title: Polarization insensitive silicon immersion grating based on total internal reflection.
abstract: We describe an immersion grating (IG) with both low polarization-dependent loss (PDL) and high diffraction efficiency. Our immersion grating consists of a silicon (Si) prism and a Si grating coated with dielectric film. We analyze the effect of the refractive index of dielectric film and clarify the refractive index ratio between a Si grating and dielectric film. Selecting an adequate material for the dielectric film, we design the diffraction efficiency of TM polarization without changing that of TE polarization. The simulation results for the optimized IG show a PDL of 0.2 dB and diffraction efficiency of -0.4 dB. A prototype with high dispersion power provides a low PDL of 0.6 dB, while maintaining a high diffraction efficiency of -0.4 dB.
authors.affiliation: NTT Microsystem Integration Labs., NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-0198, Japan. higuchi.yuichi@lab.ntt.co.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Higuchi
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Ishii
authors.forename: Koichi
authors.initials: K
authors.lastname: Hadama
authors.forename: Joji
authors.initials: J
authors.lastname: Yamaguchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D012031:Refractometry / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D012825:Silicon