Optical System for Asymmetrical Crossed Czerny-Turner Raman Spectrometer with High Luminous Flux

为克服分立式便携拉曼光谱仪光通量低的缺点,设计了一种集拉曼探头光路与分光系统于一体的光学系统。探头光路采用大数值孔径的非球面透镜实现样品的有效激发和信号的高效收集,通过胶合透镜组缩小会聚光路尺寸、消除轴向色差。分光系统基于交叉非对称Czerny-Turner结构,为获得期望的光谱分辨率和光谱范围,建立了分光系统光谱分辨率及光谱范围与交叉非对称Czerny-Turner结构参数的关系。由测得的汞灯谱图可知,分光系统的光谱分辨率优于6 cm~(-1)(0.37 nm),光谱范围为790~950 nm(200~2000 cm~(-1))。将设计的光学系统对CCL4进行测试,实验结果表明在相同积分时间内由这种整体式的光学系统检测到的CCL4光谱谱峰强度是用商业探头通过光纤连接分光系统检测到的近3倍,验证了光学系统设计的合理性。To overcome the low luminous flux in separated portable Raman spectrometer, an optical system embodies the probe of Raman spectrometer and monochromator is designed. An aspherical lens with high numerical aperture is used to obtain the effective excitation of sample and the efficient collection of signal in the optical system of the probe. A cemented lens group is used to minish the size of converging path and eliminate chromatic aberration.The monochromator is based on asymmetrical crossed Czerny-Turner structure. For the purpose of achieving desired spectrum resolution and spectrum range, the relationship between the spectrum resolution and spectrum range of the monochromator and the structural parameters of the asymmetrical crossed Czerny-Turner system is established. According to the tested spectrogram of mercury lamp, the spectrum resolution of the monochromator is better than 6 cm~(-1)(0.37 nm), and spectrum range is 790~950 nm(200~2000 cm~(-1)). A sample of CCL4 is introduced to examine the performance of the optical system, the experimented results demonstrate that the peak intensity of spectrogram of CCL4 measured by this incorporative optical system is almost three times as high as that using a commercial probe couples to the monochromator, which verifies the rationality of the design of the optical system.国家自然科学基金(21503171);; 中央高校基本科研业务费项目(20720150091、20720150094);; 福建省高端装备制造协同创新中心资

Development of STM Head for TERS Instrument

在针尖增强拉曼光谱(TERS)技术中，有一种组合方式是将具有高空间分辨率的扫描隧道微镜(STM)与表面增强拉曼光谱(SERS)技术相结合，从而实现对样品表面纳米尺度的形貌表征和纳米局域的拉曼光谱探测。目前，大多数实验室中使用的TERS仪器是将拉曼光谱仪与商品化的STM简单联用得到的。由于其中的STM并不是专门针对TERS仪器设计的，因此会带来功能浪费、扫描方式不匹配、操作空间狭小等问题。部分厂商也提供了一体化的TERS仪器，但其昂贵的价格也让大多数实验室难以承担，同时，由于仪器的封闭性，也使得其难以适应多样化的科研需求。因此，有必要研制一套TERS仪器专用的针尖扫描头，用于解决商品化STM的部...Scanning tunneling microscopy (STM) with high spatial resolution combined with surface-enhanced raman spectroscopy (SERS) is one of combination in tip-enhanced raman spectroscopy (TERS) instruments. This combination can be used to detect nanoscale appearance characterization and nano-local Raman spectroscopy. At present, TERS instruments used in most laboratories are a simple combination of Raman ...学位：工学硕士院系专业：航空航天学院_测试计量技术及仪器学号：1992014115289

Design of Raman Spectroscopy Rapid Detection System for Synthetic Edible Pigment Based on PERS

基于等离激元增强拉曼光谱技术,研制出适合现场分析检测的食用合成色素快速检测系统,适用于饮料、肉制品、蜜饯等食品中合成色素的快速检测。检测系统的硬件部分主要由双CPU(ARM和FPGA)主控板、样品前处理模块(含有增强粒子施加装置)、半导体激光光源、光谱数据采集模块构成;软件部分控制样品前处理模块自动运行,并可读取被测样品的拉曼谱图。利用快速检测系统对三种实际样品(蜜饯、汽水、火腿肠)中的食用合成色素胭脂红、柠檬黄、诱惑红进行检测,以验证该系统在食用合成色素检测中的性能。样品检测结果的相对标准偏差小于±5%,表明此检测系统具有良好的灵敏度和重现性,且检测时间短,能够满足食品中合成色素现场快速检测的要求。Based on Plasmon-enhanced Raman Spectroscopy(PERS) technology,the detection system for rapid field determination of synthetic edible pigments in food,such as beverage,meat productsand preserves,is presented.The hardware framework of this detection system is mainly composed of double central control chips(ARM and FPGA),a sample pretreatment module(containing a nanoparticle giving device),a laser diode source,and a spectral data acquisitioning module;Besides,the software can run the sample pretreatment module automatically while receiving the Raman spectrogram.To verify its performance in edible synthetic pigments,the rapid detection system was applied to determine carmine,citrine,allure red in three actual samples(i.e.preserves,sodas,sausage).The relative standard deviations of the sample detection were in the range of ±5%,which indicated that the system developed in this paper have the advantage of favorable sensitivity,excellent repeatability and short testing time.Thus,it meets the requirements for rapid field determination of synthetic pigments in food.国家重大科学仪器设备开发专项(2011YQ03012417);; 厦门大学中央高校基本科研业务费项目(20720150091,20720150094);; 福建省高端装备制造协同创新中心资金项目资

Design of Micro-Drive Positioning System Based on Differential Capacitance Sensor

设计并加工了一种结构简单、小巧的微动定位系统,该系统精度较高、扫描范围大且成本低廉。采用簧片结构设计系统的机械结构,使用压电陶瓷作为执行器件,使; 用差动电容传感器作为位移反馈,实现闭环控制,从而有效克服了压电陶瓷执行器件的迟滞和蠕变效应。介绍了微动定位系统的机械组成和差动电容传感器信号检测; 电路的工作原理,并对系统进行了测试和标定实验。实验结果显示:该平台能够实现15 m的扫描,精度约为15 nm,且动态性能良好。A simple and compact micro-drive positioning system is designed and; manufactured, and the system is of high precision, wide scanning scope; and low cost. The mechanical structure of the system is designed with; spring structure, and driven by piezoelectric ceramics, and the; differential capacitance sensor is taken as displacemen feedback to; achieve closed loop control, which effectively compensates the; hysteresis and creep of piezoelectric ceramic actuator. The structure of; the system and the working principle of the detection circuit are; introduced, and the test and calibration for the system are carried out.; The experiment results indicate that the micro-drive positioning system; can achieve a scanning scope of 15 m with a resolution of about 15 nm,; and the dynamic performance is fine.福建省高端装备制造协同创新中心资金资助项目; 国家自然科学基金项目; 中央高校基本科研业务费项

Baseline Correction Algorithm for Raman Spectroscopy Based on Non-Uniform B-Spline

基线校正是一种常用的消除光谱荧光干扰的方法,是拉曼光谱数据处理的必要步骤之一。传统的多项式拟合基线校正算法,简单且易于实现,但是拟合阶次难以确定,灵活性较差。使用非均匀B样条代替多项式进行拟合,在保留原有算法优点的基础上,利用原始拉曼谱图的峰位置信息自适应地确定非均匀B样条的节点向量,然后以固定阶次拟合光谱基线。B样条自身具有分段光滑的特性,而计算样条节点的节点向量自适应选取算法中的峰位置信息通过使用两次具有不同母函数的连续小波变换(continuous wavelet transform,CWT)来获取,既加强了原始光谱数据与B样条算法本身的联系,也克服了传统多项式拟合的不足。为了验证本文算法的有效性,选取了甲基对硫磷和某品牌菜籽油两种被测物进行实验,并使用该算法进行了基线校正,并与两种其他的基线校正算法与进行了对比。实验结果表明,该方法利用固定的拟合阶次就能达到较好的校正效果,所需要的参数较少,校正结果不会出现过拟合或欠拟合的现象,是一种有效的拉曼光谱基线校正算法。As one of the necessary steps for data processing of Raman spectroscopy,baseline correction is commonly used to eliminate the interference of fluorescence spectra.The traditional baseline correction algorithm based on polynomial fitting is simple and easy to implement,but its flexibility is poor due to the uncertain fitting order.In this paper,instead of using polynomial fitting,non-uniform B-spline is proposed to overcome the shortcomings of the traditional method.Based on the advantages of the traditional algorithm,the node vector of non-uniform B-spline is fixed adaptively using the peak position of the original Raman spectrum,and then the baseline is fitted with the fixed order.In order to verify this algorithm,the Raman spectra of parathion-methyl and colza oil are detected and their baselines are corrected using this algorithm,the result is made comparison with two other baseline correction algorithms.The experimental results show that the effect of baseline correction is improved by using this algorithm with a fixed fitting order and less parameters,and there is no over or under fitting phenomenon.Therefore,non-uniform B-spline is proved to be an effective baseline correction algorithm of Raman spectroscopy.国家重大科学仪器设备开发专项(2011YQ03012417)资

Design of Rapid Detection System for Urotropine in Food Based on SERS

基于表面增强拉曼光谱技术(surface enhanced Raman; spectroscopy,SERS),研制出对食品中乌洛托品进行现场快速分析检测的系统。检测系统由多功能前处理模块、拉曼光学模块、嵌入式主控模块; 三部分组成,实现了待测样品的前处理,拉曼光谱数据的产生、收集、传输与处理。其中,多功能前处理模块将化学实验中经常用到的离心、超声、挥发三种功能集; 于一体,精简了前处理实验中需要用到的设备;拉曼光学模块采用探头光路与分光系统合为一体的整体式设计,并在探头光路中使用数值孔径为0.6的非球面透镜; ,同时利用交叉非对称Czerny-Turner结构对分光系统进行了设计;嵌入式主控模块采用自主研发的FPGA+; ARM双核心主控电路,配合CCD的制冷电路与驱动电路,搭载muC/OS-Ⅲ操作系统,实现了对CCD上拉曼光谱数据的采集、传输与处理。利用柠檬酸钠; 制备纳米金(liquid colloidal gold; nanoparticle,LCP-1)作为增强试剂对乌洛托品进行检测,将乌洛托品的拉曼特征峰选取在1 047; cm~(-1)处,对乌洛托品标准品和含有乌洛托品的腐竹与米粉样品进行检测实验,实验结果表明所设计的检测系统可以实现对乌洛托品的准确识别,对乌洛托; 品标准品的检测限可达0.01 mg·L~(-1),对腐竹和米粉样品中乌洛托品的检出限可达0.5 mg· L~(-1),检测时间小于20; min,实现了食品中乌洛托品的现场快速检测。Based on surface enhanced Raman spectroscopy (SERS) technology, the detection system for rapid fild determination of urotropine in food is proposed. The detecting system consists of multifunctional pretreating module, Roman optical module and embedded master control module. It completed the pretreatment of sample, the generation, collection and transmission of the Raman spectral data. The multifunctional pretreating module integrate centrifuge, ultrasound and volatile functions all together, reducing the equipments used in the pretreatment experiment. Besides, it is portable and convenient for operation. The Roman optical module we designed embodies the probe of Raman spectrometer and monochromator, and the numerical aperture of the aspherical lens we used in the optical system of the probe was 0. 6. Besides, the monochromator was designed based on Asymmetrical crossed Czerny-Turner structure. The hardware part of the embedded master control module is made up of ARM and FPGA, and its peripheral circuits. The software part of the module is made up of real time operation system mu C/OS-HE graphics library emWin, file system FatFs and various types of equipment components. Thus, accomplished the collection, transmission and calculation of the Raman spectral data from CCD. The liquid colloidal gold nanoparticle (LCP-1) was used in the detection experiments of urotropine, while the characteristic peaks at 1 047 cm(-1) was chosen as the identity infoiniation of urotropine. The result of detection experiments shows that the system has the ability to identify the urotropine accurately, the detection limit of urotropine standards was 0. 01 mg . L-1, with detection limit of urotropine in yuba and rice-noodle was 0. 5 mg . L-1. Besides, the testing time was less than 20 minutes, which meets the requirements for rapid field determination of urotropine in food.国家自然科学基金项目（21503171）资

基于B样条的TERS形貌成像背景扣除方法

在针尖增强拉曼光谱(TERS)形貌成像过程中,由于针尖与扫描台无法绝对平行、样品电子密度骤变处针尖快速升降以及扫描控制系统响应时间特性差等综合原因的影响,往往使形貌图中带有倾斜或边界面卷曲的成像背景。成像背景对样品形貌的识别和分析带来十分不利的影响,而背景扣除就是解决该问题的重要手段,也是形貌成像预处理的重要组成部分。背景扣除的原理一般是通过拟合背景的方法来扣除成像中的背景。传统的背景扣除方法是利用多项式拟合的方法对成像进行逐行的基线校正,但是该方法在处理形貌成像时常常会由于过拟合而造成样品形貌的失真,同时容易在图片上留下明显的线条纹理。针对传统方法的缺点,本文提出采用B样条曲面拟合方法,直接对样品形貌图进行曲面背景拟合,发挥B样条低阶光滑的优点,能够有效克服传统方法的缺陷。在实验中,同时利用传统方法和该方法对金单晶和合成金片的形貌图进行背景扣除,实验结果表明,两种方法都能够扣除样品形貌图中的成像背景,但与传统方法相比,所提出的方法不会造成样品形貌的失真,且不会留下线条纹理,获得了更加良好的背景扣除效果,为进一步分析样品形貌特征提供了更准确可靠的信息,是一种更加有效的TERS形貌成像背景扣除算法。福建省高端装备制造协同创新中心项目;;国家自然科学基金项目(21503171)资