Spectral and Spatial Filtering Using Waveguide Grating Mirror
Ivan Avrutsky, Rabi Rabady, Kirill Zinoviev
Department of Electrical and Computer Engineering
Wayne State University, Detroit, MI 48202
Abstract: Resonant reflection of light by a waveguide grating provides simultaneous
spectral and spatial filtering of the reflected beam. Narrowband transmission filter based
on a plasmon resonance shows high out-of-band suppression in a wide spectral range.
Dielectric waveguide grating mirror improves spatial coherence of a semiconductor laser.
OCIS codes: (050.1950) Diffraction gratings; (130.2790) Guided waves; (140.3410) Laser resonators;
(240.6680) Surface plasmons; (120.2440) Filters.
Excitation and re-emission of guided modes in a planar waveguide grating structure is known to result in
sharp features in wavelength and angular reflectance spectra. The resonant reflection was predicted in
1965  and experimentally demonstrated in 1985 [2, 3]. By physical nature, the resonant reflection
from a waveguide grating is similar to the Wood anomalies of light diffraction at metallic gratings
associated with excitation and re-emission of surface plasmons. Due to much lower absorption in
dielectric structures, the quality factor of the resonant waveguide mode excitation can be very high. To
the best of our knowledge the highest reported finesse is 1.5104