Orbital angular momentum (OAM) of an optical vortex has attracted great interest from the scientific community due to its significant values in high-capacity optical communications such as mode or wavelength division multiplexer/demultiplexer. Although several configurations have been developed to demultiplex an optical vortex, the multiwavelength high-order optical vortex (HOOV) demultiplexer remains elusive due to lack of effective control technologies. In this study, we present the design, fabrication, and test of metasurface optical elements for multiwavelength HOOV demultiplexing based on optical gyrator transformation transformations in the visible light range. Its realization in a metasurface form enables the combined measurement of OAM, the radial index p, and wavelength using a single optical component. Each wavelength channel HOOV can be independently converted to a high-order Hermitian–Gaussian beam mode, and each of the OAM beams is demultiplexed at the converter output. Furthermore, we extend the scheme to realize encoding of the three-digit gray code by controlling the wavelength or polarization state. Experimental results obtained at three wavelengths in the visible band exhibit good agreement with the numerical modeling. With the merits of ultracompact device size, simple optical configuration, and HOOV recognition ability, our approach may provide great potential applications in photonic integrated devices and systems for high-capacity and demultiplex-channel OAM communication.

传统的线性渐变滤光片型高光谱成像仪，把线性渐变滤光片置于探测器窗口前，因线性渐变滤光片与探测器焦平面的位置差异，会产生光谱分辨率降低等问题。为了解决这个问题，设计了基于线性渐变滤光片的高光谱成像仪样机，整个系统包括望远系统、线性渐变滤光片元件、中继系统和探测系统四部分。将线性渐变滤光片置于望远系统的焦平面上，中继系统把线性渐变滤光片成像在探测系统靶面上，使线性渐变滤光片与探测系统焦面重合。高光谱成像仪系统的光谱范围为400~700 nm，谱段数为31，光谱分辨率为10 nm，视场角为±8°，焦距为55 mm。搭建样机并开展光谱定标与应用实验，效果良好。相比传统采用棱镜或光栅分光的高光谱成像仪系统，该系统省去了准直系统，具有体积小、重量轻、光通量大的优势，可为高光谱成像仪的小型化提供参考。