title: High Q-factor microring resonator wrapped by the curved waveguide.
abstract: In this work, we study the performances of ring resonators of different type by analyzing the bending loss and the condition of the critical coupling. We propose that the bending loss of microring can be reduced by wrapping a concentrically curved waveguide. The difference of propagation constant between two concentrically curved waveguides can be tuned by adjusting the bus waveguide width to optimize the critical coupling. Furthermore, we propose to enlarge the difference of the propagation constant between two concentrically curved waveguides to maintain the circulating light in the ring to obtain higher quality factor. In this study, the highest quality factor that we measured is 7 × 10(5).
authors.affiliation: Department of Optics and Photonics, National Central University, 32001 Jhongli, Taiwan.
authors.forename: Dong-Po
authors.initials: DP
authors.lastname: Cai
authors.affiliation: Department of Optics and Photonics, National Central University, 32001 Jhongli, Taiwan.
authors.forename: Jyun-Hong
authors.initials: JH
authors.lastname: Lu
authors.affiliation: Department of Optics and Photonics, National Central University, 32001 Jhongli, Taiwan.
authors.forename: Chii-Chang
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Optical Sciences Center, National Central University, 32001 Jhongli, Taiwan.
authors.forename: Chien-Chieh
authors.initials: CC
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Chu-En
authors.initials: CE
authors.lastname: Lin
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Ta-Jen
authors.initials: TJ
authors.lastname: Yen