What is the stimulated emission? Define this term briefly.
Stimulated emission:
a. While photon interacts along with atom that is in the excited state E2, in that case de-excitation of this atom to the lower energy state E1 arises with emission of photon of energy hν. Thus, stimulated emission is the process by that, while perturbed by
a photon, matter may lose energy resulting into the creation of other photon.
b. The perturbing photon is not vanished within the process, and the second photon is created with similar phase, frequency and direction as well as polarization of travel as the original.
c. The process can be consideration of as "optical amplification" and this forms the origin of both the laser and maser.
Stimulated emission.