Question

tell me answer fast (ii)

Answer 1

Answer:

To explain the process of light amplification in a laser requires an understanding of the energy transition phenomena in the atoms of its active medium. They include: spontaneous emission, stimulated emission/absorption and non-radiative decay.

The theory of quantum mechanics states that the electrons of atoms can take different energy states, E1, E2, E3, for example, with E1<E2<E3.