FUNDAMENTAL LIMITS ON OPTICAL PULSE DETECTION AND DIGITAL-COMMUNICATION

In this paper, the techniques of statistical decision theory are appli ed to direct detection of optical pulses. A realistic and general mode l of a classical photodetector/amplifier receiver is considered. Optim um decision strategies and corresponding receiver sensitivities are de rived both for single-pulse detection and for continuous digital commu nication in which the intersymbol interference is constrained to be ze ro. A comparison is made to the classic work of Personick and Smith. T heir results are shown to be remarkably close to the fundamental limit s at high bit rates, At low bit rates, the optimal filter for small du ty-cycle pulses gives much better performance than the filters analyze d by Personick and Smith. Optimum values for the Personick integrals a re also given, Results are given for a number of cases of practical im portance including a photodiode/FET receiver.