Dong Ning Wang

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We report the modeling results of an all-fiber gas detector that uses photonic crystal fiber (PCF). The relative sensitivity of the PCF as a function of the fiber parameters is calculated. Gas-diffusion dynamics that affect the sensor response time is investigated theoretically and experimentally. A practical PCF sensor aiming for high sensitivity gas(More)
A long period fiber grating (LPFG) temperature sensor system based on intensity modulation is developed. The LPFG employed is fabricated by the use of a focused CO2 laser beam to carve periodic grooves on the fiber. The temperature measurement resolution of up to 0.1 degrees C has been obtained within the temperature range between 20 degrees C and 100(More)
A simple self-seeding scheme is developed to generate tunable dual-wavelength optical short pulses in a flexible manner and with an increased wavelength-tuning range. The wavelength selection and tuning are achieved by simultaneous use of a fiber Bragg grating and a tunable optical filter. The side-mode suppression ratio of the output pulses is better than(More)
Asymmetric transverse-load characteristics and the polarization dependence of long-period fiber gratings (LPFGs) written by high-frequency CO(2) laser pulses are investigated in detail. It is demonstrated that the resonant wavelength is dependent on the direction of the applied force and on the polarization state of the input light; however, the coupling(More)
A heavily distorted high resolution electron microscopy (HREM) image of a cesium-niobium oxide-fluoride sample wa reconstructed by crystallographic image processing (CIP). In the reconstructed image, showing 4bm symmetry, all metal atom were clearly seen with correct contrast, whereas in the original micrograph the fourfold symmetry was lost and only sore(More)
A method for measuring the length of an optical fiber by use of an optical fiber ring laser pulse source is proposed and demonstrated. The key element of the optical fiber ring laser is a gain-switched Fabry-Perot laser diode operated in a self-injection seeding scheme. This method is especially suitable for measuring a medium or long fiber, and a(More)
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