Metallic thermal emitters consisting of two layers of differently structured nickel gratings on a homogeneous nickel layer are fabricated by soft lithography and studied for polarized thermal radiation. A thermal emitter in combination with a sub-wavelength grating shows a high extinction ratio, with a maximum value close to 5, in a wide mid-infrared range from 3.2 to 7.8 mum, as well as high emissivity up to 0.65 at a wavelength of 3.7 microm. All measurements show good agreement with theoretical predictions. Numerical simulations reveal that a high electric field exists within the localized air space surrounded by the gratings and the intensified electric-field is only observed for the polarizations perpendicular to the top sub-wavelength grating. This result suggests how the emissivity of a metal can be selectively enhanced at a certain range of wavelengths for a given polarization.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/oe.16.008742 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Metallic gratings can be used as infrared filters, but their performance is often limited by bandwidth restrictions due to metallic losses. In this work, we propose a metallic groove-slit-groove (GSG) structure that overcomes these limitations by exhibiting a large bandwidth, angularly independent, extraordinary optical transmission. Our design achieves high transmission efficiency in the longwave infrared range, driven by Fano-type resonances created through the interaction between the grooves and the central slit.
View Article and Find Full Text PDFOne-dimensional sub-wavelength gratings are versatile photonic platforms supporting diverse resonances, including symmetry-protected bound states in the continuum. However, practical access to these bound modes relies on their quasi-bound form, which necessitates the introduction of perturbations in either geometry or material properties. Despite having a large, finite quality factor, quasi-bound modes retain their characteristically strong field confinement.
View Article and Find Full Text PDF3D Light-Direction Sensor Based on Segmented Concentric Nanorings Combined with Deep Learning.
Micromachines (Basel)
September 2024
Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
High-precision, ultra-thin angular detectable imaging upon a single pixel holds significant promise for light-field detection and reconstruction, thereby catalyzing advancements in machine vision and interaction technology. Traditional light-direction angle sensors relying on optical components like gratings and lenses face inherent constraints from diffraction limits in achieving device miniaturization. Recently, angle sensors via coupled double nanowires have demonstrated prowess in attaining high-precision angle perception of incident light at sub-wavelength device scales, which may herald a novel design paradigm for ultra-compact angle sensors.
View Article and Find Full Text PDFMetasurface-Embedded Contact Lenses for Holographic Light Projection.
Adv Sci (Weinh)
October 2024
Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
Contact lenses have been instrumental in vision correction and are expected to be utilized in augmented reality (AR) displays through the integration of electronic and optical components. In optics, metasurfaces, an array of sub-wavelength nanostructures, have offered optical multifunctionality in an ultra-compact form factor, facilitating integration into various imaging, and display systems. However, transferring metasurfaces onto contact lenses remains challenging due to the non-biocompatible materials of extant imprinting methods and the structural instability caused by the swelling and shrinking of the wetted surface.
View Article and Find Full Text PDFArticle Synopsis
- Fabrication imperfections like roughness and discontinuities in photonic wire waveguides can severely impact their performance, leading to high insertion losses and reduced production efficiency.
- The study focuses on a new platform using silicon nano-pillars to create a sub-wavelength grating waveguide that exhibits robustness to these types of discontinuities.
- Experimental results show that this innovative waveguide design experiences significantly lower transmission losses, measuring less than 2.2 dB for certain discontinuities, making it a promising solution for developing low-loss optical waveguides across the telecommunication spectrum.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!