Structured light projection provides a promising approach to achieving fast and non‐contact three‐dimensional (3D) imaging. The resolution is a crucial index that represents security and accuracy in applications such as face recognition and robot vision. It depends on the density of dots in the projection. However, further improving the density of dots in the current system must be at the cost of speed or volume. Here, an all‐dielectric ultra‐thin metasurface is designed and fabricated to project a multi‐wavelength dot array. The density of dots is improved because projected dots with different wavelengths fill the gaps with each other. The experimental results demonstrate that the multi‐wavelength projection improves the resolution of 3D imaging. Furthermore, the multi‐wavelength system is beneficial to measuring a surface with varying colors. The approach has the potential to achieve a new generation of high‐resolution systems for tiny fluctuations and colorful 3D imaging in dark environments.

Panoramic perception, as a technology for comprehensive information acquisition, is a fascinating research topic across various disciplines. Acoustic, being one of the most familiar channels for human information conveyance, holds considerable potential for harnessing in panoramic perception. In nature, the spider is able to sense acoustic-induced air particle motion using a slender web. The unique acoustic response mechanism approaches maximum physical efficiency, which is much better than all previously known acoustic responsiveness of tympanic membranes. Herein, inspired by such unique structural and functional features of the spider auditory system, we propose a bio-inspired web-like structure that exhibits superior mechanical compliance (23.6 ~ 0.016 μm/Pa), high sensitivity (9.36 mm/s/Pa @100 Hz), excellent low-frequency response (10 Hz in experiment, 1 Hz in simulation), fine frequency resolution (0.05 Hz) and inherent directionality to acoustic. These excellent features demonstrate that the bio-inspired web-like structure is well-suited for high-performance acoustic detection and holds potential for panoramic acoustic perception. Meanwhile, the sensing system demonstrates promise in automatic driving, disaster monitoring and early warning, human-computer interaction, national defense security, etc.

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm². The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.

The reflective optical multi-films with high damage thresholds are widely used in intense-light systems. Metasurfaces, which can manipulate light peculiarly, give a new approach to achieve highly reflective films by a single-layer configuration. In this study, reflective metasurfaces, composed of silicon nanoholes, are numerically investigated to achieve high damage thresholds. These nanoholes can confine the strongest electric field into the air zone, and, subsequently, the in-air electric field does not interact directly with silicon, attenuating the optothermal effect that causes damage. Firstly, the geometrical dependencies of silicon nanoholes’ reflectance and field distribution are investigated. Then, the excitation states of electric/magnetic dipoles in nanostructures are analyzed to explain the electromagnetic mechanism. Furthermore, the reflection dependences of the nanostructures on wavelength and incident angle are investigated. Finally, for a typical reflective meta-film, some optothermal simulations are conducted, in which a maximum laser density of 0.27 W/µm² can be handled. The study provides an approach to improve the laser damage threshold of reflective nanofilms, which can be exploited in many intense-light applications.