Path: ...!feed.opticnetworks.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Cursitor Doom Newsgroups: sci.electronics.design Subject: Re: how the laser happened Date: Fri, 21 Jun 2024 17:56:36 +0100 Organization: A noiseless patient Spider Lines: 39 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Fri, 21 Jun 2024 18:56:36 +0200 (CEST) Injection-Info: dont-email.me; posting-host="7d710e142c378f3c0814d874ebb75d9b"; logging-data="3430654"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+s5BWcEqKD5dDu82167BAAho/5tyyqwNQ=" User-Agent: ForteAgent/8.00.32.1272 Cancel-Lock: sha1:7Uu48MdArDiRuCebC0WY62JrTp0= Bytes: 2318 On Fri, 21 Jun 2024 06:05:21 -0700, john larkin wrote: >There was a thread somewhere above about photon wave/particle duality. > > >This is worth reading: > >https://www.amazon.com/How-Laser-Happened-Adventures-Scientist/dp/0195153766 > >Einstein, in one of his fits of genius, predicted in around 1916 that >under the right conditions, a photon could pass by an excited atom and >the atom would kick in another photon, or add to the wave amplitude, >depending on how you feel about these things. He called it stimulated >emission. He also declared that the laws of thermodynamics made this >effect impossible to use in practical situations. > >In 1951, Charles Townes invented a work-around trick and built the >maser, a gaseous microwave oscillator. His superiors thought he was >crazy to dispute Einstein and almost threw him out of grad school, but >it worked. > >In 1960, Theodore Maiman at HRL made the first ruby laser, and Bell >Labs soonafter made a HeNe. > >What's interesting is that any decent neon sign shop could have built >a HeNe laser in 1920. > >HRL sounds like a very cool place, up in the hills above Malibu. Wasn't that where Jane Mansfield used to go out bathing? > >https://www.hrl.com/ > > >Some details: > >https://www.aps.org/archives/publications/apsnews/200312/history.cfm