scholarly journals Characterization of focusing grating couplers for telecom wavelengths in the first and second diffraction order

2021 ◽  
Vol 2086 (1) ◽  
pp. 012052
Author(s):  
A Elmanova ◽  
I Elmanov ◽  
P An ◽  
V Kovalyuk ◽  
A Kuzin ◽  
...  
Keyword(s):  
Filling Factor ◽  
Near Infrared ◽  
Numerical Study ◽  
Diffraction Order ◽  
Infrared Range ◽  
Etching Depth ◽  
Central Wavelength ◽  
Grating Couplers ◽  
Near Infrared Range

Abstract In this work we studied how focusing grating couplers, developed for telecommunication C-band wavelength range, can be applied in the near infrared range. In the paper we presented prospects of usage of both first and second diffraction maxima of theoretically computed diffraction grating couplers for photonic aims. The dependence of the central wavelength of the grating on the etching depth of the photonic layer, on the period and filling factor of the grating was studied. We have compared our experimental results with numerical study, performed using finite elements method of solving differential equations. The work is important for different photonic applications and introduces new prospects in application of the already fabricated devices, developed for telecommunication wavelengths.

Standardized Characterization of Optical Losses from the Ultraviolet to Near-Infrared Range

2007 ◽  
Author(s):  
Kai Starke ◽  
I Balasa ◽  
H Blaschke ◽  
L Jensen ◽  
M Jupé ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Range ◽  
Optical Losses ◽  
Near Infrared Range

Hayabusa2 Returned Samples: First Results From the MicrOmega Investigation Within the ISAS Curation Facility

2021 ◽  
Author(s):  
Lucie Riu ◽  
Rosario Brunetto ◽  
John Carter ◽  
Brigitte Gondet ◽  
Vincent Hamm ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Range ◽  
First Results ◽  
Ftir Spectrometer ◽  
Formation And Evolution ◽  
Color Filters ◽  
Non Destructive ◽  
Near Earth Objects ◽  
Near Infrared Range

<p><strong>Introduction:</strong> On December 6, 2020, the Hayabusa2 mission successfully returned to Earth ~ 5.4 g of samples collected at the surface of the C-type asteroid Ruygu [1,2]. Its surface was first sampled on February 22, 2019, then on July 12, 2019, close to a 10-meter large artificial crater, so as to possibly access sub-surface material [3]. The collected samples are now kept at the Extraterrestrial Samples Curation Center of JAXA at ISAS in Sagamihara, Japan, for a first round of preliminary analyses, with the objective to characterize in a non-destructive manner both the bulk samples and a few hundreds of grains extracted from them [4]. In particular, the objective is 1) to support their further detailed characterization by the international initial analysis teams, which will start their activity in July 2021, and 2) to catalog the grains, accessible to the international community through AO selection, starting mid-2022.</p> <p>The preliminary characterization of these samples is being conducted with a visible microscope with four color filters, a FTIR spectrometer operating in the 1-5 µm range and MicrOmega, a hyperspectral NIR microscope developed at Institut d'Astrophysique Spatiale (Université Paris-Saclay/CNRS, Orsay, France), operating in the near-infrared range (0.99-3.65 µm) [5]. It is noteworthy that never before have the preliminary analyses of returned extraterrestrial samples included the characterization by a NIR hyperspectral microscope.</p> <p><strong>Results: </strong>Preliminary outcomes of the analyses performed with MicrOmega will be presented at the conference. In particular, the question of the representativity of the samples collected by the Hayabusa2 spacecraft will be addressed thanks to the comparison of the spectra obtained by MicrOmega and the NIRS3 remote sensing IR spectrometer [6] which performed a spectral characterization (1.8-3.2 µm) of Ryugu's surface, including the sites of the samples' collection [7,8]. A preliminary analysis of the spatial compositional heterogeneity will be presented. Specific signatures, detected in grains typically present in <1% of the pixels, but of high relevance regarding the processes determining Ryugu formation and evolution, will also be discussed.</p> <p><strong>References: </strong>[1] Binzel R. P. et al. (2002), Physical Properties of Near-Earth Objects. pp. 255-271, [2] Vilas F. (2008) <em>The Astronomical Journal</em> 135 (4), 1101-1105, [3] Morota et al. (2020) <em>Science</em> 368, Issue 6491, pp. 654-659, [4] Yada T. et al., in preparation, [5] Bibring J.-P. et al. (2017) <em>Astrobiology</em> 17, Issue 6-7, pp.621-626, [6] Iwata T. et al. (2017) <em>Space Science Reviews</em> 208 (1-4), 317-337, [7] Kitazato K. et al. (2019) <em>Science</em> 364 (6437), 272-275, [8] Kitazato K. et al. (2020) <em>Nature Astronomy</em>, Volume 5, p. 246-250.</p>

scholarly journals Challenges in nanofabrication for efficient optical metasurfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adelin Patoux ◽  
Gonzague Agez ◽  
Christian Girard ◽  
Vincent Paillard ◽  
Peter R. Wiecha ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Near Infrared ◽  
Optical Response ◽  
Infrared Range ◽  
Optical Components ◽  
Optical Functions ◽  
Fabrication Errors ◽  
Fabrication And Characterization ◽  
Near Infrared Range

AbstractOptical metasurfaces have raised immense expectations as cheaper and lighter alternatives to bulk optical components. In recent years, novel components combining multiple optical functions have been proposed pushing further the level of requirement on the manufacturing precision of these objects. In this work, we study in details the influence of the most common fabrication errors on the optical response of a metasurface and quantitatively assess the tolerance to fabrication errors based on extensive numerical simulations. We illustrate these results with the design, fabrication and characterization of a silicon nanoresonator-based metasurface that operates as a beam deflector in the near-infrared range.

Coupling of Er light emissions to plasmon modes on In2O3: Sn nanoparticle sheets in the near-infrared range

2014 ◽  
Vol 105 (4) ◽  
pp. 041903 ◽  
Author(s):  
Hiroaki Matsui ◽  
Wasanthamala Badalawa ◽  
Takayuki Hasebe ◽  
Shinya Furuta ◽  
Wataru Nomura ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Range ◽  
Near Infrared Range ◽  
Sn Nanoparticle ◽  
Plasmon Modes

scholarly journals Fabrication of Dy2O3 Transparent Ceramics by Vacuum Sintering Using Precipitated Powders

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Dianjun Hu ◽  
Xin Liu ◽  
Ziyu Liu ◽  
Xiaoying Li ◽  
Feng Tian ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Quality ◽  
Precipitation Method ◽  
Infrared Range ◽  
Transparent Ceramics ◽  
Vacuum Sintering ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Liquid Precipitation ◽  
Near Infrared Range

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals.

scholarly journals Joint Measurements of PM<sub>2.5</sub> and light-absorptive PM in woodsmoke-dominated ambient and plume environments

2017 ◽  
Author(s):  
K. Max Zhang ◽  
Bo Yang ◽  
Geng Chen ◽  
Jiajun Gu ◽  
James Schwab ◽  
...  
Keyword(s):  
Near Infrared ◽  
Uv Light ◽  
Operating Conditions ◽  
Infrared Range ◽  
Wood Combustion ◽  
Near Ultraviolet ◽  
Linear Relationships ◽  
Saranac Lake ◽  
Near Infrared Range ◽  
Strong Linear Relationship

Abstract. DC, also referred to as Delta-C, measures enhanced light absorption of particulate matter (PM) samples at the near-ultraviolet (UV) range relative to the near-infrared range, which has been proposed previously as a woodsmoke marker due to the presence of enhanced UV light absorbing materials from wood combustion. In this paper, we further evaluated the applications and limitations of using DC as both a qualitative and semi-quantitative woodsmoke marker via joint continuous measurements of PM2.5 (by nephelometer pDR-1500) and light-absorptive PM (by 2-wavelength and 7-wavelength Aethalometer®) in three Northeastern U.S. cities/towns including Rutland, VT, Saranac Lake, NY and Ithaca, NY. We compared the pDR-1500 against a FEM PM2.5 sampler (BAM 1020), and identified a close agreement between the two instruments in a woodsmoke-dominated ambient environment. The analysis of seasonal and diurnal trends of DC, BC (880 nm) and PM2.5 concentrations supports the use of DC as an adequate qualitative marker. The strong linear relationships between PM2.5 and DC in both woodsmoke-dominated ambient and plume environments suggest that DC can reasonably serve as a semi-quantitative woodsmoke marker. We proposed a DC-based indicator for woodsmoke emission, which was then shown to exhibit relatively strong linear relationship with heating demand. While we observed reproducible PM2.5-DC relationships in similar woodsmoke-dominated ambient environments, those relationships differ significantly with different environments, and among individual woodsmoke sources. DC correlated much more closely with PM2.5 than EcoChem PAS2000-reported PAH in woodsmoke-dominated ambient environments. Our analysis also indicates the potential for PM2.5-DC relationships to be utilized to distinguish different combustion and operating conditions of woodsmoke sources, and that DC-Heating demand relationships could be adopted to estimate woodsmoke emissions. However, future studies are needed to elucidate those relationships.

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