Editing Optical communication (section)

=== Optical fiber ===
{{Main|Fiber-optic communication}}
Optical fiber is the most common type of channel for optical communications. The transmitters in optical fiber links are generally [[light-emitting diode]]s (LEDs) or [[laser diode]]s.  [[Infrared]] light is used more commonly than [[visible light]], because optical fibers transmit infrared wavelengths with less [[attenuation (electromagnetic radiation)|attenuation]] and [[Dispersion (optics)|dispersion]]. The signal encoding is typically simple [[intensity modulation]], although historically optical phase and [[frequency modulation]] have been demonstrated in the lab. The need for periodic [[signal regeneration]] was largely superseded by the introduction of the [[erbium-doped fiber amplifier]], which extended link distances at significantly lower cost. The commercial introduction of dense [[wavelength-division multiplexing]] (WDM) in 1996 by [[Ciena|Ciena Corp]] was the real start of optical networking.<ref>{{Cite news|last=Markoff|first=John|date=1997-03-03|title=Fiber-Optic Technology Draws Record Stock Value|language=en-US|work=The New York Times|url=https://www.nytimes.com/1997/03/03/business/fiber-optic-technology-draws-record-stock-value.html|access-date=2021-11-08|issn=0362-4331}}</ref><ref>{{Cite book|last=Cvijetic|first=Milorad|title=Advanced optical communication systems and networks|date=2013|others=Ivan Djordjevic|isbn=978-1-60807-556-0|location=Boston|oclc=875895386}}</ref> WDM is now the common basis of nearly every high-capacity optical system in the world.<ref>{{Cite book|last1=Grobe|first1=Klaus|title=Wavelength Division Multiplexing: A Practical Engineering Guide (Wiley Series in Pure and Applied Optics)|last2=Eiselt|first2=Michael|publisher=Wiley; 1st edition|year=2013|page=2}}</ref>

The first optical communication systems were designed and delivered to the U.S. Army and Chevron by Optelecom, Inc.,<ref>{{Cite book|last=Nick|first=Taylor|title=Laser: The Inventor the Nobel Laureate and the Thirty-Year Patent War|publisher=Jonas Street Books|year=2019|page=226}}</ref> the venture co-founded by Gordon Gould, the inventor of the optical amplifier<ref>{{Cite book|last=Nick|first=Taylor|title=Laser: The Inventor the Nobel Laureate and the Thirty-Year Patent War|publisher=Jones Street Books|year=2019|page=212}}</ref> and the laser.<ref>{{Cite book|last=Nick|first=Taylor|title=Laser: The Inventor the Nobel Laureate and the Thirty-Year Patent War|publisher=Jones Street Books|year=2019|page=283}}</ref>