Dark modes in symmetric bulk Dirac semimetal dimers excited by cylindrical vector beams

2021 ◽  
Author(s):  
Lian-Gang Zhang ◽  
Rui Ma ◽  
Tian-Qi Long ◽  
Guidong Liu ◽  
Ling-Ling Wang ◽  
...  
Keyword(s):  
Fluorescence Enhancement ◽  
Resonance Peak ◽  
Mid Infrared ◽  
Direct Excitation ◽  
Dirac Semimetal ◽  
Plasmonic Sensing ◽  
Vector Beams ◽  
Infrared Spectral ◽  
Radially Polarized ◽  
Spectral Responses

Abstract Dark plasmonic modes with sharp spectral resonance peak and exceptionally high quality factor makes it essential for applications in bio-chemical sensing and fluorescence enhancement. Here, we investigate the mid-infrared spectral responses of bulk Dirac semimetal (BDS) dimers under focused azimuthally polarized and radially polarized cylindrical vector beams (CVB). Through numerical simulations, we obtained direct excitation of dark modes and revealed how the beams manipulate the dipole hybridization to produce these modes. By tuning Fermi energy of BDS, the resonant wavelength of the dark modes can be further adjusted. Our results may find the application of CVB in plasmonic sensing.

scholarly journals Group delay dispersion measurements in the mid-infrared spectral range of 2-20 µm

2016 ◽  
Vol 24 (15) ◽  
pp. 16705 ◽  
Author(s):  
Florian Habel ◽  
Michael Trubetskov ◽  
Vladimir Pervak
Keyword(s):  
Spectral Range ◽  
Group Delay ◽  
Group Delay Dispersion ◽  
Mid Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral

scholarly journals Mid‐Infrared Spectral Diagnostics of Nuclear and Extranuclear Regions in Nearby Galaxies

2006 ◽  
Vol 646 (1) ◽  
pp. 161-173 ◽  
Author(s):  
D. A. Dale ◽  
J. D. T. Smith ◽  
L. Armus ◽  
B. A. Buckalew ◽  
G. Helou ◽  
...  
Keyword(s):  
Mid Infrared ◽  
Spectral Diagnostics ◽  
Infrared Spectral ◽  
Nearby Galaxies

Determination of Wavelength Accuracy in the Near-Infrared Spectral Region Based on NIST's Infrared Transmission Wavelength Standard SRM 1921

2000 ◽  
Vol 54 (3) ◽  
pp. 450-455 ◽  
Author(s):  
Stephen R. Lowry ◽  
Jim Hyatt ◽  
William J. McCarthy
Keyword(s):  
Reference Material ◽  
Standard Reference Material ◽  
Spectral Region ◽  
Near Infrared ◽  
Cost Effective ◽  
Infrared Transmission ◽  
Internal Reference ◽  
Mid Infrared ◽  
Infrared Spectral Region ◽  
Infrared Spectral

A major concern with the use of near-infrared (NIR) spectroscopy in many QA/QC laboratories is the need for a simple reliable method of verifying the wavelength accuracy of the instrument. This requirement is particularly important in near-infrared spectroscopy because of the heavy reliance on sophisticated statistical vector analysis techniques to extract the desired information from the spectra. These techniques require precise alignment of the data points between the vectors corresponding to the standard and sample spectra. The National Institute of Standards and Technology (NIST) offers a Standard Reference Material (SRM 1921) for the verification and calibration of mid-infrared spectrometers in the transmittance mode. This standard consists of a 38 μm-thick film of polystyrene plastic. While SRM 1921 works well as a mid-infrared standard, a thicker sample is required for use as a routine standard in the near-infrared spectral region. The general acceptance and proven reliability of polystyrene as a standard reference material make it a very good candidate for a cost-effective NIR standard that could be offered as an internal reference for every instrument. In this paper we discuss a number of the parameters in a Fourier transform (FT)-NIR instrument that can affect wavelength accuracy. We also report a number of experiments designed to determine the effects of resolution, sample position, and optics on the wavelength accuracy of the system. In almost all cases the spectral reproducibility was better than one wavenumber of the values extrapolated from the NIST reference material. This finding suggests that a thicker sample of polystyrene plastic that has been validated with the SRM 1921 standard would make a cost-effective reference material for verifying wavelength accuracy in a medium-resolution FT-NIR spectrometer.

scholarly journals Chalcogenide Microstructured Optical Fibers for Mid-Infrared Supercontinuum Generation: Interest, Fabrication, and Applications

2018 ◽  
Vol 8 (9) ◽  
pp. 1637 ◽  
Author(s):  
Yiming Wu ◽  
Marcello Meneghetti ◽  
Johann Troles ◽  
Jean-Luc Adam
Keyword(s):  
Optical Fibers ◽  
Infrared Imaging ◽  
Supercontinuum Generation ◽  
Mid Infrared ◽  
Microstructured Fibers ◽  
Research Fields ◽  
Infrared Spectral ◽  
Purification Methods ◽  
Imaging And Spectroscopy ◽  
High Coherence

The mid-infrared spectral region is of great technical and scientific importance in a variety of research fields and applications. Among these studies, mid-infrared supercontinuum generation has attracted strong interest in the last decade, because of unique properties such as broad wavelength coverage and high coherence, among others. In this paper, the intrinsic optical properties of different types of glasses and fibers are presented. It turns out that microstructured chalcogenide fibers are ideal choices for the generation of mid-infrared supercontinua. The fabrication procedures of chalcogenide microstructured fibers are introduced, including purification methods of the glass, rod synthesis processes, and preform realization techniques. In addition, supercontinua generated in chalcogenide microstructured fibers employing diverse pump sources and configurations are enumerated. Finally, the potential of supercontinua for applications in mid-infrared imaging and spectroscopy is shown.

Ablation Dynamics in Laser Sclerostomy Ab Externo by Means of Pulsed Lasers in the Mid-Infrared Spectral Range

1997 ◽  
Vol 28 (10) ◽  
pp. 853-865
Author(s):  
Ralf Brinkmann ◽  
Gerit Dröge ◽  
Frank Schröer ◽  
Manfred Scheu ◽  
Reginald Birngruber
Keyword(s):  
Spectral Range ◽  
Pulsed Lasers ◽  
Mid Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Laser Sclerostomy

Precision Mid-Infrared Frequency Comb Spectroscopy using a Cross-Dispersed Spectrometer

2021 ◽  
Author(s):  
D. Michelle Bailey ◽  
Gang Zhao ◽  
Adam J. Fleisher
Keyword(s):  
Frequency Comb ◽  
Difference Frequency Generation ◽  
Laser Frequency ◽  
Trace Gas ◽  
Molecular Fingerprint ◽  
Mid Infrared ◽  
Optical Frequency Combs ◽  
Frequency Combs ◽  
Infrared Spectral ◽  
Fingerprint Region

<p>Advances in optical technology have led to the commercialization and widespread use of broadband optical frequency combs for multiplexed measurements of trace-gas species. Increasingly available in the mid-infrared spectral region, these devices can be leveraged to interrogate the molecular fingerprint region where many fundamental rovibrational transitions occur. Here we present a cross-dispersed spectrometer employing a virtually imaged phased array etalon and ruled diffraction grating coupled with a difference frequency generation comb centered near 4.5 µm. The spectrometer achieves sub-GHz spectral resolution with a 30 cm<sup>-1</sup> instantaneous bandwidth. Laboratory results for nitrous oxide isotopic abundance retrieval will be presented. Challenges relating to characterizing the instrument lineshape function, constructing a frequency axis traceable to the comb, and accurate spectral modelling will be addressed and progress towards incorporating a more compact laser frequency comb source into the system will be discussed.</p>

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