As a comprehensive description of the polarization state of light, the Stokes vector serves as a key information carrier for analyzing the interaction between light and media [1]. It demonstrates distinctive applied merit in analyzing the internal structure and surface topography of substances [2], and has been widely applied in important fields such as astronomical observation [3], biomedical diagnosis [[4], [5], [6], [7]], and atmospheric remote sensing [[8], [9], [10]].

State-of-the-art polarization imaging technologies enable accurate and reliable measurement of full Stokes parameters, including the division-of-focal-plane (DoFP) [[11], [12], [13]], division-of-amplitude (DoAM) [14], and division-of-aperture (DoAP) approaches [15,16]. The DoFP method stands out for its high integration and measurement accuracy. Conventional polarization measurement devices, however, are typically plagued by complex architectures, large volumes, and limited dynamic response capabilities, which render them unable to meet the demands of miniaturized and dynamic measurement scenarios.

Metasurfaces are planar nanopillar structures that enable multidimensional light field manipulation, allowing control of phase [11], polarization [12], and amplitude [14,17] at the subwavelength scale. As periodic arrays of subwavelength dielectric or metallic resonators, they locally interact with incident waves to flexibly tailor the wavefront and polarization state of the outgoing light [[18], [19], [20]]. In recent years, metasurfaces have emerged as core information-processing components, mapping the polarization information of incident light into a readily detectable spatial intensity distribution. For instance, dielectric metasurfaces have been demonstrated to achieve broadband angular spectrum differentiation [21] and phase-contrast imaging [22] in the visible range, verifying their potential for polarization-related optical processing. Chiral metasurfaces have realized efficient linear polarization conversion and asymmetric transmission [20], providing new insights for polarization decomposition. These advances have pioneered novel approaches for Stokes parameter inversion, broken traditional limitations in holographic multiplexing [[23], [24], [25]], imaging [26,27], communications [[28], [29], [30]], and dynamic modulation, and advanced optical systems toward high integration and enhanced functionality.

Nevertheless, existing metasurface-based polarization measurement methods still face significant challenges in terms of performance and practical application. Most studies focus on metasurfaces operating at single wavelengths [13,31] or the near-infrared band [[32], [33], [34]]. In the design of metasurfaces operating in the visible light band, issues such as aberration, stray light, dispersion, and efficiency attenuation become more pronounced. Consequently, once the operating band deviates from the designed range, the polarization modulation performance of metasurfaces degrades significantly [32,[35], [36], [37], [38]]. Although some chiral metasurfaces exhibit remarkable orthogonal separation characteristics, they fail to achieve complete analysis of all Stokes parameters [39]. Compared with the high-efficiency designs reported in visible-light phase-contrast imaging and terahertz polarization manipulation, the low focusing efficiency of metasurfaces applied to polarization and wavefront measurement limits their use in weak-light detection applications [38]. Existing visible-light metasurface designs often struggle with trade-offs between bandwidth, efficiency, and integration, while infrared-microwave compatible metasurfaces have shown that appropriate material selection (e.g., indium tin oxide, ITO) and structural optimization can mitigate such limitations, offering useful guidance for visible-light system design [40,41]. Overall, constraints in operating bandwidth, optical efficiency, and system integration in existing technologies make it difficult to meet the urgent demand for high-performance visible-light polarization devices in fields such as material analysis, bioimaging, and industrial inspection.

To address these challenges, this paper proposes a visible-light full-Stokes parameter measurement system based on a TiO2 cross-shaped nanopillar metasurface. Independent phase manipulation of the orthogonal polarization components of incident waves, along with high-precision measurement of incident polarization states within the 500∼650 nm visible band, is achieved via the strategic optimization of the geometric dimensions of cross-shaped nanopillars. This design delivers an optical focusing efficiency exceeding 70% across the entire operating bandwidth, offering a critical technical support for the development of high-performance, integrated polarization detection modules tailored for next-generation spaceborne atmospheric remote sensors, spatial planetary spectrometers, and ground-based astronomical telescopes.