Abstract

All the theoretical models of lasing without inversion (LWI) studied until now were phenomenological in some sense.¹ Namely, the pumping and relaxation processes were described by the introduction of the corresponding phenomenological constants into the master equation. However, these processes play an essential role in inversionless systems. They have two different and very important functions: population of upper operating level (like in usual lasers) and preparation of a coherent superposition of two sublevels which is responsible for the occurrence of LWI. Hence a verification of the phenomenological treatment is needed.

© 1994 IEEE