Reflected properties Analysis of Thin-film Waveguide-grating Filters
薄膜波导光栅滤光片反射特性研究

Waveguide-grating filters with single-layer and triple-layer thin-film structure were designed, which were based on the theory that reflected sidebands depressed more by introducing antireflection structures of thin-film into waveguide-gratings. The purpose was to obtain narrow linewidth and high peak response in wide spectral range by using layers as few as possible. Rigorous coupled-wave theory was used in precise calculation on the possible structures of single-layer and triple-layer thin-film waveguide filters, and good reflected curves were obtained. Furthermore, a good triple-layer thin-film structure which was easy achieved in experiment in wide spectral range was also obtained.