A proposed design for ultralow-loss waveguide grating routers

We propose a design for a dense wavelength-division multiplexing (WDM) demultiplexer whose total fiber-to-fiber insertion loss can be as low as 0.3881 dB. Our three-dimensional (3-D) models-beam propagation and mode solver-show that waveguide bending losses and fiber coupling losses are almost insignificant. Most of the loss comes from the star couplers and from material losses.