Transient distribution of the population inversion and pumping-power absorption in ruby

Microwave Generation in Ruby due to Population Inversion produced by Optical Absorption

Microwave Generation in Ruby Due to Population Inversion Produced by Optical Absorption

The Effect of Cross Relaxation on Population Inversion in Ruby

Lasing without population inversion in ruby by using low-frequency coupling

Amplification and generation of coherent phonons in ruby under conditions of spin-level population inversion

Population-inversion characteristics of ruby in the middle part of the millimeter-wave range