Temporal response of optical intensity modulation based on side-mode injection locked single-mode Fabry-Perot laser diode

Abstract

In this paper, we have experimentally demonstrated time domain characteristics of all-optical intensity modulation using cross-gain modulation induced by side-mode injection locking in a single-mode Fabry-Perot laser diode (SMFP-LD). Both bistable hysteresis and injection locking behaviors are observed and discussed for different wavelength detuning between the injection beam and the selected side mode, which is the direct physical mechanism to successfully perform optical intensity modulation in the laser chip. Both the modulation depth of the injection signal and wavelength detuning have very important influences on the optical characteristics, including the modulation depth, and rise and fall time of the output signal at the dominant mode. The obtained modulation depth in the output signal can reach as high as similar to 25 dB when a pulsed injection beam with a time duration of 8 ns is introduced into the laser chip under conditions of a bias current of 12 mA and an operating temperature of 16 degrees C.