Search results for "Radiant intensity"
showing 8 items of 8 documents
The closed form of the second-order energy shift for the discrete spectrum of atomic hydrogen
2004
The closed form of the second-order energy shift for the discrete spectrum of atomic hydrogen is obtained, which allows us to evaluate the level shift in both cases, when the intermediate states are in continuum and in the discrete spectrum, except the resonances. The values of the second-order shift of the energy of the ground state calculated by us are in good agreement with those obtained by us and other authors using the nonperturbative Floquet method in average up to a radiation intensity of 1015 W cm−2.
Artificial neural networks for nonlinear pulse shaping in optical fibers
2020
International audience; We use a supervised machine-learning model based on a neural network to predict the temporal and spectral intensity profiles of the pulses that form upon nonlinear propagation in optical fibers with both normal and anomalous second-order dispersion. We also show that the model is able to retrieve the parameters of the nonlinear propagation from the pulses observed at the output of the fiber. Various initial pulse shapes as well as initially chirped pulses are investigated.
Kinetics of Photorefractive Light Scattering in Stoichiometric LiNbO3Single Crystals Grown from Melt Containing 58.6 Mole% of Li2O
2011
A study of kinetics of photo-refractive light scattering in ostensibly pure stoichiometric LiNbO3 (Li/Nb = 1) single crystal grown from melt containing 58.6 mole% Li2O excited by laser radiation of 0.53 μm is reported. Asymmetry of the distribution of scattered light intensity is revealed and found to be a linear function of the intensity of the exciting radiation in the 35–160 mW range. Due to heating of the crystal, at farther increase of the radiation intensity the distribution of scattered light contracts.
<title>Pressure sensitivity of the side-glowing optical fibers</title>
2001
Remarkable impact of external mechanical pressure to the transmitted radiation intensity has been observed for glowing fibers with various silica core diameters and side- scattering efficiencies. A physical model on deformation- simulated light scattering has been developed and discussed. The results of experimental studies confirmed the basic model assumptions.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Phase evolution of Peregrine-like solitons in nonlinear fiber optics
2019
Optical fiber systems are well-known to provide convenient platforms in which one may investigate a large variety of fascinating fundamental nonlinear coherent structures such as solitons or self-similar patterns. Interestingly, one of the major conclusions of the studies dealing with extreme-value fluctuations is that the temporal and spectral characteristics of localization processes can be well described in terms of solitons over finite background and in particular in terms of Peregrine soliton (PS) [1]. Whereas the longitudinal evolution of the temporal and spectral intensity of the PS have been characterized in detail [2], much less attention has been experimentally devoted to the evol…
Laboratory Studies of Scattering Properties of Polluted Cloud Droplets: Implications for FSSP Measurements
2008
Abstract Laboratory experiments were conducted in the Mainz vertical wind tunnel to study the effects of pollutants dissolved or suspended in cloud droplets on the droplet size measurements of a Forward Scattering Spectrometer Probe (FSSP). The FSSP is a widely used instrument to derive microphysical properties of atmospheric clouds. Individual droplets of different well-defined sizes were freely falling at their terminal velocities in the wind tunnel while the intensity of radiation emitted by the He–Ne laser of the FSSP and scattered by the droplets was measured. For this purpose, the FSSP was adapted and mounted to the wind tunnel. The intensity of radiation scattered by the droplets in …
Investigation of the Electromagnetic Radiation Emitted by Sub-GeV Electrons in a Bent Crystal.
2015
The radiation emitted by 855 MeV electrons via planar channeling and volume reflection in a $30.5\text{\ensuremath{-}}\ensuremath{\mu}\mathrm{m}$-thick bent Si crystal has been investigated at the MAMI (Mainzer Mikrotron) accelerator. The spectral intensity was much more intense than for an equivalent amorphous material, and peaked in the MeV range in the case of channeling radiation. Differently from a straight crystal, also for an incidence angle larger than the Lindhard angle, the spectral intensity remains nearly as high as for channeling. This is due to volume reflection, for which the intensity remains high at a large incidence angle over the whole angular acceptance, which is equal t…
Ordered structures of DNA on Au(110)
2008
Reflection Anisotropy Spectroscopy (RAS) is used to confirm that both single stranded (ss) and double stranded (ds) DNA formed ordered structures when adsorbed at Au(110)/phosphate buffer interface. The variation of the spectral intensity shows a cos 2θ dependence on the angle θ, which lies between the electric vector of the incident polarised light and the optical axes of the surface plane of the Au(110) establishing that the optical axes of both molecules are aligned with those of the Au(110) surface. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)