Femtosecond-time-resolved imaging of the dielectric function of ZnO in the visible to near-IR spectral range

2019 ◽  
Vol 115 (21) ◽  
pp. 212103 ◽  
Author(s):  
O. Herrfurth ◽  
T. Pflug ◽  
M. Olbrich ◽  
M. Grundmann ◽  
A. Horn ◽  
...  
Keyword(s):  
Dielectric Function ◽  
Spectral Range ◽  
Time Resolved ◽  
Near Ir ◽  
Time Resolved Imaging

Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

2018 ◽  
pp. 7-13
Author(s):  
Anton M. Mishchenko ◽  
Sergei S. Rachkovsky ◽  
Vladimir A. Smolin ◽  
Igor V . Yakimenko
Keyword(s):  
Spatial Structure ◽  
Unmanned Aerial Vehicle ◽  
Wavelength Range ◽  
Spectral Range ◽  
Near Ir ◽  
Optoelectronic Systems ◽  
Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

From Semiconductor to Metal in a Flash: Observing Ultrafast Laser-Induced Phase Transformations

1997 ◽  
Vol 481 ◽  
Author(s):  
J. P. Callan ◽  
A. M.-T. Kim ◽  
L. Huangt ◽  
E. N. Glezer ◽  
E. Mazur
Keyword(s):  
Phase Transformations ◽  
Dielectric Function ◽  
Spectral Range ◽  
Laser Excitation ◽  
Spectroscopic Technique ◽  
Ultrafast Laser ◽  
Lattice Heating ◽  
Fs Laser

ABSTRACTWe use a new broadband spectroscopic technique to measure ultrafast changes in the dielectric function of a material over the spectral range 1.5–3.5 eV following intense 70-fs laser excitation. The results reveal the nature of the phase transformations which occur in the material following excitation. We studied the response of GaAs and Si. For GaAs, there are three distinct regimes of behavior as the pump fluence is increased — lattice heating, lattice disordering, and a semiconductor-to-metal transition.

scholarly journals Giant enhancement of THz-frequency optical nonlinearity by phonon polariton in ionic crystals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yao Lu ◽  
Qi Zhang ◽  
Qiang Wu ◽  
Zhigang Chen ◽  
Xueming Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Nonlinearity ◽  
Ionic Crystals ◽  
Nonlinear Optical Susceptibility ◽  
Time Resolved ◽  
Light Coupling ◽  
Tremendous Progress ◽  
Fundamental Research ◽  
Ionic Contribution ◽  
Time Resolved Imaging

AbstractThe field of nonlinear optics has grown substantially in past decades, leading to tremendous progress in fundamental research and revolutionized applications. Traditionally, the optical nonlinearity for a light wave at frequencies beyond near-infrared is observed with very high peak intensity, as in most materials only the electronic nonlinearity dominates while ionic contribution is negligible. However, it was shown that the ionic contribution to nonlinearity can be much larger than the electronic one in microwave experiments. In the terahertz (THz) regime, phonon polariton may assist to substantially trigger the ionic nonlinearity of the crystals, so as to enhance even more the nonlinear optical susceptibility. Here, we experimentally demonstrate a giant second-order optical nonlinearity at THz frequency, orders of magnitude higher than that in the visible and microwave regimes. Different from previous work, the phonon-light coupling is achieved under a phase-matching setting, and the dynamic process of nonlinear THz generation is directly observed in a thin-film waveguide using a time-resolved imaging technique. Furthermore, a nonlinear modification to the Huang equations is proposed to explain the observed nonlinearity enhancement. This work brings about an effective approach to achieve high nonlinearity in ionic crystals, promising for applications in THz nonlinear technologies.

scholarly journals Possible Effect of Human-Experimenter on Homeopathic-Like Aqueous Preparations

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1475
Author(s):  
Vladimir Korenbaum ◽  
Tatiana Chernysheva ◽  
Victorya Galay ◽  
Roman Galay ◽  
Alexandr Ustinov ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Spectral Range ◽  
Placebo Effect ◽  
Measuring Process ◽  
Observer Effect ◽  
Spectral Changes ◽  
Near Ir ◽  
Patient Side

Homeopathy is one of the applications in structured water influencing human health. The objective is to search for the physical basis of homeopathy. This methodology includes a study of absorption in the far IR spectral range, absorption and refraction in THz diapason, dynamic light scattering in the UV–near IR spectral range for the blinded samples of homeopathic-like preparations (HLP) of several parent substances and hidden/apparent controls, and statistical analysis on the significance of distinctions in spectral data between ensembles of HLP of each parent substance and ensembles of hidden/apparent controls. The analysis of nine independent blind studies of aqueous HLP of several parent substances gave statistically significant spectral differences in some preparations with an apparent control (25 comparisons of 35) and a hidden control (11 comparisons of 40). The revealed dominance in the occurrence frequency of differences in any HLP with an apparent control can be treated as involving most of these changes to the samples by the spectral measuring process. This allows interpreting the main mechanism of manifestation of the spectral changes found as the “observer effect”. The therapeutic effect of HLP may be assumed as a combination of the “observer effect” from the physician side and a “placebo effect” from the patient side.

Excited States of C70and the Intersystem Crossing Process Studied by Picosecond Time-Resolved Spectroscopy in the Visible and Near-IR Region

1996 ◽  
Vol 100 (25) ◽  
pp. 10518-10522 ◽  
Author(s):  
Akira Watanabe ◽  
Osamu Ito ◽  
Motoyuki Watanabe ◽  
Haruhisa Saito ◽  
Musubu Koishi
Keyword(s):  
Excited States ◽  
Intersystem Crossing ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Near Ir

scholarly journals Time-resolved imaging refractometry of microbicidal films using quantitative phase microscopy

2011 ◽  
Vol 16 (12) ◽  
pp. 120510 ◽  
Author(s):  
Matthew T. Rinehart ◽  
Tyler K. Drake ◽  
Francisco E. Robles ◽  
Lisa C. Rohan ◽  
David Katz ◽  
...  
Keyword(s):  
Time Resolved ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Time Resolved Imaging

scholarly journals Time-Resolved Imaging of Electrochemical Switching in Nanoscale Resistive Memory Elements

2015 ◽  
Vol 21 (S3) ◽  
pp. 1911-1912
Author(s):  
William A. Hubbard ◽  
E. R. White ◽  
Alexander Kerelsky ◽  
G. Jasmin ◽  
Jared J. Lodico ◽  
...  
Keyword(s):  
Resistive Memory ◽  
Time Resolved ◽  
Time Resolved Imaging
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