Scaling in photocount experiments (A)

József Janszky, Петер Адам, Yu. Ya. Yushin

F. T. Arecchi, Vittorio Degiorgio

Gerard Lachs, Neil F. Ruggieri

For many photocounting experiments, it is desirable to know the theoretical photocount distribution for radiation whose spectral shape may be altered by an optical filter or truncated in some manner. The effect of spectral truncation (band limiting) is investigated by computing the photocount distribution by a method that makes direct use of the power spectral density. Some data are presented for truncated Lorentzian spectra.

Dennis E. Koppel, Dale W. Schaefer

The photocount autocorrelation of non-Gaussian scattered laser light is discussed as a tool for the study of both very dilute or highly correlated scattering systems. A scaled photocount correlation technique is introduced and shown to produce a function directly proportional to the correlation function of the integrated scattered intensity, independent of the field statistics. This technique overcomes the serious problems of interpretation that can arise when the commonly used clipped correlation technique is applied to non-Gaussian fields. The scaled correlation technique is demonstrated experimentally with a simple scattering system, a small number of particles under uniform translational motion.

J. Lyons, GORDON J. TROUP

Jean Olivier Simoneau, Stéphane Virally, Christian Lupien +1 more

Parametric amplifiers are known to squeeze the vacuum state of the electromagnetic field, thus the statistics of the photocounts at their output should be that of squeezed vacuum. However, several theoretical works predict a very different statistical distribution. We have measured the photocount statistics of a Josephson parametric amplifier and recover the expected squeezed vacuum statistics. We explain this discrepancy by showing theoretically how the photocount statistics is dictated by the detection process. Namely, most experiments will naturally measure a single mode of the electromagnetic field, while the aforementioned theoretical works implicitly describe massively multimode detection.