scispace - formally typeset
Search or ask a question

Showing papers on "Light field published in 1985"


Patent
Günter Makosch1
23 Dec 1985
TL;DR: In this paper, a surface is subjected to a light field whose intensity is periodically modulated in a vertical direction to evaluate a scattered light pattern, where the light field is obtained from interference between a first or central beam with vertical incidence and two symmetrical laterally disposed beams with oblique incidence.
Abstract: A surface is subjected to a light field whose intensity is periodically modulated in a vertical direction to evaluate a scattered light pattern. The light field is obtained from interference between a first or central beam with vertical incidence and two symmetrical laterally disposed beams with oblique incidence. All beams are focussed to a common spot if the profile is obtained by scanning the surface or are superimposed as collimated beams if large area profiling is desired. The surface is imaged onto a diaphragm which selects appropriate locations of the surface for measurements by a photodetector to record sinusoidal intensity variations that are obtained when the light is periodically shifted in a vertical direction by phase modulating the first or central beam with respect to the lateral beams.

28 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of the spatial grating of the cooled atoms, the particle velocity bunching, and the recoil-effect dependence on the nonlinear absorption are considered for slow particles.
Abstract: Kinetic phenomena of resonant-particle motion in a standing-light-wave field are theoretically discussed. The light-pressure force and its fluctuations are found in a wide range of the parameters: the atomic velocity, the intensity, and the detuning of the field. There are two characteristic regions of the detunings in a strong field: the adiabatic region and the region of Landau–Zener resonances. The quantum fluctuations of the inner atomic state that are due to the Landau–Zener transitions result, specifically, in the interference effect in the mean light-pressure force. The effects of the spatial grating of the cooled atoms, the particle velocity bunching, and the recoil-effect dependence on the nonlinear absorption are considered for slow particles. The effect of optical pumping by linearly polarized light taking into account the recoil effect is fundamentally new. Because of this effect, the anisotropic resonance medium becomes gyrotropic.

25 citations


Journal ArticleDOI
TL;DR: In this paper, the atomic beam is split symmetrically into two peaks whose separation increases with the field strength, and the short interaction time ensures that this deflection is due to induced forces; these are described using a semiclassical dressed-atom treatment.
Abstract: We have observed momentum transfer from a standing-wave light field to an atomic beam. The atomic beam is split symmetrically into two peaks whose separation increases with field strength. The short interaction time ensures that this deflection is due to induced forces; these are described using a semiclassical dressed-atom treatment, which gives good agreement with the data. In addition to the splitting, we have observed diffraction of the atomic beam due to the exchange of even numbers of photons with the field.

20 citations


Journal ArticleDOI
TL;DR: In this paper, the authors discuss two possible processes that may lead to unidirectional momentum transfer to atoms from a near-resonant standing-wave light field, including Bragg scattering of the matter waves from the tilted light grating, leaving the atoms unexcited.
Abstract: We discuss two possible processes that may lead to unidirectional momentum transfer to atoms from a near-resonant standing-wave light field. The first is Bragg scattering of the matter waves from the tilted light grating—this process leaves the atoms unexcited. The second is a multiphoton (Doppleron) process in which the atom, by sequential absorption/emission of photons from/into the two traveling-wave components of the standing wave (which appear at different frequencies owingto the motion of the atom in the field), can complete the energy resonance condition for excitation to its excited state. Detailed consideration of the inteferring process of spontaneous emission and experimental factors such as the interplay among interaction length, angular collimation of the standing wave, and transit-time frequency broadening of the light frequency show that the two processes are both potentially observable but under considerably different experimental conditions.

20 citations


Patent
10 Sep 1985
TL;DR: In this article, an electrooptic modulator compensates stress-optic retardation on a measured model by using controlled EO retardation, and a pair of optical-rotatory devices are set out of both sides of the test model so that they could rotate relatively to the linearly polarized orthogonal light field by using a controlled rotative angle.
Abstract: The invention makes use of a non-homogeneous light source to realise two wavelength measurement. An electrooptic modulator compensates stress-optic retardation on a measured model by using controlled electrooptic retardation.A pair of optical-rotatory devices (e.g. Faraday cells) set out of both sides of the test model so that they could rotate relatively to the linearly polarized orthogonal light field by using controlled rotative angle, and a microcomputer controlling automatically, the measuring procedure and process of experimental data. The measurement to photo-elastic stress analysis is thus improved on level of automation, experimental accuracy and period involved.

4 citations


Journal ArticleDOI
TL;DR: In this paper, the quasiclassical theory of the Landau-Zener resonance arising because of the atomic motion in the field of a strong standing light wave is developed, where a resonance atom in a spatially inhomogeneous field as two effective potentials and two trajectories of motion.
Abstract: The quasiclassical theory of the Landau-Zener resonance arising because of the atomic motion in the field of a strong standing light wave is developed. A resonance atom in a spatially inhomogeneous field as two effective potentials and two trajectories of motion. The Landau-Zener (LZ) transitions from one trajectory to the other take place in the regions of quasi-intersection of the terms (standing-wave nodes). This effect leads to the appearance of strong quantum fluctuations which break the potential character of the atomic motion and result in the interference of the translational motion states. Therefore a number of the features of the atomic dispersion in the standing-wave field arise (anomalous widths of the forbidden gaps and allowed bands in the under-barrier energetic region and oscillations of the density of states in the over-barrier energetic region). The manifestation of LZ resonance in non-linear spectroscopy and for bipotential scattering of atoms by light is considered.

1 citations


Patent
14 Feb 1985
TL;DR: In this article, the surface of a transparent disc is made opaque and light is coupled to the optical system through the edge of the disc by reflection from the internal surface of the disk.
Abstract: A device for providing a substantially flat light field to a light imaging medium includes a transparent disc and an optical system. The surface of the disc is made opaque and light is coupled to the optical system through the edge of the disc by reflection from the internal surface of the disc. The intensity of light passing through the disc to the optical system decreases as the distance from the coupling edge increases. The combined effects of the disc and the optical system result in a substantially flat light field.

1 citations


Journal ArticleDOI
TL;DR: In this paper, a linear molecule in a strong monochromatic field is considered within the framework of a numerically solvable quantum-mechanical model, and a new mechanism of the laser cooling of molecular rotation is discussed.

1 citations


Proceedings ArticleDOI
01 Feb 1985
TL;DR: In this article, the authors studied the process of light propagation in random inhomogenious media and found the optical properties of the medium from the results of detection of a scattered field of a certain structure.
Abstract: The study of the process of light propagation in random inhomogenious media leads, as a rule, to the solution of two principal problems. The first one is to find out the optical properties of the medium from the results of detection of a scattered field of a certain structure. The second problem is to find out the structure of light field, that propagates through the scattering medium, with its optical characteristics being known. These problems are solved, as a rule, by spectrometric methods; and the solution appears either in the form of determining the integral characteristics, or eliciting the properties of a sought value in a small volume /1/.