Monolithic integrated photoreceiver implemented with GaAs/GaAlAs heterojunction bipolar phototransistor and transistors

Abstract

The first monolithic integrated photodetector-preamplifier implemented with GaAs/GaAlAs heterojunction phototransistor and transistors has been fabricated and tested. This photoreceiver has been designed for local networks of optical transmission links operating at 0.85 μm wavelength with multimode fibres. A heterojunction phototransistor (HPT), two heterojunction bipolar transistors (HBTs) and four resistors are integrated in a 0.5 × 0.5 mm2 GaAs chip. The photoreceiver with a 26 kΩ external feedback resistor has a bandwidth of 80 MHz with a transimpedance gain of 7000 V/A. The noise measurements indicate that a minimum detectable power of −30 dBm is obtained at 140 Mbit/s for an error rate of 10−9.