Massively-Parallel Optical Data Links -

An ultra-low-power, long-wavelength photoreceiver based on InGaAsanP heterojunction bipolar transistors is reported. The photoreceivers were designed for massively parallel applications where low-power density is necessary for both electrical and thermal reasons. We demonstrate two-dimensional, four-by-four arrays of photoreceivers for free-space optical data links that interface directly with 3.3 V CMOS ASICs and dissipate less than 12 mW/channel; lower power is possible. Propagation delays of -1 nsec were measured and large signal operation to 800 Mbitslsec is demonstrated. The array is on a 500 pm pitch and can be easily scaled to much higher density. The photoreceivers can be utilized in both free-space and guided-wave applications.