Deep learning facilitated superhigh-resolution recognition of structured light ellipticities.

Elliptical beams (EBs), an essential family of structured light, have been investigated theoretically due to their intriguing mathematical properties. However, their practical application has been significantly limited due to the inability to determine all their physical quantities, particularly the ellipticity factor, a unique parameter for EBs of different families. In this paper, to our knowledge, we proposed the first high-accuracy approach that can effectively distinguish EBs with an ellipticity factor difference of 0.

Bias-drift insensitive full-field frequency response characterization of a thin-film lithium niobate-based intensity modulator.

We propose a rapid and precise scheme for characterizing the full-field frequency response of a thin-film lithium niobate-based intensity modulator (TFLN-IM) via a specially designed multi-tone microwave signal. Our proposed scheme remains insensitive to the bias-drift of IM. Experimental verification is implemented with a self-packaged TFLN-IM with a 3 dB bandwidth of 30 GHz.

Insight into the solvent effects on ethanol oxidation on Ir(100).

Solvent effects have always been a non-negligible factor for aqueous catalytic reactions, though few studies have been devoted towards the molecular understanding and impact of solvent effects on catalysis. In this work, we investigated ethanol dehydrogenation and C-C bond cleavage over Ir(100) in an aqueous solution using density functional theory calculations with both the implicit and explicit solvent models and transition state theory-based kinetics simulations. The results show that solvent polarization assists the α- and β-dehydrogenation of ethanol on Ir(100) in the aqueous solution and hydrogen bonding also assists the ethanol β-dehydrogenation and C-C bond cleavage in CHCO.

Simultaneous Spatiotemporal Measurement of Structural Evolution in Dynamic Complex Media.

When the properties of soft materials evolve in time, the simultaneous measurement of different characteristics is critical. Here, we demonstrate an experimental system that permits monitoring both the spatial and temporal evolution of the optical and mechanical properties. An integrated fiber-optic-based system allows determining the mechanical vibrations of structural elements over 5 orders of magnitude and over a broad frequency range.

Insights and Activation Energy Surface of the Dehydrogenation of C H O Species in Ethanol Oxidation Reaction on Ir(100).

Dehydrogenation of an organic compound is the first and the most fundamental elementary reaction in many organic reactions. In ethanol oxidation reaction (EOR) to form CO , there are a total of 46 pathways in C H O (x=1-6) species leading to the removal of all six hydrogen atoms in five C-H bonds and one O-H bond. To investigate the degree of dehydrogenation in EOR under operando conditions, we performed density function theory (DFT) calculations to study 28 dehydrogenation steps of C H O on Ir(100).

Passive high-frequency microrheology of blood.

Indicative of various pathologies, blood properties are under intense scrutiny. The hemorheological characteristics are traditionally gauged by bulk, low-frequency indicators that average out critical information about the complex, multi-scale, and multi-component structure. In particular, one cannot discriminate between the erythrocytes contribution to global rheology and the impact of plasma.

Colloidal density control with Bessel-Gauss beams.

Optical manipulation of colloidal systems is of high interest for both fundamental studies and practical applications. It has been shown that optically induced thermophoresis and nonlinear interactions can significantly affect the properties of dense colloidal media. However, macroscopic scale phenomena can also be generated at thermal equilibrium.

Composites of Vanadium (III) Oxide (VO) Incorporating with Amorphous C as Pt-Free Counter Electrodes for Low-Cost and High-Performance Dye-Sensitized Solar Cells.

To replace precious Pt-based counter electrodes (CEs) with a low-cost Pt-free catalyst of CEs is still a motivating hotspot to decrease the fabrication cost of dye-sensitized solar cells (DSSCs). Herein, four different VO@C composite catalysts were synthesized by pyrolysis of a precursor under N flow at 1100 °C and further served as catalytic materials of CEs for the encapsulation of DSSCs. The precursors of VO@C composites have been prepared via a sol-gel method using different proportions of VO with soluble starch in a HO solution.

Impact of the degree of dehydrogenation in ethanol C-C bond cleavage on Ir(100).

A lack of comprehensive studies of the C-C bond cleavage in organic molecules hampers the rational design of catalysts for many applications, such as in fuel cells and steam reforming technologies. Employing ethanol on Ir(100) as an example, we studied 14 C-C bond cleavages of various species involved in the ethanol oxidation reaction using density functional theory calculations and used the degree of dehydrogenation (DoDH) of the reactant species as a variable to correlate the C-C bond cleavage barrier and reaction energy. This correlation method was also applied to the dehydrogenation reactions of ethanol on various catalysts, and great insight was obtained.

Nonstationary Intensity Statistics in Diffusive Waves.

It is a long-standing belief that, in the diffusion regime, the intensity statistics is always stationary and its probability distribution follows a negative exponential decay. Here, we demonstrate that, in fact, in reflection from strong disordered media, the intensity statistics changes through different stages of the diffusion. We present a statistical model that describes this nonstationary property and takes into account the evolving balance between recurrent scattering and near field coupling.

Tubulin Polarizability in Aqueous Suspensions.

We report accurate optical measurements of tubulin polarizability in aqueous suspensions. We determined the dependence of polarizability on tubulin concentration and on the suspension's pH, providing benchmark numbers for quantifying the optical response of this protein in various artificial and cellular environments. We compare our measurement data with a few estimates found in the previous literature and also with our simplified model estimations.

Marine-Biomass-Derived Porous Carbon Sheets with a Tunable N-Doping Content for Superior Sodium-Ion Storage.

Synthesis of the electrode materials of sodium-ion storage devices from sustainable precursors via green methods is highly desirable. In this work, we fabricated a unique N, O dual-doped biocarbon nanosheet with hierarchical porosity by direct pyrolysis of low-cost cuttlebones and simple air oxidation activation (AOA) technique. With prolonging AOA time, thickness of the carbon sheets could be reduced controllably (from 35 to 5 nm), which may lead to tunable preparation of carbon nanosheets with a certain thickness.

Designed Er(3+)-singly doped NaYF4 with double excitation bands for simultaneous deep macroscopic and microscopic upconverting bioimaging.

Simultaneous deep macroscopic imaging and microscopic imaging is in urgent demand, but is challenging to achieve experimentally due to the lack of proper fluorescent probes. Herein, we have designed and successfully synthesized simplex Er(3+)-doped upconversion nanoparticles (UCNPs) with double excitation bands for simultaneous deep macroscopic and microscopic imaging. The material structure and the excitation wavelength of Er(3+)-singly doped UCNPs were further optimized to enhance the upconversion emission efficiency.

Visible-to-visible four-photon ultrahigh resolution microscopic imaging with 730-nm diode laser excited nanocrystals.

Further development of multiphoton microscopic imaging is confronted with a number of limitations, including high-cost, high complexity and relatively low spatial resolution due to the long excitation wavelength. To overcome these problems, for the first time, we propose visible-to-visible four-photon ultrahigh resolution microscopic imaging by using a common cost-effective 730-nm laser diode to excite the prepared Nd(3+)-sensitized upconversion nanoparticles (Nd(3+)-UCNPs). An ordinary multiphoton scanning microscope system was built using a visible CW diode laser and the lateral imaging resolution as high as 161-nm was achieved via the four-photon upconversion process.

Optical depletion mechanism of upconverting luminescence and its potential for multi-photon STED-like microscopy.

Simulated emission depletion (STED) microscopy is very powerful, but still suffers from small tissue penetration depth, photobleaching of fluorescent probes and complicated imaging systems. Here, we propose an optical luminescence depletion mechanism employing upconverting nanoparticles (UCNPs) and explore its potential for multi-photon STED-like microscopy. With the addition of Yb³⁺ ions in NaYF₄:Er³⁺ UCNPs, the two-photon green emission of Er³⁺ under 795-nm excitation was successfully depleted by 1140-nm laser through the synergetic effect of the excited state absorption and the interionic energy transfer.

Deep, high contrast microscopic cell imaging using three-photon luminescence of β-(NaYF4:Er(3+)/NaYF4) nanoprobe excited by 1480-nm CW laser of only 1.5-mW.

It is challenging to achieve deep microscopic imaging for the strong scattering in biotissue. An efficient three-photon luminescence can effectively increase the penetration depth. Here we report that β-NaYF4: Er(3+)/NaYF4 UCNPs were excited by a 1480-nm CW-laser and emitted 543/653-nm light through a three-photon process.