Abstract Parity-time (PT) symmetry has been unveiling new photonic regimes in non-Hermitian systems, with opportunities for lasing, sensing and enhanced light-matter interactions. The most exotic responses emerge at the exceptional point (EP) broken PT-symmetry phase, yet conventional PT-symmetric systems these require large levels of gain loss, posing remarkable challenges practical settings. Floquet PT-symmetry, which may be realized by periodically flipping effective gain/loss...

Frequent observations to a quantum system modify its coherent evolution through the Zeno effect and dynamics. Generally, measurement process destroys environment of monitored system, making repeated remain challenge. Here, using analogy experiments, we realize engineer dynamics in optical waveguide arrays, where modes correspond distinct states, temporal is mapped into spatial propagation. We propose new, extensible experimental strategy for realizing an analog stroboscopic measurements,...

Topological pumping connects the topological features of a modulated system with its transport behavior. It provides powerful means for robust between distant nodes even in one-dimensional chain, which may find applications wave manipulation and quantum information processing. Here, we experimentally demonstrate an adiabatic scheme, defect state, by introducing Fock photonic lattice, is classical analog Fock-state lattice two-mode Jaynes-Cummings model. Since this always protected energy gap...

We demonstrated an AlGaN-based multiple-quantum-well (MQW) deep ultraviolet (DUV) laser at 278 nm using a nanoporous (NP) n-AlGaN as the bottom cladding layer grown on sapphire substrate. The has very-low-threshold optically pumped power density of 79 kW/cm 2 room temperature and transverse electric (TE)-polarization-dominant emission. high optical confinement factor 9.12% benefiting from low refractive index is key to enable low-threshold lasing. I–V electrical measurement demonstrates that...

The edge-to-edge topological transport of the one-dimensional odd-sized Su-Schrieffer-Heeger model plays a crucial role in robust energy transfer and information processing. However, it has not been verified experimentally. Here we report on an experimental demonstration this photonic lattice coupled waveguides. When slowly varying spacings adjacent waveguides, light from leftmost to rightmost channels successfully observed. Moreover, speed efficiency are enhanced considerably by introducing...

We present experimental observations of topological edge states in photonic bilayer Su–Schrieffer–Heeger (SSH) lattices. Using the femtosecond laser direct writing technology, we establish two distinct types nontrivial SSH lattices with varying interlayer couplings, allowing us to observe different states. Interestingly, find that these can either remain within bandgap or transition into gapless bound continuum without hybridization under couplings. Our work illustrates a scheme investigate...

Currently, mountainous wind farm layout optimization generally does not take fatigue loads into account. However, due to the complexity of flow characteristics, focusing solely on power generation may lead excessive certain turbines, which could affect long-term profitability entire farm. To address this issue, study proposes a approach for complex terrain considering turbine load constraint. This consists three basic parts, i.e., computational fluid dynamics, complex-terrain wake model, and...

The mechanism of the charge and energy flow at metal-molecule interface has attracted much attention, especially with recent rise plasmonic nanomaterials for light-to-chemical conversion. Although numerous studies have demonstrated irreplaceable effects energetic electrons on accelerating chemical reactions, detangling direct electron transfer (DET) from indirect (IET) understanding their roles are still challenging. Here, by combining electrochemical dark field scattering spectroscopy,...

The China Space Station (CSS) modules feature many areas that are difficult to clean and thus susceptible microbial outbreaks. A new sampling method utilizing an equivalent material sheet was applied characterize the diversity of microbes accumulated in inaccessible orbit on CSS. Equivalent is a membrane made same as wall module. Fifty samples were collected from interior surfaces (work, sleeping, sanitary areas) Tianhe core module Wentian Mengtian experimental modules, covering three...

Recently, there has been a surge of interest in square-root higher-order topological insulators (HOTIs) due to their unique properties inherited from squared Hamiltonian. Different conventional HOTIs, HOTIs support paired corner states that exist different bandgaps. In this work, we experimentally establish series two-dimensional photonic decorated Su-Schrieffer-Heeger (SSH) lattices by using the femtosecond-laser writing technique and thereby directly observe states. Interestingly, such are...

The magnetic properties of a mixed spin-2 and spin-1/2 ferromagnetic diamond chain are studied by effective-field theory Monte Carlo (MC) simulation based on the Ising model. temperature dependences magnetization, susceptibility, internal energy, specific heat studied, respectively. exchange interaction magnetization critical calculated MC simulation. changes depending field increasing then decreasing under steady-static conditions also given.

Bound states in the continuum (BICs) are intriguing localized that possess eigenvalues embedded within of extended states. Recently, a combination topological band theory and BIC physics has given rise to novel form matter known as BICs. In this work, we experimentally demonstrate photonic subspace-induced By using femtosecond-laser writing, establish nontrivial three-leg ladder lattice, thereby directly observe propagation two kinds edge which exist at different boundaries. Interestingly,...

In recent years, topological insulators have been extensively studied in one-dimensional periodic systems, such as Su-Schrieffer-Heeger and trimer lattices. The remarkable feature of these models is that they support edge states, which are protected by lattice symmetry. To further study the role symmetry insulators, here we design a modified version conventional lattices, i.e., decorated Using femtosecond laser writing technique, experimentally establish series photonic lattices with without...

Abstract The size‐ and shape‐dependent localized surface plasmon properties of metallic nanoparticles (NPs) enable nanoscale‐enhanced near‐field applications in a wide range fields, including spectroscopy, nonlinear optics, sensing. Orderly assembled NPs can construct plasmonic metamaterials for light manipulation at subwavelength scale, exhibiting new collective resonant modes regulated by coupling between their fundamental components. Despite the recognition its significant advantages...

Abstract Second‐order topological bound states in the continuum (SOTBICs) have received widely attention photonics due to theirs counterintuitive localized properties. A model of square‐root SOTBICs is proposed that not only inherit features from its parent Hamiltonian, but also support multiple corner with different propagation constants, a unique feature found Hamiltonian. Using femtosecond laser‐writing technology, photonic nontrivial 2D edge‐centered SSH lattice fabricated and observe...

We report on the experimental observation of topological Anderson phase in one-dimensional quasi-periodical waveguide arrays produced by femtosecond laser writing. The evanescently coupled waveguides are with alternating coupling constants, constructing photonic lattices analogous to Su-Schrieffer-Heeger model. Dynamic tuning interdimer hopping amplitudes array generates quasi-periodic disorder constants for As light propagates corresponding waveguides, it exhibits different modes depending...

We report for the first time on optical waveguides in zinc oxide (ZnO) crystals fabricated by femtosecond laser direct writing. The confocal Raman microscopy under 488 nm excitation is used to investigate micro-modifications of irradiation, and guiding properties are studied via end-face coupling at 632.8 nm. mode modulation has been achieved adjustment writing parameters. A minimum propagation loss ∼6 dB/cm obtained double-line waveguide structures. Y-branch beam splitter also fabricated,...

In this paper, we reported on wafer-scale nanoporous (NP) AlGaN-based deep ultraviolet (DUV) distributed Bragg reflectors (DBRs) with 95% reflectivity at 280 nm, using epitaxial periodically stacked n-Al0.62Ga0.38N/u-Al0.62Ga0.38N structures grown AlN/sapphire templates via metal-organic chemical vapor deposition (MOCVD). The DBRs were fabricated by a simple one-step selective wet etching in heated KOH aqueous solution. To study the influence of temperature electrolyte nanopores formation,...

Quantum tunneling is considered the cornerstone of many physical processes. So far, its evolution over time, especially under an external field superimposed on periodic potential field, has not been directly observed experimentally due to harsh requirements and extremely short time scale. In this paper, we fabricate twisted photonic lattices consisting three-dimensional waveguide arrays illustrate optical process parabolic through route. Optical inhibition experimentally, reduced required...

A topological bound state in the continuum (TBIC) is a novel phase that has attracted significant attention. Different from conventional insulators (TIs), where boundary states reside within gaps, TBICs can support unconventional remain isolated surrounding bulk states. In this work, we experimentally demonstrate multiple photonic bilayer trimer lattices using femtosecond laser writing technology. By modulating interlayer coupling between two chains, observe emergence of distinct types...

Niobium oxide dichloride (NbOCl2), a van der Waals crystal, exhibits exceptional second-harmonic generation (SHG) with high conversion efficiency, making it promising candidate for on-chip quantum light sources, photon modulators, and sensors. To increase its suitability integrated photonic systems, is crucial to explore strategies further improving optical nonlinear efficiency. In this article, dielectric metasurfaces are employed enhance SHG from patterned NbOCl2 nanodisks. By precisely...

We demonstrate the first, to best of our knowledge, experimental observation higher-order topological corner states in photonic two-dimensional (2D) trimer lattices. Using a femtosecond laser direct writing technology, we experimentally fabricate series 2D lattices with different open boundary conditions and thereby observe two kinds 0D states, i.e., defect states. Interestingly, these can not only exist bandgap but also coexist bulk show obvious localization properties. This work provides...