In this paper, we propose a novel vertical SU-8 waveguide for evanescent analyte sensing. The waveguide is designed to possess a vertical and narrow structure to generate evanescent waves on both sides of the waveguide's surface, aimed at increasing the sensitivity by enlarging the sensing areas. We performed simulations to monitor the influence of different parameters on the waveguide's performance, including its height and width. E-beam lithography was used to fabricate the structure, as this one-step direct writing process enables easy, fast, and high-resolution fabrication. Furthermore, it reduces the sidewall roughness and decreases the induced scattering loss, which is a major source of waveguide loss. Couplers were added to improve the coupling efficiency and alignment tolerance, and will contribute to the feasibility of a plug-and-play optical system. Optical measurements show that the transmission loss is 1.03 ± 0.19 dB/cm. The absorption sensitivity was measured to be 4.8 dB per refractive index unit (dB/RIU) for saline solutions with various concentrations.

High quality cylindrical resonators are extremely important to guarantee the performance of cylindrical vibratory gyroscope. Cylindrical resonators’ damping asymmetry is one of the major sources which result in the gyroscope's drift. In this paper, the method of evaluating damping asymmetry based on the Q factors of the damping axes is proposed. The dynamic model of cylindrical resonators is established to analyze the Q factor's variation under the effect of mode superposition. The weakness of measuring Q factors by amplitude-frequency response analysis is figured out. Theoretical calculation analysis based on amplitude-frequency response is also carried out to investigate the laws of Q factor circumferential distribution in detail. Theoretical results show that the Q factor circumferential distribution is influenced by the frequency difference, Q factor difference and the angle difference between damping axes and frequency axes. Furthermore, the Q factors of the damping axes can be obtained from the Q factor circumferential distribution under certain conditions when the frequency difference is relatively large. The Q factor circumferential distribution will be almost the same to the real Q factor distribution of the cylindrical resonator when the frequency difference is small enough. Furthermore, the Q factors and locations of the damping axes are able to be acquired more easily. Experiments of amplitude-frequency response analysis are also set up to validate the theoretical analysis results, from which damping asymmetry and damping axes of the cylindrical resonator can be identified.