Physical Review A
Nonclassical effects and antibunching in the external photodetection of cavity radiation
Ching Tsung Lee
Abstract
The nonclassical effects of radiation are defined to be when its P function [R. J. Glauber, Phys. Rev. Lett. 10, 84 (1963)] is not positive definite, and antibunching is defined to be when the conditional waiting time in the photodetection is longer than the unconditional one. Based on these two definitions, it is proven rigorously that antibunching implies nonclassical effects of cavity radiation detected externally by an imperfect detector.