Open AccessPerpendicular coupler for standing wave excitation and wavelength selection in high-Q silicon microresonators
Author(s) -
Shanhong Wan,
Fangjie Shu,
Rui Niu,
GuangCan Guo,
ChangLing Zou,
ChunHua Dong
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.392989
Subject(s) - resonator , whispering gallery wave , optics , power dividers and directional couplers , whispering gallery , wavelength , q factor , perpendicular , photonics , optoelectronics , waveguide , coupled mode theory , output coupler , physics , materials science , refractive index , geometry , mathematics
High quality factor (Q) whispering gallery mode (WGM) resonators have been widely applied in photonics, while the excitation and collection of WGMs are mostly restricted to traveling wave coupler. Here, we experimentally demonstrate a novel on-chip perpendicular coupler (PC) for high-Q (∼1.1 × 10 5 ) silicon whispering gallery microresonators. The PC is compact and allows efficiently tunneling coupling between the waveguide and the microresonator, hence it holds great potential for fan-out photonic devices. Drastically different from the traveling wave couplers, standing wave mode can be excited through the PC. In addition, a PC working as an output coupler can also selectively collect the resonance of different wavelengths by locating on different azimuth angles. Our results show the feasibility of such novel coupler for WGM resonators and its potential use in future applications of integrated high Q microresonators.