Probe amplification from Raman gain to inversionless gain

摘要

By the advantage of a metastable state, amplification without inversion has been exhibited with the remarkable characteristic that the population distribution of the upper state for the amplified transition is produced by the coupling coherent laser rather than direct incoherent pumping. We proposed two similar models which involve light amplification arising from either coherence or stimulated Raman scattering. Our density-matrix calculations provide the steady-state condition for probe amplification from different origin, including net Raman gain, dressed-state inversion gain and amplified transition, which could simplify the experiment design, With our model, the amplification condition is not the same as the usual three-level situation, which is important to choose the materials used to realize the LWI. We hope that these results could have potential application in lasers without inversion for generating a short-wavelenght laser. (C) 2000 Published by Elsevier Science. All rights reserved. [References: 26]