GaAs/GaAlAs Heterojunction Bipolar Phototransistor for Monolithic Photoreceiver Operating at 140 Mbit/s

The first monolithic integrated photodetector-preamplifier implemented with GaAs-GaAIAs heterojunction phototransistor and transistors has been fabricated and tested. A heterojunction phototransistor (HPT), two heterojunction bipolar transistors (HBT´s) and four resistors are integrated in a 0.5 x 0.5 mm/sup 2/ GaAs chip. The photoreceiver with a 26 kOmega external feedback resistor has a bandwidth of 80 MHz with a transimpedance gain of 7000V/A. The noise measurements indicate that a minimum detectable power of -30 dBm is obtained at 140 Mbit/s for an error rate of 10/sup -9/.