SAGM avalanche photodiode optical receiver for 2 Gbit/s and 4 Gbit/s

A high-sensitivity optical receiver has been designed using an InGaAs avalanche photodetector and a low capacitance (0.63 pF) hybrid GaAs FET preamplifier. Measured receiver sensitivities at 1.51 μm wavelength of −36.6 dBm at 2 Gbit/s and −31.2 dBm at 4 Gbit/s are the best obtained to date at these bit rates.