Abstract: A photon detection system comprising an avalanche photodiode configured to generate a photodiode signal in response to an incident photon. The photon detection system also comprises a biasing circuit configured to supply a gating signal to the avalanche photodiode. The gating signal is a periodic signal configured to reverse bias the avalanche photodiode above and below its breakdown voltage for photon detection during each period. The photon detection system further comprises a non-reflective filter circuit configured to receive, at an input port, the photodiode signal, and provide, at a first output port, a first filtered output signal by applying a low-pass filter with a first cut-off frequency to the received photodiode signal.