Search

A new, to the best of our knowledge, family of partially coherent beams incorporating a set of nonseparable phases is introduced. Due to the nonnegative definiteness of the cross-spectral density function, these phases cannot survive in the limit of full coherence, which distinguishes them from conventional phase terms. An example of a nonuniform model beam with a quartic nonseparable phase is presented. It is shown that the presence of such a phase in effect stretches the beam in a specific direction upon propagation. In particular, the interplay between the magnitude and phase of the source coherence state endows the beam with a wing-like structure. The fundamental concept developed here brings into evidence the countless nonseparable phases differing from twist, and can be exploited to generate customized partially coherent beams for applications in optics.

We describe MGARD, a software providing MultiGrid Adaptive Reduction for floating-point scientific data on structured and unstructured grids. With exceptional data compression capability and precise error control, MGARD addresses a wide range of requirements, including storage reduction, high-performance I/O, and in-situ data analysis. It features a unified application programming interface (API) that seamlessly operates across diverse computing architectures. MGARD has been optimized with highly-tuned GPU kernels and efficient memory and device management mechanisms, ensuring scalable and rapid operations.

Optical twists are the rotation of light structures along the beam axis, which can be caused by the quadratic twist phase of a partially coherent field. Here, we introduce a new class of partially coherent beams whose spectral density and degree of coherence tend to rotate during propagation. Unlike the previously reported twisted Gaussian Schell-model beams, this family of rotating beams is constructed without the framework of rotationally invariant cross-spectral density functions. Thus, these beams have different underlying physics and exhibit distinctive twist effects. It is shown that such beams can undergo a twist of more than 90 deg, providing larger degrees of freedom for flexibly tailoring the beam twist. Our results may pave the way toward synthesizing rotating beams for applications in optics and, in particular, inspire further studies in the field of twist phase proposed 25 years ago.

The physical properties of light fields at the subwavelength scale have emerged as extensively pursued objectives in nano-optics, photonics, and plasmonics. Here, we report that in the paraxial regime, the spectral density and the spectral axial coherence (z-coherence) structures in a submicron range can be generated by employing a light beam with a suitably chosen spatial coherence state in a counter-propagating configuration, in an open-end cavity. It is established that while the spectral density forms an optical standing wave, the z-coherence state depends on the symmetry of the selected point pair and in particular, the phenomenon termed as periodical coherence switch is found. Our findings shed new light on the discussion of the role of spatial coherence in the photonic cavities, possibly inspiring further studies in the field of enhanced light-nanomaterials interactions by optical cavity. This provides a versatile framework for tailoring coherence in subwavelength space with promising applications in metrology and imaging.

We introduce, to the best of our knowledge, a new class of twisted partially coherent sources for producing rotating Gaussian array profiles. The general analytical formula for the cross-spectral density function of a beam generated by such a novel source propagating in free space is derived, and its propagation characteristics are analyzed. It is shown that both the irradiance profile of each element of the array and the degree of coherence rotate during propagation, but in opposite directions. Further, the twist effects of the spectral density and the degree of coherence are quantified. It is shown that the direction of rotation is changeable upon propagation. Our results may provide new insight into the twist phase and may be applied in optical trapping.

LaNbON2has narrow bandgap and wide visible-light absorption band, yet no photocatalytic water oxidation on LaNbON2has been reported. By a post-annealing treatment in Ar, anion vacancies were brought into LaNbON2as shown by EPR spectroscopy. These could act as donors in the semiconductor. And consequently the oxidative power of holes was enhanced as indicated by the difference between fermi level and valence band maximum (EF-EVBM) evaluated from valence band XPS. The annealed LaNbON2photocatalyst acquired water oxidation ability for the first time, which was improved by combining CoOxas cocatalyst. Annealed LaNbON2derived from La3NbO7had smaller particle size, higher concentration of anion vacancies, bigger EF-EVBMand better performance for photocatalytic oxygen evolution reaction than LaNbON2derived from LaNbO4.

•The composite material was synthesized by high-energy ball milling method.•The exchange–coupling interaction led to outstanding magnetic properties.•The adsorption mechanism might be reactions of ion exchange or complexation.•Heavy metal was removed by adsorption-magnetic separation processing.

We present ADIOS 2, the latest version of the Adaptable Input Output (I/O) System. ADIOS 2 addresses scientific data management needs ranging from scalable I/O in supercomputers, to data analysis in personal computer and cloud systems. Version 2 introduces a unified application programming interface (API) that enables seamless data movement through files, wide-area-networks, and direct memory access, as well as high-level APIs for data analysis. The internal architecture provides a set of reusable and extendable components for managing data presentation and transport mechanisms for new applications. ADIOS 2 bindings are available in C++11, C, Fortran, Python, and Matlab and are currently used across different scientific communities. ADIOS 2 provides a communal framework to tackle data management challenges as we approach the exascale era of supercomputing.