Large-signal analysis of all-optical wavelength conversion using two-mode injection-locking in semiconductor lasers

A large-signal analysis is presented for a DC-biased Fabry-Perot laser locked by simultaneous strong optical injection of a CW signal and a modulated signal into different modes. The model is based on the description of injection-locking by Lang (1982) which is shown to hold even under the condition of strong injection and large detuning of the input signals. The following results are obtained: the configuration allows all-optical wavelength conversion in the multigigabit range, and both logically noninverting and inverting conversion is possible. In both operation modes, the conversion mechanism is mainly attributed to dispersive switching which is shown to be very fast above threshold due to injection-locking. Operation up to data rates of 20 Gb/s is possible with reasonable output extinction ratio. The bandwidth is determined by the relaxation oscillation frequency of the laser. It will be extended by decreasing the resonator length, increasing the injected current, and increasing the injected optical power. The output signal is nearly chirp-free. The model is able to explain the main results of previously published experiments.