Research on the Wavelength Conversion Technology Based on Semiconductor Optical Amplifier (SOA)

波长转换技术在光纤通信中有着广泛的应用，尤其是在基于波分复用的全光网络中将发挥关键性的作用。通过波长转换技术，可以提高波长的利用率，有效地解决网络中的阻塞问题，简化网络管理，增强网络对故障的适应能力。基于半导体光放大器的波长转换器具有结构简单、容易实现等优点，因此成为近年来研究的热点。本文针对半导体光放大器交叉增益调制型、交叉相位调制型和四波混频型波长转换技术进行了深入的理论和实验研究，具体工作如下：1、分析了进行波长转换技术研究的重要意义，较为全面地概述了波长转换器的种类和发展状况。2、详细分析了半导体光放大器用于波长转换的理论基础，建立了比较完善的半导体光放大器用于模拟交叉增益调制型、交叉...Wavelength conversion technology could be widely used in optical fiber communication, it will play the key role especially in the all-optical network based on wavelength division multiplexing (WDM). Wavelength conversion can increase the utilization efficiency of wavelengths, efficiently solve the blocking problem in the networks, simplify the management of the networks, enhance the adaptability t...学位：工学博士院系专业：物理与机电工程学院机电工程系_测试计量技术及仪器学号：1822005140304

Study on optical methods for 3-D shape measurement

为了加快产品开发和保证产品制造质量需要对物体的三维形貌进行精确的测量。光学形貌测量技术由于其高分辨率、无破坏、数据获取速度快等优点而被认为是最有前途的三维形貌测量方法。介绍了各种基于光学原理的三维形貌测量技术,并作了比较深入的分析和对比,为正确和广泛应用三维形貌测量技术提供了参考。给出了在该领域的发展方向和研究热点。In modern industry,it is necessary to measure accurately the 3-D shape of object to speed up product development and ensure manufacturing quality.Optical methods for shape measurement are considered as the most promising one because of the high resolution,rapid obtainment of the data,and nondestructive quality.Various optical methods for 3-D shape measurement are discussed,their basic principle,advantages and disadvantages are also presented.A reference is given out for right use and wide application of 3-D optical measurement.The current research focus and some idea about perspective trend are presented

电器产品塑料部件成份比对的拉曼光谱分析方法

文章通过对三种塑料样品ABS、PP、PC的拉曼光谱进行分析和比较,根据光谱的相似度算法定量计算相关的特征参数,从而区分开这三种样品。我们采用自适应迭代重加权惩罚最小二乘法（air-PLS）对2002000cm-1波段的原始光谱进行预处理,并分别采用夹角余弦法和广义Jaccard系数法计算测量样品的相似度,显示两种计算方法在判别相同和不同样品的相似性上各有优势。研究表明采用激光拉曼光谱技术结合相似性分析可以鉴别ABS、PP、PC三种塑料样品成份的差别

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

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