Design, Fabrication And Characteristics Research Of Micro-ring Resonator For Micro Displacement Sensor

As a sensitive device to micro-displacement, micro-displacement sensors have important applications in high-precision control, micro-operations, micro-nano-positioning systems, engineering thickness measurement and other testing fields. With the rapid development of MEMS\NEMS technology, there is a higher precision requirement for micro-displacement sensor, even ultra-sensitive and rapid displacement detection in nanometer scale. A novel micro-displacement detecting method was designed using optical properties of micro-nano structure based on force-optics properties. Such a new micro-displacement sensor is the most promising method for its high precision, compact and other unmatched advantages.In this paper, micro-ring resonator displacement sensor is designed, indicating that the micro-displacement sensor performance is determined by the characteristics of micro-ring resonator. Aiming to high precision micro-displacement, some research around micro-ring cavities have been done in this paper. The main works are as follows.The infrastructure of micro-ring resonator displacement sensor was designed, and the relationship between ring resonator parameters and the displacement sensitivity was analyzed.Based on finite difference time domain method (FDTD), optical properties simulation was carried out for micro-ring resonator subsystem with SOI material. Finally, optimized structure of the ring resonator was obtained.With the help of Cooperation Unit about micro-machining line, the above-mentioned optimized design of micro-ring resonator was realized, and morphology was tested to compare the designing and the physical parameters. Through optimizing the experimental scheme, an appropriated test system has been set up. As a high-efficiency single-cone coupling component, tapered fiber was used between external optical signal and the ring resonator-chip. Using narrow NewFocus (TLB-6328) continuously tunable laser (power> 20mW, 1520nm-1570nm continuous variable) with line-width (300KHZ) as the excitation light, and rapid response NewFocus 25GHz photo-detector as the Optical receiver, we successfully tested the micro-cavity structure. Testing results showed that: the designed micro-ring resonator has a quality factor about 103, with great potential in realization of ultra-high sensitivity micro-displacement sensor.