Fig. 2: Linewidth, ring-down, and photo-thermal absorption loss measurements of the UHQR and control devices.
a Spectral scan of the fundamental 1570 nm transverse electric field (TE) mode for the control (blue curve) and ultra-high quality factor (Q) resonator (UHQR) (orange curve) devices. The total and intrinsic linewidths are extracted from a Lorentzian fit. The yellow sinusoidal signal is a radio frequency (RF) calibrated fiber Mach-Zehnder interferometer (free spectral range (FSR) = 5.871 ± 0.004 MHz, see the Supplementary Information). M, Million. b UHQR ring-down time (τ) measurement at 1570 nm with calculated loaded and intrinsic Q factors (QL and Qin). The experimental data (blue curve) is fitted with an exponential curve (orange curve). c Summary of the total (blue circle) and intrinsic (blue dot) linewidths for the control and total (orange circle) and intrinsic (orange dot) linewidths for the UHQR devices from 1550 nm to 1600 nm. d Measured intrinsic Q from 1550 nm to 1600 nm for the control (blue dot) and UHQR (orange dot) resonators. e Photo-thermal absorption loss measurement from 1550 nm to 1600 nm for UHQR and control. The highest UHQR 422 Million intrinsic Q at 1570 nm and the absorption-limited Q (Qabs) of 3.4 Billion at 1600 nm are indicated. The non-absorption loss is fit to the surface scattering loss model (dash lines). The blue dot, cross, and diamond data represent the intrinsic, absorption, and non-absorption losses for the control resonators. The orange dot, cross, and diamond data represent the intrinsic, absorption, and non-absorption losses for the UHQR resonators.
