Abstract

The semi classical theory of photo detection treats the electromagnetic field as a classical entity and assumes that the fundamental noise observed in converting a light beam into an electrical current is the shot noise associated with the discreteness of the electron charge. Statistically, this leads to a conditional Poisson-process model for direct detection, i.e., given knowledge of the short- time average optical power illuminating the active region of the photo detector, the resulting photoemissions are Poisson distributed. From this model the signal plus additive white Gaussian noise models for optical homodyne and heterodyne (coherent optical) detection are easily derived

© 1984 Optical Society of America