Optical design of a novel Wynne-Offner snapshot hyperspectral imaging system

Abstract

In response to the demands of wide field of view (FOV), high spatial resolution and high spectral resolution real time spectral imaging of dynamic scenes, a novel large aperture Wynne-Offner snapshot hyperspectral imaging system of concentric structure is designed. Astigmatism is the main residual aberration over the full FOV. Firstly, based on the first-order theory and aberration characteristics, the anastigmatic condition of the novel large aperture Wynne-Offner snapshot hyperspectral imaging system is analyzed. Then, to achieve a large FOV and to obtain minimum astigmatism, an aspheric surface was introduced to the proper surface. Finally, with a numerical aperture of 0.22 and the FOV of 14mm×3mm, a novel large aperture Wynne-Offner snapshot hyperspectral imaging system is optimized. The optimized system provides a data-cube of 112×24×293 samples over the 450-650nm working wave band. It achieves a spatial resolution of 9μm and a spectral resolution of 0.7nm. The astigmatism is less than 4μm and it verifies the correctness of the forward theory. The image quality evaluation shows that the root-mean-square radius of the spot diagram of the optimized system is less than 1μm and the MTF value is over 0.85@56 lp/mm. The smile and keystone are less than 1.4μm and 2.4μm, respectively. The excellent spectral imaging results demonstrate that the optimized system has a great potential application for real-time recognition of dynamic scenes. Moreover, the design method provides a profound theoretical reference for the design of snapshot hyperspectral imaging spectrometers