[8a-Z16-1~10] 3.14 Optical control devices and optical fibers

△ [8a-Z16-9] Narrowband focusing retroreflection by cavity-resonator-integrated guided-mode resonance filter

〇Ryohei Ueda¹, Toshiki Kusuura¹, Junichi Inoue¹, Kenji Kintaka², Shogo Ura¹ (1.Kyoto inst. Tech., 2.AIST)

Keywords:Optical waveguide, Wavelength filter, Waveguide grating

Cavity-resonator-integrated guided-mode resonance filter (CRIGF) consists of a grating coupler (GC) and two distributed Bragg reflectors integrated on a thin-film waveguide, and shows a narrowband reflection spectrum. In this study, CRIGF having a focusing GC and a reflective substrate (focusing CRIGF) was proposed and designed, and its narrowband focusing retroreflection for an incidence of a divergent wave was experimentally confirmed. The focusing CRIGF of 20-micron-size aperture and 50-micron focal distance was fabricated, and the retroreflection spectrum of 4-nm width and the peak reflectance of more than 80% was obtained.