Hyperspectral ghost imaging camera based on a flat-field grating

Abstract

A spectral camera based on ghost imaging via sparsity constraints (GISC) acquires a three-dimensional (3D) spatial-spectral data cube of the target through a two-dimensional (2D) detector in a single snapshot. However, the spectral and spatial resolution are interrelated because both of them are modulated by the same spatial random phase modulator. In this paper, we theoretically and experimentally demonstrate a system by equipping the GISC spectral camera with a flat-field grating to disperse the light fields before the spatial random phase modulator, hence consequently decoupling the spatial and spectral resolution. By theoretical derivation of the imaging process we obtain the spectral resolution 1nm and spatial resolution 50μm about the new system which are verified by the experiment. The new system can not only modulate the spatial and spectral resolution separately, but also provide a possibility of optimizing the light field fluctuations of different wavelengths according to the imaging scene.

Spectral ghost imaging camera with super-Rayleigh modulator

“…Simultaneously, simulation and experimental results indicate that the noise immunity of the system and the quality of the reconstructed results can be improved by using super-Rayleigh speckle patterns. In order to obtain super-Rayleigh speckles over a broader spectral range, equipping the GISC spectral camera with a flat-field grating [32] may be a feasible method. GISC spectral camera with super-Rayleigh modulator can be applied to many practical imaging areas, such as single photon imaging [33], super-resolution imaging [34] and GISC nanoscopy [35].…”

Research on target recognition technology of GISC spectral imaging based on active laser lighting

“…In 2018, the research group [15] used an 800-mhigh tethered balloon to carry a snapshot-type GISC spectroscopic camera to achieve snapshot-type passive optical multispectral quantum correlation imaging of natural scenes. In the same year, the research group [16] proposed adding a flat-field grating to the snapshot GISC spectroscopic camera, which can increase the spectral resolution to 1 nm and realize the imaging function of the GISC hyperspectral camera, but the system structure is complex, which is not conducive to engineering applications. From 2020 to 2021, the research group will improve the anti-noise capability and imaging signal-tonoise ratio of the GISC spectroscopic camera through the optimized design of the hyper-Rayleigh speckle field and polarization characteristics [17]; [18].…”