The presence of a magnetic field gradient in a sample cell containing spin-polarized ¹²⁹Xe atoms will cause an increased relaxation rate. We measured the transverse spin relaxation time of ¹²⁹Xe verse the applied magnetic field gradient and the cell temperature. We then compared the different transverse spin relaxation behavior of dual isotopes of xenon (¹²⁹Xe and ¹³¹Xe) due to magnetic field gradient in the same cell. The experiment results show the residual magnetic field gradient can be measured and compensated by applying a negative magnetic gradient in the sample cell. The transverse spin relaxation time of ¹²⁹Xe could be increased 2–7 times longer when applying an appropriate magnetic field gradient. The experiment results can also be used to determine the diffusion constant of ¹²⁹Xe in H₂ and N₂ to be 0.4 ± 0.26 cm²/sec and 0.12 ± 0.02 cm²/sec. The results are close with theoretical calculation.

The cylindrical resonator gyroscope (CRG) is a typical Coriolis vibratory gyroscope whose performance is determined by the Q factor and frequency mismatch of the cylindrical resonator. Enhancing the Q factor is crucial for improving the rate sensitivity and noise performance of the CRG. In this paper, for the first time, a monolithic cylindrical fused silica resonator with a Q factor approaching 8 × 10⁵ (ring-down time over 1 min) is reported. The resonator is made of fused silica with low internal friction and high isotropy, with a diameter of 25 mm and a center frequency of 3974.35 Hz. The structure of the resonator is first briefly introduced, and then the experimental non-contact characterization method is presented. In addition, the post-fabrication experimental procedure of Q factor improvement, including chemical and thermal treatment, is demonstrated. The Q factor improvement by both treatments is compared and the primary loss mechanism is analyzed. To the best of our knowledge, the work presented in this paper represents the highest reported Q factor for a cylindrical resonator. The proposed monolithic cylindrical fused silica resonator may enable high performance inertial sensing with standard manufacturing process and simple post-fabrication treatment.

The hemispherical resonator gyroscope (HRG) has attracted the interest of the world inertial navigation community because of its exceptional performance, ultra-high reliability and its potential to be miniaturized. These devices achieve their best performance when the differences in the frequencies of the two degenerate working modes are eliminated. Mechanical treatment, laser ablation, ion-beams etching, etc., have all been applied for the frequency tuning of resonators, however, they either require costly equipment and procedures, or alter the quality factors of the resonators significantly. In this paper, we experimentally investigated for the first time the use of a chemical etching procedure to decrease the frequency splits of hemispherical resonators. We provide a theoretical analysis of the chemical etching procedure, as well as the relation between frequency splits and mass errors. Then we demonstrate that the frequency split could be decreased to below 0.05 Hz by the proposed chemical etching procedure. Results also showed that the chemical etching method caused no damage to the quality factors. Compared with other tuning methods, the chemical etching method is convenient to implement, requiring less time and labor input. It can be regarded as an effective trimming method for obtaining medium accuracy hemispherical resonator gyroscopes.

Optical properties, which determine the application of optical devices in different fields, are the most significant properties of optical thin films. In recent years, Metal-organic framework (MOF)-based optical thin films have attracted increasing attention because of their novel optical properties and important potential applications in optical and photoelectric devices, especially optical thin films with tunable optical properties. This study reports the first example of tuning the optical properties of a MOF-based optical thin film via post-modification. The MOF-based optical thin film was composed of NH₂-MIL-53(Al) nanorods (NRs) (MIL: Materials from Institute Lavoisier), and was constructed via a spin-coating method. Three aldehydes with different lengths of carbon chains were chosen to modify the MOF optical thin film to tune their optical properties. After post-modification, the structural color of the NH₂-MIL-53(Al) thin film showed an obvious change from purple to bluish violet and cyan. The reflection spectrum and the reflectivity also altered in different degrees. The effective refractive index (n_eff) of MOFs thin film can also be tuned from 1.292 to 1.424 at a wavelength of 750 nm. The success of tuning of the optical properties of MOFs thin films through post-modification will make MOFs optical thin films meet different needs of optical properties in various optical and optoelectronic devices.

The precise calibration and compensation of detetion, drive, system phase, and resonator errors in whole-angle (WA) hemispherical resonator gyroscope (HRG) are essential to improve performance. This paper comprehensively considers the influences of four kinds of errors, including the gain mismatch and angle misalignment of detection and drive electrodes; the nonlinearity of capacitance detection and electrostatic drive; the phase delay of each module in the measurement and control system; the anisodamping and anisoelasticity of resonator. A novel self-excitation enabled decoupling, calibration, and compensation (SE-DCC) process is proposed based on the analysis and modeling of these errors. The detection errors are first calibrated and compensated under high-speed turntable excitation. The drive and system phase errors are then self-calibrated and self-compensated under self-excitation operation. Finally, the characteristics of resonator appear, and the self-calibration and force-compensation of anisodamping are completed. Experimental results demonstrate that the angle-dependent errors under high-speed rotation are effectively suppressed, the peak-to-peak value of angle-dependent bias (ADB) is reduced by more than two orders from 31.44°/h to 0.25°/h, the scale factor (SF) nonlinearity in ±500°/s range is reduced by 85 times from 74.6ppm to 0.879ppm, the bias stability (1σ) is reduced from 0.7740°/h to 0.0134°/h, and the bias instability (BI) is reduced by one order from 0.0991°/h to 0.0092°/h. The SE-DCC process is proven to push the accuracy of the tested WA HRG to inertial-level and shows promise for expanding to all types of WA gyroscopes with high Q factor and low frequency spilt.

Cylindrical shell fused silica resonators coated with 8 axisymmetric Pb(Zr_0.53Ti_0.47)O₃ (PZT) thin film electrodes (thickness ~2 μm) were reported. The resonators were firstly designed and fabricated, then annealed and processed by chemical etching to increase mechanical quality factor (Q factor) of resonators, which achieved as high as 2.89 million for n = 2 wineglass modes after being coated with PZT thin film electrodes. The n = 2 wineglass modes of the resonators were driven by PZT thin film electrodes in experiment and simulation with fine vibratory shape, which demonstrated the feasibility of the cylindrical fused silica resonator driven by PZT thin film electrodes. The application of PZT thin film electrodes to drive and detect cylindrical shell fused silica resonator can significantly improve Q factor of resonators and improve the sensitivity of Coriolis Vibratory Gyroscope (CVG).