时间门控拉曼光谱仪的原理与技术发展历史及其应用

Principles and technological development history of time-gated Raman spectrometers and their applications

时间门控拉曼光谱(TGRS)已被证明是解决荧光对拉曼信号干扰最有效的方法之一。自早期大型昂贵实验室设备(如光学克尔门)诞生以来,至今荧光抑制技术已取得了长足进步。如今,有更好更经济实惠的小型设备可供选择使用。这些精进主要归功于光谱仪和电子元件生产技术的进步,从而降低了设备的复杂性和成本。时间门控拉曼光谱仪的关键组成部分是精确的时间同步(皮秒范围),即脉冲激光激发源与灵敏快速的检测器之间的同步。在激光脉冲期间,检测器能够收集拉曼信号,而在检测器的关闭期间,由于荧光发射具有更长的延迟时间,因此可以将其排斥。由于其较短的测量周期,TG拉曼光谱还具有对环境光和热辐射的抗干扰能力。近年来,超灵敏快速探测器的研究重点集中在门控和增益型电荷耦合器件(ICCDs)上,或者集中在CMOS单光子雪崩二极管(SPADs)阵列上,这些器件同样适用于进行TG拉曼。与门控CCDs相比,SPADs阵列具有更高的灵敏度和更好的时间分辨率,并且不需要过度冷却探测器。本文旨在回顾从早期至今国内外TG Raman技术的技术发展成果,并且介绍用TG Raman技术研究纳米二氧化锡颗粒和指甲实验结果,并且还简要讨论TG技术可能的扩展应用。

Time-gated Raman spectroscopy(TGRS)has been proven to be one of the most effective methods for solving the interference of fluorescence on Raman signals.Since the birth of large and expensive laboratory equipment such as optical Kerr gates,significant progress has been made in fluorescence suppression technology.Today,better and more affordable small-scale equipment is available for use.These improvements are mainly due to advancements in spectral and electronic component production technology,which have lowered the complexity and cost of the equipment.The key component of time-gated Raman spectroscopy is precise time synchronization(in the picosecond range),i.e.synchronization between the pulsed laser excitation source and the sensitive and fast detection device.During the laser pulse period,the detector can collect Raman signals,while during the dead time of the detector,the longer delay time of fluorescence emission can be excluded.Due to its shorter measurement cycle,TG Raman spectroscopy also has the ability to resist interference from ambient light and thermal radiation.In recent years,research on ultra-sensitive and fast detectors has focused on gate-controlled and gain-type charge-coupled devices(ICCDs)or on CMOS single-photon avalanche diodes(SPADs)arrays,which are also suitable for TG Raman.Compared to gate-controlled CCDs,SPADs arrays have higher sensitivity and better time resolution,and do not require overcooling of the detector.This paper aims to review the technical development achievements of TG Raman technology from the early days to the present both at home and abroad,and to introduce the experimental results of studying nano-SnO 2 grains and nails using TG Raman technology,as well as to briefly discuss the possible extended applications of TG technology.