SUB-POISSON PHOTOELECTRON STATISTICS IN SATURATED LIGHT-ABSORPTION

Abstract

We show that sub-Poisson photoelectrons can result from the finite relaxation time of the fundamental photoelectron-emitting entities, which could be individual atoms, or valence-band electrons, etc., depending on the type of the detectors. After identifying the precise quantum-mechanical criterion for a light without the intrinsic antibunching property, it is demonstrated that the variance to mean ratio of photoelectron counts within a fixed time period can be reduced to as small as 1/2, even for such light. The condition for strong fluctuation reduction is found to be the saturation of light absorption. Semiconductor photodetectors are considered in relative details, and their photoelectron statistics are expressed in terms of the intrinsic material parameters.