An imaging spectroscopic system that enables spatially-resolved detection of single-particle scattering with polarization-controlled waveguide excitation scheme is presented. The detected microscopic images of inhomogeneous nanostructures are recorded in a time sequence into a data cube based on a Michelson interferometer. The interferograms on selected pixels are Fourier-transformed into multiple spectra. The waveguide excitation scheme is presented for both transmission and reflection measurements while the dark-field excitation scheme is presented in transmission measurements for comparison. Gold nanoparticles, nanorods, and particles on film are utilized in the detection of polarization-dependent spectra. Measurement results are verified with the finite-difference time-domain (FDTD) simulations. The polarization-controlled coupling conditions in nanorods and particle-on-film systems are discussed with simulated field distributions around the nanostructures.
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http://dx.doi.org/10.1364/OE.446724 | DOI Listing |
Adv Mater
January 2025
Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials, College of Materials, Xiamen University, Xiamen, 361005, P. R. China.
Quantum dot (QD)-converted micrometer-scale light-emitting diodes (micro-LEDs) are regarded as an effective solution for achieving high-performance full-color micro-LED displays because of their narrow-band emission, simplified mass transfer, facile drive circuits, and low cost. However, these micro-LEDs suffer from significant blue light leakage and unsatisfactory electroluminescence properties due to the poor light conversion efficiency and stability of the QDs. Herein, the construction of green and red QD luminescence microspheres with the simultaneously high conversion efficiency of blue light and strong photoluminescence stability are proposed.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore; Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore 639798, Singapore. Electronic address:
Bound states in the continuum (BICs) are notable in photonics for their infinite Q factors. Perturbed BICs, or quasi-BICs (QBICs), have finite but ultra-high Q factors, enabling external coupling. So far, most studies have focused on the momentum-space properties of BICs and QBICs, with few discussions on their properties in real space.
View Article and Find Full Text PDFWe present both experimental and simulation results for a fully etched, C-band GC fabricated in an 800 nm silicon nitride platform that significantly reduces backreflections. They are minimized by truncating the initial grates, which deflect reflected light at an oblique angle and excite higher-order modes in the tapered waveguide that is filtered out. Insertion losses resulting from this modification of the grating coupler are mitigated by an adaptive redesign of the grates that corrects incurred errors in the generated phase front.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Electrical Engineering, Iran University of Science and Technology, Tehran, 16846-1314, Iran.
The holographic technique is one of the simplest methods for designing antennas based on metasurface. This paper presents a spoof surface plasmon polariton (SSPP) leaky-wave antenna (LWA) based on the concept of impedance modulated metasurfaces by the anisotropic holographic technique. Instead of parasitic elements, anisotropic SSPP elements are exploited to achieve radiation with circular polarization.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Centre-Energie Materiaux et Telecommunications, Institut National de la Recherche Scientifique, Montreal, QC H5A 1K6, Canada.
This paper presents a high-performance circularly polarized (CP) magneto-electric (ME) dipole antenna optimized for wideband millimeter-wave (mm-wave) frequencies, specifically targeting advancements in 5G and 6G technologies. The CP antenna is excited through a transverse slot in a printed ridge gap waveguide (PRGW), which operates in a quasi-transverse electromagnetic (Q-TEM) mode. Fabricated on Rogers RT 3003 substrate, selected for its low-loss and cost-effective properties at high frequencies, the design significantly enhances both impedance and axial ratio (AR) bandwidths.
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