Small-signal equivalent circuit model of photonic crystal fano laser

We develop a new small-signal equivalent circuit model for photonic crystal Fano laser based on standard linearized equations. The results are compared with those obtained by the numerical simulation approach. This novel circuit model being a cost-effective fast tool is advantageous over solving the rate equations for designing and extending the photonic crystal Fano laser. Using this circuit model, we have investigated the laser current modulation via the conventional method and via modulating the Fano mirror. The results show that the bandwidths of the amplitude modulation of the laser through-port and the frequency modulation of its cross port are both in the range of THz. It is also shown that the larger the nanocavity detuning, the greater the relaxation oscillation frequency, increasing the possibility of widening the laser bandwidth, through which the modulation efficiency may decrease. Moreover, we show that the longer the laser active region, the narrower the modulation response bandwidth. The results show that the circuit model accurately explains the photonic crystal Fano laser small-signal modulation characteristics.