Editing Optical communication (section)

=== Photophone ===
{{Main|Photophone}}
The photophone (originally given an alternate name, [[radiophone]]) is a communication device which allowed for the [[transmission (telecommunications)|transmission]] of speech on a beam of [[light]]. It was invented jointly by [[Alexander Graham Bell]] and his assistant [[Charles Sumner Tainter]] on February 19, 1880, at Bell's 1325 'L' Street laboratory in Washington, D.C.<ref>Bruce 1990, pg. 336</ref><ref name="SDU">Jones, Newell. [http://history.sandiego.edu/gen/recording/ar304.html First 'Radio' Built by San Diego Resident Partner of Inventor of Telephone: Keeps Notebook of Experiences With Bell] {{webarchive|url=https://archive.today/20060904235846/http://history.sandiego.edu/gen/recording/ar304.html |date=2006-09-04 }}, San Diego Evening Tribune, July 31, 1937. Retrieved from the University of San Diego History Department website, November 26, 2009.</ref> Both were later to become full associates in the [[Volta Laboratory and Bureau#Laboratory projects|Volta Laboratory Association]], created and financed by Bell.

On June 21, 1880, Bell's assistant transmitted a wireless voice telephone message of considerable distance, from the roof of the [[Franklin School (Washington, D.C.)|Franklin School]] to the window of Bell's laboratory, some 213 meters (about 700&nbsp;ft) away.<ref>Bruce 1990, pg. 338</ref><ref name="Carson-2007-gvttw">Carson 2007, pg. 76-78</ref><ref name="Groth">Groth, Mike. [http://www.bluehaze.com.au/modlight/GrothArticle1.htm Photophones Revisted], 'Amateur Radio' magazine, [[Wireless Institute of Australia]], Melbourne, April 1987 pp. 12–17 and May 1987 pp. 13–17.</ref><ref name="Mims 1982, p. 11">Mims 1982, p. 11.</ref>

Bell believed the photophone was his most important [[invention]]. Of the 18 [[patent]]s granted in Bell's name alone, and the 12 he shared with his collaborators, four were for the photophone, which Bell referred to as his "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone".<ref name="Mims 1982, p. 14">Mims 1982, p. 14.</ref>

The photophone was a precursor to the [[fiber-optic communication]] systems which achieved popular worldwide usage starting in the 1980s.<ref name="Morgan">Morgan, Tim J. "The Fiber Optic Backbone", [[University of North Texas]], 2011.</ref><ref name="AmericanScientist-1984.V72.No1">Miller, Stewart E. "Lightwaves and Telecommunication", ''[[American Scientist]]'', Sigma Xi, The Scientific Research Society, January–February 1984, Vol. 72, No. 1, pp. 66-71, [https://www.jstor.org/stable/i27852430 Issue Stable URL].</ref><ref name="Gallardo+Mims">Gallardo, Arturo; [[Forrest Mims|Mims III, Forrest M.]] [http://www.mysanantonio.com/default/article/Fiber-optic-communication-began-130-years-ago-783469.php Fiber-optic Communication Began 130 Years Ago], ''[[San Antonio Express-News]]'', June 21, 2010. Accessed January 1, 2013.</ref> The master patent for the photophone ({{US patent|235199}} ''Apparatus for Signalling and Communicating, called Photophone''), was issued in December 1880,<ref name="Groth" /> many decades before its principles came to have practical applications.