基于平场光栅的稀疏约束鬼成像高光谱相机

Hyperspectral Camera Based on Ghost Imaging via Sparsity Constraints with Application of Flat-Field Grating

基于稀疏约束的鬼成像光谱相机,能够通过单次曝光获得目标场景的三维空间光谱数据立方体。但是由于不同波长的散斑场在探测器的同一位置处,使得仪器的光谱分辨率和信噪比受到限制。为了解决上述问题,提出了利用平场光栅分光将不同波长的光场在探测面上错开一定距离的系统,实现了基于平场光栅的稀疏约束鬼成像高光谱相机。通过对系统成像过程的理论推导,得到了系统的关联函数,并通过实验和数值模拟验证了理论推导结果。在保证原先光谱相机优点的同时,基于稀疏约束的鬼成像高光谱相机可以分别调控光谱分辨率和空间分辨率,实现可控的信噪比。此外,还能够根据不同波长的光场特性来优化测量矩阵,从而提高图像恢复质量。

A spectral camera based on the ghost imaging via sparsity constrains acquires a three-dimensional spatial- spectral data cube of information about a target in a single exposure. However, the spectral resolution and signal-to- noise ratio are limited, since the speckle field with different wavelengths are at the same location in the detector. To deal with these issues, a system which utilizes a flat-field grating to disperse the optical fields with different wavelengths in the detector to realize hyperspectral camera based on the ghost imaging via sparsity constraints is demonstrated. Through theoretical derivation of the imaging process, the correlation function of the system is obtained, and the derived result is verified by the experiments and numerical simulations. Under guaranteeing the advantages of previous ghost imaging spectral camera spectral camera, the proposed system can modulate the spatial and spectral resolution separately, meanwhile, the signal-to-noise ratio becomes controllable. Additionally, the measurement matrix will be better optimized according to the characteristics of optical fields with different wavelengths to improve the quality of imaging in the future.