Zichun Le

Monocular vision provides essential spatial information when binocular input is unavailable, yet systematic research on its underlying mechanisms remains limited. This study quantified sensitivity to distance under four monocular cue contexts—linear perspective, relative size, light and shadow, and sparse scenes—across viewing distances of 0.4–1.2 m in depth (Z-axis) and vertical (Y-axis) dimensions using a controlled VR paradigm. Nineteen adults made monocular judgments with one eye physically occluded. Results revealed a pronounced dimensional dissociation: depth distance was heavily compressed (perceived/actual ≈ 0.28) while vertical distance was only mildly compressed (≈0.84, 3-fold gap, p < 0.001). No significant differences in compression were detected across the four cue contexts. The centered and scaled errors showed a shared distance-dependent pattern of deviations from participants’ mean perceived baselines, with positive values at nearer target depths and negative values at farther depths. These findings are consistent with the Intrinsic Constraint (IC) theory and describe a dimensional difference in distance scaling, with no significant differences detected among the tested cue contexts. Beyond theoretical implications, this work informs cue-based rehabilitation for monocular patients and the optimization of VR environments where binocular information is limited.

On-chip metasurfaces provide a compact route for wavefront shaping under guided-wave illumination, but their multiplexing capacity is often limited by conjugate phase degeneracy between counter-propagating guided waves and by insufficient degrees of freedom in single-meta-atom designs. Here, we demonstrate a guided wave driven metasurface that encodes eight channels through the joint use of propagation direction and output spin. The fundamental TE0 mode is launched from four in-plane directions, and the LCP and RCP components of the radiated field are separated to reconstruct two different holographic images for each input direction. Unlike supercell designs composed of multiple nanobricks, each unit cell in our metasurface employs a single anisotropic nanobrick whose length, width, in-plane displacements, and rotation angle jointly regulate the propagation, detour, and geometric phase responses. The optimization links these five structural variables to the optical responses of the eight channels while incorporating diffractive propagation and a collision-avoidance constraint. Numerical reconstructions demonstrate clear eight-channel holographic images with strong channel selectivity under guided-wave excitation. The scheme removes the need for free space illumination or mechanical switching and provides a compact route to high-capacity integrated holography, optical encryption, and multifunctional photonic chips.

Despite rapid advances in laser display technology, existing evaluation frameworks remain confined to isolated physical metrics, decoupled from human visual perception. This study presents the laser display comprehensive testing system (LD-CTS003), a unified platform integrating physical characterization and visual perceptual assessment. Grounded in opponent-process theory, the system implements a complete color conversion pipeline from display RGB through CIE XYZ and LMS to the Derrington–Krauskopf–Lennie space, linking spectral output to retinal cone responses. The hardware architecture features five-axis precision motion and multi-sensor synchronous acquisition, while the software supports both conventional optical measurements and psychophysical experiments. Static image resolution was evaluated via stripe-pattern modulation analysis across viewing distances, and visual contrast sensitivity was measured using Gabor stimuli under varying luminance and eccentricity. The results demonstrate that reduced viewing distances enhance effective resolution, with text display imposing stricter requirements than image display. Contrast sensitivity functions exhibit band-pass profiles, with luminance and eccentricity strongly modulating achromatic and red–green channels, whereas yellow–violet responses remain relatively robust peripherally. By unifying objective metrology and subjective evaluation, this work establishes a perception-oriented framework for laser display quality assessment, providing a physiologically grounded foundation for display optimization and standard development.

For compact spectrometers, the enduring technical challenge lies in the simultaneous optimization of high optical performance and miniaturization. Here we report a solid immersion grating microspectrometer with wedge prism correction (SIG-W-µSPEC), which realizes both high spectral resolution and a highly compact structure across a broad spectral range. The SIG-W-µSPEC integrates a solid immersion grating (SIG), planar reflectors, an optical wedge, a convex lens, a silicon microslit, and a CMOS linear array sensor into a single optical module. The SIG endows the system with high angular dispersion but inevitably induces focal plane tilt; the optical wedge not only compensates for this tilt with high precision but also effectively compresses the optical path length. Following high-precision encapsulation, the SIG-W-µSPEC achieves an average spectral resolution of 4.4 nm in the 600–1000 nm wavelength range, with an overall volume of merely 0.63 cm ³ . We applied this device to collect the reflectance spectra of fruits for the prediction of soluble solids content (SSC), yielding a high correlation coefficient (R ² =0.941). This ultra-compact spectrometer demonstrates broad application prospects in diverse fields, including agricultural quality monitoring, biomedical sensing, and real-time non-invasive on-site detection.

Holographic displays offer promising capabilities for realistic three-dimensional visual experiences, yet their practical implementation is hindered by limited spatial bandwidth product (SBP) and the demand for high-quality image reconstruction across the entire field of view. Here, we propose a gaze-aware neural holography framework that leverages human visual system (HVS) characteristics to optimize holographic image quality. We introduce two complementary approaches: gaze-aware holography (GAH) based on iterative optimization and gaze-aware neural holography (GANH) based on neural networks. In GANH, we develop a gaze patch (GP) strategy to ensure real-time performance for hologram generation, enabling the neural network to adapt to spatially dependent gaze-aware loss functions. Both numerical simulations and optical experiments demonstrate that our framework significantly enhances image quality in the foveal region while maintaining acceptable performance in peripheral regions. This hardware-agnostic approach provides a promising solution for next-generation near-eye holographic displays with integrated gaze tracking capabilities.

Microfluidics is expected to replace traditional medical detection methods as the next generation medical detection technology due to its high throughput, less sample required, and fast mass transfer. However, microfluidic chips mostly need a peristaltic pump to provide pressure to feed the sample, which limits its capability of immediate detection as well as portability. In this paper, a gravity-driven droplet-based microfluidic multiplexed Raman sensor has been developed, which is applicable to both rigid and flexible substrates. Furthermore, the fabrication method is also proposed. The developed gravity-driven multiplexed Raman sensor is easy to manufacture, thin, cheap and does not require external energy input. The performance of the developed sensor was characterized by using malachite green, and the minimum 10-8 mol/L malachite green can be detected with 633 nm laser irradiation. Moreover, we optimized its dimensions, while retaining its excellent features such as easy fabrication, cost-effectiveness and thinness. The proposed sensor provides a new view for portable on-chip detection of liquid droplets.

A methodology for designing optical systems with multilevel volumetric recording for long-term data storage is proposed. A new recording medium based on pyrazoline luminophores with high photostability and efficient luminescence was synthesized. The structure of the data carrier was optimized to increase recording density and ensure stable readout. A direct laser writing method was applied to achieve high- precision microrelief formation.

Holography is a promising approach to recreate lifelike 3D scenes. However, due to the current Spatial Light Modulators (SLMs) lacking sufficient pixels, the defocused planes of holograms always exhibit obvious interference phenomena. The methods based on random phase can alleviate this problem, but they always affect the imaging quality of the focal plane. Meanwhile, direct current (DC) noise of nondiffracted light in SLMs, coupled with ubiquitous dynamic noise, has long been a fundamental issue affecting holographic display quality. In this study, we proposed a method based on static high-pass filtering and time-multiplexing that overcomes the traditional tradeoff between divergence capability of holograms and display quality in focal planes. Simultaneously, the proposed method can eliminate DC and dynamic noise with a simple and robust structure. Moreover, we further extended artificial intelligence-driven algorithms to achieve higher-quality on-axis amplitude-only holograms. The Simulations and experiments demonstrated that the developed method is a promising and easily generalized solution for time-multiplexing holography.