Metalenses, featuring ultra-compactness and CMOS compatibility, are limited by the compromise between the diameter, numerical aperture, and working waveband. To address this problem, we propose and ...numerically demonstrate a centimeter-scale metasurface-refractive hybrid metalens working in the band of 440 - 700 nm. Revisiting the general Snell law, we present the phase profile of a chromatic aberration correction metasurface that can apply to a plano-convex refractive lens of an arbitrary surface type. Simulated by our semi-vector method, the designed achromatic hybrid metalens achieves 81% chromatic aberration suppression and polarization insensitivity. Broadband imaging results of the hybrid metalens are further provided, verifying the achromatism of the designed hybrid metalens. It can find applications in camera lenses and other optical systems that need compact, high-performance lenses.
Multiplexed planar printings, made of single or few layer micro and nano optical platforms, are essential for high capacity display, information storage and encryption. Although having been developed ...rapidly, the demonstrated channels are still limited and also lack instantaneity. Here, holograms and printings, always regarded as two independent information coding domains with totally different principles, are combined together through our proposed angle multiplexing framework, leading to multiplexed printings with hundreds of channels. Based on such approach, we experimentally encode respectively 25 gray scale printings into 25 angles and even 8 gray scale videos into 8 angles with a phase-only spatial light modulator. As a bridge between printings and holograms, our method allows to generate printings combining various holographic methods. Beneficial from this, we demonstrate a gradient metasurface based 324 channel printing which multiplexes angles, polarizations and wavelengths simultaneously. Our work paves the way to flexibly angle-dependent printing display and massively multiplexed encryption systems.
Zoom metalens doublet exhibits unprecedented advantages over the traditional zoom lens in many aspects, like ultra-compactness, CMOS compatibility, and miniaturization. However, most of them can only ...work in a narrow band due to chromatic aberration. Here, we numerically demonstrate a broadband achromatic zoom metalens doublet inspired by the Moiré lens principle. This design is achieved by globally optimizing the multi-wavelength phase profiles of the metalens doublet in the visible. The doublet can achieve achromatic continuous 1-10 zoom range at wavelengths of 440 nm, 540 nm, and 640 nm, featuring high focusing efficiency up to 86.5% and polarization insensitivity.
A phase-slip flux qubit, exactly dual to a charge qubit, is composed of a superconducting loop interrupted by a phase-slip junction. We propose a tunable phase-slip flux qubit by replacing the ...phase-slip junction with a charge-related superconducting quantum interference device （SQUID） consisting of two phase-slip junctions connected in series with a superconducting island. This charge-SQUID acts as an effective phase-slip junction controlled by the applied gate voltage and can be used to tune the energy-level splitting of the qubit. In addition, we show that a large inductance inserted in the loop can reduce the inductance energy and consequently suppress the dominating flux noise of the phase-slip flux qubit. This enhanced phase-slip flux qubit is exactly dual to a transmon qubit.
Metasurface-based lenses (metalenses) offer specific conceptual advantages compared to ordinary refractive lenses. For example, it is possible to tune the focal length of a metalens doublet by ...varying the relative angle between the two metalenses while fixing their distance, leading to an extremely compact zoom lens. An improved polarization-insensitive design based on silicon-nanocylinders on silica substrates is presented. This design is realized and characterized experimentally at 1550 nm wavelength. By varying the relative angle between the metalenses in steps of 10 degrees, tuning of the doublet focal length is demonstrated from -54 mm to -+3 mm to +54 mm. This results in a zoom factor of an imaging system varying between 1 and 18. For positive focal lengths, the doublet focusing efficiency has a minimum of 34% and a maximum of 83%. Experiment and theory are in very good agreement.
To determine the morphologic and physiochemical properties of bovine jugular conduit with valves stabilized by dye-mediated photo-oxidation.
Twenty-four bovine jugular conduits with valves were ...divided into 3 groups and treated with dye-mediated photo-oxidation (Group I), glutaraldehyde (Group II) and untreated group (Group II), respectively. Morphologic and physiochemical properties of the 3 groups, including wall thickness, diameter, tissue water content, heat shrinking temperature, breaching strength, and tissue protein extraction assay were studied.
There was no difference in wall thickness, diameter, tissue water content, and heat shrinking temperature between Group I and II ,but there was significant difference between Group I and II. The breaching strength of Group I was higher than that of Group IU (P < 0.05), but lower than that of Group II (P < 0. 05). A decrease in extractable tissue protein was found in Group I and II.
The dye-mediated photooxidation can effectively preserve the structure and the
Background： In vivo quantification of choroidal neovascularization （CNV） based on noninvasive optical coherence tomography （OCT） examination and in vitro choroidal flatmount immunohistochemistry ...stained of CNV currently were used to evaluate the process and severity of age-related macular degeneration （AMD） both in human and animal studies. This study aimed to investigate the correlation between these two methods in murine CNV models induced by subretinal injection. Methods： CNV was developed in 20 C57BL6/j mice by subretinal injection of adeno-associated viral delivery of a short hairpin RNA targeting sFLT-1 （AAV.shRNA.sFLT- 1）, as reported previously. After 4 weeks, CNV was imaged by OCT and fluorescence angiography. The scaling factors for each dimension, x, y, and z （ktm/pixel） were recorded, and the corneal curvature standard was adjusted from human （7.7） to mice （1 .4）. The volume of each OCT image stack was calculated and then normalized by multiplying the number of voxels by the scaling factors for each dimension in Seg3D software （University of Utah Scientific Computing and Imaging Institute, available at http：//www.sci.utah.edu/cibc-software/seg3d.html）. Eighteen mice were prepared for choroidal flatmounts and stained by CD31. The CNV volumes were calculated using scanning laser confocal microscopy after immunohistochemistry staining. Two mice were stained by Hematoxylin and Eosin for observing the CNV morphology. Results： The CNV volume calculated using OCT was, on average, 2.6 times larger than the volume calculated using the laser confocal microscopy. The correlation statistical analysis showed OCT measuring of CNV correlated significantly with the in vitro method （R： = 0.448, P = 0.001, n = 18）. The correlation coefficient for CNV quantification using OCT and confocal microscopy was 0.693 （n = 18, P = 0.001 ）. Conclusions： There is a fair linear correlation on CNV volumes between in vivo and in vitro methods in CNV models induced by subretinal injection. The result might provide a useful evaluation of CNV both for the studies using CNV models induced by subretinal injection and human AMD studies.
Carboxymethyl cellulose sodium （CMC）/multi-walled carbon nanotube （MWCNT） composite was prepared by dissolving CMC with ionic liquid as solvent. The microstructure and electrochemical properties of ...CMC/MWCNTs were studied using field emis- sion scanning electron microscopy （FE-SEM）, high-resolution transmission electron microscopy （HR-TEM）, X-ray diffraction （XRD） system and electrochemical workstation. The experimental results indicated that the CMC dissolved with ionic liquid could be uniformly enwrapped on the surface of MWCNTs, and the coating thickness of CMC was about 5.4 nm. There are obvi- ous oxidation peaks in the cyclic voltammograms curves of glassy carbon electrode coated with a CMC/MWCNT composite in H2O2 phosphate buffer solution. The MWCNT content and ultrasonic time strongly affected the dispersivity and electrochemical property of CMC/MWCNT composite. While the MWCNT content and ultrasonic processing time was 2 wt% and 2 h respectively, CMC/MWCNT composite exhibited excellent electrocatalytic activity.
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The abundance of low-temperature waste heat produced by industry and automobile exhaust necessitates the development of power generation with thermoelectric (TE) materials. Commercially available ...bismuth telluride-based alloys are generally used near room temperature. Materials that are composed of p-type bismuth telluride, which are suitable for low-temperature power generation (near 380 K), were successfully obtained through Sb-alloying, which suppresses detrimental intrinsic conduction at elevated temperatures by increasing hole concentrations and material band gaps. Furthermore, hot deformation (HD)-induced multi-scale microstructures were successfully realized in the high-performance p-type TE materials. Enhanced textures and donor-like effects all contributed to improved electrical transport properties. Multiple phonon scattering centers, including local nanostructures induced by dynamic recrystallization and high-density lattice defects, significantly reduced the lattice thermal conductivity. These combined effects resulted in observable improvement of ZT over the entire temperature range, with all TE parameters measured along the in-plane direction. The maximum ZT of 1.3 for the hot-deformed Bi0.3 Sb1.7 Te3 alloy was reached at 380 K, whereas the average ZTav of 1.18 was found in the range of 300-480 K, indicating potential for application in low-temperature TE power generation.
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