Optical Properties of Soot Remelted Silica Irradiated with Excimer Lasers

1991 ◽  
Vol 244 ◽  
Author(s):  
Yasutaka Matsumoto ◽  
Nobu Kuzuu ◽  
Masataka Murahara
Keyword(s):  
Optical Properties ◽  
Absorption Band ◽  
Laser Irradiation ◽  
Emission Band ◽  
Excimer Lasers ◽  
Absorption Bands ◽  
Before And After ◽  
Arf Laser

ABSTRACTCharacteristics of ArF laser induced luminescence, and absorption bands in soot remelted silica, before and after annealing in various atmospheres, were investigated. A soot remelted silica containing no OH has an absorption band at 5.1 eV which can be annealed out with H2, but an absorption band at 5.8 eV is induced by subsequent the ArF laser irradiation. In a soot remelted silica containing 50 ppm of OH, an emission band at 1.9 eV was induced by the ArF laser irradiation. The 1.9 eV band can be annealed out with He and H2, but, by annealing in H2, the 5.8 eV absorption band was induced by the ArF laser irradiation as in the case of the silica containing no OH.

The Optical Properties of ION Implanted Silica

1997 ◽  
Vol 504 ◽  
Author(s):  
C. C. Smith ◽  
D. Ila ◽  
E. K. Williams ◽  
D. B. Poker ◽  
D. K. Hensley
Keyword(s):  
Optical Properties ◽  
Absorption Band ◽  
Optical Absorption ◽  
Electron Microscopic ◽  
Absorption Bands ◽  
Optical Absorption Band ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Before And After ◽  
Microscopic Techniques

ABSTRACTWe present the results of our investigation of the change in the optical properties of silica, "suprasil", after keV through MeV implantation of copper, tin, silver and gold and after annealing. Suprasil, name brand of silica glass produced by Hereaus Amersil, which is chemically highly pure with well known optical properties. Both linear and nonlinear optical properties of the implanted silica were investigated before and after thermal annealing. All implants showed strong optical absorption bands in agreement with Mie theory. For implants with a measurable optical absorption band we used Doyle's theory and the full width half maximum of the absorption band to calculate the predicted size of the formed nanoclusters at various heat treatment temperatures. These results are compared with those obtained from direct observation using transmission electron microscopic techniques.

scholarly journals Pressure Effects on the Optical Properties of NdVO4

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 237 ◽  
Author(s):  
Enrico Bandiello ◽  
Josu Sánchez-Martín ◽  
Daniel Errandonea ◽  
Marco Bettinelli
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Absorption Band ◽  
Phase Change ◽  
Band Gap ◽  
Pressure Dependence ◽  
Structural Changes ◽  
Pressure Effects ◽  
Absorption Bands ◽  
Fundamental Absorption Band

We report on optical spectroscopic measurements in pure NdVO4 crystals at pressures up to 12 GPa. The influence of pressure on the fundamental absorption band gap and Nd3+ absorption bands has been correlated with structural changes in the crystal. The experiments indicate that a phase transition takes place between 4.7 and 5.4 GPa. We have also determined the pressure dependence of the band-gap and discussed the behavior of the Nd3+ absorption lines under compression. Important changes in the optical properties of NdVO4 occur at the phase transition, which, according to Raman measurements, corresponds to a zircon to monazite phase change. In particular, in these conditions a collapse of the band gap occurs, changing the color of the crystal. The changes are not reversible. The results are analyzed in comparison with those deriving from previous studies on NdVO4 and related vanadates.

scholarly journals Influence of Laser Radiation on Optical Properties of Semiconductor Materials

2019 ◽  
Vol 20 (4) ◽  
pp. 384-390
Author(s):  
P.O. Gentsar ◽  
S.M. Levytskyi
Keyword(s):  
Optical Properties ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Semiconductor Materials ◽  
Surface Layers ◽  
Defective Structure ◽  
Before And After ◽  
532 Nm ◽  
Transmission And Reflection ◽  
Pulsed Laser Irradiation

In this paper, the transmission and reflection spectra of n-Si(100) single crystals are measured; n-GaAs(100); solid solutions of Ge1-хSiх (х = 0.85) in the range (0.2 - 1.7)·10-6 m before and after laser irradiation at the wavelength λ = 532 nm. It is established that the main mechanism of influence of pulsed laser irradiation on the optical properties of thin surface layers of the investigated crystals is structural gettering, that is, the absorption due to the presence of sections of semiconductors that have a defective structure and have the ability to actively absorb defects and points.

Time-Resolved Ellipsometry and Reflectivity Measurements of the Optical Properties of Silicon During Pulsed Excimer Laser Irradiation

1984 ◽  
Vol 35 ◽  
Author(s):  
G. E. Jellison ◽  
D. H. Lowndes
Keyword(s):  
Optical Properties ◽  
Laser Irradiation ◽  
Crystalline Silicon ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Time Resolved ◽  
High Reflectivity ◽  
Use Of Time ◽  
Before And After ◽  
Melting Threshold

ABSTRACTSeveral advances in time-resolved optical measurement techniques have been made, which allow a more detailed determination of the optical properties of silicon immediately before, during, and after pulsed laser irradiation. It is now possible to follow in detail the time-resolved reflectivity signal near the melting threshold; measurements indicate that melting occurs in a spatially inhomogeneous way. The use of time-resolved ellipsometry allowed us to accurately measure the optical properties of the high reflectivity (molten) phase, and of the hot, solid silicon before and after the laser pulse. We obtain n = 3.8, k = 5.2 (±10.1) at λ = 632.8 nm for the high reflectivity phase, in minor disagreement with the published values of Shvarev et al. for liquid silicon. Before and after the high reflectivity phase, the time-resolved ellipsometry measurements are entirely consistent with the known optical properties of crystalline silicon at temperatures up to its melting point.

scholarly journals Influence of laser radiation on optical properties of high resistivity crystals CdTe and solid solutions Cd1-xZnxTe

2020 ◽  
Vol 21 (1) ◽  
pp. 68-72
Author(s):  
P. O. Gentsar ◽  
S. M. Levytskyi
Keyword(s):  
Optical Properties ◽  
Energy Range ◽  
Laser Irradiation ◽  
Solid Solutions ◽  
High Resistivity ◽  
Surface Layers ◽  
Defective Structure ◽  
Before And After ◽  
532 Nm ◽  
Transmission And Reflection

In this paper, the transmission and reflection spectra of single crystals р-CdTe(111) are measured; solid solutions of Cd1-хZnхTe (х=0.1) in the range (0.2 – 1.7)·10-6 m before and after laser irradiation at the wavelength λ = 532 nm in the energy range 66 - 164 mJ/cm2 for CdTe(111) and in the energy range 46.6 mJ/cm2 - 163.5 mJ/cm2 for Cd1-хZnxTe (x = 0.1). It is established that the main mechanism of influence of pulsed laser irradiation on the optical properties of thin surface layers of the investigated crystals is structural gettering, that is, the absorption due to the presence of sections of semiconductors that have a defective structure and have the ability to actively absorb defects and points.

First Nano-Infrared Spectroscopy and Imaging Measurements of Single Phospholipid Bilayers

2018 ◽  
Author(s):  
Adrian Cernescu ◽  
Michał Szuwarzyński ◽  
Urszula Kwolek ◽  
Karol Wolski ◽  
Paweł Wydro ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Absorption Band ◽  
Spectral Region ◽  
Near Field ◽  
Phospholipid Bilayers ◽  
Model Systems ◽  
Absorption Bands ◽  
Protein Complement ◽  
20 Nm

<div><div>Scattering-mode Scanning Near-Field Optical Microscopy (sSNOM) allows one to obtain absorption spectra in the mid-IR region for samples as small as 20 nm in size. This configuration has made it possible to measure FTIR spectra of the protein complement of membranes. (Amenabar 2013) We now show that mid-IR sSNOM has the sensitivity required to measure spectra of phospholipids in individual bilayers in the spectral range 800 cm<sup>-1</sup>–1400 cm<sup>-1</sup>. We have observed the main absorption bands of the dipalmitoylphosphatidylcholine headgroups in this spectral region above noise level. We have also mapped the phosphate absorption band at 1070 cm<sup>-1</sup> simultaneously with the AFM topography. We have shown that we could achieve sufficient contrast to discriminate between single and multiple phospholipid bilayers and other structures, such as liposomes. This work opens the way to further research that uses nano-IR spectroscopy to describe the biochemistry of cell membranes and model systems.</div></div><div></div>

Structure and microstructure of near infrared-absorbing Au–Au2S nanoparticles

2007 ◽  
Vol 22 (9) ◽  
pp. 2531-2538 ◽  
Author(s):  
Mei Chee Tan ◽  
Jackie Y. Ying ◽  
Gan Moog Chow
Keyword(s):  
Optical Properties ◽  
Surface Segregation ◽  
Near Infrared ◽  
Small Degree ◽  
Core Shell ◽  
Shell Microstructure ◽  
Absorption Bands ◽  
Interfacial Effects ◽  
Nir Absorption ◽  
Structure And Microstructure

Near infrared (NIR) absorbing nanoparticles synthesized by the reduction of HAuCl4 with Na2S exhibited absorption bands at ∼530 nm, and in the NIR region of 650–1100 nm. The NIR optical properties were not found to be related to the earlier proposed Au2S–Au core-shell microstructure in previous studies. From a detailed study of the structure and microstructure of as-synthesized particles in this work, S-containing, Au-rich, multiply-twinned nanoparticles were found to exhibit NIR absorption. They consisted of amorphous AuxS (where x = 2), mostly well mixed within crystalline Au, with a small degree of surface segregation of S. Therefore, NIR absorption was likely due to interfacial effects on particle polarization from the introduction of AuxS into Au particles, and not the dielectric confinement of plasmons associated with a core-shell microstructure.

Composition, particle size, and near-infrared irradiation effects on optical properties of Au–Au2S nanoparticles

2008 ◽  
Vol 23 (1) ◽  
pp. 281-293 ◽  
Author(s):  
Mei Chee Tan ◽  
Jackie Y. Ying ◽  
Gan Moog Chow
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Thermal Effects ◽  
Near Infrared ◽  
Sodium Sulfide ◽  
Irradiation Effects ◽  
Absorption Bands ◽  
Molar Ratios ◽  
Nir Absorption ◽  
Structure And Microstructure

Near-infrared (NIR)-absorbing nanoparticles synthesized by the reduction of tetrachloroauric acid (HAuCl4) using sodium sulfide (Na2S) exhibited absorption bands at ∼530 nm and at the NIR region of 650−1100 nm. A detailed study on the structure and microstructure of as-synthesized nanoparticles was reported previously. The as-synthesized nanoparticles were found to consist of amorphous AuxS (x = ∼2), mostly well mixed within crystalline Au. In this work, the optical properties were tailored by varying the precursor molar ratios of HAuCl4 and Na2S. In addition, a detailed study of composition and particle-size effects on the optical properties was discussed. The change of polarizability by the introduction of S in the form of AuxS (x = ∼2) had a significant effect on NIR absorption. Also, it was found in this work that exposure of these particles to NIR irradiation using a Nd:YAG laser resulted in loss of the NIR absorption band. Thermal effects generated during NIR irradiation had led to microstructural changes that modified the optical properties of particles.

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