Wafer-Scale Transfer and Integration of Tungsten-Doped Vanadium Dioxide Films.

Modern optoelectronic devices trend toward greater flexibility, wearability, and multifunctionality, demanding higher standards for fabrication and operation temperatures. Vanadium dioxide (VO), with its metal-insulator transition (MIT) at 68 °C, serves as a crucial functional layer in many optoelectronic devices. However, VO usually needs to grow at >450 °C in an oxygen-containing atmosphere and to function across its MIT temperature, leading to low compatibility with most optoelectronic devices, especially on flexible substrates.

Atomic spin precession electro-optic modulation detection based on guided mode resonant lithium niobate metasurfaces.

Low-frequency noise in detection systems significantly affects the performance of ultrasensitive and ultracompact spin-exchange relaxation-free atomic magnetometers. High frequency modulation detection helps effectively suppress the 1/ noise and enhance the signal-to-noise ratio, but conventional modulators are bulky and restrict the development of integrated atomic magnetometer modulation-detection systems. Resonant metasurface-based thin-film lithium-niobate (TFLN) active optics can modulate free-space light within a compact configuration.

Transient Exciton-Charge Interconversion in Single-Crystal Hybrid Perovskites.

Ultrafast oscillatory transient absorption (TA) dynamics are observed in single crystals of hybrid organic-inorganic perovskite (CHNH)PbX with X = I, Br, Cl. High-density photoinduced charges, low binding energy of the excitons, efficient generation and high mobility of charges, and long diffusion length of both excitons and charges led to transient interconversion between excitons and charges with high efficiency, which is responsible for the oscillatory TA dynamics at re-excitation by the probe pulses. The pump pulses initiated a quasi-equilibrium scheme of coexisting excitons and charges with high densities, the probe pulse triggered a perturbation through interconversion between these two kinds of excited "particles," which was overlapped on the intrinsic exciton relaxation dynamics, producing an oscillatory modulation with time delay.

Nonlinear Optical Properties from Engineered 2D Materials.

Two-dimensional (2D) materials with atomic thickness, tunable light-matter interaction, and significant nonlinear susceptibility are emerging as potential candidates for new-generation optoelectronic devices. In this review, we briefly cover the recent research development of typical nonlinear optic (NLO) processes including second harmonic generation (SHG), third harmonic generation (THG), as well as two-photon photoluminescence (2PPL) of 2D materials. Nonlinear light-matter interaction in atomically thin 2D materials is important for both fundamental research and future optoelectronic devices.

A self-supported ultrathin plasmonic film for ultrafast optical switching.

Self-supporting gold nanowire (AuNW) gratings with a thickness of about 200 nm are produced by solution-processing and flexible-transfer techniques. Such an ultrathin structure is applied as an ultrafast optical switch that enables low-threshold optical modulation with a high signal contrast and a high signal-to-noise ratio. Transient energy-band modification in gold under excitation by femtosecond laser pulses is the main responsible mechanism.

Releasable Water Charge-Trapping and Water-Resistant Photodetection using 1D Perovskitoid Hydrate Single Crystal.

Hydrates of hybrid organic-inorganic perovskites have been discovered with MAPbI and are proved to be unstable in atmosphere. However, the influence of water molecules on the performance of optoelectronic devices is still not fully understood. Here, using a dication, 2-(dimethylamino) ethylamine (DMEN ), a stable quasi-1D perovskitoid hydrate single crystal is designed and successfully synthesized, which is formulated as DMENPb I ·H O.

Secondary Exciplex by Electromer Mediated Charge Transfer for Multiband Electroluminescence.

Charge-transfer states have been observed extensively in heterojunctions of organic semiconductors, which are also referred to as exciplexes in polymer blends. Such mechanisms have been well understood in the conventional material systems. However, electromer states may be produced only in some polymeric molecules with folded chains.

Long noncoding RNA DARS-AS1 regulates TP53 ubiquitination and affects ovarian cancer progression by modulation miR-194-5p/RBX1 axis.

Background: Ovarian cancer is a malignant tumor with a poor prognosis, its underlying mechanism is still unclear.

Objective: In this study, long noncoding RNA DARS-AS1 was studied to identify its function in the development of ovarian cancer.

Methods: Perform functional experiments to detect the effects of DARS-AS1 on the proliferation, apoptosis, and migration of ovarian cancer cells A2780.

Exciton Self-Trapping Dynamics in 1D Perovskite Single Crystals: Effect of Quantum Tunnelling.

We present experimental and theoretical investigations of the photophysics in the one-dimensional (1D) hybrid organic-inorganic perovskite (HOIP) white-light emitter, [DMEDA]PbBr. It is found that the broadband-emission nature of the 1D perovskite is similar to the case of two-dimensional (2D) HOIP materials, exciton self-trapping (ST) is the dominant mechanism. By comprehensive spectroscopic investigations, we observed direct evidence of exciton crossing the energy barrier separating free and ST states through quantum tunnelling.

A spatially pinned surface plasmon through short-circuiting electronic oscillation in waveguide-sustained SPPs.

A spatially pinned surface plasmon is constructed by connecting a gold nanoshell grating with a planar gold nanofilm, forming a periodical array of gold nanoloops. Dramatic electric field modulation and high charge carrier density on the contact sites enable balanced plasmonic electron distribution over the spatially pinned nanostructures. Compared with its counterpart, spacer-supported double-layer surface plasmon polaritons (SPPs), the pinned structure not only changed the electronic oscillation channels but also short-circuited the propagating SPPs at the top and bottom interfaces.

Topological Phase Transition in the Non-Hermitian Coupled Resonator Array.

In a two-dimensional non-Hermitian topological photonic system, the physics of topological states is complicated, which brings great challenges for clarifying the topological phase transitions and achieving precise active control. Here, we prove the topological phase transition exists in a two-dimensional parity-time-symmetric coupled-resonator optical waveguide system. We reveal the inherent condition of the appearance of topological phase transition, which is described by the analytical algebraic relation of coupling strength and the quantity of gain-loss.

A bottom-up strategy toward a flexible vanadium dioxide/silicon nitride composite film with infrared sensing performance.

Vanadium dioxide (VO2) attracts great attention due to its well-known metal-to-insulator transition. However, traditional VO2 films grown on rigid substrates are inflexible, which limits their applications. In this work, we successfully prepared VO2/silicon nitride (VO2/SN) composite films by a simple template method.

Distributed feedback organic lasing in photonic crystals.

Considerable research efforts have been devoted to the investigation of distributed feedback (DFB) organic lasing in photonic crystals in recent decades. It is still a big challenge to realize DFB lasing in complex photonic crystals. This review discusses the recent progress on the DFB organic laser based on one-, two-, and three-dimensional photonic crystals.

Transient Electronic Depletion and Lattice Expansion Induced Ultrafast Bandedge Plasmons.

Strong optical excitation of plasmonic nanostructures may induce simultaneous interband and intraband electronic transitions. However, interaction mechanisms between interband, intraband, and plasmon-band processes have not been thoroughly understood. In particular, optical-heating-induced lattice expansion, which definitely leads to shift of the Fermi level, has not been taken into account in plasmonic studies.

Flexible Random Laser Using Silver Nanoflowers.

A random laser was achieved in a polymer membrane with silver nanoflowers on a flexible substrate. The strong confinement of the polymer waveguide and the localized field enhancement of silver nanoflowers were essential for the low-threshold random lasing action. The lasing wavelength can be tuned by bending the flexible substrate.

Structural colors: from natural to artificial systems.

Structural coloration has attracted great interest from scientists and engineers in recent years, owing to fascination with various brilliant examples displayed in nature as well as to promising applications of bio-inspired functional photonic structures and materials. Much research has been done to reveal and emulate the physical mechanisms that underlie the structural colors found in nature. In this article, we review the fundamental physics of many natural structural colors displayed by living organisms as well as their bio-inspired artificial counterparts, with emphasis on their connections, tunability strategies, and proposed applications, which aim to maximize the technological benefits one could derive from these photonic nanostructures.

Enhancing light absorption within the carrier transport length in quantum junction solar cells.

Colloidal quantum dot (CQD) solar cells have attracted tremendous attention because of their tunable absorption spectrum window and potentially low processing cost. Recently reported quantum junction solar cells represent a promising approach to building a rectifying photovoltaic device that employs CQD layers on each side of the p-n junction. However, the ultimate efficiency of CQD solar cells is still highly limited by their high trap state density in both p- and n-type CQDs.

Modeling photovoltaic performance in periodic patterned colloidal quantum dot solar cells.

Colloidal quantum dot (CQD) solar cells have attracted tremendous attention mostly due to their wide absorption spectrum window and potentially low processability cost. The ultimate efficiency of CQD solar cells is highly limited by their high trap state density. Here we show that the overall device power conversion efficiency could be improved by employing photonic structures that enhance both charge generation and collection efficiencies.

Dynamic Optical Gratings Accessed by Reversible Shape Memory.

Shape memory polymers (SMPs) have been shown to accurately replicate photonic structures that produce tunable optical responses, but in practice, these responses are limited by the irreversibility of conventional shape memory processes. Here, we report the intensity modulation of a diffraction grating utilizing two-way reversible shape changes. Reversible shifting of the grating height was accomplished through partial melting and recrystallization of semicrystalline poly(octylene adipate).

Anther development of maize (Zea mays) and longstamen rice (Oryza longistaminata) revealed by cryo-SEM, with foci on locular dehydration and pollen arrangement.

Key message: Pollen maturation in Poaceae. Another development has been extensively examined by various imaging tools, including transmission electron microscopy, scanning electron microscopy, and light microscopy, but none is capable of identifying liquid water. Cryo-scanning electron microscopy with high-pressure rapid freeze fixation is excellent in preserving structures at cellular level and differentiating gas- versus liquid-filled space, but rarely used in anther study.

[Analysis of human papillomavirus infection and typing in Shanxi province].

Objective: To investigate human papilloma virus (HPV) infection and typing in 7 640 cases of women in Shanxi province in order to provide theoretical basis for the prevention and treatment of the cervical cancer.

Methods: Totally, 7 640 cases of cervical cell specimens in Shanxi provincial tumor hospital, screening and physical examination from 2012 January to 2013 May and 23 HPV genotypes were analyzed by PCR and reverse dot blot gene chip technology.

Results: A total of 1 441 cases of patients with HPV infection were to be found in 7 640 cases of women with an average age of (42.

Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range.

Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm(2) order.

All-optical logic gates based on nanoscale plasmonic slot waveguides.

We report realizations of nanoscale integrated all-optical XNOR, XOR, NOT, and OR logic gates using plasmonic slot waveguides based on linear interference between surface plasmon polariton modes. The miniature device size with lateral dimensions smaller than 5 μm, precisely controlled optical phase difference, and quasi-monochromatic surface plasmon polariton modes excited by a continuous wave 830 nm laser beam ensure a high intensity contrast ratio of 24 dB between the output logic states "1" and "0". Compared with previous reported results, the intensity contrast ratio is enhanced 4-fold, whereas the lateral dimension is reduced 4-fold.