A situation known as "population inversion" is needed for lasing action. What does "population inversion" mean?
A) Electrons in the ms = 1/2 state switch to −1/2 and vice versa.
B) Excited atoms must be at the top of the laser tube.
C) Excited atoms must be at the bottom of the laser tube.
D) More atoms are in the higher-energy state than the lower-energy state.
E) More atoms are in the lower-energy state than the higher-energy state.

Question

Quizplus · Accepted Answer

Population inversion refers to the condition where more atoms or molecules are in an excited, higher-energy state than in a lower-energy state, which is essential for the operation of a laser.

A Situation Known as "Population Inversion" Is Needed for Lasing