Low-Noise Large-Area Quad Photoreceivers Based on Low-Capacitance Quad InGaAs Photodiodes

We report a large-area quad photoreceiver (2 times 2 array) having an equivalent input current noise density of <3.2 pA/radicHz per quadrant up to a 3-dB bandwidth of ~20 MHz. The low-noise photoreceiver performance is enabled by a 1-mm diameter quad p-i-n InGaAs photodiode having 2.5-pF capacitance per quadrant at 5-V reverse bias.