Recent advancements in photonic bound states in the continuum (BICs) have opened up exciting new possibilities for the design of optoelectronic devices with improved performance. In this perspective article, we provide an overview of recent progress in photonic BICs based on metamaterials and photonic crystals, focusing on both the underlying physics and their practical applications. The first part of this article introduces 2 different interpretations of BICs, based on far-field interference of multipoles and near-field analysis of topological charges. We then discuss recent research on manipulating the far-field radiation properties of BICs through engineering topological charges. The second part of the article summarizes recent developments in the applications of BICs, including chiral light and vortex beam generation, nonlinear optical frequency conversion, sensors, and nanolasers. Finally, we conclude with a discussion of the potential of photonic BICs to advance terahertz applications in areas such as generation and detection, modulation, sensing, and isolation. We believe that continued research in this area will lead to exciting new advancements in optoelectronics, particularly in the field of terahertz devices.
2023, 3(1): 0033
Bound states in the continuum (BICs) have exhibited extraordinary properties in photonics for enhanced light-matter interactions that enable appealing applications in nonlinear optics, biosensors, and ultrafast optical switches. The most common strategy to apply BICs in a metasurface is by breaking symmetry of resonators in the uniform array that leaks the otherwise uncoupled mode to free space and exhibits an inverse quadratic relationship between quality factor (Q) and asymmetry. Here, we propose a scheme to further reduce scattering losses and improve the robustness of symmetry-protected BICs by decreasing the radiation density with a hybrid BIC lattice. We observe a significant increase of radiative Q in the hybrid lattice compared to the uniform lattice with a factor larger than 14.6. In the hybrid BIC lattice, modes are transferred to Г point inherited from high symmetric X, Y, and M points in the Brillouin zone that reveal as multiple Fano resonances in the far field and would find applications in hyperspectral sensing. This work initiates a novel and generalized path toward reducing scattering losses and improving the robustness of BICs in terms of lattice engineering that would release the rigid requirements of fabrication accuracy and benefit applications of photonics and optoelectronic devices.bound states in the continuum metasurfaces terahertz photonics radiative losses Fano resonances
2023, 2(4): 230006
为解决罗兰光栅光谱成像不易直接读取、平面场凹面光栅成像算法复杂等问题,设计了一种基于全息凹面光栅原理的用于特定蛋白分析仪生化检测的分光光度计。该结构以罗兰光栅为基底,采用双透镜作为过渡元件,将罗兰光栅的曲面成像过渡成平场光谱,同时采用光学设计软件Zemax对该结构进行模拟和优化。优化结果表明,分光光度计能够实现光谱平场化,工作波段为320~800 nm,最高分辨率可达0.5 nm,整体分辨率优于1.7 nm,可被光电二极管阵列直接读取,结构特性满足特定蛋白分析仪的测量要求。样机实验结果与模拟结果一致,仪器重复性、准确度、稳定性及线性度均达到行业标准。光谱学 特定蛋白分析仪 全息凹面光栅 Zemax 仪器性能 spectroscopy specific protein analyzer holographic concave grating Zemax instrument performance