Optical Pumping & Laser Wavelengths

[JG1009]

During optical pumping in a laser, is the wavelength of light that corresponds to the transition from the metastable state that yields the laser light removed? Otherwise, wouldn't a population inversion not be possible as these photons from the optical pumping would cause stimulated emission immediately.

 

[blue_leaf77]

During optical pumping in a laser, is the wavelength of light that corresponds to the transition from the metastable state that yields the laser light removed?

Do you mean, removed from the spectrum of the pumping pulse due to absorption? This indeed might happen for a three-state laser, which of course constitute one of the disadvantages of this type of laser. However, pulsed laser, whose bandwidth may indeed be big enough to cover the laser transition, is not always used in most laser system, instead CW lasers enjoy more frequent use in pumping most laser systems.

Otherwise, wouldn't a population inversion not be possible as these photons from the optical pumping would cause stimulated emission immediately.

It depends which laser system you are talking about, if it's 2-level system then yes population inversion can never be realized.