基于量子点滤光阵列的近红外成像光谱仪的关键问题研究

Compared with the traditional imaging spectrometry, the near-infrared (NIR) imaging spectrometer based on colloidal quantum dot filter film has the advantages of wide spectrum, high resolution, high signal-to-noise ratio, light and miniaturization, and which can be used in many fields, such as target detection and tracking, environmental monitoring and component analysis. But, due to the unclear absorption regulation mechanism of quantum dot filter film and the unknow law of spectral images reconstruction, the performance and application of imaging spectral system is restricted. We propose to deeply investigate the quality control mechanism of the filter film and the efficient reconstruction of the spectrum and image. The related research mainly has three aspects: (1) Studying the related law of absorption characteristics, extinction coefficient and energy level structure, the controllable preparation of the high quality filter film can be achieved. (2) Through the study of optical properity of filter film, the spectral transmittance which is dependent on size, temperature, and concentration is investigated to reveal the regulation law of material properties to film quality. (3) Analyzing the influence of the optical characteristics and geometric parameters on the imaging and spectral signals, the analytic method and the reconstruction model of the two types of signals are set up. On the basis, the quality control mechanism of the filter film and the efficient reconstruction of the spectrum and image could be clarified, and which can lay the foundation for the development of high-performance NIR imaging spectrometer system.

与传统成像光谱技术比较，基于量子点滤光膜的近红外成像光谱系统具有轻小型、宽光谱、高分辨率、高信噪比等优点，在目标探测和跟踪、环境监测和成分分析等领域有着良好的应用前景。但是，由于影响量子点滤光膜质量的物性结构和吸收调控机制不清、光谱及图像重构规律不明，限制了量子点滤光膜成像光谱系统的性能和应用。申请人拟围绕胶体量子点滤光膜质量的调控机制和光谱图像的高效重构两个关键问题，一是研究近红外胶体量子点消光系数、能级结构与其吸收特性的相关规律，实现高质量滤光膜材料的可控制备；二是研究近红外胶体量子点滤光膜的光学特性，分析量子点尺寸、温度、浓度依赖的滤光膜光谱透过率，揭示材料物性对薄膜质量的调控规律；三是分析滤光膜光学特性、几何参数等因素对成像光谱信号影响，建立图像和光谱的解析方法和重构模型。在此基础上，探明量子点滤光膜质量的调控机制和光谱及图像的高效重构方法，为研制高性能近红外成像光谱系统奠定基础。

与传统成像光谱技术比较，基于量子点滤光膜的近红外成像光谱系统具有轻小型、宽光谱、高分辨率、高信噪比等优点，在目标探测及跟踪、环境监测和成分分析等领域有着良好的应用前景。在本项目的研究中，我们以构建高光通量、高分辨率、近红外全谱段的光谱仪为目的，围绕胶体量子点滤光膜质量的调控机制和光谱图像的高效重构两个关键问题，通过近红外胶体量子点滤光膜阵列的可控制备，制备出尺寸可调的PbS和PbSe胶体量子点材料，获得了光谱范围在780-2500nm之间的量子点材料，研究近红外胶体量子点材料的吸收光谱，PL光谱，结合量子点能级结构分析，以建立光谱透过率与消光系数、尺寸、厚度、浓度等多种因素间的关系模型，揭示了材料的消光系数、能级结构与其吸收特性的相关规律；应用 sonoplot 高精量级纳米沉积系统制作出了微型滤光片阵列，通过对其线宽和间隙的优化调节，建立匹配参数、光谱响应函数与成像光谱仪性能间的数学模型，探明了胶体量子点滤光膜的阵列结构、几何参数（量子点沉积面积、间隙分布等）、与 CCD 阵列匹配等因素对系统性能的影响规律；通过对滤光阵列的光谱透过率的研究，建立光谱重构模型，揭示了光谱的重构精度与滤光阵列中滤光单元个数之间的规律，进而实现不同光源的近红外光谱重构。通过本项目的研究，我们发表了SCI检索论文9篇，EI检索论文1篇，申请国家发明专利2项，培养博士研究生1名，硕士研究生4名。