Lightweight Spectro-Polarimetric Imaging Enabled by Freely Height-Varying Metasurface via Two-Photon Polymerization Lithography

The pursuit of high-dimensional optical information, particularly spectrum and polarization, has been a persistent goal in both scientific research and engineering applications. However, conventional spectro-polarimetric imaging systems are typically constrained by bulky hardware, complex optical configurations, and heavy computational burdens, which severely limit their deployment on miniaturized platforms. In this study, we propose a lightweight spectro-polarimetric imaging method enabled by a height-varying metasurface via two-photon polymerization lithography, where out-of-plane height modulation and in-plane geometric shapes are jointly exploited to achieve a broader spectral modulation range and different polarimetric responses. By combining the designed metasurface with a newly built reconstruction algorithm, spectro-polarimetric images are successfully reconstructed from a single grayscale image, with an average polarization angle error of 3.02° for uniform objects and an average PSNR of 35.86 dB, SSIM of 0.93, and spectrum fidelity of 98.45% for a complex object, demonstrating the high reconstruction quality of the proposed method. This work provides a compact and efficient route toward snapshot acquisition of high-dimensional light information, offering strong potential for integration into miniaturized imaging platforms.