A novel hybrid diffraction method is introduced to simulate the diffraction and imaging of a planar-integrated concave grating that has total internal reflection (TIR) facets. The Kirchhoff–Huygens diffraction formula is adopted to simulate the propagation of the lightwave field in the free-propagation region, and a rigorous coupled-wave analysis is used to calculate the polarization-dependent diffraction by the grating. The hybrid diffraction method can be used to analyze accurately the imaging properties as well as the polarization-dependent diffraction characteristics of a concave grating. The dependence of several merit parameters of a concave grating with TIR facets on its basic geometric parameters is studied. Compared with one with metallic echelle facets, a concave grating with TIR facets shows a much lower polarization-dependent loss. Since more performance specifications can be considered in the design of a concave grating than with the conventional scalar method, design error can be reduced greatly with the present hybrid diffraction method.
© 2004 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(060.1810) Fiber optics and optical communications : Buffers, couplers, routers, switches, and multiplexers
(130.0130) Integrated optics : Integrated optics
(250.5300) Optoelectronics : Photonic integrated circuits
(260.6970) Physical optics : Total internal reflection
Zhimin Shi, Jian-Jun He, and Sailing He, "Analysis and design of a concave diffraction grating with total-internal-reflection facets by a hybrid diffraction method," J. Opt. Soc. Am. A 21, 1198-1206 (2004)