Ideal or near ideal filter for reflecting or transmitting electromagnetic waves having wavelength range of approximately 100 nm to 10 cm are disclosed. These filters combine a dielectric multilayer structure with a resonant waveguide grating and they are valid for both TE and TM polarized waves. High...http://www.google.ca/patents/US5598300?utm_source=gb-gplus-sharePatent US5598300 - Efficient bandpass reflection and transmission filters with low sidebands based on guided-mode resonance effects
