Wavy optical grating: wideband reflector and Fabry-Perot BICs

In this study, we theoretically and numerically investigate the resonant modes and reflectance of an optical grating consisting of a wavy dielectric slab by applying the spectral element method. The presence of the wavy shape transforms the waveguide modes into leaky resonant modes. A few resonant modes with specific longitudinal wave number have infinitely large Q factor, while the other resonant modes have finite Q factor. For the leaky resonant mode with zero longitudinal wave number, the Q factor is inversely proportional to the amplitude of the wavy shape. An array of multiple low-Q wavy gratings has a high reflectance in a large bandwidth. A double-layer wavy grating forms a Fabry-Perot cavity, which hosts Fabry-Perot bound states in the continuum (BICs) at the resonant frequency. The Q-factor of the Fabry-Perot cavity can be tuned by adjusting the distance between the two wavy slabs. The wavy shape could be generated by a vibrational wave in a flat dielectric slab so that the BICs mode and wideband reflectance could be controlled on-demand

Multi-agent planning with high-level human guidance

Planning and coordination of multiple agents in the presence of uncertainty and noisy sensors is extremely hard. A human operator who observes a multi-agent team can provide valuable guidance to the team based on her superior ability to interpret observations and assess the overall situation. We propose an extension of decentralized POMDPs that allows such human guidance to be factored into the planning and execution processes. Human guidance in our framework consists of intuitive high-level commands that the agents must translate into a suitable joint plan that is sensitive to what they know from local observations. The result is a framework that allows multi-agent systems to benefit from the complex strategic thinking of a human supervising them. We evaluate this approach on several common benchmark problems and show that it can lead to dramatic improvement in performance

Supplementary document for Wide-angle polarization selectivity based on anomalous defect mode in photonic crystal containing hyperbolic metamaterials - 5764081.pdf

In this supplementary material, we give a numerical example on the polarization-insensitive characteristic of conventional defect modes and analyze the effect of the absorption within hyperbolic metamaterial layers on the polarization selectivity

Multi-agent planning with high-level human guidance

Planning and coordination of multiple agents in the presence of uncertainty and noisy sensors is extremely hard. A human operator who observes a multi-agent team can provide valuable guidance to the team based on her superior ability to interpret observations and assess the overall situation. We propose an extension of decentralized POMDPs that allows such human guidance to be factored into the planning and execution processes. Human guidance in our framework consists of intuitive high-level commands that the agents must translate into a suitable joint plan that is sensitive to what they know from local observations. The result is a framework that allows multi-agent systems to benefit from the complex strategic thinking of a human supervising them. We evaluate this approach on several common benchmark problems and show that it can lead to dramatic improvement in performance

Quasibound states in the continuum in terahertz free-standing metal complementary periodic cross-shaped resonators

We numerically and experimentally achieve quasi-bound states in the continuums (BICs) with high-Q factors in the free-standing metal complementary periodic cross-shaped resonators (CPCRs) at terahertz (THz) frequencies. Such induced quasi-BICs arises from the breaking of the mirror symmetry of CPCRs. By properly tuning the asymmetric factor, the measured Q factor of quasi-BIC can reach 102, which is lower than the simulated Q factor of 166 due to the limited system resolutions. We also simulate the electric field magnitude and vector distributions at the quasi-BICs, where the out-phase alignment between the electric dipoles is found. The sharp quasi-BICs realized in this thin free-standing metal structure may immediately boost the performance of filters and sensors in terahertz wave manipulation or biomolecular sensing

sj-docx-1-cll-10.1177_09636897231198167 – Supplemental material for SUV39H1 Inhibits Angiogenesis in Limb Ischemia of Mice

Supplemental material, sj-docx-1-cll-10.1177_09636897231198167 for SUV39H1 Inhibits Angiogenesis in Limb Ischemia of Mice by Wenhao Niu, Wenyue Cao, Feng Wu and Chun Liang in Cell Transplantation</p

Fe(OTf)₃ versus Bi(OTf)₃ as Mild Catalysts in Epoxide Oxidative Ring-Opening, Urea α‑Diketone Condensation, and Glycoluril Diether Synthesis

The salt Fe­(OTf)₃ has been shown to function as an effective catalyst in three different reactions, epoxide oxidative ring-opening to an α-hydroxy ketone, urea α-diketone condensation to form glycolurils, and glycoluril diether synthesis by formaldehyde condensation. In each of these reactions, Fe­(OTf)₃ was compared to Bi­(OTf)₃, a viable alternative catalyst with few or no prior examples of this type. Differences and advantages are highlighted but in most cases yields were generally high, and both catalysts outperformed conventional acid catalyzed methods

Dual-band nonreciprocal thermal radiation by coupling optical Tamm states in magnetophotonic multilayers

Kirchhoff s law is one of the most fundamental law in thermal radiation. The violation of traditional Kirchhoff s law provides opportunities for higher energy conversion efficiency. Various micro-structures have been proposed to realize single-band nonreciprocal thermal emitters. However, dual-band nonreciprocal thermal emitters remain barely investigated. In this paper, we introduce magneto-optical material into a cascading one-dimensional (1-D) magnetophotonic crystal (MPC) heterostructure composed of two 1-D MPCs and a metal layer. Assisted by the nonreciprocity of the magneto-optical material and the coupling effect of two optical Tamm states (OTSs), a dual-band nonreciprocal lithography-free thermal emitter is achieved. The emitter exhibits strong dual-band nonreciprocal radiation at the wavelengths of 15.337 um and 15.731 um when the external magnetic field is 3 T and the angle of incidence is 56 degree. Besides, the magnetic field distribution is also calculated to confirm that the dual-band nonreciprocal radiation originates from the coupling effect between two OTSs. Our work may pave the way for constructing dual-band and multi-band nonreciprocal thermal emitters