Optical characterization of liquid crystals by combined ellipsometry and half-leaky-guided-mode spectroscopy in the visible-near infrared range

2007 ◽  
Vol 101 (7) ◽  
pp. 073105 ◽  
Author(s):  
G. Abbate ◽  
V. Tkachenko ◽  
A. Marino ◽  
F. Vita ◽  
M. Giocondo ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Near Infrared ◽  
Optical Characterization ◽  
Infrared Range ◽  
Guided Mode ◽  
Mode Spectroscopy ◽  
Near Infrared Range

Photorefractive properties of new liquid crystals in the near-infrared range

2011 ◽  
Vol 38 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Janusz Parka ◽  
Rafał Kowerdziej ◽  
Marcin Romaniuk
Keyword(s):  
Liquid Crystals ◽  
Near Infrared ◽  
Infrared Range ◽  
Near Infrared Range

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 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.

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.

Optical Absorption Spectroscopy of DNA-Wrapped HiPco Carbon Nanotubes

2019 ◽  
Vol 943 ◽  
pp. 95-99
Author(s):  
Li Jun Wang ◽  
Kazuo Umemura
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
Optical Absorption Spectroscopy ◽  
Double Stranded Dna

Optical absorption spectroscopy provides evidence for individually dispersed carbon nanotubes. A common method to disperse SWCNTs into aqueous solution is to sonicate the mixture in the presence of a double-stranded DNA (dsDNA). In this paper, optical characterization of dsDNA-wrapped HiPco carbon nanotubes (dsDNA-SWCNT) was carried out using near infrared (NIR) spectroscopy and photoluminescence (PL) experiments. The findings suggest that SWCNT dispersion is very good in the environment of DNA existing. Additionally, its dispersion depends on dsDNA concentration.

Electro-Optical Characterization of E48:PVP Polymer Dispersed Liquid Crystals

2001 ◽  
Vol 365 (1) ◽  
pp. 305-311
Author(s):  
Cheryll Lei E. Mahinay ◽  
Claire M. Macale ◽  
Fairland F. Amos ◽  
Zenaida B. Domingo ◽  
Leonorina G. Cada
Keyword(s):  
Liquid Crystals ◽  
Optical Characterization ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed
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