A reconfigurable 14-bit 60GPhoton/s Single-Photon receiver for visible light communications

A reconfigurable Single-Photon Avalanche Diode integration mode receiver in 130nm CMOS is presented for optical links with an array readout bandwidth of 100MHz. The all-digital 32×32 SPAD array achieves a minimum dead time of 5.9ns, and a median dark count rate of 2.5kHz per SPAD. Pulse shortening increases the dynamic range by preventing pulse overlap. An in-pixel feedback loop allows synchronous or self-clocked asynchronous time division multiplexing. The internal gain of SPADs and spatio-temporal summation removes the need for analogue amplification. A maximum count rate of 58GHz is observed, with SNR of 79dB, a sensitivity of -31.7dBm at 100MHz and a BER of 10^-9. The sensor core draws 89mW at maximum count rate.