Papers by Author: Li Shuang Feng

Abstract: As one of the new optical sensing devices, Resonant Micro-optic Gyro (RMOG) measures the rotation rate due to the resonance frequency difference based on the optical Sagnac effect. In order to reduce the influence of the light path and circuit noise and the output edge pulse signal, the mean filtering algorithm based on Labview is put forward to improve the gyros performance. The mean filtering algorithm is simulated and realized with Labview, which approves that the algorithm is effective in noise restraining. The test of RMOG demonstrates that the zero bias stability is 1.4 °/s during 1 hour with 10-second smoothing.

Abstract: The electrode layout determines the piezoelectric performance of quartz resonator and directly affects the precision of the quartz VBA. We presented a novel monolithic differential quartz VBA with optimized electrode layout and solved the lock-in problem due to mechanical coupling. Based on the mass-equivalent system, an analytical model was developed and the uncoupling condition of the monolithic differential quartz VBA was deduced. Then we proposed five different electrode layouts and the optimum one was determined via simulation of piezoelectric and harmonic characteristics of quartz resonator with ANSYS. As a result, the mechanical coupling can be eliminated and at the same time, ±100 g measurement range and 80Hz/g scale factor can be achieved. The optimum electrode layout can drive quartz resonator in the desired modal. The presented device with advantages of miniaturization, low mechanical coupling, none assembly errors and high electromechanical coupling efficiency is very promising in the high-precision quartz VBA.

Abstract: In order to realize the opto-electronic integration of optic gyro, the quasi-planar ridge SOI waveguide resonator is proposed due to its low loss and small bend radius. First, the single mode condition and smallest bend radius were simulated by using the 3-dimension finite difference beam propagation method (3-D BPM). Then the relationship between the sensitivity of gyro and the resonator characteristics, such as radius and coupling coefficient, was analyzed by applying the model of the integrated optical gyro. Based on these simulations, the ridge height and width of the waveguide were 220 nm and 1.2 μm respectively and the smallest bend radius was 600μm. It is shown that the theoretical detection limit of the gyro was 0.031 °/s when the resonator diameter was 5cm and the couplers splitting ratio was 46.7:53.3. This gyro system is suitable for tactical and civil applications.

Abstract: There are two types of coupling structures for the photonic crystal of triangular array of air holes. The two types of coupling structure between dielectric taper waveguide(DTW) and photonic crystal waveguide(PCW) is investigated. The coupling transmission efficiency is calculated for different coupling structure of the input and output, we found that the coupling transmission efficiency is changed with different coupling width and distance. The highest transmission efficiency is 92.6% and 99.6% for the input and output port respectively.

Abstract: The nanostructures and nanodevices special fabrication technology including electron beam lithography (EBL), focused ion beam (FIB) technology, microcontact printing (μCP) and nanoimprinting were introduced in this paper. The examples of Y-shape waveguide coupler and high precision nanopattern of China Seal were designed and fabricated based the EBL and FIB technology respectively. Their structures can be characterized by scanning electron microscopy (SEM), scanning tunnel microscopy (STM) and atom force microscopy (AFM) etc. The C60 molecular on a Si (111)-(7×7) surface in variable temperature is deposited and detected by STM. The fabricated pattern and structures results indicated that the novel fabrication and characterization technology is very important and effective tools in nanoscale science field.

Abstract: The uniform, well designed nano-gratings have been successfully fabricated by using a dual beam focused ion beam (FIB)/scanning electron microscopy (SEM) system on the silicon substrates coated with 15 nm thick Au layer. The nano-gratings were designed with period of 840 nm, groove of 425 nm and beam of 415 nm. By adjusting the FIB parameters of milling like beam current, dwell time and scanning model, the fabricated nano-gratings were uniform in width and the side wall had good verticality. The currently fabricated nano-gratings using focused ion beam can be adjusted to serve as sub-wavelength optical resonant sensor which can be extended to nano-grating accelerometer with resolution of 10^-9g.