Multi-channel RF-optical receiver enabled by a high performance p-i-n InP-InGaAs based photodetector array

We propose an integrated back-illuminated InP/InGaAs p-i-n photodetector array (PDA) with high responsivity and external quantum efficiency. The photodetector array was characterized and packaged for small-signal response and transmission experiments. At the bias voltage of -5V, the dark current is below 0.35nA and the average optical responsivity reaches up to 1 A/W for each ∅ = 50μm element at 1550nm. The external quantum efficiency is as high as 81% at -5V at 1550nm. Under the photocurrent of 63μA at -5V bias, the proposed InP/InGaAs PDA exhibits an average 3dB bandwidth of 3.6GHz. We finally demonstrate a BER below 10−12 at a 2.25Gbit/s data rate. The compact size and large photosensitive area of the PDA will enable new applications for Radio on Free Space Optical communications(RoFSO).