The saturation effect in multilevel laser media

V. I. Lvov, A. A. Stepanov, Vladimir A. Shcheglov

Lloyd W. Hillman

Alexander Cerjan, Ardavan F. Oskooi, Song-Liang Chua +1 more

This technical note describes the physical model, numerical implementation, and validation of multilevel atomic media for lasers and saturable absorbers in Meep: a free/open-source finite-difference time-domain (FDTD) software package for electromagnetics simulation. Simulating multilevel media in the time domain involves coupling rate equations for the populations of electronic energy levels with Maxwell's equations via a generalization of the Maxwell--Bloch equations. We describe the underlying equations and their implementation using a second-order discretization scheme, and also demonstrate their equivalence to a quantum density-matrix model. The Meep implementation is validated using a separate FDTD density-matrix model as well as a frequency-domain solver based on steady-state ab-initio laser theory (SALT).

Yakir Reuven, Michael Baer

Jan I. H. Askne

E. A. Gazazyan, V. O. Chaltykyan

We propose in this work an alternative method of easier calculation of necessary conditions for lossless propagation of short laser pulses in multilevel atomic media. Method is based on the quasienergy approach and illustrated with example of a five-level system. We also demostrated effective population transfer in this system.