Photoelectron statistics of laser light modulated by Gaussian noise

Julian Blake, Richard G. Barakat

Francesco Ghielmetti

S. Machida, Y. Yamamoto

A P Bark, Steven Rathgeb Smith

Experimental results on the effects of finite-aperture detectors on the statistics of Gaussian light are presented. A laser illuminating a rotating diffusing screen was used to provide a source with a long coherence time, and the photoelectron statistics of a photomultiplier detector were recorded electronically. The data, which were taken with circular apertures and a linear polarizer in front of the detector, agree with calculations of factorial cumulant correction factors published by Cantrell and Fields.

Bahaa E. A. Saleh

Y. Yamamoto, Shuichiro Inoue, Wayne H. Richardson +1 more

Quantum statistical properties of laser light have been extensively studied for the last thirty years by using an operator Langevin equation, a density operator master equation, and a quantum mechanical Fokker-Planck equation. It has been generally accepted among physicists and quantum electronics engineers that an ideal laser operating at far above the threshold generates a coherent state of light. Various experimental facts such as the Poissonian photoelectron statistics, the shot noise limited photocurrent fluctuations, and the Gaussian distributions of optical homodyne detector output seem to support this. However, recent careful studies on a semiconductor laser have revealed that a semiconductor laser does not necessarily produce a coherent state of light, but generates a number-phase squeezed state, in which the photon-number noise is smaller than the standard quantum limit (shot noise limit or Poisson limit). This paper reviews the theoretical and experimental aspects of number-phase squeezed state generation by a semiconductor laser.