MONTE-CARLO SIMULATION OF GAIN COMPRESSION EFFECTS IN GRINSCH QUANTUM-WELL LASER STRUCTURES

Gain compression is widely acknowledged to be a serious limitation to the ultimate modulation bandwidth of a semiconductor laser. We have de veloped a numerical technique to study the gain compression effects in graded-index separate confinement heterostructure (GRINSCH) quantum w ell laser structures. This technique is based on the combination of th e Monte Carlo simulation of the carrier dynamics in the device while u nder intense stimulated photon emission, and the calculation of the op tical gain using a 4 x 4k . p Hamiltonian. From the simulated results, we calculated a gain compression coefficient epsilon = 1.1 x 10(-17) cm3 for a linearly graded quantum well laser structure having a 50 ang strom In0.2Ga0.8As well. We find good agreement between our results an d published experiments. We have also demonstrated that our calculatio n method is capable of simulating the gain dynamics in the laser struc ture, such as those studied with femtosecond pump-probe experimental t echniques.