Micro-nano optomechanical accelerometers are widely used in automobile, aerospace, and other industrial applications. Here, we fabricate mechanical sensing components based on an electrically pumped GaN light-emitting diode (LED) with a beam structure. The relationship between the blueshift of the electroluminescence (EL) spectra and the deformation of the GaN beam structure based on the quantum-confined Stark effect (QCSE) of the InGaN quantum well (QW) structure is studied by introducing an extra mass block. Under the equivalent acceleration condition, in addition to the elastic deformation of GaN-LED, a direct relationship exists between the LED’s spectral shift and the acceleration’s magnitude. The extra mass block (gravitational force: 7.55×10-11N) induced blueshift of the EL spectra is obtained and shows driven current dependency. A polymer sphere (PS; gravitational force: 3.427×10-12N) is placed at the center of the beam GaN-LED, and a blueshift of 0.061 nm is observed in the EL spectrum under the injection current of 0.5 mA. The maximum sensitivity of the acceleration is measured to be 0.02m/s2, and the maximum measurable acceleration is calculated to be 1.8×106m/s2. It indicates the simultaneous realization of high sensitivity and a broad acceleration measurement range. This work is significant for several applications, including light force measurement and inertial navigation systems with high integration ability.

随着红外探测技术手段的多样化发展，红外隐身技术的需求日益迫切。由于传统的红外隐身技术面临着多途径目标探测和多功能兼容的严峻挑战，因此研究光学微纳结构红外隐身技术有着十分重要的意义。基于局域共振机制的亚波长尺度的光学微纳结构，极大地丰富了人们对光的传输行为的调控。在红外隐身技术领域，光学微纳结构可以针对红外辐射特性进行材料和结构的精细化设计，从而满足理想红外隐身发射光谱的需求，为发展更加多光谱、多功能、自适应的红外隐身技术提供全新的解决方案。文中围绕红外隐身技术的相关研究，首先介绍了多层薄膜吸收体、金属表面等离子激元、基于相变材料薄膜可调吸收体、智能化设计光学微纳结构实现光谱响应的基本原理，在此基础上，重点回顾了近年来基于光学微纳结构的红外隐身技术新特点，包括多光谱红外隐身技术、多功能红外隐身技术、自适应红外隐身技术的发展现状。最后，梳理了光学微纳结构红外隐身技术所存在的不足及面临的困难并对未来的研究方向和发展趋势进行了展望。

报道了高功率、高光束质量的垂直腔面发射半导体激光器(VCSEL)侧泵的Nd:YAG激光振荡器。从VCSEL泵浦源的主动冷却的热沉结构出发，设计了5个227 W的VCSEL线阵，并且通过优化侧面泵浦大口径激光棒的结构，研制成了具备480 W输出能力的棒状激光模块，相应的光-光效率为49.7%。在此基础上，设计了一种高功率、高光束质量的VCSEL侧面泵浦棒状Nd:YAG激光振荡器。腔内插入望远镜光学元件，并通过优化各光学元件的参数使其工作在热近非稳区域，以达到增大基横模体积和抑制高阶横模目的。最终，获得114 W的输出功率，相应的平均光束质量因子M²为1.42。由于VCSEL具备优秀的波长-温度稳定性，这种高功率、高光束质量的VCSEL泵浦的固体激光器在工业、空间等领域，具有极为广阔的应用前景。

Silicon nitride, with ultralow propagation loss and a wide transparency window, offers an exciting platform to explore integrated photonic devices for various emerging applications. It is appealing to combine the intrinsic optical properties of two-dimensional layered materials with high-quality optical waveguides and resonators to achieve functional devices in a single chip. Here we demonstrate a micro-ring resonator-based phase modulator integrated with few-layer MoS2. The ionic liquid is employed directly on the surface of MoS2 to form a capacitor configuration. The effective index of the composite MoS2–SiN waveguide can be modulated via adjusting bias voltages to achieve different charged doping induced electro-refractive responses in MoS2 film. The maximum effective index modulation of the composite MoS2–SiN waveguide can be achieved to 0.45×10-3. The phase tuning efficiency is measured to be 29.42 pm/V, corresponding to a VπL of 0.69 V·cm. Since the micro-ring resonator is designed near the critical coupling regime, the coupling condition between the bus waveguide and micro-ring resonator can also be engineered from under-coupling to over-coupling regime during the charged doping process. That can be involved as a degree of freedom for the coupling tailoring. The ability to modulate the effective index with two-dimensional materials and the robust nature of the heterostructure integrated phase modulator could be useful for engineering reliable ultra-compact and low-power-consumption integrated photonic devices.

Second-order topological insulators (SOTIs) have recently attracted much attention due to their capability to support lower-dimensional topological states, namely, the corner states. Here, we demonstrate that properly designed supercell metasurfaces can support photonic corner states, meanwhile further serving as an ideal platform for the implementations of topological polaritons and dynamically reconfigurable corner states by assembling two-dimensional materials. Such metasurfaces consist of an array of finite-sized SOTIs mimicking the two-dimensional Su–Schrieffer–Heeger model. We reveal that the topological transition happens in unit cells without the bandgap, and nondegenerate multipolar corner states emerge in the supercell metasurface due to the inter- and intrasupercell coupling effects. Especially since these corner states are above the light line of the metasurface, we realize the collective stimulation of the two dipolar corner states and their superposition state via far-field excitation. By stacking monolayer hexagonal boron nitride film onto the metasurface, we further achieve the topological phonon polaritons through the strong coupling between the corner state and the phonon, which is confirmed by the Rabi splitting as well as anticrossing behavior emerging in the transmission spectra. Furthermore, we reveal the robustness of the corner state and strong coupling by introducing defects into the metasurface. Finally, tunable corner state and strong coupling with on-demand control are realized by assembling monolayer graphene onto the metasurface. Our theoretical study proposes a unique hybrid-material platform for topological polaritonics and reconfigurable topological photonics, which can promote large-area topological applications in practice.

In order to meet the practical needs of all-fiber conductivity-temperature-depth sensors with high sensitivity, compact structure, and easy packaging, this Letter uses a microfiber coupler combined with fiber loop (MCFL) reflective photonic device to conduct salinity, temperature, and deep sensing experiments. These MCFLs’ dynamic range and resolution of salinity, temperature, and depth can meet the requirements of actual marine environment monitoring. This structure opens up a new design idea for the practical research of microfiber coupler-based marine environmental parameter sensors.

Because they possess excellent visible light absorption properties, lead-free colloidal copper-based chalcogenide quantum dots (QDs) have emerged in photoelectronic fields. By means of localized surface plasmonic resonance (LSPR), the absorption properties of QDs can be enhanced. In this paper, we fabricate a lead-free CuInSe2 QD field effect phototransistor (FEpT) by utilizing the LSPR enhancement of Au nanoparticles (NPs). The plasmonic FEpT demonstrates responsivity up to 2.7 μA·W 1 and a specific detectivity of 7×103 Jones at zero bias under illumination by a 532 nm laser, values that are enhanced by approximately 200% more than devices without Au NPs. Particularly, the FEpT exhibits a multi-wavelength response, which is photoresponsive to 405, 532, and 808 nm irradiations, and presents stability and reproducibility in the progress of ON–OFF cycles. Furthermore, the enhancement induced by Au NP LSPR can be interpreted by finite-difference time domain simulations. The low-cost solution-based process and excellent device performance strongly underscore lead-free CuInSe2 QDs as a promising material for self-powered photoelectronic applications, which can be further enhanced by Au NP LSPR.