This paper presents a strain gauge using the mechanical-optical coupling method. The Si-based optical microring resonator was employed as the sensing element, which was embedded on the microcantilevers. The experimental results show that applying external strain triggers a clear redshift of the output resonant spectrum of the structure. The sensitivity of 93.72  pm/MPa was achieved, which also was verified using theoretical simulations. This paper provides what we believe is a new method to develop micro-opto-electromechanical system (MOEMS) sensors.

A hybrid structure with higher linearity to compensate the thermal refraction effect based on a ruby microsphere resonator is proposed and has been realised. The thermal refractive effect of the hybrid structure is theoretically and experimentally demonstrated, which showed that it is limited by the diameter of the resonator and the Q factor. By increasing the diameter, the transmission spectrum experiences a transition from blueshift to redshift induced by thermal absorption and when it is equal to a specific value the thermal refraction effect can be reduced or even eliminated. Experiments showed that there is no shift with varying input optical power since the thermal refraction of ruby can be completely compensated at the diameter of the microsphere d = 1.5 μm and Q = 2.3 × 106 when the KD‐310 coated thickness is 60 μm. This reported work shows that the structure could be used to improve stability and is sensitive in high‐Q resonators for applications in laser, biosensor and nonlinear optics.

Optical resonator with high Q value can be used as a core component of the resonator optic gyro, with which the miniaturization and integration would be achieved. The coupling system composed of the disk cavity which is made by traditional micro-electro-mechanical system process and the tapered fiber which is drawn by melting method. When the disk cavity is coupled with the fiber at different places of the tapered region, by swapping input and output there is observed the deviation in the output transmission spectrum, also the resonant frequency, coupling efficiency and the Q value are changed, i.e., the non-reciprocity phenomenon appears. Then the distribution characteristics of the tapered fiber evanescent field are simulated with Rsoft software. The reason of the non-reciprocity is analyzed theoretically. According to the statistics of the output data when the disk cavity is coupled with the fiber at different places of the tapered region, it is found that the non-reciprocity can be eliminated effectively when the coupling happens at the center of the fiber tapered region. And this finding can be used to suppress the non-reciprocity noise produced by the coupling system composed of tapered fiber and resonant cavity in the resonator optic gyros application.

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Based on the development of high sensitivity, low cost, high integration and miniaturization demand of the resonant micro-optical gyro(R-MOG), and in order to achieve a resonant micro-optical-mechano-electrical integrative gyro having high sensitivity, a microsphere optical resonator key sensitive element for producting a cavity with high quality value (Q value) and large diameter in the field of integrated optical micro resonator is proposed, for making a resonant micro optical gyro. Microsphere optical resonator is made by means of water-hydrogen flame melting, and the SiO2 microspherical cavity is formed under the natural cooling and contraction surface tension. Microsphere optical resonator with its diameter D ranging from 300 μm to 2200 μm is fabricated by melting method with hydrogen flame as a heat source through controlling the hydrogen flame’s area by regulating the flow of hydrogen gas. The resonator serves as the key unit of the resonant optical gyro sensitive parts, its Q value and diameter D have direct effect on the performance of the resonant angular velocity sensor. Affect parameters on the performance of the microsphere optical resonator with different diameters is tested and processed to obtain the result. The corresponding relationship among Q value, DQ product, resonant micro-optical gyro’s sensitivity and microspherical cavity diameter D is analyzed, and the reason for them is given. With the increase of microspherical cavity diameter D, the Q value and DQ product reduce after rising first, while the gyro sensitivity goes to rise and fall. Based on the microsphere optical resonator DQ product optimization research, the resonant micro-optical gyro’s key sensitive unit with best parameters is obtained. When the microspherical cavity diameter D varies from 600 to 200 μm, the gyro sensitivity can meet the condition that δΩ D is 1260 μm, the Q value of microsphere optical resonator is 7.18×107 and the corresponding optimal limited sensitivity of the resonant micro-optical gyro is almost 10°/h, and this result adequately meets the requirement of business level gyro applications. This work can serve as an experimental foundation in the research of new type resonant micro optical gyro at chip level, high accuracy and low cost, and will also provide a technical reference for further study of high integrated and high precision resonant micro optical gyro.