Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials, making them promising candidates for use in smart tunable device. Here, we propose and experimentally demonstrate that integrating metamaterial design principles with the intrinsic features of natural materials can engineer thermal smart metadevices. Tunable extraordinary optical transmission like (EOT-like) phenomena have been achieved in the microwave regime using shape memory alloy (SMA). The strongly localized fields generated by designed metadevices, combined with the intense interference of incident waves, enhance transmission through subwavelength apertures. Leveraging the temperature-responsive properties of SMA, the morphology of the metadevice can be recontructed, thereby modifying its response to electromagnetic waves. The experiments demonstrated control over the operating frequency and transmission amplitude of EOT-like behavior, achieving a maximum transmission enhancement factor of 126. Furthermore, the metadevices with modular design enable the realization of multiple functions with independent control have been demonstrated. The proposed SMA-based metamaterials offer advantages in terms of miniaturization, easy processing, and high design flexibility. They may have potential applications in microwave devices requiring temperature control, such as sensing and monitoring.

In this study, we developed a single-beam optical trap-based surface-enhanced Raman scattering (SERS) optofluidic molecular fingerprint spectroscopy detection system. This system utilizes a single-beam optical trap to concentrate free silver nanoparticles (AgNPs) within an optofluidic chip, significantly enhancing SERS performance. We investigated the optical field distribution characteristics within the tapered fiber using COMSOL simulation software and established a MATLAB simulation model to validate the single-beam optical trap's effectiveness in capturing AgNPs, demonstrating the theoretical feasibility of our approach. To verify the particle capture efficacy of the system, we experimentally controlled the optical trap's on-off state to manage the capture and release of particles precisely. The experimental results indicated that the Raman signal intensity in the capture state was significantly higher than in the non-capture state, confirming that the single-beam optical trap effectively enhances the SERS detection capability of the optofluidic detection system. Furthermore, we employed Raman mapping techniques to investigate the impact of the capture area on the SERS effect, revealing that the spectral intensity of molecular fingerprints in the laser-trapping region is significantly improved. We successfully detected the Raman spectrum of crystal violet at a concentration of 10⁻⁹ mol/L and pesticide thiram at a concentration of 10⁻⁵ mol/L, further demonstrating the ability of the single-beam optical trap in enhancing the molecular fingerprint spectrum identification capability of the SERS optofluidic chips. The optical trapping SERS optofluidic detection system developed in this study, as a key component of an integrated optoelectronic sensing system, holds the potential for integration with portable high-power lasers and high-performance Raman spectrometers. This integration is expected to advance highly integrated technologies and significantly enhance the overall performance and portability of optoelectronic sensing systems.

Attributable to the complex distribution of tactile vesicles under the skin and the ability of the brain to process specific tactile parameters (shape, hardness, and surface texture), human skin can have the capacity for tactile spatial reconstruction and visualization of complex object geometry and surface texture. However, current haptic sensor technologies are predominantly point sensors, which do not have an interlaced distribution structure similar to that of haptic vesicles, limiting their potential in human-computer interaction applications. Here, we report an optical microfiber array skin (OMAS) imitating tactile vesicle interlaced structures for tactile visualization and object reconstruction sensing. This device is characterized by high sensitivity (−0.83 N/V) and fast response time (38 ms). We demonstrate that combining the signals collected by the OMAS with appropriate artificial intelligence algorithms enables the recognition of objects with different hardnesses and shapes with 100% accuracy. It also allows for the classification of fabrics with different surface textures with 98.5% accuracy and Braille patterns with 99% accuracy. As a proof-of-concept, we integrated OMAS into a robot arm to select mahjong among six common objects and successfully recognize its suits by touch, which provides a new solution for tactile sensory processing for human-computer interaction.

Lithium niobate (LN) has remained at the forefront of academic research and industrial applications due to its rich material properties, which include second-order nonlinear optic, electro-optic, and piezoelectric properties. A further aspect of LN’s versatility stems from the ability to engineer ferroelectric domains with micro and even nano-scale precision in LN, which provides an additional degree of freedom to design acoustic and optical devices with improved performance and is only possible in a handful of other materials. In this review paper, we provide an overview of the domain engineering techniques developed for LN, their principles, and the typical domain size and pattern uniformity they provide, which is important for devices that require high-resolution domain patterns with good reproducibility. It also highlights each technique's benefits, limitations, and adaptability for an application, along with possible improvements and future advancement prospects. Further, the review provides a brief overview of domain visualization methods, which is crucial to gain insights into domain quality/shape and explores the adaptability of the proposed domain engineering methodologies for the emerging thin-film lithium niobate on an insulator platform, which creates opportunities for developing the next generation of compact and scalable photonic integrated circuits and high frequency acoustic devices.

Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics, micro-mechanics, and biomedicine. However, its adoption is limited by the large size, complexity, high cost, and low flexibility of optical systems. Metasurfaces enable precise multidimensional control of light fields, aligning well with the development trend toward compact, high-performance optical systems. Here, we review several recent studies on the application of metasurfaces in laser processing technologies, including 3D nanolithography, direct laser writing, and laser cutting. Metasurfaces provide an integrated operational platform with exceptional performance, poised to disrupt conventional laser processing workflows. This combination presents significant cost efficiency and substantial development potential, with promising applications in areas such as imaging, optical storage, advanced sensing, and space on-orbit manufacturing.