We address the long-standing unresolved problem concerning the V parameter in a photonic crystal fiber. In formulating the parameter appropriate for a core defect in a periodic structure, we argue that the multimode cutoff occurs at a wavelength lambda* that satisfies VPCF(lambda*) = pi. By comparing this approach with numerics and recent cutoff calculations we confirm this result.
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http://dx.doi.org/10.1364/ol.28.001879 | DOI Listing |
Eur Radiol Exp
January 2025
Department of Neuroradiology, University hospital RWTH Aachen, Aachen, Germany.
Background: To define optimal parameters for the evaluation of vessel visibility in intracranial stents (ICS) and flow diverters (FD) using photon-counting detector computed tomography angiography (PCD-CTA) with spectral reconstructions.
Methods: We retrospectively analyzed consecutive patients with implanted ICS or FD, who received a PCD-CTA between April 2023 and March 2024. Polyenergetic, virtual monoenergetic, pure lumen, and iodine reconstructions with different keV levels (40, 60, and 80) and reconstruction kernels (body vascular [Bv]48, Bv56, Bv64, Bv72, and Bv76) were evaluated by two radiologists with regions of interests and Likert scales.
Phys Rev Lett
December 2024
University of Michigan, Department of Physics, Ann Arbor, Michigan 48109, USA.
Anisotropy is a fundamental property of both material and photonic systems. The interplay between material and photonic anisotropies, however, has hardly been explored due to the vastly different length scales. Here we demonstrate exciton polaritons in a 2D antiferromagnet, CrSBr, coupled with an anisotropic photonic crystal cavity, where the spin, atomic, and photonic anisotropies are strongly correlated.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Wyant College of Optical Sciences, University of Arizona, 1630 E University Blvd, Tucson, AZ, USA.
Nanophotonic devices control and manipulate light at the nanometer scale. Applications include biological imaging, integrated photonic circuits, and metamaterials. The design of these devices requires the accurate modeling of light-matter interactions at the nanoscale and the optimization of multiple design parameters, both of which can be computationally demanding and time intensive.
View Article and Find Full Text PDFJ Biophotonics
January 2025
Research and Development Center of Biomedical Photonics, Orel State University, Orel, Russia.
The work is devoted to the study of the physiological variability of the microcirculatory-tissue system (MTS) parameters under normal conditions and during functional tests. The results were obtained in vivo using multimodal wearable analyzers implementing methods of laser Doppler flowmetry and fluorescence spectroscopy. Comprehensive data analysis and calculation of the coefficients of variation of the MTS parameters of the human body for various topographic and anatomical areas of the skin were carried out.
View Article and Find Full Text PDFThe mid-wave multispectral detector combines the traditional spectrometer and infrared detector technologies to provide image information and spectral information at the same time, which has an important role in both civil and military fields. To solve the working band limitation and low energy utilization, this paper presents an integrated superlattice mid-wave multispectral hypersurface detector that can be used for computational multispectroscopy for the first time, which consists of photonic crystal (PC) plates of GaSb material, and uses PC microstructures to modulate the incident spectra, which can be used to reconstruct incident signals with computational multispectroscopy methods. In this paper, the finite difference time domain method (FDTD) is used to simulate the structural parameters of different PCs, and finally calculate the correlation coefficients of the transmission spectra of the different structures as well as the energy utilization rate.
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