Theory and simulation of a concave diffraction grating demultiplexer for coarse WDM systems

Reflective concave diffraction gratings in multimode planar waveguide geometries are considered as wavelength separation devices for coarse wavelength division multiplexing (WDM) systems. General expressions are derived relating the number of channels, the wavelength and channel wavelength separation, and the numerical aperture of the planar slabwaveguide. Scalar electromagnetic simulations performed for a particular grating design show that acceptable performance is theoretically achievable.