Cascadability of passband-flattened arrayed waveguide-grating filters in WDM optical networks

The cascadability of passband-flattened arrayed waveguide-grating (AWG) filters is studied using experimental and theoretical transfer functions. The formalism is general and can be used to cascade any type of filter at any channel spacing. For example, modeling indicates that transmission through 100 such AWG (de)multiplexers at 200-GHz channel spacing, assuming 10-Gb/s data streams introduces distortion-induced penalties below the widely acceptable 0.3-dB limit, provided that certain filter design requirements are satisfied. All simulations focus on the filter cascadability and central frequency misalignment effects, and neglect nonlinearities and crosstalk.