Photon Shot Noise
Abstract
A recent theory is reviewed for the shot noise of coherent radiation propagating through a random medium. The Fano factor P/bar {I} (the ratio of the noise power and the mean transmitted current) is related to the scattering matrix of the medium. This is the optical analogue of Büttiker's formula for electronic shot noise. Scattering by itself has no effect on the Fano factor, which remains equal to 1 (as for a Poisson process). Absorption and amplification both increase the Fano factor above the Poisson value. For strong absorption P/bar {I} has the universal limit 1+(3)/(2)f, with f the BoseEinstein function at the frequency of the incident radiation. This is the optical analogue of the onethird reduction factor of electronic shot noise in diffusive conductors. In the amplifying case the Fano factor diverges at the laser threshold, while the signaltonoise ratio bar {I}^{2}/P reaches a finite, universal limit.
 Publication:

Modern Physics Letters B
 Pub Date:
 1999
 DOI:
 10.1142/S0217984999000439
 arXiv:
 arXiv:condmat/9905024
 Bibcode:
 1999MPLB...13..337B
 Keywords:

 Mesoscopic Systems and Quantum Hall Effect
 EPrint:
 11 pages, 4 figures (caption to figure 3 corrected)