Editing Continuous wave (section)

== Laser physics ==
In [[laser physics]] and engineering, "continuous wave" or "CW" refers to a [[laser]] that produces a continuous output beam, sometimes referred to as "free-running," as opposed to a [[q-switched]], [[gain-switching|gain-switched]] or [[modelocking|modelocked]] laser, which has a pulsed output beam.

The continuous wave [[semiconductor laser]] was invented by Japanese physicist [[Izuo Hayashi]] in 1970.{{citation needed|date=May 2017}} It led directly to the light sources in [[fiber-optic communication]], [[laser printer]]s, [[barcode reader]]s, and [[optical disc drive]]s, commercialized by Japanese entrepreneurs,<ref name=burning>{{cite book|last=Johnstone|first=Bob|title=We were burning : Japanese entrepreneurs and the forging of the electronic age.|year=2000|publisher=BasicBooks|location=New York|isbn=9780465091188|page=252}}</ref> and opened up the field of [[optical communication]], playing an important role in future [[communication network]]s.<ref>S. Millman (1983), [http://doc.telephonecollectors.info/dm/BTL_History_Physical_Sciences_1983_op_r.pdf#page=34 ''A History of Engineering and Science in the Bell System'', page 10] {{Webarchive|url=https://web.archive.org/web/20171026002823/http://doc.telephonecollectors.info/dm/BTL_History_Physical_Sciences_1983_op_r.pdf#page=34 |date=2017-10-26 }}, [[AT&T Bell Laboratories]]</ref> Optical communication in turn provided the hardware basis for [[internet]] technology, laying the foundations for the [[Digital Revolution]] and [[Information Age]].<ref name="soh">[http://www.soh-vehe.jp/english/background3.html The Third Industrial Revolution Occurred in Sendai], Soh-VEHE International Patent Office, [[Japan Patent Attorneys Association]]</ref>