A photodetection circuit includes an avalanche photodiode and a mode switching circuit that may be configured to selectively switch an operating mode of the photodetection circuit between linear mode and Geiger mode. The photodetection circuit may further include a quenching circuit configured to quench and reset the avalanche photodiode in response to an avalanche event when the photodetection circuit is operated in Geiger mode. The photodetection circuit may additionally include an integration circuit configured to integrate photocurrent output by the photodiode and generate integrated charge units when the photodetection circuit is operated in linear mode. The photodetection circuit may also include a counter configured to count pulses output by the avalanche photodiode when the photodetection circuit is operated in Geiger mode and to count integrated charge units generated by the integration circuit when the photodetection circuit is operated in linear mode.