多波长激发高分辨率微型拉曼光谱仪设计

针对不同激光波长激发测试样品所需拉曼光谱范围的差异性问题,同时为了保证拉曼光谱仪的小型化及高分辨率需求,提出一种以Czerny-Turner光路结构为基础的微型拉曼光谱仪,通过Zemax光学设计软件对光谱仪的准直镜、聚焦镜、柱面镜、光栅以及CCD的倾角及距离进行了优化。该仪器激光波长为633 nm,光谱范围为640～800 nm。进一步优化光栅旋转角度并配合聚焦镜,可使此光学系统同时适用于激光波长532 nm、光谱范围540～650 nm和激光波长785 nm、光谱范围790～1 000 nm两个波段。拉曼光谱仪分辨率为0.1 nm,该光谱仪在保证高分辨率的情况下解决了不同波段范围光学结构差异性大而导致光机设计很难整合在一起的问题。

Design of miniature Raman spectrometer with multi-wavelength excitation and high resolution

In order to solve the problem concerning different ranges of Raman spectrum required by different test samples with multi-wavelength excitation in the research process, and to ensure the miniaturization and high resolution of Raman spectrometer, a kind of miniature-Raman spectrometer system based on Czerny-Turner optical path was proposed. By using Zemax (an optical design software), the angle and distance of the collimating mirror, focusing mirror, cylindrical mirror, diffraction grating, and CCD were optimized to let this optical system excited by 633 nm meet the requirement that spectral range covers from 640 to 800 nm. Furthermore, by optimizing grating rotations and adjusting the parameters of the focusing mirror, this Raman spectrometer system can also be applied to 532 nm excitation wavelength with a spectral range from 540 to 650 nm and to 785 nm excitation wavelength with a spectral range from 790 to 1000 nm at the same time. In case of high resolution requirement, this micro-Raman spectrometer achieving 0.1 nm resolution solves the problem that it is hard to integrate the optical-mechanical designs due to significant difference between optical structures for different spectral ranges.