Fig. 1. Schematic configurations of the proposed ultrahigh-Q MRR. (a) 3D view and (b) top view.
Fig. 2. (a) Cross section of the SOI waveguide. (b) Mode field distribution at a waveguide width . (c) Calculated transmission loss as the waveguide core width increases with different mean deviation at the wavelength of 1550 nm.
Fig. 3. (a) Calculated MERs of the TE modes at the SMWG–MWB junction as the radius varied when the mode is launched from the SMWG. Calculated light transmissions in the waveguide consisting of an input SMWG, a 180° Euler MWB, and an output SMWG when (b) , (c) , and (d) . The insets show the simulated light propagation in the designed waveguide and the modal profile at the output port.
Fig. 4. (a) Microscope images of the fabricated ultrahigh-Q resonator. (b) Zoom-in view of bent DC. Inset: Enlarged view of coupling region around . (c) Grating couplers for chip–fiber coupling.
Fig. 5. (a) Measured spectral responses at the through port of the fabricated MRRs. (b) Enlarged view of the measured major fundamental mode resonance peak with the Lorentzian transmission matrix model fitted. (c) Enlarged view of the measured mode splitting.