To be more specific:

> Albert Einstein first broached the possibility of stimulated emission in a 1917 paper

http://www.aps.org/publications/apsnews/200508/history.cfm

You need more than stimulated emission for a laser. I think that figuring out how to create a population inversion in an excited state is the best candidate for the inception point of the laser as a specific possibility, and I believe the honor for that achievement goes to Townes circa 1950.

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/Dennis_Gabor

Interesting. 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

The closer you look, the less the history of innovation looks like a simple sequence.

If you're gonna be that way, you could have said that they date back to Newton and the prism.

"Lasers? yeah, the theory dates back to the first micro-organism with a photo-sensitive organelle. Took a little while to put it together tho. '

I don't think I'm being "that way", I think that's more or less the meaning of theory used in the quote. There is a pretty straight line between lasers and the photoelectric effect.

> There is a pretty straight line

I strongly disagree, and that gives very little credit to the various brilliant people involved in the various stages of the history. Everything seems obvious in retrospect.

But it doesn't change the timeline very significantly, so it's a side issue.

I don't understand it well enough to call any of it obvious.

My meaning was more that it was foundational, not that the stuff that built from it was obvious (fortunately I drew my straight line backwards, not forwards)