcriHf-6vfeL41W_eRNKy47nP52yK24tLm96Obcyt5SbZ9INYToIXc2J8xjRGEMKEIvoEeyTwMEUaJakdOBxmveKSEsRpYoP86pfLw" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_jmXeSZNqhh6ayjrVIlS8rDw3mcnQaE5dzE2ZwwPSzNA.css?delta=3&amp;language=en&amp;theme=nist_www&amp;include=eJxFTosKwyAM_KGufpJovbWh0YjRuv39XLdSCEfuBefdstsq47Lx929pkTQl0mrrhoihCXtXbJRgAqnzDMuU9knfWhFHV3HmzcriHf-6vfeL41W_eRNKy47nP52yK24tLm96Obcyt5SbZ9INYToIXc2J8xjRGEMKEIvoEeyTwMEUaJakdOBxmveKSEsRpYoP86pfLw" />
<script src="/sites/default/files/js/js_GM8kl6wk698qKTTwusj83bCoGHHtOZ1UinjY1sE_Qbk.js?scope=header&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdTm0OwjAIvdCUIxE6sMOxMtvq1NPbbRqNCT_g8b4C9SNWbzND-O54Ll10jyZIiexRtS_wD3RJS8WTNox9SebEWHMz0RQh0v4uWkWnOftN4B9YUzasDjJJy3ULlHFyBtZCoRmbpnHjQDQPZIe3BAYhlvw5cVmWH4bc6yoEzteZ7Pg-u5uyOMoUhFttMQaj5-OwFt9N5XIlw0E0DvUFDORvTA"></script>
</head>
<body class="node-1079971">
<a href="#main-content" class="visually-hidden focusable" data-elastic-exclude>
Skip to main content
</a>
<div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>
<!-- nist-index-ignore-start -->
<section data-elastic-exclude class="usa-banner" aria-label="Official government website">
<div class="usa-accordion">
<header class="usa-banner__header">
<div class="usa-banner__inner">
<div class="grid-col-auto">
<img class="usa-banner__header-flag" src="/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag">
</div>
<div class="grid-col-fill tablet:grid-col-auto">
<p class="usa-banner__header-text">An official website of the United States government</p>
<p class="usa-banner__header-action" aria-hidden="true">Heres how you know</p>
</div>
<button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default">
<span class="usa-banner__button-text">Heres how you know</span>
</button>
</div>
</header>
<div class="usa-banner__content usa-accordion__content" id="gov-banner-default">
<div class="grid-row grid-gap-lg">
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Official websites use .gov</strong>
<br/>
A <strong>.gov</strong> website belongs to an official government organization in the United States.
</p>
</div>
</div>
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Secure .gov websites use HTTPS</strong>
<br/>
A <strong>lock</strong> ( <span class="icon-lock">
<svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false">
<title id="banner-lock-title">Lock</title>
<desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg>
</span>
) or <strong>https://</strong> means youve safely connected to the .gov website. Share sensitive information only on official, secure websites.
</p>
</div>
</div>
</div>
</div>
</div>
</section>
<!-- nist-index-ignore-end -->
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<div class="nist-print-header" style="display:none;">
<p class="nist-print-header__url">https://www.nist.gov/optical-physics-and-communications</p>
<img class="nist-print-header__logo" width="289" height="38" src="/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology" />
</div>
<div class="usa-overlay"></div>
<header class="usa-header nist-header--www nist-header--minimal" role="banner">
<div class="usa-navbar">
<div class="usa-logo flex-fill">
<a href="/" title="National Institute of Standards and Technology" aria-label="Home">
<img src="/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px" />
</a>
</div>
<div class="usa-header__right grid-row flex-auto">
<div class="grid-col-fill nist-header__search-group">
<form class="usa-search usa-search--small"
accept-charset="UTF-8"
action="/search"
id="search_form"
method="get">
<div role="search">
<label class="usa-sr-only" for="search-form">Search NIST</label>
<input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128">
<button class="usa-button" type="submit"><img src="/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button>
</div>
</form>
</div>
<div class="grid-col-auto padding-left-1">
<button class="usa-menu-btn">Menu</button>
</div>
</div>
</div>
<nav aria-label="Primary navigation" class="usa-nav">
<div class="usa-nav__inner">
<button class="usa-nav__close">Close</button>
<ul class="usa-nav__primary usa-accordion">
<li class="usa-nav__primary-item">
<a class="usa-nav__link" href="/publications">Publications</a>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-2"><span>What We Do</span></button>
<div id="primary_menu-2" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/topics" class="usa-nav__link">All Topics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/advanced-communications" class="usa-nav__link">Advanced communications</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/bioscience" class="usa-nav__link">Bioscience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/buildings-construction" class="usa-nav__link">Buildings and construction</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/chemistry" class="usa-nav__link">Chemistry</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/cybersecurity" class="usa-nav__link">Cybersecurity</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/electronics" class="usa-nav__link">Electronics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/energy" class="usa-nav__link">Energy</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/environment" class="usa-nav__link">Environment</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/fire" class="usa-nav__link">Fire</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/forensic-science" class="usa-nav__link">Forensic science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/health" class="usa-nav__link">Health</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/information-technology" class="usa-nav__link">Information technology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/infrastructure" class="usa-nav__link">Infrastructure</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/manufacturing" class="usa-nav__link">Manufacturing</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/materials" class="usa-nav__link">Materials</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/metrology" class="usa-nav__link">Metrology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nanotechnology" class="usa-nav__link">Nanotechnology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/neutron-research" class="usa-nav__link">Neutron research</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/performance-excellence" class="usa-nav__link">Performance excellence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/physics" class="usa-nav__link">Physics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/public-safety" class="usa-nav__link">Public safety</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/quantum-information-science" class="usa-nav__link">Quantum information science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/resilience" class="usa-nav__link">Resilience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/standards" class="usa-nav__link">Standards</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/transportation" class="usa-nav__link">Transportation</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs &amp; Major Programs</span></button>
<div id="primary_menu-3" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/adlp" class="usa-nav__link">Assoc Director of Laboratory Programs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories" class="usa-nav__link">Laboratories</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ctl" class="usa-nav__link">Communications Technology Laboratory</a>
</li>
<li>
<a href="/el" class="usa-nav__link">Engineering Laboratory</a>
</li>
<li>
<a href="/itl" class="usa-nav__link">Information Technology Laboratory</a>
</li>
<li>
<a href="/mml" class="usa-nav__link">Material Measurement Laboratory</a>
</li>
<li>
<a href="/pml" class="usa-nav__link">Physical Measurement Laboratory</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/user-facilities" class="usa-nav__link">User Facilities</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a>
</li>
<li>
<a href="/cnst" class="usa-nav__link">CNST NanoFab</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/projects-programs" class="usa-nav__link">Research Projects</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/tools-instruments" class="usa-nav__link">Tools &amp; Instruments</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/major-programs" class="usa-nav__link">Major Programs</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a>
</li>
<li>
<a href="/chips" class="usa-nav__link">CHIPS for America Initiative</a>
</li>
<li>
<a href="/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a>
</li>
<li>
<a href="/oam" class="usa-nav__link">Office of Advanced Manufacturing</a>
</li>
<li>
<a href="/spo" class="usa-nav__link">Special Programs Office</a>
</li>
<li>
<a href="/tpo" class="usa-nav__link">Technology Partnerships Office</a>
</li>
</ul>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services &amp; Resources</span></button>
<div id="primary_menu-4" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/content/standards-measurements" class="usa-nav__link">Standards and Measurements</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/calibrations" class="usa-nav__link">Calibration Services</a>
</li>
<li>
<a href="/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a>
</li>
<li>
<a href="/nist-quality-system" class="usa-nav__link">Quality System</a>
</li>
<li>
<a href="/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a>
</li>
<li>
<a href="/sri" class="usa-nav__link">Standard Reference Instruments (SRIs)</a>
</li>
<li>
<a href="/standardsgov" class="usa-nav__link">Standards.gov</a>
</li>
<li>
<a href="/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a>
</li>
<li>
<a href="/pml/owm" class="usa-nav__link">Office of Weights and Measures</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/services-resources/software" class="usa-nav__link">Software</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/data" class="usa-nav__link">Data</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a>
</li>
<li>
<a href="https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a>
</li>
<li>
<a href="/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a>
</li>
<li>
<a href="/srd" class="usa-nav__link">Standard Reference Data (SRD)</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="https://shop.nist.gov/" class="usa-nav__link">Storefront</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/tpo" class="usa-nav__link">License &amp; Patents</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nist-research-library" class="usa-nav__link">NIST Research Library</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News &amp; Events</span></button>
<div id="primary_menu-5" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/news-events/news" class="usa-nav__link">News</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/news-events/events" class="usa-nav__link">Events</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/blogs" class="usa-nav__link">Blogs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/feature-stories" class="usa-nav__link">Feature Stories</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/awards" class="usa-nav__link">Awards</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/video-gallery" class="usa-nav__link">Video Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/image-gallery" class="usa-nav__link">Image Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/pao/media-contacts" class="usa-nav__link">Media Contacts</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button>
<div id="primary_menu-6" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist" class="usa-nav__link">About Us</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/director/leadership" class="usa-nav__link">Leadership</a>
</li>
<li>
<a href="/director/nist-organization-structure" class="usa-nav__link">Organization Structure</a>
</li>
<li>
<a href="/about-nist/budget-planning" class="usa-nav__link">Budget &amp; Planning</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/contact-us" class="usa-nav__link">Contact Us</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/visit" class="usa-nav__link">Visit</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/careers" class="usa-nav__link">Careers</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/iaao/academic-affairs-office" class="usa-nav__link">Student programs</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist/work-nist" class="usa-nav__link">Work with NIST</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/history" class="usa-nav__link">History</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a>
</li>
<li>
<a href="/nist-museum" class="usa-nav__link">NIST Museum</a>
</li>
<li>
<a href="/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/education" class="usa-nav__link">Educational Resources</a>
</li>
</ul>
</div>
</div>
</div>
</li>
</ul>
</div>
</nav>
</header>
<!-- nist-index-ignore-end -->
</div>
<div class="grid-container">
</div>
<div
id="block-nist-www-content" class="nist-block"
>
<section class="nist-page__content usa-section clearfix" >
<a id="main-content" tabindex="-1"></a>
<div>
<div class="nist-section-header nist-section-header--menu nist-section-header--topic nist-section-header--hero">
<div class="nist-section-header__top grid-container">
<a href="/physics">Physics</a>
</div>
<div class="nist-section-header__sub">
<div class="nist-section-header__main grid-container">
<div class="grid-row">
<div class="nist-section-header__title">
<h1 class="nist-page__title">Optical physics and communications</h1>
</div>
</div>
</div>
</div>
</div>
</div>
<section
class="nist-page__content usa-section clearfix"
>
<a id="main-content" tabindex="-1"></a>
<div class="grid-container margin-top-4">
<div class="grid-row grid-gap-6">
<aside class="nist-page__region nist-page__region--sidebar-first tablet-lg:grid-col-4 desktop-lg:grid-col-3">
<div>
<!-- nist-index-ignore-start -->
<div
data-elastic-exclude="" class="nist-block"
>
<nav>
<ul class="usa-sidenav usa-accordion ">
<li class="usa-sidenav__item">
<a href="/topics/physics/optical-frequency-combs" data-drupal-link-system-path="">Optical Frequency Combs</a>
</li>
<li class="usa-sidenav__item">
<a href="/physics/what-are-optical-lattices" data-drupal-link-system-path="">Optical Lattices</a>
</li>
</ul>
</nav>
</div>
<!-- nist-index-ignore-end -->
<div
class="nist-block nist-social__wrapper--block"
>
<h2
class="nist-block__title"
>Sign Up to Get NIST News</h2>
<div><a href="https://public.govdelivery.com/accounts/USNIST/subscriber/new?topic_id=USNIST_1" class="nist-social nist-social--envelope" title="GovDelivery" ><span>GovDelivery</span></a></div>
</div>
</div>
</aside>
<div
class="nist-page__region nist-page__region--content tablet-lg:grid-col-8 desktop-lg:grid-col-9"
>
<div
class="nist-block"
>
<div class="bg-accent-warm-lighter nist-content-row--bg paragraph paragraph--type--video-bg-color paragraph--view-mode--default nist-content-row">
<div class="grid-container">
<div class="nist-region-heading">
<h2> <div class="string">What a Frequency Comb Can Do</div>
</h2>
</div>
</div>
<div class="nist-content-row__inner">
<figure data-media-id="623316" class="nist-video">
<div class="video-embed-field"><div data-video-embed-field-lazy="&lt;div class=&quot;video-embed-field-provider-nist-kaltura video-embed-field-responsive-video&quot;&gt;&lt;iframe width=&quot;854&quot; height=&quot;480&quot; frameborder=&quot;0&quot; allow=&quot;autoplay *; fullscreen *; encrypted-media *&quot; allowfullscreen=&quot;allowfullscreen&quot; src=&quot;https://www.kaltura.com/p/684682/embedPlaykitJs/uiconf_id/55674542?iframeembed=true&amp;amp;entry_id=1_ytre0aai&quot;&gt;&lt;/iframe&gt;
&lt;/div&gt;
" class="video-embed-field-lazy"><img loading="lazy" src="https://cdnsecakmi.kaltura.com/p/684682/sp/68468200/thumbnail/entry_id/1_ytre0aai/width/1280" alt="What a Comb Can Do" typeof="foaf:Image" />
<button class="video-embed-field-lazy-play"></button>
<div class="video-embed-field-lazy-title">What a Comb Can Do</div>
</div>
</div>
<figcaption data-caption-editable="true" class="nist-video__caption">
<div class="text-long">By making a simple measurement, the optical frequency comb has changed science. So what can a comb do? A lot—and the possibilities are constantly expanding. Learn more:&nbsp;<a target="_blank" rel="nofollow noopener noreferrer" href="https://www.nist.gov/topics/physics/optical-frequency-combs">https://www.nist.gov/topics/physics/optical-frequency-combs</a></div>
</figcaption>
</figure>
</div>
</div>
<div class="margin-y-4">
<h2 class="nist-block__title">News and Updates</h2>
<div class="margin-bottom-5">
<div class="entity-reference">
<div class="nist-card nist-card--horizontal nist-card--horizontal-full">
<div class="nist-card__inner">
<div class="nist-card__image">
<a href="/news-events/news/2024/08/tiny-new-lasers-fill-long-standing-gap-rainbow-visible-light-colors-opening"> <div class="entity-reference"> <img loading="lazy" src="/sites/default/files/styles/600w_x_360h/public/images/2024/08/28/thumb.png.webp?itok=Dc-xXCx6" width="600" height="360" alt="green laser" typeof="foaf:Image" />
</div>
</a> </div>
<div class="nist-card__title">
<h3><span property="schema:name">Tiny New Lasers Fill a Long-Standing Gap in the Rainbow of Visible-Light Colors, Opening New Applications</span>
</h3>
</div>
<div class="nist-card__content">
<div property="schema:text" class="text-with-summary"> Researchers have created orange, yellow and green lasers tiny enough to fit on a chip.
</div>
</div>
<div class="nist-card__links">
<div class="nist-card__button">
<a href="/news-events/news/2024/08/tiny-new-lasers-fill-long-standing-gap-rainbow-visible-light-colors-opening" class="usa-button ">Read more</a>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="paragraph paragraph--type--dynamic-news-list-topic paragraph--view-mode--default">
<div class="views-element-container"><div class="js-view-dom-id-0a369e2ba5f835fe494549266c18aac8a3946695ff83fb2251c6b025661d74b9">
<div class="grid-row grid-gap-2">
<div class="nist-card tablet:grid-col-4 nist-card--topic ">
<div class="nist-card__inner">
<div class="nist-card__image">
<a href="/news-events/news/2024/12/nist-offers-new-calibration-service-wavemeters"> <div class="entity-reference"> <img loading="lazy" src="/sites/default/files/styles/400_x_250_focal_point/public/images/2024/12/23/wavemeter%20image%20of%20Costa%20Rican%20metrologist.jpg?h=3bd4ce23&amp;itok=753bjgqA" width="400" height="250" alt="Johnny Jiménez" typeof="foaf:Image" />
</div>
</a> </div>
<div class="nist-card__title padding-y-5">
<h3><span property="schema:name">NIST Offers New Calibration Service for Wavemeters</span>
</h3>
</div>
<div class="nist-card__links">
<div class="nist-card__button">
<a href="/news-events/news/2024/12/nist-offers-new-calibration-service-wavemeters" class="usa-button ">Read more</a>
</div>
</div>
</div>
</div>
<div class="nist-card tablet:grid-col-4 nist-card--topic ">
<div class="nist-card__inner">
<div class="nist-card__image">
<a href="/news-events/news/2024/07/pandemics-pedicures-nist-rebuilds-world-class-uv-calibration-system"> <div class="entity-reference"> <img loading="lazy" src="/sites/default/files/styles/400_x_250_focal_point/public/images/2024/07/19/uv-calibration-lab.png?itok=9pfTEXID" width="400" height="250" alt="A high-tech laboratory with large black equipment featuring two circular insets showing detailed machinery setups. A computer workstation is in the foreground." typeof="foaf:Image" />
</div>
</a> </div>
<div class="nist-card__title padding-y-5">
<h3><span property="schema:name">From Pandemics to Pedicures: NIST Rebuilds World-Class UV Calibration System</span>
</h3>
</div>
<div class="nist-card__links">
<div class="nist-card__button">
<a href="/news-events/news/2024/07/pandemics-pedicures-nist-rebuilds-world-class-uv-calibration-system" class="usa-button ">Read more</a>
</div>
</div>
</div>
</div>
<div class="nist-card tablet:grid-col-4 nist-card--topic ">
<div class="nist-card__inner">
<div class="nist-card__image">
<a href="/news-events/news/2024/06/some-bumps-nist-scientists-devise-novel-way-extend-wavelength-range"> <div class="entity-reference"> <img loading="lazy" src="/sites/default/files/styles/400_x_250_focal_point/public/images/2024/05/17/pump-laser.png?itok=Q8i7nP41" width="400" height="250" alt="pump laser illustration" typeof="foaf:Image" />
</div>
</a> </div>
<div class="nist-card__title padding-y-5">
<h3><span property="schema:name">With Some Bumps, NIST Scientists Devise a Novel Way to Extend the Wavelength Range of Microcombs</span>
</h3>
</div>
<div class="nist-card__links">
<div class="nist-card__button">
<a href="/news-events/news/2024/06/some-bumps-nist-scientists-devise-novel-way-extend-wavelength-range" class="usa-button ">Read more</a>
</div>
</div>
</div>
</div>
</div>
<footer>
<div class="link-list"><a href="/news-events/news-updates/topic/249276">View All News and Updates</a></div>
</footer>
</div>
</div>
</div>
</div>
<div class="margin-y-8">
<a href="/news-events/events/search?k=&topic-op=or&topic-area-fieldset%5B%5D=249276" class="nist-topic-big-button" role="button" aria-label="Check out NIST events about optical physics and communications">
View optical physics and communications events
<span class="nist-icon nist-icon--before nist-icon--chevron-right-blue" aria-hidden="true"></span>
</a>
</div>
<div class="margin-y-8">
<a href="/publications/search?ta%5B0%5D=249276" class="nist-topic-big-button" role="button" aria-label="Check out NIST publications about optical physics and communications">
View optical physics and communications publications
<span class="nist-icon nist-icon--before nist-icon--chevron-right-blue" aria-hidden="true"></span>
</a>
</div>
<div class="margin-y-4">
</div>
<div class="margin-y-4">
<div class="paragraph paragraph--type--dynamic-content-list-topic paragraph--view-mode--default">
<h2 class="nist-block__title"> <div class="string">Projects and Programs</div>
</h2>
<div
class="nist-block "
>
<div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-e982926c1596c053d673452766afd9361fe7e6ecc5835ec9abc68af31c781858">
<div>
<article
about="/programs-projects/optical-and-optoelectronic-materials-characterization" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/programs-projects/optical-and-optoelectronic-materials-characterization" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2020/01/02/fig1.JPG?itok=7H3wqx0e" width="100" height="35" alt="Spectroscopic ellipsometry measurement of a 2D monolayer and the optical property for such a thin layer." typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/programs-projects/optical-and-optoelectronic-materials-characterization"><span>Optical and Optoelectronic Materials Characterization</span>
</a></h3>
<div class="nist-teaser__type">
<div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Today's electronics have reached a point where sheer computation power has combined form and function as the key driver of large consumer markets. The demand for portable and pervasive electronics with greater functionality promises significant changes over the next decades in how society interacts
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/programs-projects/frequency-conversion-interfaces-photonic-quantum-systems" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/programs-projects/frequency-conversion-interfaces-photonic-quantum-systems" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/cnst/nrg/single_photon_qft_schematic.jpg?itok=OqMbTz0q" width="100" height="57" alt="single_photon_QFT_schematic" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/programs-projects/frequency-conversion-interfaces-photonic-quantum-systems"><span>Frequency Conversion Interfaces for Photonic Quantum Systems</span>
</a></h3>
<div class="nist-teaser__type">
<div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Our research on quantum frequency conversion follows two main tracks. First, we combine relatively mature frequency conversion technology based on periodically-poled lithium niobate waveguides with quantum light generated by single semiconductor quantum dots in proof-of-principle experiments that
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/programs-projects/quantum-radiometry" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/programs-projects/quantum-radiometry" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2022/12/16/Quantum-Radiometry.png?itok=ykvLe1SD" width="75" height="100" alt="equipment" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/programs-projects/quantum-radiometry"><span>Quantum Radiometry</span>
</a></h3>
<div class="nist-teaser__type">
<div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> For quantum applications, it is important to generate quantum states of light and detect them with extremely high efficiency. This project explores the metrology challenges associated with precision measurement of single photon sources and detectors. The classical photonic radiometry techniques used
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/programs-projects/light-matter-interactions-semiconductor-nanostructures" class="nist-teaser"
>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/programs-projects/light-matter-interactions-semiconductor-nanostructures"><span>Light-matter interactions in Semiconductor Nanostructures</span>
</a></h3>
<div class="nist-teaser__type">
<div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> We investigate the interaction of light with semiconductor-based nanostructures. We extend concepts of entanglement and coherence in atomic physics to our solid-state systems. Our devices are based on semiconductors, like GaAs. We use InAs quantum dots (QDs) in GaAs as artificial atoms; they have
</div>
</div>
</div>
</article>
</div>
<footer>
<div class="link-list"><a href="/laboratories/projects-programs/topic/249276">View All Projects/Programs</a></div>
</footer>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="margin-y-4">
<div class="paragraph paragraph--type--dynamic-content-list-topic paragraph--view-mode--default">
<h2 class="nist-block__title"> <div class="string">Software</div>
</h2>
<div
class="nist-block "
>
<div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-ae79c1c469b1d52ead33280bca09ef37298ceb3027547f246f49704ad59de1fd">
<div>
<article
about="/services-resources/software/holografree" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/services-resources/software/holografree" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/mml/msed/functional_nanostructure/nbfluxon_1.jpg?itok=1p6Rz4Ry" width="100" height="100" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/services-resources/software/holografree"><span>HolograFREE</span>
</a></h3>
<div class="nist-teaser__date">
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> An electron hologram is a fringe modulated image containing the amplitude and phase information of an electron transparent object. The HolograFREE routines
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/services-resources/software/modeled-integrated-scatter-tool-mist" class="nist-teaser"
>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/services-resources/software/modeled-integrated-scatter-tool-mist"><span>Modeled integrated scatter tool (MIST)</span>
</a></h3>
<div class="nist-teaser__date">
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> The MIST program has been developed to provide users with a general application to model an integrated scattering system. The program performs an integration of
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/services-resources/software/scatmech-polarized-light-scattering-c-class-library" class="nist-teaser"
>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/services-resources/software/scatmech-polarized-light-scattering-c-class-library"><span>SCATMECH: Polarized light scattering C++ class library</span>
</a></h3>
<div class="nist-teaser__date">
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> SCATMECH is an object-oriented C++ class library developed to distribute models for light scattering applications. Included in the library are models for
</div>
</div>
</div>
</article>
</div>
<footer>
<div class="link-list"><a href="/services-resources/software/topic/249276">View All Software</a></div>
</footer>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="margin-y-4">
<div class="paragraph paragraph--type--dynamic-content-list-topic paragraph--view-mode--default">
<h2 class="nist-block__title"> <div class="string">Tools and Instruments</div>
</h2>
<div
class="nist-block "
>
<div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-9355aaf13ee195421770fcc5b512fc0e01856a1e81c077c19974898a5ee0b0ae">
<div>
<article
about="/laboratories/tools-instruments/ultraviolet-scale-realization-facility-uv-srf" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/laboratories/tools-instruments/ultraviolet-scale-realization-facility-uv-srf" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/03/24/IMG_1140.JPG?itok=5B66ajnZ" width="100" height="75" alt="NIST Ultraviolet Scale Realization Facility" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/laboratories/tools-instruments/ultraviolet-scale-realization-facility-uv-srf"><span>Ultraviolet Scale Realization Facility UV SRF</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> A new facility has been commissioned to the establish ultraviolet spectral power responsivity in the air-ultraviolet spectral range between 200 nm and 400 nm
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/laboratories/tools-instruments/beamline-4-euv-and-uv-detector-calibrations" class="nist-teaser"
>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/laboratories/tools-instruments/beamline-4-euv-and-uv-detector-calibrations"><span>Beamline 4: EUV and UV Detector Calibrations</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Detector calibrations are a crucial component of the United States industry's extreme ultraviolet (EUV) calibrations needs. Both EUV source manufacturers and
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/laboratories/tools-instruments/normal-incidence-diffuse-optical-scatter-instrument-ndosi" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/laboratories/tools-instruments/normal-incidence-diffuse-optical-scatter-instrument-ndosi" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/01/28/SOSI_picture.jpg?itok=oJ7ZE4t6" width="94" height="100" alt="NDOSI" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/laboratories/tools-instruments/normal-incidence-diffuse-optical-scatter-instrument-ndosi"><span>Normal incidence Diffuse Optical Scatter Instrument (NDOSI)</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Summary The Normal incidence Diffuse Optical Scatter Instrument (NDOSI) is a new facility for measuring the hemispherical reflectance and transmittance of
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/laboratories/tools-instruments/system-infrared-spectral-emittance-materials" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/laboratories/tools-instruments/system-infrared-spectral-emittance-materials" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/05/05/emittance_fig.jpg?itok=z_uh5uEZ" width="100" height="74" alt="Emittance System diagram" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/laboratories/tools-instruments/system-infrared-spectral-emittance-materials"><span>System for infrared spectral emittance of materials</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> This facility enables the measurement of spectral emittance using the direct method of radiance comparison of the sample with a blackbody reference source
</div>
</div>
</div>
</article>
</div>
<footer>
<div class="link-list"><a href="/laboratories/tools-instruments/topic/249276">View All Tools &amp; Instruments</a></div>
</footer>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="margin-y-4">
<div class="paragraph paragraph--type--dynamic-content-list-topic paragraph--view-mode--default">
<h2 class="nist-block__title"> <div class="string">Awards</div>
</h2>
<div
class="nist-block "
>
<div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-b09eea871b182affb10d8fddd6a4ee4c1603bbe8e1cd182cd71186e4f00e836f">
<div>
<article
about="/awards/2023-apl-rising-stars-collection-benedikt-hampel-daniel-slichter-dietrich-leibfried-richard" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/awards/2023-apl-rising-stars-collection-benedikt-hampel-daniel-slichter-dietrich-leibfried-richard" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/12/12/2023-APL-Rising-Stars-Collection.png?itok=sOO3vVyy" width="92" height="100" alt="Photomicrograph of the linear ion trap with integrated SNSPD" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/awards/2023-apl-rising-stars-collection-benedikt-hampel-daniel-slichter-dietrich-leibfried-richard"><span>2023 APL Rising Stars Collection - Benedikt Hampel, Daniel Slichter, Dietrich Leibfried, Richard Mirin, Sae Woo Nam, Varun Verma</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-long"> The Rising Stars Collection features notable APL papers by emerging investigators. These papers were identified by the editors and Rising
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/awards/2023-breakthrough-new-horizons-physics-prize-adam-kaufman" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/awards/2023-breakthrough-new-horizons-physics-prize-adam-kaufman" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2022/09/21/Kaufman_photo.jpg?itok=Z0Ja8WFV" width="100" height="95" alt="Adam Kaufman poses for a head shot with a shelf of library books in the background. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/awards/2023-breakthrough-new-horizons-physics-prize-adam-kaufman"><span>2023 Breakthrough New Horizons in Physics Prize - Adam Kaufman</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-long"> Kaufman shares the $100,000 prize with selected winners, all from different institutions (Hannes Bernien, Manuel Endres, Kang-Kuen Ni
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/awards/halo-takes-runner-opn-photo-contest" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/awards/halo-takes-runner-opn-photo-contest" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2020/12/01/43-Contest-20.jpg?itok=Yl-Gy70Z" width="100" height="67" alt="Tracing of green laser light in HALO" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/awards/halo-takes-runner-opn-photo-contest"><span>HALO Takes Runner-Up in OPN Photo Contest</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-long"> The High Amplification Laser pressure Optic (HALO) was developed by NIST to measure kilo-watts of laser power with best-in-class accuracy
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/awards/2020-rising-stars-light-final-winners-amit-agrawal" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/awards/2020-rising-stars-light-final-winners-amit-agrawal" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2020/12/15/Amit%20Agrawal-Second%20Prize.jpg?itok=2oA9R3GB" width="100" height="72" alt="2020 Rising Stars of Light certificate for Amit Agrawal" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/awards/2020-rising-stars-light-final-winners-amit-agrawal"><span>2020 Rising Stars of Light Final Winners - Amit Agrawal</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-long"> A joint second place prize between Amit and Dr. Shuo Sun from UC Boulder: Their research efforts are focused on developing novel measurement
</div>
</div>
</div>
</article>
</div>
<footer>
<div class="link-list"><a href="/awards/topic/249276">View All Awards</a></div>
</footer>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="margin-y-4">
</div>
</div>
</div>
</div>
</div>
<div class="grid-container">
</div>
</section>
</section>
</div>
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<footer class="nist-footer padding-bottom-4">
<div class="grid-container nist-footer__info">
<div class="grid-row">
<div class="tablet:grid-col-6">
<div class="nist-footer__logo">
<a href="/" title="National Institute of Standards and Technology" rel="home">
<img class="nist-footer__logo-img" src="/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px" />
</a>
</div>
<div class="nist-footer__contact">
<h3 class="nist-footer__contact-heading">HEADQUARTERS</h3>
<address>
100 Bureau Drive<br>
Gaithersburg, MD 20899<br>
<a href="tel:301-975-2000">301-975-2000</a>
</address>
<p>
<a href="mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://www.nist.gov/visit">Our Other Offices</a>
</p>
</div>
</div>
<div class="tablet:grid-col-6">
<div class="nist-footer__social-links">
<a class="nist-social nist-social--x-white" href=" https://x.com/NIST">
<span>X.com</span>
</a>
<a class="nist-social nist-social--facebook-white" href=" https://www.facebook.com/NIST">
<span>Facebook</span>
</a>
<a class="nist-social nist-social--linkedin-white" href=" https://www.linkedin.com/company/nist">
<span>LinkedIn</span>
</a>
<a class="nist-social nist-social--instagram-white" href=" https://www.instagram.com/nist/">
<span>Instagram</span>
</a>
<a class="nist-social nist-social--youtube-white" href=" https://www.youtube.com/NIST">
<span>YouTube</span>
</a>
<a class="nist-social nist-social--giphy-white" href=" https://giphy.com/nist">
<span>Giphy</span>
</a>
<a class="nist-social nist-social--rss-white" href=" https://www.nist.gov/news-events/nist-rss-feeds">
<span>RSS Feed</span>
</a>
<a class="nist-social nist-social--envelope-white" href=" https://public.govdelivery.com/accounts/USNIST/subscriber/new">
<span>Mailing List</span>
</a>
</div>
<div class="nist-footer__feedback">
How are we doing? <a class="usa-button" rel="nofollow" href="/form/nist-gov-feedback?destination=/optical-physics-and-communications" title="Provide feedback">Feedback</a>
</div>
</div>
</div>
</div>
<div class="grid-container">
<div class="nist-footer__nav" role="navigation">
<ul>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy-policy">Site Privacy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/accessibility">Accessibility</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy">Privacy Program</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/copyrights">Copyrights</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/office-director/freedom-information-act">FOIA</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/environmental-policy-statement">Environmental Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/">Commerce.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.science.gov/">Science.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.usa.gov/">USA.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://vote.gov/">Vote.gov</a>
</li>
</ul>
</div>
</div>
</footer>
<!-- nist-index-ignore-end -->
</div>
</div>
<script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","pathPrefix":"","currentPath":"node\/1079971","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_speed":1200,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":".ck-editor, .nist-video-thumbnail__lightbox-trigger, a.nist-icon--mail-blue","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"after","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"bd6a443844dbe99b4e6942f3b1397526e760137efd2b1ee6b2d588fc414dff20"}}</script>
<script src="/sites/default/files/js/js_jDaFaXhHm6gPUKstNYX9eIyoQXghVs3g7rbR0QoqpYY.js?scope=footer&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdTm0OwjAIvdCUIxE6sMOxMtvq1NPbbRqNCT_g8b4C9SNWbzND-O54Ll10jyZIiexRtS_wD3RJS8WTNox9SebEWHMz0RQh0v4uWkWnOftN4B9YUzasDjJJy3ULlHFyBtZCoRmbpnHjQDQPZIe3BAYhlvw5cVmWH4bc6yoEzteZ7Pg-u5uyOMoUhFttMQaj5-OwFt9N5XIlw0E0DvUFDORvTA"></script>
<script src="https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script>
<script src="/sites/default/files/js/js_LfV-cFUigoW5qp-1G9GpVLjEOVYhWgpY-BL-35J8j_0.js?scope=footer&amp;delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxdTm0OwjAIvdCUIxE6sMOxMtvq1NPbbRqNCT_g8b4C9SNWbzND-O54Ll10jyZIiexRtS_wD3RJS8WTNox9SebEWHMz0RQh0v4uWkWnOftN4B9YUzasDjJJy3ULlHFyBtZCoRmbpnHjQDQPZIe3BAYhlvw5cVmWH4bc6yoEzteZ7Pg-u5uyOMoUhFttMQaj5-OwFt9N5XIlw0E0DvUFDORvTA"></script>
<script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFkVVVABoWlcAUQQ=","queueTime":3,"applicationTime":26,"atts":"TBtXQQMaH0k=","errorBeacon":"bam.nr-data.net","agent":""}</script></body>
</html>