Answer to Question #155620 in Optics for Huzaifa Rehman

Question

Briefly, describe the advantages of a 4-level laser system over 3-level laser system.

Answer 1

1.The less population in the lower laser energy level makes the atomic system population of the 4-level laser system to be inverted easily reason being that the transition from a state of metastability is indirect to ground state.

2.The additional level in the 4-level laser system makes the transition not to end in the ground state. Therefore, if the lower level runs out of population faster than the high level in transition of the laser hence the inversion of population will be assured independent of the speed or competence of pumping the system.