用于微米球形颗粒超分辨尺度测量的背向弹性散射光谱的获取  

Acquisition of elastic backscattering spectra for microsphere sizing beyond diffraction limit

作　　者：方晖[1] 杨爱萍[1] 

机构地区：[1]南开大学现代光学研究所光学信息技术科学教育部重点实验室,天津300071

出　　处：《光学精密工程》2014年第3期547-554,共8页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.11074134);教育部博士点基金资助项目(No.20090031120043);教育部新世纪优秀人才支持计划资助项目(No.NCET-10-0502)

摘　　要：背向弹性散射光谱法可用于研究生物细胞内部颗粒的结构组成,本文探讨了背向弹性散射光谱测量获取光谱的不同实验方法及其优缺点。针对微米量级的球形颗粒测量,基于实验分析比较了目前普遍使用的光纤探头测量和透镜系统测量这两种背向散射光谱获取方法的优缺点。研究表明,由于透镜系统获取光谱所对应的散射角有更明确的定义,故透镜系统获取光谱与Mie散射计算的互相关拟合系数(0.96)高于光纤探头优化条件下获取光谱的结果(0.93)。因此,在提取颗粒尺度精度要求较高时,应该选用透镜测量方法,并且采用滤波去噪声信号处理的手段来提高颗粒尺寸提取精度;而提取颗粒尺度精度要求不高时,光纤探头光谱获取方法具有简单易行的优点。Elastic backscattering spectroscopy is an effective approach to study the particulate composi- tion of biological cells. This paper explores the experimental methods to measure and obtain the elas- tic backscattering spectra and their advantages and disadvantages. Regarding the microsphere meas- urement, the pros and cons of two popular spectral acquiring methods are experimentally compared and analyzed, including the method based on a fiber probe and that based on a lens system. The ex- periments demonstrate that the cross-correlation coefficient between measured spectra by lens system and the Mie calculation is 0.96, higher than 0.93 that is by the fiber probe under an optimum condi- tion, because the lens system results in a well-defined scattering angle for the acquired spectrum. Therefore, it points out when a higher precision in particle sizing is required, the lens system is a bet- ter choice and also the filtering denoising will be used to improve the precision of particle sizing. As the spectrum capturing by the optical probe is simple and easy to be implemented, it can be used in a spectral capturing needed by a lower precision.

关 键 词：颗粒尺度测量 背向弹性散射光谱 微米球形颗粒 超衍射极限 Mie散射光谱 

分 类 号：TB921[一般工业技术—计量学] O433.4[机械工程—测试计量技术及仪器]