Error rate analysis of optical receivers with Fabry-Perot optical filter and equalizing postdetection filtering

A complete analytic solution in form of the moment-generating function is presented for the statistical distribution of the decision variable of an on-off system with a Fabry-Perot optical filter. The results include ASE noise, photodetector shot noise and dark current together with thermal noise in the decision circuit. The influence of intersymbol interference is incorporated into the analysis and the optimal bandwidth of the optical filter is determined. It is shown that an equalizing electrical post-detection filter may make a significant improvement in performance. The analysis is extended to cover receivers with an arbitrary optical filter and arbitrary postdetection filtering by making use of a Gaussian approximation.