Modeling of reflection-transmission grating based 2DIO wavelength router

This paper presents an analytic study of a singlemode linear reflection-transmission-grating (RTG)-based twodimensional-integrated-optic (2DIO) N × N wavelength router. To determine its performance, the optical field propagation in the router is simulated using a slab waveguide based on the ABCD matrix theory for low diverging Gaussian beams. In predicting the limits of operation, sources of crosstalk are determined, and their dependence upon fabrication errors such as mask alignment errors is also analyzed. Methods to minimize these are discussed. Finally, the model shows that the device is equally suitable for coarse and dense wavelength division multiplexing applications.