Information in Noisy Photon Beams
Ellen Hisdal · Journal of the Optical Society of America · 1968
The fluctuations in a thermal beam due to the superposition of two similar thermal beams are computed. The information loss due to superimposing a quasi-monochromatic thermal-noise beam on a similar signal beam is investigated for two types of noise beams, sample noise, and path noise. In the Wien and Rayleigh–Jeans limits, the information loss j23 per macrocell is found to depend only on the signal-to-noise ratio. The relative loss in maximum obtainable information, I3,max/I2,max, for given signal and noise beams is given as well as some numerical examples.