Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Phil Hobbs Newsgroups: sci.electronics.design Subject: Re: how the laser happened Date: Mon, 24 Jun 2024 23:09:06 -0000 (UTC) Organization: A noiseless patient Spider Lines: 41 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 25 Jun 2024 01:09:06 +0200 (CEST) Injection-Info: dont-email.me; posting-host="85f304439f23d09303e0a6f482b45e27"; logging-data="1238417"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+qarYFCNVOJL53xYm3AzHT" User-Agent: NewsTap/5.5 (iPhone/iPod Touch) Cancel-Lock: sha1:QcUX9f7asHX9B3BkPUTD+RjURyE= sha1:CyqZl4mh/xX41fS23lpPp3r+WvU= Bytes: 2660 Lasse Langwadt wrote: > On 6/21/24 15:05, 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. >> > > you could build a laser in your living room if you want to > http://jarrodkinsey.org/co2laser/co2laser.html You can build a monster N2 laser using FR4 and some flashing copper, plus a low current HV supply. See C. L. Stong, Scientific American, June 1974. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics