# Photon Number Distributions

Photon Number Distributions

This Demonstration shows photon count distributions (probability distributions) of an ideal laser light source (Poisson distribution) and a thermal radiation source (Bose-Einstein distribution). In the interactive plots both functions have the same expectation value (mean). For the Poisson distribution, the expectation value and variance of the photon number coincide; on the other hand, the variance of the thermal photon number distribution goes beyond its expectation value.

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