Optimizing Lasing Performance of CsPbBr Microplates by Regulating Exciton Recombination Dynamics with Pressure.

This study aims to achieve an ultralow lasing threshold in CsPbBr microplates (MPs), a crucial step toward developing electrically driven micro/nanolasers for optics integrated chips. We investigate the lasing behavior of CsPbBr MPs under varying pressures by using static-state photoluminescence (PL), time-resolved PL (TRPL), and first-principles theory calculations based on density functional theory (DFT). Our results reveal that the lasing threshold initially decreases and then increases, with a critical turning point at 0.

Fabrication of Helical Carbon Fiber Skeleton Using Arc Glow Discharge Method.

An arc glow discharge device was used to prepare a helical carbon fiber skeleton with helical carbon fibers hooked to each other by spraying a hydrogen and ethanol mixture onto the iron wire substrate through the discharge area, using anhydrous ethanol as the carbon source. The samples were characterized by SEM, EDS, Raman and XPS. A growth mechanism of helical carbon fiber driven by C sp3 was proposed.

The Dissociation of Exciton During the Lasing of a Single CsPbBr Microplate.

In this work, the lasing of a single CsPbBr microplate (MP) fabricated with chemical vapor deposition (CVD) is investigated from the viewpoint of exciton dissociation characterized with steady-state photoluminescence (PL) and time-resolved photoluminescence (TRPL). It is confirmed that the lasing performance is disturbed by the dissociation of excitons. The increase of lasing threshold with temperature originates from the dissociation of free excitons (FEs) to localized carriers (LCs), and the lasing failure is mostly ascribed to the dissociation of FEs to free carriers (FCs).

Dynamic Selective Network for RGB-D Salient Object Detection.

RGB-D saliency detection is receiving more and more attention in recent years. There are many efforts have been devoted to this area, where most of them try to integrate the multi-modal information, i.e.

Scene Segmentation With Dual Relation-Aware Attention Network.

In this article, we propose a Dual Relation-aware Attention Network (DRANet) to handle the task of scene segmentation. How to efficiently exploit context is essential for pixel-level recognition. To address the issue, we adaptively capture contextual information based on the relation-aware attention mechanism.

Ultraviolet nanolaser of inverted hexagonal ZnO pyramid resonating in helical whispering-gallery-like mode.

ZnO nanocavities have advantage to working as optoelectrical nanodevices integrated on chip at high temperature owing to high exciton binding energy. In this work, a single inverted hexagonal ZnO pyramid (HZOP) nanolaser is fabricated successfully by reducing the defect with chemical vapor deposition (CVD). The optical leakage of HZOP is conquered by the inverted configuration to increase the refractive index contrast between ZnO pyramid and surrounding media.

Temperature-Dependent Lasing of CsPbI Triangular Pyramid.

In this work, the lasing performance of a microsized single-crystal CsPbI triangular pyramid (MSCTP) is evaluated by measuring the lasing threshold at low temperature. The MSCTPs of well-defined facets are synthesized on a Si/SiO substrate with chemical vapor deposition. The MSCTP shows a spontaneous emission around 719 nm at room temperature and a stimulated emission resonant in a single Fabry-Perot mode within 148-223 K.

Lasing-Mode Switch of a Hexagonal ZnO Pyramid Driven by Pressure within a Diamond Anvil Cell.

Nanolasers are expected to be integrated on chips as miniaturized coherent light sources, and their application is strongly dependent on their lasing behavior. In this work, the lasing behavior of a single hexagonal ZnO pyramid (HZOP) is tailored by tuning the electronic bandgap with pressure. The lasing of the HZOP nanolaser is dominated by a helical whispering-gallery-like mode, and the lasing threshold varies little with increasing pressure.

Hiding a realistic object using a broadband terahertz invisibility cloak.

The invisibility cloak has been a long-standing dream for many researchers over the decades. Using transformation optics, a three-dimensional (3D) object is perceived as having a reduced number of dimensions, making it "undetectable" judging from the scattered field12345. Despite successful experimental demonstration at microwave and optical frequencies6789101112, the spectroscopically important Terahertz (THz) domain13141516 remains unexplored due to difficulties in fabricating cloaking devices that are optically large in all three dimensions.

Role of interference between localized and propagating surface waves on the extraordinary optical transmission through a subwavelength-aperture array.

We report in this Letter that when radiation is incident on a metal surface perforated with an array of ring-shaped subwavelength apertures, the phase difference between the propagating surface Bloch wave and the localized surface wave can be tailored by the geometrical parameters of the array so as to affect the shape of the transmission spectrum. Above the resonant frequency of the aperture, interference between the two kinds of surface waves leads to a minimum in the transmission spectrum, whereas below it, the interference leads to a maximum. We suggest that this feature provides flexibility in engineering surface-wave-based all-optical devices.