How does stimulated emission work?

Stimulated emission occurs under the specific circumstances of a population inversion, that is, when there are more electrons in a higher energy level than one below it. There will be a certain energy difference between these two energy levels.

When a photon with energy equal to the gap passes, it stimulates an electron to drop down to the lower energy level, emitting the energy it lost as a photon with the same wavelength, phase and direction (coherent with) the starting photon.

This differs from an electron spontaneously dropping down an energy level in that the photon is not emitted randomly. If this occurs many times, as in a laser, intense, coherent and monochromatic (one wavelength) is produced.

KE
Answered by Konrad E. Physics tutor

5272 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

If a wire loop moves at constant speed into a region where there is a magnetic field, why is a current induced in the wire?


A pendulum of mass m is released from height h with a speed v at the bottom of its swing. a) What is the gravitational potential energy at height h and the kinetic energy at the bottom of its swing? b) Use conservation of energy to define the speed v.


What does the photoelectric effect demonstrate?


A ball is kicked off a cliff at a height of 20m above ground and an angle of 30 degree from the horizontal, it follows projectile motion and lands after a time t. Its velocity at the maximum height it reaches is 20m/s, how long does it take it to land?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences