Tunable Enhanced Second-Harmonic Generation in InP-InAsP Quantum Well Nanomembranes.

Second-harmonic generation (SHG) offers a convenient approach for infrared-to-visible light conversion in tunable nanoscale light sources and optical communication. Semiconductor nanostructures offer rich possibilities to tailor their nonlinear optical properties. In this study, strong second-harmonic generation in InP nanomembranes with InAsP quantum well (QW) is demonstrated.

Effects of haze pollution and institutional environment on demand for commercial health insurance.

What countermeasures should the public take as they become aware of the dangers of haze pollution? Insurance has the function of risk diversification, and little existing literature has focused on the relationship between haze pollution and commercial health insurance. This paper analyzes the impact of haze pollution on residents' demand for commercial health insurance and the heterogeneous impact of institutional environment using the 2017 China Household Finance Survey cross-sectional data (CHFS). The study finds that haze pollution raises residents' demand for commercial health insurance as their health risk perception level rises.

Nonlinear microscopy of lead iodide nanosheets.

Lead iodide (PbI) is a van der Waals layered semiconductor with a direct bandgap in its bulk form and a hexagonal layered crystalline structure. The recently developed PbI nanosheets have shown great promise for high-performance optoelectronic devices, including nanolasers and photodetectors. However, despite being widely used as a precursor for perovskite materials, the optical properties of PbI nanomaterials remain largely unexplored.

Green credit, environmental protection investment and debt financing for heavily polluting enterprises.

The paper takes listed companies in the heavily polluting industry from 2009-2017 as a research sample to explore whether heavy pollution enterprises' environmental protection investment helps their debt financing under the institutional background of China's continuous implementation of green credit policy. It is found that, in general, the environmental protection investment of heavy pollution enterprises helps them to obtain more and relatively long-term new loans; in terms of time, this effect is more evident after the release of China's Green Credit Guidelines in 2012; in addition, the level of regional environmental pollution, the level of financial development and the green fiscal policy also have a moderating effect on this. This paper enriches the study of the economic consequences of corporate environmental protection investment from the perspective of debt financing.

Tunable unidirectional nonlinear emission from transition-metal-dichalcogenide metasurfaces.

Nonlinear light sources are central to a myriad of applications, driving a quest for their miniaturisation down to the nanoscale. In this quest, nonlinear metasurfaces hold a great promise, as they enhance nonlinear effects through their resonant photonic environment and high refractive index, such as in high-index dielectric metasurfaces. However, despite the sub-diffractive operation of dielectric metasurfaces at the fundamental wave, this condition is not fulfilled for the nonlinearly generated harmonic waves, thereby all nonlinear metasurfaces to date emit multiple diffractive beams.

High-Efficiency Visible Light Manipulation Using Dielectric Metasurfaces.

The development of a miniaturised device that provides efficient beam manipulation with high transmittance is extremely desirable for the broad range of applications including holography, metalens, and imaging. Recently, the potential of dielectric metasurfaces has been unleashed to efficiently manipulate the beam with full 2π-phase control by overlapping the electric and magnetic dipole resonances. However, in the visible range for available materials, it comes with the price of higher absorption that reduces efficiency.