具有抗漂移特性的激光共焦拉曼光谱成像技术与系统

发布时间：2018-06-02 13:42

本文选题：共焦拉曼 + 抗漂移　；参考：《光谱学与光谱分析》2017年10期

【摘要】：共焦拉曼技术结合了共焦显微技术和拉曼光谱技术,具有高分辨率、高灵敏度、可层析成像的优势,广泛应用于物理、材料科学、生物医学、文物鉴定以及刑侦等领域。由于拉曼光谱成像需要较长时间,测量中系统易受环境等因素影响产生漂移,造成离焦,而现有商用共焦拉曼光谱仪并无定焦能力,容易影响测量结果。针对此问题,研制了一种具有抗漂移能力的激光共焦拉曼光谱探测系统。在不改变共焦拉曼探测基本原理的基础上,利用拉曼轴向响应曲线最大值对应显微物镜焦面这一特性,对每个探测点进行轴向扫描,采集一定数量的轴向信号,通过曲线拟合寻找光谱强度极值位置,保证扫描过程中样品始终处于系统的焦点位置处,抑制离焦影响,改善拉曼光谱成像效果。以单层石墨烯样品进行单点测试,证明仪器在5μm离焦范围内可以实现实时定焦,定焦后采集到的拉曼光谱强度几乎不变,具有良好的抗漂移能力;对硅台阶样品进行成像测试,结果表明成像过程中,信号强度未发生明显变化,且横向分辨率有一定改善,效果明显优于普通共焦拉曼光谱探测系统。
[Abstract]:Confocal Raman technology, which combines confocal microscopy and Raman spectroscopy, has the advantages of high resolution, high sensitivity, and can be used in many fields such as physics, material science, biomedicine, cultural relic identification and criminal investigation. Because Raman spectroscopy imaging takes a long time, the measurement system is prone to drift under the influence of environment and other factors, resulting in defocusing. However, the existing commercial confocal Raman spectrometers do not have the ability to fix the focus, which can easily affect the measurement results. To solve this problem, a laser confocal Raman spectrum detection system with anti-drift capability is developed. On the basis of not changing the basic principle of confocal Raman detection, the maximum value of Raman axial response curve is used to correspond to the focal plane of the microscopic objective lens. The axial scanning of each probe point is carried out, and a certain number of axial signals are collected. The maximum position of spectral intensity can be found by curve fitting to ensure that the sample is always in the focal position of the system during the scanning process, to restrain the defocusing effect and to improve the Raman spectral imaging effect. The single-point test of graphene monolayer shows that the instrument can realize real-time focusing in the range of 5 渭 m defocusing, the Raman spectrum intensity of the sample collected after focusing is almost invariable, and it has good anti-drift ability, and the imaging test of silicon step sample is carried out. The results show that the signal intensity has not changed obviously and the lateral resolution has been improved in the imaging process, and the effect is obviously better than that of the conventional confocal Raman spectrum detection system.
【作者单位】：北京理工大学光电学院精密光电测试仪器及技术北京市重点实验室;中国科学院物理研究所;
【基金】：国家自然科学基金优秀青年基金项目(51422501);国家自然科学基金面上基金项目(61475020) 国家重大科学仪器设备开发专项任务项目(2011YQ04013607,2011YQ04013601)资助
【分类号】：O657.37

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