Multireflection modal method for wideband fused-silica transmission gratings

A multireflection modal method is proposed to give a clear physical picture for explanation of the diffraction process that takes place in a wideband fused-silica transmission grating. Using rigorous coupled-wave analysis, the optimized grating exhibits diffraction efficiency greater than 93.9% for TE polarization over a bandwidth of 126 nm (from 735 to 861 nm). The designed wideband fused-silica transmission grating is fabricated using holographic interference recording and inductively coupled plasma etching technology. Experimental results are in agreement with the theoretical values.