Metasurface, as an innovative 2D material, is promoting the technological development of optical control through its extraordinary capacity to precisely ma

Metasurface, as an innovative 2D material, is promoting the technological development of optical control through its extraordinary capacity to precisely manipulate electromagnetic wavefront. We introduce a bilayer metasurface utilizing vanadium dioxide (VO2), which has the characteristic of a reversible insulator-to-metal transition. This metasurface utilizes the mutual interference of a diatomic structure to induce phase delay, enabling the transformation of an arbitrary polarized wave into a specified polarization. Leveraging propagation and geometric phases, it is designed to generate anomalously reflected vortex beams. Furthermore, by controlling the temperature, this approach enables selective switching of incident polarization between linear and circular states, as well as independent control over vortex beams. Specifically, when the temperature exceeds 68°C, the electromagnetic wave is modulated by VO2 patches. Utilizing the propagation phase, the y-polarized reflection port produces a vortex beam carrying topological charge (TC) l = 1, exhibiting an anomalous reflection at 30 deg. As the temperature is below 68°C, the gold patch array modulates the incident wave. Leveraging the geometric phase, the metasurface generates an anomalous vortex beam possessing TC l = - 2 and anomalous reflection at -30 deg in the right-handed circularly polarized reflection channel. This innovative metasurface opens up possibilities for reconfigurable optical devices and dynamic vortex control, holding great promise for applications in optical communication and information processing.show less

With the advancement of high-intensity laser (HIL) technology, laser-induced plasma can produce short-lived nuclear isomers, which hold significant researc

With the advancement of high-intensity laser (HIL) technology, laser-induced plasma can produce short-lived nuclear isomers, which hold significant research value in fields such as nuclear-excitation mechanisms, nuclear clocks and radioactive medicine. However, due to intense electromagnetic pulses (EMPs) and X-rays, the detection of the short-lived isomers is still challenging today. To address this, an optical-fiber-coupled scintillator detection method is proposed in this study. The method can overcome the dilemma that traditional real-time detection methods face when struggling with the complex electromagnetic and radiation environment generated by HIL experiments, enabling real-time detection of characteristic signals on the nanosecond time scale during experiments. Employing a PW-level femtosecond laser-pumping ${}^{83}$ Kr to the $7/2+$ metastable state, which has a half-life of 156.94 ns, the de-excitation gamma-rays were detected successfully by the proposed detection system for the first time. This method addresses critical challenges in EMP-dominated HIL environments, enables investigations of ultra-fast nuclear processes and further advances experiments related to high-repetition-rate intense lasers.show less

Harnessing defect emission in CdS quantum dots (QDs) for efficient near-infrared (NIR) emission remains difficult. We report a synergistic strategy combini

Harnessing defect emission in CdS quantum dots (QDs) for efficient near-infrared (NIR) emission remains difficult. We report a synergistic strategy combining crystal-phase and defect engineering. High-concentration synthesis stabilizes the metastable wurtzite phase. A sulfur-rich stoichiometry (Cd:S=1:1.25) increases the concentration of sulfur vacancies (V_S), which is electron paramagnetic resonance (EPR)-confirmed and enables broadband NIR emission at 740 nm. Trace Zn2+ incorporation, confirmed as surface-adsorbed, further enhances monodispersity and passivates non-radiative traps, boosting emission intensity. A prototype light-emitting diode (LED) integrated with the Zn2+-modified CdS QDs exhibits broad emission (580–1100 nm), demonstrating dual functionality for visible lighting and NIR night vision.show less

Overcoming the optical memory effect range to achieve large field-of-view imaging through scattering media without prior information has remained a signifi

Overcoming the optical memory effect range to achieve large field-of-view imaging through scattering media without prior information has remained a significant challenge. We present a single-shot large field-of-view imaging technique based on the spatial sparsity characteristics theory of speckle pattern, enabling blind reconstruction of multiple targets beyond the optical memory effect range without prior information or wavefront modulation. The theoretical innovation lies in revealing the spatially sparse distribution of speckles when multiple isolated targets exceed the optical memory effect separation distance. By establishing a sparse mapping relationship between scattering transmission and object space, the method achieves unsupervised decoupling of low-cross-talk speckle regions while simultaneously reconstructing target intensity and positional information. Combined with the modified phase retrieval algorithm, the complete scene of multiple targets beyond the optical memory effect range is reconstructed. Experiments show that under varying scattering media and spectral bandwidths, this approach achieves a field-of-view expansion exceeding 6.82 times that of conventional methods, with a relative localization accuracy of 97.5%. We present the first introduction of spatial sparsity concepts into speckle field analysis; it establishes a new theoretical framework for deep-tissue biological observation and optical sensing in complex environments.show less