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Li X.-J.,Shenzhen University | Li X.-J.,Shenzhen Key Laboratory of Sensors Technology | Qiu C.-J.,Heilongjiang University | Deng Y.-L.,Shenzhen Key Laboratory of Sensors Technology | And 2 more authors.
International Journal of Nonlinear Sciences and Numerical Simulation | Year: 2010

A simple MEMS optical fiber pressure sensor with the Fabry-Perot interferometer configuration is constructed that is based on a square silicon diaphragm and the intensity demodulation technology. A large area ratio of the moving mirror to the stationary one is employed to minimize the non-planarity of the deflection, and a reference light generated by a 2×2 optical fiber coupler is used to reduce the errors that are produced by the intensity variations of the light source. The theoretical analysis, simulation and experimental results all show that the pressure sensor has reasonable sensitivity, stability and measurement range. With a low cost and simple fabrication process, this sensor has great potentials for mass production and commercialization. © Freund Publishing House Ltd.

Lee W.,University of Michigan | Luo Y.,University of Michigan | Luo Y.,Jinan University | Luo Y.,Shenzhen Key Laboratory of Sensors Technology | And 2 more authors.
Optics Express | Year: 2011

We develop a novel nL-sized microdroplet laser based on the capillary optofluidic ring resonator (OFRR). The microdroplet is generated in a microfluidic channel using two immiscible fluids and is subsequently delivered to the capillary OFRR downstream. Despite the presence of the high refractive index (RI) carrier fluid, the lasing emission can still be achieved for the droplet formed by low RI solution. The lasing threshold of 1.54 μJ/mm 2 is achieved, >6 times lower than the state-of-the-art, thanks to the high Q-factor of the OFRR. Furthermore, the lasing emission can be conveniently coupled into an optical fiber. Finally, tuning of the lasing wavelength is achieved via highly efficient fluorescence resonance energy transfer processes by merging two different dye droplets in the microfluidic channel. Versatility combined with improved lasing characteristics makes our OFRR droplet laser an attractive platform for high performance optofluidic lasers and bio/chemical sensing with small sample volumes. © 2011 Optical Society of America.

Hu J.,Shenzhen University | Hu J.,Shenzhen Key Laboratory of Sensors Technology | Diao X.,Shenzhen University | Li X.,Shenzhen University | And 7 more authors.
Chinese Journal of Sensors and Actuators | Year: 2011

MgZnO films were prepared with KrF excimer pulsed laser deposition(PLD) method on quartz substrate at 300 °C ∼600 °C. Films were characterized using Raman spectroscopy, AFM, and UV/Vis spectrophotometer. The results show that the film prepared at 600 °C has the largest band gap of 3. 78 eV, and best crystal quality. Al electrode was deposited on the film to make a UV sensor. I-V curve, spectral response and time response under 365 nm UV irradiation characteristics were detected. The results show that, the response peak is at about 320 nm, the rising response time constant is 9. 1 ms,falling time is 16.5 ms.

Hu J.,Shenzhen University | Tang H.,Shenzhen University | Li Q.,Shenzhen University | Li X.,Shenzhen University | And 5 more authors.
Shenzhen Daxue Xuebao (Ligong Ban)/Journal of Shenzhen University Science and Engineering | Year: 2013

CuIn1-xGaxSe2(CIGS) films were deposited on quartz substrate by pulsed laser deposition as precursors and annealed by the 1 064 nm near infrared pulse laser at different energy density. The optical properties, microstructures, surface morphology were characterized with spectrophotometer, X-ray diffractometry (XRD), scanning electron microscopy (SEM) respectively. The results show that with the laser energy density increasing, the crystallinity of CIGS films increases; grain size becomes larger; compressive stress decreases; band-gap increases. When the laser energy density reaches 325 mJ/cm2, the crystallinity of films rises up to 29.46%; the grain size reaches the maximum 15.4 nm; the compressive stress is minimum. The crystallization quality is the best, and the crystallinity of film is bad at lower or higher energy density. In addition, the formation mechanism of stripes on film surface annealed at high energy density was analyzed.

Hu J.,Shenzhen University | Hu J.,Shenzhen Key Laboratory of Sensors Technology | Li Q.,Shenzhen University | Zheng B.,Shenzhen University | And 6 more authors.
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2013

CdS and ZnS films were prepared on ITO glass substrate by pulsed laser deposition (PLD) method at 50°C, 200°C and 400°C. Transmission spectrum and Raman spectrum were measured and analyzed. Influences of temperature on the CdS, ZnS transmission spectral characteristics, optical band gap, Raman spectral characteristics were studied. The results show, (1) The transmission of ZnS films is higher than that of CdS, and ZnS has larger optical band gap; (2) ZnS films show complex Raman spectrum and weak Raman peaks, while CdS films show distinct Raman peaks; (3) With increasing temperature, CdS band gap increased significantly in comparison to that of ZnS, Raman peak became higher and narrower. These phenomena were explained. This work is for preparing CdS or ZnS films as buffer layer for CIGS solar cells.

Jia B.,Northwestern Polytechnical University | Jia B.,Shenzhen Key Laboratory of Sensors Technology | Zhang X.,Northwestern Polytechnical University | Zhang X.,Shenzhen Key Laboratory of Sensors Technology
Advanced Materials Research | Year: 2010

The tip clearance flow of axial turbomachines is important for their aerodynamic and maneuver performance. And the tip clearance gap leakage flow is of continuing concern in reducing efficiency losses that occur within turbines. In order to gain significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life of aero-engine, variation mechanism of blade tip clearance was analyzed and the equation of dynamic clearance was shown firstly, then the effect of rotor vibration in clearance variation which include flight loads and engine loads was studied in this paper; based on the dynamic measurements of blade tip clearance, a method that ensure tip clearance at optimal state in given mission profile through active rotor vibration control and active tip clearance control was presented. Besides, fuzzy control theory was used to solve the high nonlinear variation of tip clearance. The analysis result shows that this technique is useful. © (2010) Trans Tech Publications.

Jia B.,Northwestern Polytechnical University | Jia B.,Shenzhen Key Laboratory of Sensors Technology | Zhang X.,Northwestern Polytechnical University | Zhang X.,Shenzhen Key Laboratory of Sensors Technology | And 2 more authors.
Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis | Year: 2012

Based on the preliminary analysis of the change mechanism of the turbine blade tip clearance, the simplified model of blade, rotor and casing is established. The radial changes of rotor that bring by rotate speed and engine start transient state temperature is simulated. And the effect of rotor vibration amplitude of aero-craft in-flight maneuver state is discussed. The results show that vibration amplitude and radial displacement of rotor have a great effect on the turbine tip clearance.

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