4 ms·
Nothing is ever simple. Before Townes' 1951 population inversion, there's also Kastler's 1950 invention of optical pumping, and Dennis Gabor's 1947 invention of
by DougMerritt 11y ago
Nothing is ever simple. Before Townes' 1951 population inversion, there's also Kastler's 1950 invention of optical pumping, and Dennis Gabor's 1947 invention of holography (yes, 1947, before lasers, which stimulated development of lasers)
https://en.wikipedia.org/wiki/Optical_pumping https://en.wikipedia.org/wiki/Optical_pumping
https://en.wikipedia.org/wiki/Dennis_Gabor https://en.wikipedia.org/wiki/Dennis_Gabor
- mannykannot 11y agoInteresting. On following up on your links, I see that while optical pumping was invented first, Townes was able to make the first maser by using an electric field to separate out an excited state of ammonia, achieving a population inversion without pumping. http://home.fnal.gov/~kubik/FermilabWebsiteDocs/Masers.ppt http://home.fnal.gov/~kubik/FermilabWebsiteDocs/Masers.ppt The closer you look, the less the history of innovation looks like a simple sequence.