High performance InP-based phototransistors for long wavelength, HBT-based optical receivers

The performance of InAlAs/InGaAs heterojunction bipolar phototransistors (HBTs) has been studied in order to develop improved photodetectors for use in long wavelength optical receivers based on heterojunction bipolar transistors (HBTs). This paper presents experimental results for devices operated with a base bias and with frontside optical injection through the emitter demonstrating the device's high optical gain (30) and high frequency performance capabilities (f/sub r/=50 GHz). The results demonstrate that the HBT is an attractive alternative to the PIN photodetector for use in HBT-based optical receivers.