Zhu Jiacheng, Chen Xinhua, Zhao Zhicheng, Shen Weimin
Opt Express. 2021 Jul 5;29(14):22603-22613. doi: 10.1364/OE.433805.
A miniaturized immersed imaging spectrometer possessing long slit and large relative aperture is proposed. It is integrated monolithically with three concentric optical components. Through the chief ray tracing, we analyzed its astigmatism characteristic and then deduced the anastigmatic condition for long slit. Meanwhile, it is athermal by matching the suitable lens materials to compensate thermal defocus. Based on the anastigmatic and athermal conditions, we have designed a miniaturized VNIR immersed imaging spectrometer and developed the prototype. Its slit is 48 mm long and it is optically fast with an F-number of 2.5. The new form shows about 12 times smaller in volume than the classic Offner-Chrisp imaging spectrometer and weighs only 2 kg, and has excellent thermal adaptability while temperature changes between -40 °C and 60 °C. Meanwhile, fabrication of core elements and gluing process of the immersed imaging spectrometer are presented. Test results of the prototype show superior performance with high imaging quality and small smile and keystone distortions. Such miniaturized immersed imaging spectrometer will greatly improve the performance and reduce the costs of wide swath hyperspectral remote sensing, and is desirable for usage on small plane or satellite platforms.
提出了一种具有长狭缝和大相对孔径的小型化浸没式成像光谱仪。它与三个同心光学元件单片集成。通过主光线追迹，分析了其像散特性，进而推导了长狭缝的消像散条件。同时，通过匹配合适的透镜材料来补偿热离焦，实现了无热效应。基于消像散和无热条件，设计了一种小型化可见近红外浸没式成像光谱仪并研制了样机。其狭缝长48 mm，光学速度快，F数为2.5。新形式的体积比经典的奥夫纳-克里斯普成像光谱仪小约12倍，重量仅2 kg，在-40℃至60℃的温度变化范围内具有出色的热适应性。同时，介绍了浸没式成像光谱仪核心元件的制造和胶合工艺。样机测试结果显示出优异的性能，具有高成像质量以及小的微笑和梯形畸变。这种小型化浸没式成像光谱仪将大大提高宽幅高光谱遥感的性能并降低成本，适用于小型飞机或卫星平台。
