1. A method for range finding of a target comprising: a) generating a first single photon; b) transmitting the first single photon towards the target; c) generating a second single photon identical to the first single photon; d) delaying the second single photon by a time delay; e) receiving the transmitted first single photon reflected from the target; f) receiving the delayed second single photon; g) interacting the received reflected first single photon and the delayed second single photon to produce Hong-Ou-Mandel (HOM) interference; h) detecting photo-statistics at an output of the HOM interference; i) when the reflected first single photon and the delayed second single photon are output at the same output port, repeating a) to h); j) when the reflected first single photon and the delayed second single photon are output at different output ports, changing the time delay and repeating a) to h); k) repeating a) to j) for a pre-determined number of times to arrive at a final estimate for a value of the time delay; and l) determining the target range corresponding to the final estimate for the value of the time delay after said predetermined number of times, wherein an initial value of the time delay is selected in such a way to minimize the mean square error (MSE) of the target range estimate and wherein an initial value of the time delay is selected as a peak of an updated probability distribution.