scholarly journals Near-infrared to ultra-violet frequency conversion in chalcogenide metasurfaces

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiannan Gao ◽  
Maria Antonietta Vincenti ◽  
Jesse Frantz ◽  
Anthony Clabeau ◽  
Xingdu Qiao ◽  
...  
Keyword(s):  
Chalcogenide Glasses ◽  
Frequency Conversion ◽  
Near Infrared ◽  
Phase Locking ◽  
Ultra Violet ◽  
Harmonic Signal ◽  
Electromagnetic Spectrum ◽  
Infrared Sensing ◽  
Locking Mechanism ◽  
Strong Material

AbstractChalcogenide photonics offers unique solutions for a broad range of applications from mid-infrared sensing to integrated, ultrafast, ultrahigh-bandwidth signal processing. However, to date its usage has been limited to the infrared part of the electromagnetic spectrum, thus avoiding ultraviolet and visible ranges due to absorption of chalcogenide glasses. Here, we experimentally demonstrate and report near-infrared to ultraviolet frequency conversion in an As2S3-based metasurface, enabled by a phase locking mechanism between the pump and the inhomogeneous portion of the third harmonic signal. Due to the phase locking, the inhomogeneous component co-propagates with the pump pulse and encounters the same effective dispersion as the infrared pump, and thus experiences little or no absorption, consequently opening previously unexploited spectral range for chalcogenide glass science and applications, despite the presence of strong material absorption in this range.

scholarly journals Metalorganic chemical vapor deposition of InN quantum dots and nanostructures

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Caroline E. Reilly ◽  
Stacia Keller ◽  
Shuji Nakamura ◽  
Steven P. DenBaars
Keyword(s):  
Quantum Dots ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Near Infrared ◽  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Electromagnetic Spectrum ◽  
Material System ◽  
Metalorganic Chemical

AbstractUsing one material system from the near infrared into the ultraviolet is an attractive goal, and may be achieved with (In,Al,Ga)N. This III-N material system, famous for enabling blue and white solid-state lighting, has been pushing towards longer wavelengths in more recent years. With a bandgap of about 0.7 eV, InN can emit light in the near infrared, potentially overlapping with the part of the electromagnetic spectrum currently dominated by III-As and III-P technology. As has been the case in these other III–V material systems, nanostructures such as quantum dots and quantum dashes provide additional benefits towards optoelectronic devices. In the case of InN, these nanostructures have been in the development stage for some time, with more recent developments allowing for InN quantum dots and dashes to be incorporated into larger device structures. This review will detail the current state of metalorganic chemical vapor deposition of InN nanostructures, focusing on how precursor choices, crystallographic orientation, and other growth parameters affect the deposition. The optical properties of InN nanostructures will also be assessed, with an eye towards the fabrication of optoelectronic devices such as light-emitting diodes, laser diodes, and photodetectors.

scholarly journals Atmospheric Compensation of PRISMA Data by Means of a Learning Based Approach

2021 ◽  
Vol 13 (15) ◽  
pp. 2967
Author(s):  
Nicola Acito ◽  
Marco Diani ◽  
Gregorio Procissi ◽  
Giovanni Corsini
Keyword(s):  
Spectral Range ◽  
Near Infrared ◽  
Random Noise ◽  
Synthetic Data ◽  
Regression Function ◽  
Short Wave ◽  
Hyperspectral Data ◽  
Electromagnetic Spectrum ◽  
Great Opportunity ◽  
Atmospheric Compensation

Atmospheric compensation (AC) allows the retrieval of the reflectance from the measured at-sensor radiance and is a fundamental and critical task for the quantitative exploitation of hyperspectral data. Recently, a learning-based (LB) approach, named LBAC, has been proposed for the AC of airborne hyperspectral data in the visible and near-infrared (VNIR) spectral range. LBAC makes use of a parametric regression function whose parameters are learned by a strategy based on synthetic data that accounts for (1) a physics-based model for the radiative transfer, (2) the variability of the surface reflectance spectra, and (3) the effects of random noise and spectral miscalibration errors. In this work we extend LBAC with respect to two different aspects: (1) the platform for data acquisition and (2) the spectral range covered by the sensor. Particularly, we propose the extension of LBAC to spaceborne hyperspectral sensors operating in the VNIR and short-wave infrared (SWIR) portion of the electromagnetic spectrum. We specifically refer to the sensor of the PRISMA (PRecursore IperSpettrale della Missione Applicativa) mission, and the recent Earth Observation mission of the Italian Space Agency that offers a great opportunity to improve the knowledge on the scientific and commercial applications of spaceborne hyperspectral data. In addition, we introduce a curve fitting-based procedure for the estimation of column water vapor content of the atmosphere that directly exploits the reflectance data provided by LBAC. Results obtained on four different PRISMA hyperspectral images are presented and discussed.

Ultrasensitive UV-NIR Broadband Phototransistors Based on AgBiS2-organic Hybrid Films

2021 ◽  
Author(s):  
Li Jiang ◽  
Huihuang Huang ◽  
Fubing Gui ◽  
Yalun Xu ◽  
Qianqian Lin
Keyword(s):  
Absorption Coefficient ◽  
Near Infrared ◽  
Ultra Violet ◽  
Hybrid Films ◽  
Material Stability ◽  
Organic Hybrid

Recent years, AgBiS2 has received great attention in optoelectronics thanks to the fascinated merits, including suitable bandgap, large absorption coefficient from ultra-violet to near-infrared and remarkable material stability. However, the...

scholarly journals The Effect Of Thickness on The Optical Properties Of ZnS

2007 ◽  
Vol 4 (4) ◽  
pp. 647-652
Author(s):  
Baghdad Science Journal
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Near Infrared ◽  
High Vacuum ◽  
Ultra Violet ◽  
Infrared Region ◽  
Complex Dielectric Constant ◽  
Film Properties ◽  
Corning Glass ◽  
Different Thickness

Zinc sulfide(ZnS) thin films of different thickness were deposited on corning glass with the substrate kept at room temperature and high vacuum using thermal evaporation technique.the film properties investigated include their absorbance/transmittance/reflectance spectra,band gap,refractive index,extinction coefficient,complex dielectric constant and thickness.The films were found to exhibt high transmittance(59-98%) ,low absorbance and low reflectance in the visible/near infrared region up to 900 nm..However, the absorbance of the films were found to be high in the ultra violet region with peak around 360 nm.The thickness(using optical interference fringes method) of various films thichness(100,200,300,and 400) nm.The band gap measured was found to be in the range (3.52 -3.78 )eV.

Near-infrared sensing utilizing the evanescent field

1993 ◽  
Vol 281 (2) ◽  
pp. 265-270 ◽  
Author(s):  
A.R. Lennie ◽  
F. Kvasnik
Keyword(s):  
Near Infrared ◽  
Evanescent Field ◽  
Infrared Sensing

scholarly journals Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

2018 ◽  
Vol 9 ◽  
pp. 2306-2314 ◽  
Author(s):  
Valerio F Gili ◽  
Lavinia Ghirardini ◽  
Davide Rocco ◽  
Giuseppe Marino ◽  
Ivan Favero ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Near Infrared ◽  
Strong Field ◽  
Second Harmonic ◽  
Near Field ◽  
Field Enhancement ◽  
High Refractive Index ◽  
Plasmonic Nanostructures ◽  
Ohmic Losses ◽  
Order Of Magnitude

Background: Dielectric nanoantennas have recently emerged as an alternative solution to plasmonics for nonlinear light manipulation at the nanoscale, thanks to the magnetic and electric resonances, the strong nonlinearities, and the low ohmic losses characterizing high refractive-index materials in the visible/near-infrared (NIR) region of the spectrum. In this frame, AlGaAs nanoantennas demonstrated to be extremely efficient sources of second harmonic radiation. In particular, the nonlinear polarization of an optical system pumped at the anapole mode can be potentially boosted, due to both the strong dip in the scattering spectrum and the near-field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid antenna based on an AlGaAs nanopillar surrounded by a gold ring, which merges in a single platform the strong field confinement typically produced by plasmonic antennas with the high nonlinearity and low loss characteristics of dielectric nanoantennas. This platform allows enhancing the coupling of light to the nanopillar at coincidence with the anapole mode, hence boosting both second- and third-harmonic generation conversion efficiencies. More than one order of magnitude enhancement factors are measured for both processes with respect to the isolated structure. Conclusion: The present results reveal the possibility to achieve tuneable metamixers and higher resolution in nonlinear sensing and spectroscopy, by means of improved both pump coupling and emission efficiency due to the excitation of the anapole mode enhanced by the plasmonic nanoantenna.

In-Helmet Oxy-hemoglobin Change Detection Using Near-Infrared Sensing

2009 ◽  
pp. 504-513
Author(s):  
Erin M. Nishimura ◽  
Christopher A. Russell ◽  
J. Patrick Stautzenberger ◽  
Harvey Ku ◽  
J. Hunter Downs
Keyword(s):  
Change Detection ◽  
Near Infrared ◽  
Infrared Sensing
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