Re: how the laser happened

Lasse Langwadt <llc@fonz.dk> 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