Question

What steps are taken for Cascade Emission to take place?

a) Absorption, spontaneous emission, and stimulated emission
b) Absorption, reflection, and transmission
c) Retion, diftion, and interference
d) Ionization, excitation, and de-excitation

Answer 1

Cascade emission occurs through absorption, spontaneous emission, and stimulated emission. It involves the absorption of a photon, followed by the spontaneous emission of a photon, which then stimulates the emission of more photons.

Step-by-step explanation:

Cascade emission occurs through a process involving absorption, spontaneous emission, and stimulated emission. The steps are as follows:

1. An atom absorbs a photon of light, causing an electron to be excited to a higher energy level
2. After some time, the excited electron spontaneously falls back to a lower energy level, emitting a photon
3. This emitted photon then stimulates another atom to de-excite, emitting a second photon that has the same energy and wavelength as the first photon
4. This process continues, with each emitted photon stimulating the emission of more photons

All the emitted photons are in phase with each other, have the same polarization, and travel in the same direction. For cascade emission to occur and produce a net production of photons, a population inversion is necessary, where a majority of atoms are in the metastable state.