98%
921
2 minutes
20
We theoretically propose a high-efficiency tunable metalens based on an ellipse-shaped perforated graphene metasurface. By optimizing the axial length ratio of the elliptical aperture, we find the elliptical aperture with high reflectivity over a broad band by means of observing the reflectivity at different frequencies. Then, varying the orientation of the elliptical aperture from 0° to 180°, the reflected wave can generate a continuous 2 range phase shift while keeping its amplitude high, which is necessary to achieve focusing. The metalens exhibits extraordinary tunability of focal length via uniformly changing the Fermi energy of graphene. The focus can be shifted above 72 µm with focusing efficiency reaching over 70%. In addition, the tunable metalens is also capable of broadband focusing modulation and plane focusing. The presented metalens exhibits outstanding focusing efficiency in dynamic focusing, thereby manifesting great practicability in dynamic imaging and robust stable imaging.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.427381 | DOI Listing |
Opt Express
February 2025
We characterize a large-aperture gas-cooled Faraday rotator (FR) designed to mitigate stress-induced depolarization in high-energy, high-power laser systems. The rotator, based on ceramic TGG, was tested using a 150 mW probe beam at 1047 nm and a pump beam at 1070 nm. Compensating for the birefringence induced by the surrogate depolarization plate at 3.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2025
Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Xylene isomer separation is a long-standing challenge due to the nearly identical properties of para-xylene (PX), meta-xylene (MX), ortho-xylene (OX), and ethylbenzene (EB). Here, we report a rationally designed pillar-layered metal-organic framework (MOF), Ni-HDB, incorporating a cylindrical 1,4-diazabicyclo[2.2.
View Article and Find Full Text PDFMalays Orthop J
March 2025
Department of Orthopaedics and Traumatology, Ankara Acibadem Hospital, Ankara, Turkey.
Introduction: Anterior cruciate ligament (ACL) reconstruction is a commonly performed surgical procedure. The objectives of this retrospective comparative study are (1) to evaluate the obliquity, size and the intra-articular aperture shape of the tibial tunnel in patients operated with an anteromedial portal technique, and (2) to determine their possible relation with revision surgery.
Material And Methods: Patients operated for a primary ACL reconstruction between 2014 and 2018 were eligible.
Phys Rev Lett
March 2025
Institut Fresnel, Aix Marseille Univ, CNRS, Centrale Med, UMR 7249, 13397 Marseille Cedex 20, France.
We present 4D topological textures in (quasi)monochromatic nonparaxial optical lattices that contain all possible polarization ellipses with every combination of ellipticity and orientation in 3D space. These fields span the nonparaxial polarization space (a complex projective plane) and a 4-sphere within specific spatiotemporal regions, forming 4D skyrmionic structures. Constructed from five plane waves with adiabatically varying relative amplitudes, they are experimentally realizable in free space by focusing a temporally variant beam with a high numerical aperture lens.
View Article and Find Full Text PDFRev Sci Instrum
March 2025
Second Target Station, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Pioneer, a next-generation single-crystal neutron diffractometer, is under development for Oak Ridge National Laboratory's Second Target Station. Designed to address a wide range of scientific questions, Pioneer will deliver homogeneous neutron beams with customizable size and divergence and provide a polarized beam option. This article introduces its incident beam optics, highlighting the optimization methodology and the simulated performance.
View Article and Find Full Text PDF