Simulation of gain-switched picosecond pulse generation from quantum well lasers

Circuit models for gain-switched quantum well laser diodes are developed and simulated using the circuit analysis program SPICE2. Effects of cavity length and number of wells on the output pulse shape are analysed. Picosecond pulses of 7 and 2 ps full-width at half-maximum (FWHM) are observed, corresponding to second and third quantized level transitions, respectively. A remarkable reduction in the output pulse width observed for the third quantized level transition, demonstrates the significance of higher sub-band transitions for ultrashort pulse generation.