Showing papers on "Light field published in 1982"

Nonlinear optics and spectroscopy

Abstract: ing's vector it follows that the light amplitude at the focal spot would reach 108 volts per centimeter, comparable to the electric field internal to the atoms and molecules responsible for the binding of valence electrons. These are literally pulled out of their orbits in multiphoton tunneling processes, and any material will be converted to a highly ionized dense plasma at these flux densities. It is clear that the familiar notion of a linear optical response with a constant index of refraction, that is, an induced polarization proportional to the amplitude of the light field, should be dropped at much less extreme intensities. There is a nonlinearity in the constitutive relationship which may be expanded in terms of a power series in the electric field components

Nonlinear optics and spectroscopy

Abstract: ing's vector it follows that the light amplitude at the focal spot would reach 108 volts per centimeter, comparable to the electric field internal to the atoms and molecules responsible for the binding of valence electrons. These are literally pulled out of their orbits in multiphoton tunneling processes, and any material will be converted to a highly ionized dense plasma at these flux densities. It is clear that the familiar notion of a linear optical response with a constant index of refraction, that is, an induced polarization proportional to the amplitude of the light field, should be dropped at much less extreme intensities. There is a nonlinearity in the constitutive relationship which may be expanded in terms of a power series in the electric field components

Kraftfahrzeugleuchte aus leuchtdioden oder leuchtdiodenchips

Abstract: The motor vehicle lamp, particularly a signalling lamp, comprises light sources consisting of light diodes or light diode chips (11) arranged on or within a plate (12). The different light sources (11) are connected so as to form groups comprising, each of them, a certain number of series connected sources, adapted to the applied operating direct voltage. The total light surface is obtained by a matrix type parallel connection of a plurality of said groups. Owing to a statistical distribution of the series light sources, throughout the lighting surface, the initial light field is maintained also upon a failure of the whole group of series sources. By coupling shorting elements (13) in parallel to the different diodes or diode chips (11), it is further possible to avoid that the failure of a single diode (11) puts out of order the whole group of series connected sources.

The three‐parameter model of the submarine light field: Radiant energy absorption and energy trapping in nepheloid layers

Abstract: The three-parameter model of the submarine light field is here proposed. The model consists of three physical parameters: the scalar irradiance (E0), downwelling vector irradiance (Ez), and average cosine (μ) of the submarine light field. This model is derived from a general exponential decay equation that is valid for all submarine light fields free of horizontal divergence. From the exponential decay equation we derive equations for the calculation of radiant power absorbed in a given depth interval and the radiant power scattered into or out of that interval. Calculations of the radiant power attenuation in an East German lake demonstrate that a nepheloid layer functions as an energy trap.

Stimulated Raman Scattering

Abstract: Inelastic light scattering has proved to be highly valuable for the study of elementary excitations of gases, liquids and solids. The parameters of the scattered radiation, e.g. frequency position, spectral band shape, degree of polarization and scattering efficiency provide detailed information on the material under consideration. Using conventional light sources, i.e. working at low intensity the scattering intensity is very weak and is proportional to the intensity of the incident light beam. At elevated intensity level the situation may change significantly as already predicted in the 1930’s.[l] Nevertheless the first discovery of stimulated Raman scattering was accidental using a nitrobenzene Kerr shutter as Q-switch of a ruby laser.[2] With intense laser sources a variety of new scattering phenomena has been observed during the past years that are discussed in detail in the various chapters of this hook.[3] The present article intends to provide a basic understanding of stimulated scattering and to reveal the close relationship with spontaneous scattering, coherent scattering and inverse Raman effect.

Fredericks transitions induced by light fields

Abstract: The reorientation of the director of a nematic liquid crystal induced by the field of a light wave is considered An oblique (with respect to the director) extraordinary wave of low intensity yields the predicted and previously observed giant optical nonlinearity in a nematic liquid crystal For normal incidence of the light wave on the cuvette with a homeotropic orientation of the nematic liquid crystal, the reorientation appears only at light intensities above a certain threshold, and the process itself is similar to the Fredericks transition The spatial distribution of the director direction is calculated for intensities above and below threshold Hysteresis of the Fredericks transition in a light field, which has no analog in the case of static fields, is predicted

Reorientation of Liquid Crystals by Superposed Optical and Quasistatic Electric Fields

Abstract: The electric field of a CW laser beam can reorient a nematic liquid crystal. Experiments on the influence of a superposed quasistatic electric field are reported showing that this can reinforce or weaken the laser induced reorientation depending on the substance and geometry.

Photographic method for printing a viewing-screen structure using a light-transmission filter

Abstract: A method for printing a viewing-screen structure including projecting, at least three times, a light field from a light source, through a lens, an optical filter and incident upon a photosensitive layer. During one of the projecting steps, the light source and the nominal axes of the light source, the lens, the filter and the layer (which are substantially parallel to one another) are aligned along a common axis. During each of the other two projecting steps, the light source and the axis of the lens remain aligned along the common axis, and the axes of the filter and the layer are offset prescribed distances on opposite sides of the common axis.

Transport of light radiation in a spatially finite three-dimensional scattering medium

Abstract: We propose a new method for solving radiation transport problems, which permits including in analytic form for the case of normal incidence the effect of spatial finiteness of the scattering medium. The formation of the light field accompanying changes in the optical parameters and optical dimensions of the medium is analyzed.