A laser must be pumped to achieve:
A)a metastable state
B)fast response
C)stimulated emission
D)population inversion
E)the same wavelength for all photons

Question

Quizplus · Accepted Answer

For a laser to operate, it requires population inversion, which means a higher number of electrons in the excited state than the ground state. This is achieved through pumping the laser with energy, which excites the electrons to a higher energy level and creates a population inversion.

A Laser Must Be Pumped to Achieve