Picosecond gain measurements in a GaAlAs diode laser

The amplification of injected optical pulses has been used to investigate the temporal response of the gain of a GaAl- As diode laser. Near-infrared dye-laser pulses of 4-psec duration were passed through the active region of the laser diode, which was driven by 80-psec current pulses. The measured gain-buildup time of 325 psec is likely determined by the electrical circuit parameters of the device, i.e., junction capacitance and resistance and parasitic inductance. The gain decayed with a time constant of 375 psec consistent with lateral carrier outdiffusion from the junction region.