In one embodiment, a LIDAR device of an autonomous driving vehicle (ADV) includes a light emitter to emit a light beam towards a target, wherein at least a portion of the light beam is reflected from the target. The LIDAR device further includes an optical sensing unit including a first photodetector and a second photodetector. The first photodetector is a different type of photodetector from the second photodetector, where the optical sensing unit is to receive the portion of the light beam reflected from the target. When the optical sensing unit receives the portion of the light beam, the first photodetector generates a first optical sensor output signal and the second photodetector generates a second optical sensor output signal. The LIDAR device further includes a first circuitry portion to generate an intensity signal indicative of an intensity of the received portion of the light beam responsive to the first optical sensor output signal. The LIDAR device further includes a second circuitry portion to generate a time of flight (ToF) signal indicative of a ToF of the emitted light beam responsive to the second optical sensor output signal.