Explain about the term simulated absorption in brief.

Stimulated absorption:

a. For the photon-atom interaction to happen, the energy of the interacting photon h? must match with the energy difference in between the two states of the atom included in the interaction, that is hν= E₂ - E₁.

b. While the atom at the lower energy level E₁ absorbs the incident energy along with the consequent frequency, this jump to the upper energy level E₂, it is termed as stimulated absorption.

c. This process decreases the lower level population and raises the upper level population.