Spectrum-Sliced WDM Using OOK Transmission

This chapter presents one of the primary contributions of this dissertation: a mathematical model to analyze and evaluate noise-like spectrum-sliced systems which employ conventional PIN receivers, or as proposed in this dissertation, optical preamplifier receivers. As discussed in previous chapters, spectrum-slicing provides a low-cost alternative to the use of multiple coherent lasers for WDM applications by utilizing spectral slices of a single broadband noise source for creating the multichannel system. In this chapter we analyze the performance of both PIN and optical preamplifier receivers for spectrum-sliced WDM using actual noise distributions, and the results are compared with those using the Gaussian approximation. This extends prior results of Marcuse [44,45], for the detection of deterministic signals in the presence of optical amplifier and receiver noise. Although the methodology is similar, the results are considerably different when the signal is itself noise-like. For the case of noise-like signals, it is shown that when an optical preamplifier receiver is used, there exists an optimum filter bandwidth which minimizes the detection sensitivity for a given error probability. Moreover the evaluated detection sensitivity, in photons/bit, represents an order of magnitude (>10 dB) improvement over conventional detection techniques that employ PIN receivers. The Gaussian approximation is shown to be overly conservative when dealing with small ratios of the receiver optical to electrical bandwidth, for both PIN and preamplifier receivers. Finally it is shown how the use of forward error correction (FEC) coding can lead to significant improvement in the transmission capacity of SS-WDM systems. The chapter is organized as follows. The motivation for this analysis is discussed in Section 3.1. Section 3.2 introduces the basic concepts of the incoherent detection of noise-like signals. An outline of the receiver structure used in the analysis and a detailed discussion of the