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Zhou Y.,Beihang University | Shang G.,Beihang University | Cai W.,Beihang University | Yao J.-E.,Key Laboratory of Micro Nano Measurement Manipulation and Physics
Review of Scientific Instruments | Year: 2010

A cantilevered bimorph-based resonance-mode scanner for high speed atomic force microscope (AFM) imaging is presented. The free end of the bimorph is used for mounting a sample stage and the other one of that is fixed on the top of a conventional single tube scanner. High speed scanning is realized with the bimorph-based scanner vibrating at resonant frequency driven by a sine wave voltage applied to one piezolayer of the bimorph, while slow scanning is performed by the tube scanner. The other piezolayer provides information on vibration amplitude and phase of the bimorph itself simultaneously, which is used for real-time data processing and image calibration. By adjusting the free length of the bimorph, the line scan rate can be preset ranging from several hundred hertz to several kilohertz, which would be beneficial for the observation of samples with different properties. Combined with a home-made AFM system and a commercially available data acquisition card, AFM images of various samples have been obtained, and as an example, images of the silicon grating taken at a line rate of 1.5 kHz with the scan size of 20 μm are given. By manually moving the sample of polished Al foil surface while scanning, the capability of dynamic imaging is demonstrated. © 2010 American Institute of Physics. Source

Liu H.-L.,Science and Technology on Inertial Laboratory | Liu H.-L.,Key Laboratory of Micro Nano Measurement Manipulation and Physics | Liu H.-L.,Beihang University | Wang Y.,The Aerospace Corporation | And 4 more authors.
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2013

Spatial resonator is the key element of MOEMS gyroscope. Adjustment of the micro-mirrors of spatial resonator is important for realization of the resonator. An adjustment method based on coupling theory for the vertical micro-mirrors in the spatial resonator was presented. For the production of the vertical micro-mirror by micro-processing technology, the principle of the regulation based on coupling was used to complete the space-conditioning as a useful means, rather than avoiding the coupling volume. The basic structure of regulation and the method of implementation were introduced, and the spatial resonator made up of this structure was simulated and analyzed by MATLAB and ANSYS respectively. The results show that the structure based on the method could implement the micro-mirror's spatial regulation with high precision. For the adjustments of the MOEMS gyroscope spatial resonator, this method has its own reliable stability and higher integration, which provide a new method for realization of the spatial resonator MOEMS gyroscope. Source

Yu H.-Y.,Beihang University | Zhang C.-X.,Beihang University | Zhang C.-X.,Key Laboratory of Micro Nano Measurement Manipulation and Physics | Feng L.-S.,Beihang University | And 3 more authors.
Guangdianzi Jiguang/Journal of Optoelectronics Laser | Year: 2012

The scheme of silicon-based integrated optical gyroscope is proposed firstly, and the curve radius and transmission loss of the curve waveguide are calculated theoretically. The essential parameters which are the width and length, are simulated with the relationship with transmission loss, and the "K" shape coupler is designed by the R-soft simulation based on the theoretical analysis result. The experimental setup is constructed, and the loss and the optical mode are tested, respectively. The loss measurement results show that the loss is 0.014 dB/cm, which validates the theoretical calculation result that the transmission can be neglected when the ratio of l 2/h is greater than 5000. Finally, the optical mode is tested by beam-scan, which shows the perfect fitting result with the ideal Gauss mode curve. Source

Dong Q.-L.,Beihang University | Dong Q.-L.,Science and Technology on Inertial Laboratory | Dong Q.-L.,Key Laboratory of Micro Nano Measurement Manipulation and Physics | Liu X.-P.,Beihang University | And 6 more authors.
Jiliang Xuebao/Acta Metrologica Sinica | Year: 2013

The magnetic field distribution varies with the dislocation of coaxial drive coils. The basic Biot-Savart law and the superposition theorem is applied to work out the calculation formulas of the magnetic field, and with the help of MATLAB the numerical solution of the variation magnetic induction is calculated and the field plots is drawn. Based on these, the effects of the coil winding rules on the magnetic field distribution were judged and reasonable theory suggests is given about the magnetic field incentive and maintenance calculation results show that the effect of dislocation of a double coaxial coil on magnetic field is less than the order of 10-6 that is acceptable to actual application currently. Source

Peng L.,Beihang University | Peng L.,Key Laboratory of Micro Nano Measurement Manipulation and Physics | Feng L.,Beihang University | Feng L.,Key Laboratory of Micro Nano Measurement Manipulation and Physics | And 4 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Polarization-maintaining fiber (PMF) has attracted great attentions not only due to its ability to realize coherent optic communication with ultrahigh-capacity, but also because it can be widely employed in high-precise fiber-optic sensors and optic information processors, e.g., fiber-optic gyroscope and fiber-optic amperemeter. Distinct with common monomode optic fibers, additional birefringence is introduced in the PMF, minimizing the effect of mode coupling between two orthogonal polarization modes in optic fibers. Thus, light polarization can be maintained after long distance transmission in the PMF. However, beat-length, which reflects the characteristic of induced birefringence and evaluates the ability of polarization maintaining, is one of the most important parameters for PMF. Accurate measurement of PMF beat length becomes more and more important along with the expanding of its application field. The uniqueness of the measurement results determines the identity of PMF fabrication and the resolution of fiber-optic sensors. The existing measurement methods for PMF beat length are introduced first. Most testing setups are established by several individual components, which lead to complicated setup, inconvenient testing, and unsteady measurement. In this paper, a novel all fiber beat length measurement system is presented, where optic source, integrated optic modulator, stress apply structure, polarization detector, and polarization indicator of output light are included. The configuration and working principle of the whole system, and the designing and realization of each components, are addressed in the paper. Furthermore, the influence on measurement results by the relative direction between applied stress and principal axis of the optic fiber is analyzed. Moreover, optimized designs, including polarized light incidence, pressure apply, and precise movement systems, are performed, which ensure the identical pressure apply direction in the moving process. Finally, measurement of PMF samples is carried out on experimental setup. In comparison with the other existing system, due to its all fiber light incidence structure, the novel beat length measurement system represents great stability and high reliability. © 2011 SPIE. Source

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