Stretchable and wearable opto-electronics have attracted worldwide attention due to their broad prospects in health monitoring and epidermal applications. Resistive strain sensors, as one of the most typical and important device, have been the subject of great improvements in sensitivity and stretchability. Nevertheless, it is hard to take both sensitivity and stretchability into consideration for practical applications. Herein, we demonstrated a simple strategy to construct a highly sensitive and stretchable graphene-based strain sensor. According to the strain distribution in the simulation result, highly sensitive planar graphene and highly stretchable crumpled graphene (CG) were rationally connected to effectively modulate the sensitivity and stretchability of the device. For the stretching mode, the device showed a gauge factor (GF) of 20.1 with 105% tensile strain. The sensitivity of the device was relatively high in this large working range, and the device could endure a maximum tensile strain of 135% with a GF of 337.8. In addition, in the bending mode, the device could work in outward and inward modes. This work introduced a novel and simple method with which to effectively monitor sensitivity and stretchability at the same time. More importantly, the method could be applied to other material categories to further improve the performance.

The switching function of traditional waveplates necessitates mechanical replacement or the superimposition of multiple waveplates, which gives rise to a complex system and a large volume. We have devised a multifunctional micro-waveplate based on the COMSOL simulation platform (v5.6), which concurrently integrates the compact nature of metasurfaces and the dynamic regulatory features of phase-change materials. When the phase-change material is in the crystalline phase, the metasurface possesses the functionality of a half-waveplate (HWP) and is capable of performing chirality inversion of circularly polarized light within the wavelength range of 1.45 μm to 1.52 μm and 1.56 μm to 1.61 μm. When the phase-change material is in the amorphous phase, the metasurface serves as a quarter-waveplate (QWP) and can achieve the conversion between linear and circular polarization through a 90° phase delay. The phase-change metasurface breaks through the constraint of fixed functions of traditional optical waveplates, facilitating the development of optical systems towards miniaturization, intelligence, and low power consumption and providing a crucial technical route for the next generation of photonic integration and dynamic optical applications.

Circular dichroism is at the core of chiral spectroscopy and polarization light manipulation. However, achieving metal-based devices with high efficiency, compactness, and easy integration in the near-infrared band remains a significant challenge. Traditional metal chiral microstructures, such as broken open rings, helical lines, or waveplates–polarizers I confirm., are limited to circular dichroism values below 50% due to their inherent ohmic losses, severely restricting practical applications. To overcome this bottleneck, this paper proposes a twisted double-layer plasmonic metasurface composed of two anisotropic metal metasurfaces. This design breaks the mirror symmetry of the structure by precisely controlling the in-plane twist angle between the layers, inducing strong coupling and interference effects in the chiral optical response. Simulation results show that this device achieves excellent multi-wavelength circular dichroism control. At a wavelength of 1660 nm, the circular dichroism value reaches 0.48, and it further increases to 0.84 at 2200 nm, significantly surpassing the performance limits of traditional metal structures. This work not only provides a simple and scalable design paradigm for high-performance chiral optical devices but also opens up new avenues for advanced applications such as chiral molecular sensing, polarization coding, and quantum optics in the near-infrared band.

Infrared cameras with narrow-band detection capability are widely used for SF6 gas detection, which is an essential part of power equipment inspection. Narrow-band detection is usually achieved by a combination of quantum well infrared photodetectors (QWIPs) and narrow-band filters. Improving the quantum efficiency of QWIPs and reducing the detection bandwidth are important ways to improve camera performance. In this study, a back-incident-type device of quantum well micropillar array targeting at a 10.5 μm central wavelength is designed and studied by three-dimensional simulation. The operating mechanism of the device was determined by investigating the effect of the device geometry on the quantum efficiency. The enhanced absorption capability of the device mainly comes from the Fabry–Pérot resonance and the antireflection effect. The final device exhibits a remarkable peak quantum efficiency of 83% at 10.5 μm and an ultra-narrow spectral bandwidth of 0.2 μm. These excellent properties are achieved without an antireflective film and narrow-band filter, which can significantly improve the narrow-band capability and integration of the system; the dark current reduces to be 0.2762 times due to the low-duty cycle. These properties indicate that the structure of the quantum well micropillar array is of great significance to the development of QWIPs used in gas detection.

Integrating metasurface-based polarizing filters atop photodetectors enables the expansion of detection capabilities from intensity to polarization, offering significant potential for applications requiring high-precision discrimination in scientific, industrial, and defense sectors. However, such metasurfaces often introduce optical efficiency losses. Here, we present a long-wave infrared (8.6 μm) circularly polarized photodetector capable of direct chiral discrimination, eliminating the need for additional optical components. The polarization selectivity arises from Guided-Mode resonances (GMRs) excited by two horizontally offset right-trapezoidal unit cells within a chiral metasurface. This design exhibits a pronounced transmittance contrast (~100%) between left circularly polarized light (LCP) and right circularly polarized light (RCP) while maintaining fabrication simplicity via a conventional single-step lithographic process. The proposed detector is expected to achieve high-dimensional physical characterization by resolving polarization-encoded vectorial information, demonstrating enhanced performance in complex environments.

The on-chip detection of circularly polarized light is pivotal for advancing applications in quantum optics, information processing, and spectroscopic sensing. However, conventional chiral metasurfaces often suffer from complex multilayer fabrication, material incompatibility, or modest performance, hindering their integration with photonic circuits. Here, we introduce a monolithic all-silicon metasurface that overcomes these limitations through a singular structural innovation. By strategically truncating four corners of a conventional Z-shaped meta-atom, we induce a hybridization of optical modes that profoundly enhances chiral light–matter interaction. This deliberately engineered perturbation yields a colossal circular dichroism with an extinction ratio exceeding 66 dB, a performance that surpasses existing state-of-the-art designs by approximately three orders of magnitude. Furthermore, the proposed metasurface exhibits remarkable fabrication robustness, owing to its single-layer architecture and CMOS-compatible material. We demonstrate that this exceptional metasurface can be directly integrated with a Mercury Cadmium Telluride (MCT) photodetector to form a highly efficient, compact circular polarization detector. Our work provides a simple yet powerful paradigm for creating high-performance chiral photonic devices, paving the way for their widespread adoption in integrated optoelectronics.