Moiré metasurfaces with tunable near-infrared-I chiroptical responses for biomolecular chirality discrimination.

Manipulating circular dichroism in chiral metasurfaces has been increasingly important for a wide range of polarization-sensitive photonic applications. However, simple methods for presenting chiral nanostructures with tunable and considerable chiroptical responses in the near-infrared-I regime remains underexplored. Herein, two sheets of suspended symmetric bilayer metagratings fabricated single-step electron beam lithography are stacked into a moiré metasurface with its circular dichroism value reaching up to 20.

A MUSE source-blind survey for emission from the circumgalactic medium.

The recent detection of optical emission lines from the circumgalactic medium (CGM) in combined, large samples of low-redshift, normal galaxy spectra hints at the potential to map the cool (∼10 kelvin) CGM in individual, representative galaxies. Using archival data from a forefront instrument (MUSE) on the VLT, we present a source-blind, wide-redshift-range ( ∼ 0 to 5) narrowband imaging survey for CGM emission. Our detected, resolved emission line sources are cataloged and include a 30-kiloparsec-wide Hα source likely tracing the CGM of a low-mass galaxy (stellar mass ∼ 10 solar mass) at = 0.

High-performance electromagnetic wave absorption in FeS/SnS@multi-walled carbon nanotube composites with honeycomb-shaped structure.

In this work, we synthesized composites of ferrous disulfide and tin disulfide with multi-walled carbon nanotubes (MWCNTs) using a straightforward hydrothermal method. The incorporation of carbon nanotubes significantly enhanced the dielectric loss capability of the composites. When the filling ratio of FeS/SnS@CNTs (20 wt%) in paraffin was 40%, the effective absorption bandwidth was 3.

Germanene saturable absorber for mode-locked operation in an all-fiber laser with multiple dispersion environments.

In this paper, a high-quality germanene-polyvinyl alcohol (PVA) saturable absorber (SA) with a modulation depth of 3.05% and a saturation intensity of 17.95 / was prepared.

Optimization of the cavity length and pulse characterization based on germanene as a saturable absorber in an Er-doped fiber laser.

In this study, germanene-nanosheets (NSs) were synthesized by liquid-phase exfoliation, followed by an experimental investigation into the nonlinear saturable absorption characteristics and morphological structure of germanene. The germanene-NSs were employed as saturable absorbers, exhibiting saturation intensity and modulation depth values of 22.64 / and 4.

Evolution between bright and dark pulses in a MoxWTe based fiber laser.

We proposed an erbium-doped fiber laser mode-locked with a MoxWTe-based nonlinear optical modulator for the first time to our best knowledge. This fiber laser can deliver bright pulses, bright-dark pulse pairs, dark pulses, bright-dark-bright pulses, and dark-dark-bright pulses. The modulation depth and saturation intensity of the MoxWTe-based saturable absorber were about 7.

High-Energy Mode-Locked Pulse Er-Doped Fiber Laser-Based GeTe as Saturable Absorber.

High-energy Er-doped fiber laser with high conversion efficiency is reported, which is mode-locked by a germanium telluride (GeTe)-based saturable absorber (SA). By adjusting the direction of the polarization controller (PC), a high-energy pulse with a central wavelength of 1533.1 nm and a fundamental repetition frequency of 1.

Early and Sensitive Detection of Pathogens for Public Health and Biosafety: An Example of Surveillance and Genotyping of SARS-CoV-2 in Sewage Water by Cas12a-Facilitated Portable Plasmonic Biosensor.

Infectious diseases severely threaten public health and global biosafety. In addition to transmission through the air, pathogenic microorganisms have also been detected in environmental liquid samples, such as sewage water. Conventional biochemical detection methodologies are time-consuming and cost-ineffective, and their detection limits hinder early diagnosis.

Impact of the bromination of carbazole-based D-π-A organic dyes on their optical and electrochemical properties and visible-light-driven hydrogen evolution.

Brominated dyes, 2C- ( = 1-5), 3C-4 and 4C-4, were prepared through bromination of three carbazole-based D-π-A dyes, 2C, 3C and 4C with -bromosuccinimide (NBS). The detailed structures of the brominated dyes were confirmed by H NMR spectroscopy and mass spectrometry (MS). The introduction of the Br atom on the 1,8-positon of carbazole moieties led to blueshifted UV-vis and photoluminescence (PL) spectra, increased initial oxidation potentials and enlarged dihedral angles, indicating bromination enhanced non-planarity of the dye molecules.

Two types of ultrafast mode-locking operations from an Er-doped fiber laser based on germanene nanosheets.

As a member of Xenes family, germanene has excellent nonlinear saturable absorption characteristics. In this work, we prepared germanene nanosheets by liquid phase exfoliation and measured their saturation intensity as 0.6 GW/cm with a modulation depth of 8%.

Nanosized indium selenide saturable absorber for multiple solitons operation in Er-doped fiber laser.

With the advances in the field of ultrafast photonics occurring so fast, the demand for optical modulation devices with high performance and soliton lasers which can realize the evolution of multiple soliton pulses is gradually increasing. Nevertheless, saturable absorbers (SAs) with appropriate parameters and pulsed fiber lasers which can output abundant mode-locking states still need to be further explored. Due to the special band gap energy values of few-layer indium selenide (InSe) nanosheets, we have prepared a SA based on InSe on a microfiber by optical deposition.

Generation of bright-dark solitons in an Er-doped fiber laser employing InSb as a saturable absorber.

In this paper, an indium antimonide (InSb) saturable absorber (SA) was successfully fabricated. The saturable absorption properties of the InSb SA were studied, and they show a modulation depth and a saturable intensity of 5.17% and 9.

Dual-shearing interferometer for multi-modal hyperspectral imaging.

A dual-shearing interferometer (DSI) for multimodal hyperspectral imaging is presented. Two orthogonally stacked pairs of coherent beams are generated by a pair of novel, to the best of our knowledge, birefringent lateral shearing splitters. Consequently, two sets of interferograms with full pixel resolution are captured alternately in a time sequence in the double Nyquist frequency mode.

Low-Threshold, Multiple High-Order Harmonics Fiber Laser Employing CrSiTe Saturable Absorber.

Abundant research findings have proved the value of two-dimensional (2D) materials in the study of nonlinear optics in fiber lasers. However, there remains two problems: how to reduce the start-up threshold, and how to improve the damage threshold, of fiber lasers based on 2D materials. A 15.

Passively mode-locked fiber laser based on GeTe as a saturable absorber.

In this work, we fabricate a saturable absorber based on GeTe with saturation intensity and modulation depth of 12.6 / and 7%, respectively. We obtain stable conventional soliton and stretched soliton mode-locking operation.

Demonstration of conventional soliton, bound-state soliton, and noise-like pulse based on chromium sulfide as saturable absorber.

Ferromagnetic semiconductor chromium sulfide (CrS), as a member of transition metal chalcogenide (TMC), exhibits the narrow bandgap value of 0.45 eV theoretically and has been applied in photoelectric field. However, the application in ultrafast fiber laser of CrS has not been investigation at present.

Third-order harmonic mode-locked and Q-switched Er-doped fiber laser based on a CrGeTe saturable absorber.

This paper reports the generation of fundamental solitons and third-order solitons in an erbium-doped fiber laser (EDFL) by a -polyvinyl alcohol (CGT-PVA) saturable absorber (SA). Stable fundamental solitons at 1559.09 nm at a repetition frequency of 5.

Generation of bright-dark soliton pairs based on a ferromagnetic insulator CrSiTe as a modulator in an Er-doped fiber laser.

In this work, a saturable absorber (SA) based on (CST), with a modulation depth of 14.90% and saturation intensity of 4.81/, was prepared by a liquid phase stripping method.

XGboost Prediction Model Based on 3.0T Diffusion Kurtosis Imaging Improves the Diagnostic Accuracy of MRI BiRADS 4 Masses.

Background: The malignant probability of MRI BiRADS 4 breast lesions ranges from 2% to 95%, leading to unnecessary biopsies. The purpose of this study was to construct an optimal XGboost prediction model through a combination of DKI independently or jointly with other MR imaging features and clinical characterization, which was expected to reduce false positive rate of MRI BiRADS 4 masses and improve the diagnosis efficiency of breast cancer.

Methods: 120 patients with 158 breast lesions were enrolled.

Ultrafast photonics applications of emerging 2D-Xenes beyond graphene.

Driven by new two-dimensional materials, great changes and progress have taken place in the field of ultrafast photonics in recent years. Among them, the emerging single element two-dimensional materials (Xenes) have also received much attention due to their special physical and photoelectric properties including tunable broadband nonlinear saturable absorption, ultrafast carrier recovery rate, and ultrashort recovery time. In this review, the preparation methods of Xenes and various integration strategies are detailedly introduced at first.

Efficient Saturable Absorber Based on Ferromagnetic Insulator CrGeTe in Er-Doped Mode-Locked Fiber Laser.

A ferromagnetic insulator CrGeTe as a saturable absorber in an Er-doped fiber laser (EDFL) was demonstrated. In this work, a CGT-PVA composite film was successfully fabricated using the liquid-phase exfoliation method and employed in an EDFL. The modulation depth and saturation intensity of the SA are 4.