<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">optics</topic></authority><related type="narrower"><topic>fiber optics</topic></related><related type="narrower"><topic>x-ray optics</topic></related><related type="other"><topic>mathematical physics</topic></related><related type="other"><topic>optical instruments</topic></related><related type="other"><topic>opticists</topic></related><related type="broader"><topic>physics</topic></related><related type="broader"><topic>optical concepts</topic></related><variant type="other"><topic>optical science</topic></variant><variant type="other"><topic>science, optical</topic></variant> <note xml:lang="en"><![CDATA[ Branch of physics that deals with the properties and phenomena of both visible and invisible light, including its generation, transmission, and detection or perception. ]]></note></mads>