A SURVEY OF THE SIGNAL-INDUCED NOISE IN PHOTOMULTIPLIER DETECTION OF WIDE DYNAMICS LUMINOUS SIGNALS

In the LIDAR sounding of wide atmospheric ranges, as in middle atmosph eric probing, signal-induced noise (SIN) from the photomultiplier (PMT ) has been known since long time as a challenging problem for scientis ts. In this article the results of investigations on SIN are reported and strategies to minimize its amount proposed. Three different types of PMTs have been tested and their response to pulsed light signals of various duration and amplitude, comparable with close range LIDAR ret urn, have been studied. An analysis of the time properties and spectra l characteristics of SIN has been performed, and a method to reduce SI N effects in photon counting acquisition has been proposed, The method is based on a careful choice of discriminator threshold level setting s, and exploits differences observed between SIN and signal cumulative pulse height distributions, The method shows dependency on single PMT behavior. (C) 1996 American Institute of Physics.