Crosstalk and loss in wavelength division multiplexed systems employing spectral slicing

A model for spectral slicing in wavelength division multiplexed (WDM) networks for local access is developed and experimentally verified. Waveguide grating routers are used for multiplexing and demultiplexing. Outside of the optical passbands, a constant transmission level equal to the average out-of-band transmission level is assumed. The dependence of slicing loss and signal-to-interference ratio (SIR) on parameters such as optical filter shape and width and misalignment between passbands in the two routers are calculated. The crosstalk levels are found to be too high for typical access applications unless measures such as equalizing the power of the received optical signals are used. Slicing loss is high, and the loss budget will benefit from reductions of router insertion losses and increases in the output power of broad-spectrum optical sources.