A High-Precision Method for Determining the FBG Peak Wavelength Shift Based on FBG Actual Reflection Spectrum Match

针对目前光纤布拉格光栅(fbg)解调方案中采用低分辨率CCd测量fbg峰值波长时存在的问题,提出一种采用基于fbg实际反射谱构建基函数匹配CCd测量获得的有限测量点确定fbg峰值波长偏移量的新方法。分别在理论和实测上对这种方法的有效性和可行性进行了研究,证明这种采用fbg实际反射谱函数匹配有限测量数据的方法比采用特定函数拟合测量数据的方法能够更准确地获得fbg峰值波长的偏移量。实现了在CCd采样点数少、光谱分辨率较低的情况下对fbg峰值波长偏移量的高精度确定,有效地提高了实际工程应用中基于低成本CCd解调fbg峰值波长及其微小偏移量的准确性。Referring to the problems in using low-resolution charge coupled device(CCD) to measure fiber Bragg grating(FBG) peak wavelength,a high-precision method for determining the FBG peak wavelength shift by matching basis function based on the FBG actual reflection and sampling data measured by CCD is proposed.The effectiveness and feasibility of the new method are studied theoretically and experimentally.It is proved that compared with fitting sampling data by specific functions,the matching method based on FBG actual reflection spectrum can determine FBG peak wavelength shift more accurately.In the case of few sampling data and low resolution of CCD measurement,the high-precision determination of FBG peak wavelength shift is achieved.The accuracy of demodulation of FBG peak wavelength shift using low-cost CCD in the practical applications is improved effectively.国家自然科学基金(61077031);国家质检总局科技计划项目(2010IK077)资助课

氨燃料缓解能源安全及替代天然气的可行性分析

文章主要针对我国面临的能源安全问题及现阶段出现的北方地区\"气荒\"现象,结合氨燃料储能密度高、燃烧清洁、热值较高、易储存运输、产业基础完善、用处广泛的特点以及厦门大学的锅炉及发电机掺氨燃烧运行成功的实验结果,定量分析氨燃料可缓解能源安全问题的程度及解决\"气荒\"问题的规模与容量。分析结果表明:引入氨能源体系可以有效优化中国的能源结构,改善过度依赖能源进口的现状,解决天然气短缺的问题。福建省闽江学者经费项目(X170300101);;\n厦门大学能源学院-金融昌氨能源及动力联合研发中心经费项目(0290K8110075

Beam transformation in laser processing

激光光束形状和能量分布直接限定了激光加工的应用。为满足不同的激光加工要求,必须对激光光束进行光束变换。应用旋转棱镜和组合光学系统能够实现实心和环状光束之间的相互变换。从几何光学角度对旋转棱镜组合光学系统进行了理论分析和实验。通过调整正负旋转棱镜的间距d,获取不同形状和能量分布的激光光束。实验结果表明,基于旋转棱镜组合光学系统的光束变换技术,有效地实现了多种形式的光束变换,提高了激光束的利用率,在激光加工领域中具有广泛的应用前景。The shape and quality of laser beam directly define its applications in the laser processing.For different requests of laser processing,the input beam always needs to be transformed.The transformation between the solid beam and annular beam can be realized by the axicon-based optical devices.The optical system is analyzed based on the geometry optical theory.By adjusting the separation of the positive and negative axicon,different shapes and the energy distributions are gained.It is shown that the axicon-based beam transformations raise the use factor of laser and have wide application prospect in laser processing field.福建省科学技术厅资助项目(2005HZ1020