Laser pulse peak estimation based on photon capture mode of quadrant photodetector

Abstract

Laser pulse peak estimation theory on quadrant photodetector (QPD) corresponding to all spots center on QPD surface is derived. The model of receiving echoed laser pulse from the target by QPD, and the composite photon detection model containing the inverted parabolic laser pulse and the ambient background noise submitted to Poisson distribution is established. The Cramer Rao lower bound (CRLB) estimation algorithm of laser pulse peak in one quadrant of QPD is derived based on the CRLB theorem. Taking the symmetry of QPD into account, laser pulse peak power CRLBs of each quadrant are calculated for all laser spots center which are located only in quadrant A of QPD, and different coefficients such as the laser pulse width factor and ambient background noise power are considered. Furthermore, the statistical mean and variance estimations of laser pulse peak power are simulated for each quadrant by Monte Carlo simulation method. The results show that: For the same spot center position, laser pulse peak power CRLBs of each quadrant are different. For different spots center positions, CRLBs of one quadrant are also different. The smaller pulse width factor, or the larger ambient background noise, the bigger laser pulse peak power CRLB.