Question

Q:1 Find the temperature at which rate of spontaneous Emission is 3/4th of stimulated emission, Given lambda =700nm. (05 Marks)
Q:2 Find the temperature where no. of atoms in excited state are 10^4 times as compared to lower excited state. Given energy difference between two levels is 5eV. (05 Marks)​

Answer 1

Answer:

Stimulated emission is the process by which an incoming photon of a specific frequency can interact with an excited atomic electron (or other excited molecular state), causing it to drop to a lower energy level. The liberated energy transfers to the electromagnetic field, creating a new photon with a frequency, polarization, and direction of travel that are all identical to the photons of the incident wave. This is in contrast to spontaneous emission, which occurs at a characteristic rate for each of the atoms/oscillators in the upper energy state regardless of the external electromagnetic field.