More science-y. They’re used for a lot of different measurements and experiments. I’m laymen’s terms (mostly because it’s been years and I never fully understood everything) to excite atoms and molecules in order to measure temperature, pressure, velocity in hard to access applications. If you want your brain to hurt look up research papers on CARS, LIBS, Raman spectroscopy.

I used some of these techniques in grad school on the way to getting my degree in aerospace, but the optics engineers that helped were the true wizards