Lasing without inversion: gain enhancement through spectrally colored population pumping

Abstract

We propose the use of spectrally colored rather than white (i.e., incoherent) population pumping in lasing-without-inversion schemes. We show that colored pumping can lead to a significant enhancement in gain by presenting explicit results for the gain in a three-level ladder system. These results are obtained from Monte Carlo simulations of the coupled density-matrix equations, which, for a colored pump, acquire the structure of Langevin equations.