GAIN DYNAMICS IN QUANTUM-WELL LASERS AND OPTICAL AMPLIFIERS - AN EXPERIMENTAL COMPARISON

We describe an experimental comparison of gain dynamics in quantum wel l lasers and optical amplifiers. We demonstrate an approximately 30% i ncrease in the time constant describing the gain recovery on the appro ximately 1 ps time scale in a laser above threshold. The increase is d ue to the high rate of stimulated emission which modifies the relative significance of the various mechanisms contributing to the gain recov ery. We suggest an explanation based on the coupling of two processes: Carrier capture and carrier cooling. We conclude that laser gain dyna mics contain details that cannot be revealed in experiments on optical amplifiers due to the vast differences in operating conditions betwee n a laser and an optical amplifier.