Sharp electromagnetic resonances play an essential role in physics general and optics particular. The last decades have witnessed the successful developments of high-quality (Q) microcavities operating below light line, which however is fundamentally challenging to access from free space. Alternatively, metasurface-based bound states continuum (BICs) offer a complementary solution creating high-Q devices above yet experimentally demonstrated Q factors under normal excitations are still...

Two-dimensional (2D) layered materials such as GaSe recently have emerged novel nonlinear optical with exceptional properties. Although exhibiting large susceptibilities, the responses of 2D are generally limited by short interaction lengths light, thus further enhancement via resonant photonic nanostructures is highly desired for building high-efficiency devices. Here, we demonstrate a giant second-harmonic generation (SHG) coupling flakes to silicon metasurfaces supporting quasi-bound...

High-index dielectric metasurfaces can support sharp optical resonances enabled by the physics of bound states in continuum (BICs) often manifested experiments as quasi-BIC resonances. They provide a way to enhance light-matter interaction at subwavelength scale bringing novel opportunities for nonlinear nanophotonics. Strong narrow-band field enhancement leads an extreme sensitivity change refractive index that may limit functionalities pump intensities beyond perturbative regime. Here we...

The pursuit of compact lasers with low thresholds has imposed strict requirements on tight light confinements minimized radiation losses. Bound states in the continuum (BICs) have been recently demonstrated as an effective mechanism to trap light. However, most reported BIC are still bulky due absence in-plane confinement. Here, we combine BICs and photonic bandgaps realize three-dimensional confinements, referred miniaturized (mini-BICs). We demonstrate highly active mini-BIC resonators a...

The Berry curvature in the band structure of transition metal dichalcogenides (TMDs) introduces a valley-dependent effective magnetic field, which induces valley Hall effect (VHE). Similar to ordinary effect, VHE spatially separates carriers or excitons, depending on their index, and accumulates them at opposite sample edges. can play key role valleytronic devices, but previous observations have been limited cryogenic temperatures. Here, we report demonstration interlayer excitons MoS2/WSe2...

This paper addresses the joint selective maintenance and repairperson assignment problem (JSM–RAP) for complex multicomponent systems. The systems perform consecutive missions separated by scheduled finite duration breaks are imperfectly maintained during breaks. Current (SM) models usually assume that only one repair channel is available or optimisation can be done at a subsequent stage. Using generalised reliability function k-out-of-n systems, we formulate JSM–RAP more than...

As optical resonances with high-quality (Q) factors, bound states in the continuum (BICs) supported a metamaterial low loss have attracted great interest due to their potential applications photonic devices different functionalities. However, most studies focus on influence of symmetry breaking constituent elements Q factors quasi-BICs, and less attention is paid coupling between elements. Here, we investigate numerically experimentally quasi-BICs revealed metasurfaces composed regularly...

Integrated photonic microcavities have demonstrated powerful enhancement of nonlinear effects, but they face a challenge in achieving critical coupling for sufficient use incident pump power. In this work, we first experimentally demonstrate that highly efficient third-harmonic generation (THG) and detectable second-harmonic (SHG) can be produced from high-Q moiré superlattice microcavities, where condition achieved via selecting magic angle. Furthermore, at the angle 13.17°, is satisfied,...

Two-dimensional transition-metal dichalcogenides (TMDC) are of great interest for on-chip nanophotonics due to their unique optoelectronic properties. Here, we propose and realize coupling tungsten diselenide (WSe2) monolayers circular Bragg grating structures achieve enhanced emission. The interaction between WSe2 the resonant mode structure results in Purcell-enhanced emission, symmetric geometrical improves directionality out-coupling stream emitted photons. Furthermore, this hybrid...

<title>Abstract</title> Layered van der Waals (VdW) materials, with their exceptional optical and electronic properties, hold great promise for advancing photonic technologies. However, integration into high-performance systems has been hindered by inefficient light-matter interactions over short interaction lengths. Here, we address this challenge integrating VdW materials multi-mode quasi-bound states in the continuum (quasi-BICs), creating a versatile platform to enhance compact scalable...

The photonic crystal (PhC)-modulated microring resonator enables engineered dispersion, the formation of bandgap, enhanced slow light effects, making it attractive platform for nonlinear optics, optical sensing, or quantum photonics. Recently, symmetry-breaking PhC microrings have shown promise realizing miniature bound states in continuum (BICs), but challenges remain, including limited Q-factor and an incomplete understanding radiated mode patterns. Here, we present a comprehensive...

Abstract Coherent light sources in silicon photonics are the long‐sought Holy Grail because silicon‐based materials have indirect bandgap. Traditional strategies for realizing such sources, e.g., heterogeneous photonic integration, strain engineering, and nonlinear process, technologically demanding. Here, a hybrid lasing device composed of perovskite nanocrystals nitride nanobeam cavity is demonstrated. SiN crystal naonobeam cavities fabricated on solid substrate with significantly improved...

Abstract Lithium niobate (LN), as a nonlinear material with large susceptibility, has been widely employed in second harmonic generation (SHG) up to ultraviolet (UV) frequency range due its broad low-absorption window. In nanophotonics, it is possible harness the Mie resonances associated single dielectric particles boost light–matter interactions. Here, we fabricate Mie-resonant LN nanospheres on SiO 2 substrate via femtosecond (fs) laser ablation technique. By exploiting magnetic dipole...

Chalcogenide glasses (ChGs) have recently emerged as enabling materials for building reconfigurable nanophotonic devices by employing their refractive index changes associated with photosensitive effects. In particular, the availability of low-loss thin-film ChGs and realization high-Q microresonators provide exciting opportunities integrated photonics. So far, ChG photonic are predominately operated in classical optics regime. this work, we present on-chip bright photon-pair quantum light...

Abstract Monolayer transition metal dichalcogenides (TMDs) have emerged as a promising platform for chip-integrated optoelectronics and non-linear optics. Here, we demonstrate two-dimensional (2D) monolayer tungsten disulfide (WS 2 ) efficiently coupled to dielectric circular Bragg resonator (CBR). The coupling of the WS CBR leads pronounced enhancements in both photoluminescence (PL) second harmonic generation (SHG) by factor 34 5, respectively. Our work provides powerful tool enhance...

In this paper, we first show that a previous proxy signature scheme by delegation with certificate is not provably secure under adaptive-chosen message attacks and warrant attacks. The does provide the strong undeniability. Then construct based on Co-GDH group from bilinear map. Our existentially unforgeable against in random oracle model. We adopt straight method of security reduction which our scheme's reduced to hardness computational co-Diffie-Hellem problem. proposed...

Colloidal CdSe/ZnS quantum dots (QDs) exhibit excellent optical properties for wide potential applications in light-emitting diodes, solar concentrators, and single-photon sources. However, the ultra-thin films with low concentration of QDs still encounter inefficient photoluminescence (PL) poor directionality radiation, which need to be enhanced using nanophotonics device designs. Here we design experimentally demonstrate an on-substrate silicon nitride (SiN) photonic crystal (PhC)...

Abstract Two-dimensional (2D) layered materials without centrosymmetry, such as GaSe, have emerged promising novel optical due to large second-order nonlinear susceptibilities. However, their responses are severely limited by the short interaction between 2D and light, which should be improved coupling them with photonic structures strong field confinement. Here, we theoretically design crystal circular Bragg gratings (CBG) based on hole a quality factor high Q = 8 × 10 3 , mode volume small...

A threshold secret sharing scheme permits a to be shared among participants in such way that only qualified subsets of can recover the secret. Threshold is useful management cryptographic keys. Based on Birkhoff interpolation, Tassa has proposed an ideal hierarchical scheme. Then based Sure interpolation and participants' identity, we present another simple easy method use At last, analyze which more compute implement real life.

Lead halide perovskite nanocrystals (NCs), especially the all-inorganic NCs, have drawn substantial attention for both fundamental research and device applications in recent years due to their unique optoelectronic properties. To build high-performance nanophotonic devices based on it is highly desirable couple NCs photonic nanostructures enhancing radiative emission rate improving directionality of NCs. In this work, we synthesized high-quality CsPbI