基于光栅复用的小型化高分辨率光栅光谱仪技术研究

Spectrometers are widely used in many fields such as biology, materials, chemistry and so on. They are important instruments to realize spectral analysis. With the rapid development of miniaturied spectrometers, spectral analysis technology has gradually entered the industrial site from the laboratory. However, the contradiction between instrument volume and resolution in the existing spectrometer design methods is becoming more and more prominent, and it is urgent to find a solution. This project proposes a new method to improve the resolution of miniaturied grating spectrometer based on grating multiplexing. A reflected prism and a reflective quarter wave plate are used to make the measured light repeatedly incident on the same high-density diffraction grating four times, which not only effectively reduces the volume of the instrument, but also greatly improves the resolution of the spectrometer. This project establishes a theoretical model of grating multiplexing light path, analyzes the mathematical relationship between resolution and parameters such as incident angle, wavelength and grating constant, and proposes a spectral calibration method. The optimal design method of achromatic quarter wave plate is explored to eliminate the influence of polarization sensitivity of subwavelength grating on system performance. On those basics, a miniaturied high-resolution multiplexed grating spectrometer system for optical communication systems and devices testing is developed by combining theoretical simulation and experimental research. The anticipated results will own certain scientific significance and research value for promoting the development of spectral analysis technology and instruments.

光谱仪在生物、材料、化学等诸多领域有着广泛的应用，是实现光谱分析的重要仪器设备。小型化光谱仪的快速发展，使得光谱分析技术由实验室逐步走入工业现场，但现有光谱仪设计方法中仪器体积和分辨率的矛盾也越来越突出，亟需找到解决途径。本项目提出一种基于光栅复用提高小型化光栅光谱仪分辨率的新方法，利用反射棱镜和反射式λ/4波片使被测光四次重复入射同一高密度衍射光栅，既有效减少仪器体积，又极大提高光谱仪的分辨率。项目建立光栅复用色散光路的理论模型，分析分辨率与入射角、波长、光栅常数等参数之间的数学关系，提出光谱标定方法；探索消色差λ/4波片的优化设计方法,消除亚波长光栅偏振敏感性对系统性能的影响；以此为依据，理论仿真和实验研究相结合，研制一种以光通信系统及器件测试为应用背景的小型化高分辨率光栅复用式光谱测量系统。预期成果对推动光谱分析技术与仪器的发展具有重要的科学意义和研究价值。

光谱仪对于现代科学研究和工业生产产生了巨大的推进作用，被广泛应用在了化学分析、生物检测、矿物勘探、环境监测、航空航天等诸多领域。根据现有光谱仪设计理论，仪器体积和分辨率相互制约，成为了阻碍其发展的技术瓶颈。本项目提出了光栅复用结构，开展了小型化高分辨率新一代光谱仪设计理论和方法研究，建立了光栅复用式光谱仪系统光路结构和理论模型，并利用ZEMAX仿真软件设计了仿真光学系统，对理论模型的研究结果进行了原理性验证，开展了光栅光谱仪偏振敏感性消除方法研究，搭建了基于光栅复用色散的小型化高分辨率光谱仪系统，验证理论模型和仿真结果，通过性能测试该系统可应用于光通信系统与器件的测试应用。