Photodetection properties of semiconductor laser diode detectors

Several commercial GaAlAs and InGaAsP injection lasers have been investigated with respect to their photodetection properties. The responsivity of the laser diode detectors is in the 0.15-0.25 A/W range and the dark current ranges from 5 nA to 500 nA at 3-V reverse bias. The high frequency performance of a laser diode detector strongly depends on the laser structure. The bandwidth is determined by the capacitance of the lasers and ranges from 70 MHz to 1.3 GHz. The structure showing the fastest response was the TJS laser due to its low junction capacitance.