Review of the dynamic characteristics of AlGaInAs/InP microlasers subject to optical injection

Semiconductor lasers subject to optical injection exhibit many nonlinear dynamic behaviors that can be applied to enhance the modulation speed and generate a microwave signal. In this paper, the dynamic characteristics of AlGaInAs/InP microdisk lasers subject to optical injection are investigated numerically and experimentally. The different dynamic states and bifurcation and stability diagrams are simulated using rate equations, and a greatly enhanced modulation bandwidth is expected based on small-signal analysis of microlasers in the injection locking state. Four-wave mixing, period-one and period-two oscillations, and injection locking states are demonstrated experimentally from the lasing spectra and photonic generation microwaves for a microdisk laser subject to optical injection at different detuning frequencies, and enhancement of the modulation bandwidth is realized for the optical injection locking state. Furthermore, low-noise photonically generated microwaves are obtained for microdisk lasers subject to optical injection and optoelectronic feedback, with the beating signal obtained from a high-speed photodetector being applied to the microdisk laser as sideband injection locking is realized in the period-one state. In addition to external optical injection, dynamic optical injection behaviors are realized for integrated twin-microdisk lasers with mutually internal optical injection, similar to semiconductor microdisk lasers subject to external optical injection. As well as obtaining microwaves by light beating at a high-speed photodetector, microwave signals are obtained from the electrode of a square microlaser subject to optical injection related to carrier density oscillation, with the microwave power versus frequency being in good agreement with the small-signal modulation response curve. It is expected that low-noise tunable microwave signals and enhanced modulation speed microlasers will be obtained from photonic integrated circuits, with the microdisk lasers subject to internal optical injection. (topical review)