title: Enhancing alignment tolerance of silicon waveguide by using a wide grating coupler.
abstract: We fabricate a 20 um wide grating coupler for a single-mode thermally-expanded-core (TEC) fiber, in order to enhance positional tolerance in alignment. The minimal coupling loss is measured at 5 dB per facet and the optical 3 dB bandwidth is measured at 40 nm. The 3 dB alignment tolerance is measured at +-7.5 microm in horizontal direction and +290 microm in vertical direction. The 1 dB alignment tolerance is measured at +-4.2 microm in horizontal direction and +125 microm in vertical direction. The alignment tolerance is enhanced twice in horizontal direction and four times in vertical direction, compared with the coupling of a standard single-mode fiber to a standard 10 microm wide grating coupler which is also fabricated in this experiment.
authors: Electronics and Telecommunications Research Institute, 161 Gajong-dong, Yusong-gu, Daejeon 305-350, Korea. jongmool@etri.re.kr
authors: Jong-Moo
authors: JM
authors: Lee
authors: Kap-Joong
authors: KJ
authors: Kim
authors: Gyungock
authors: G
authors: Kim
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D055095:Optics and Photonics / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*
chemical_list: D012825:Silicon