Application of optical preamplification to optimize receiver sensitivity in spectrum-sliced WDM communication systems

Recently there has been considerable interest in communication systems in which both the signal and noise are Gaussian stochastic processes. Examples of such systems include wavelength division-multiplexed (WDM) fiber optic communication systems which utilize the amplified spontaneous emission (ASE) noise from an erbium-doped fiber amplifier (EDFA) as a source of broadband light. The wideband ASE noise from the EDFA is "spectrum-sliced" to create multiple light sources which provide a low-cost alternative to multiple coherent lasers for such applications. Each slice of the spectrum is actually a burst of noise which may be modulated individually for a high capacity WDM system. The detection sensitivity of binary OOK and FSK spectrum-sliced communication systems, in which both the signal and noise are stochastic processes, was analyzed. It was shown that when an optical preamplifier receiver is used, there exists an optimum m which minimizes the detection sensitivity (in terms of the average number of photons/bit) for a given error probability. Moreover the evaluated detection sensitivity presents an order of magnitude improvement over conventional detection techniques for such spectrum-sliced communication systems.