Showing papers on "Light field published in 1984"

On the possibility of almost complete self-squeezing of strong electromagnetic fields

Abstract: The propagation of quantized electromagnetic fields through optically isotropic media with cubic optical nonlinearity is considered. Analytical solutions are presented in closed form showing that the light field can emerge from the medium in a squeezed quantum state. A detailed numerical analysis of the results is performed and presented graphically. Over 90 per cent of the squeezing permitted by quantum-mechanical theory is achieved in this way. The dependence of the squeezing effect on the polarization state of the field and the nonlinear molecular parameters is also discussed.

Collimation of atomic beams by resonant laser radiation pressure

Abstract: The application of the resonant light pressure created by an axially symmetrical light field for collimating atomic beams has been considered. As an example, consideration is given to the possibility of collimating an atomic beam by the light field produced by the reflection of a plane wave from the internal surface of a metal cone. It has been shown that the radiation pressure can reduce the atomic-beam transverse velocities to the value of the order of 100 cm/s which corresponds to effective temperature of about 10−3 K. A method for producing collimated beams of cold atoms based on simultaneous deceleration and collimation of atomic beams by resonant laser radiation pressure is proposed.

Dynamics of a three-level atom in a resonant light field

Abstract: The paper is devoted to a consideration of the motion of a three-level atom in two resonant light waves A kinetic equation of the Fokker-Planck type for the atomic distribution function is derived, which is valid when the recoil energy is small compared to the linewidths of the resonant transitions The detailed behaviour of the radiation force and the diffusion tensor are studied numerically The case of exact resonance and the nonresonant case are both considered It is shown that a detuning from exact resonance results in a drastic decrease of the resonant light pressure force For the detuning we determine the condition, under which an efficient action of the light pressure on a three-level atom takes place

Changes in Polarization of a Light Beam with Arbitrary Autocoherence Propagating in a Birefringent Crystal

Abstract: Based on the Mueller-Stokes matrix formalism and the Wolf autocorrelation functions, a general approach is developed for studying the polarization characteristics of a light beam with arbitrary autocoherence during its interaction with various media. This makes it possible to take into account the dispersion of the medium and the coherence properties of the light field. It is shown that the propagation of a polychromatic light beam with spectrally pure polarization in a certain medium can be described by an integrated Mueller matrix. For a linear phase plate, the matrix elements can be expressed by means of the modulus and the phase of the complex degree of autocoherence. The polarization of a light beam emitted by a black-body radiator and the influence of the dispersion in a KDP crystal in quasi-monochromatic light are discussed as applications.

Radiative interaction of electrons in a light field

Abstract: The interaction of electrons in an external light field of arbitrary intensity has been studied. The relative motion of the electrons' rotation centres is supposed to be slow. The adiabatic potential of particle interaction has been found for this case, the effects of retardation being taken into account. In a sufficiently strong field the difference from the Coulomb law of interaction may be rather essential. In particular, bound states may be created. The ultra-relativistic case of electron motion in a field has been considered in detail. The contribution to the light pressure due to collective effects has been found.

Testing coincidence of x-ray and light beam.

Abstract: Recent government legislation in many countries around the world calls for specific alignment accuracy between x‐ray and light beams for diagnostic x‐ray machines. This technical report describes an alignment model that can be used to check the coincidence of both the x‐ray field and its central ray with the light field and its cross hairs.

Dark field microscope for pattern inspection

Abstract: PURPOSE:To facilitate pattern defect detection and to allow large-area enlarged observation by providing mirrors in an illumination system and irradiating an object with a parallel light beam in one direction. CONSTITUTION:A light source 1 is increased in the quantity of illumination light by several times as great as a conventional light source and light from the light source 1 is nearly collimated through a condenser lens 2. A slit 3A is rotatable and illumination mirrors 5Aa-5Ad reflect the light selectively to irradiate on an observation point 7 on a wafer 6. Since the wafer 6 is mounted on a rotary stage, the slit 3A and illumination mirrors 5A are freely rotatable around the observation point 7 as an axis and an observer selects the position where the intensity of the diffracted light of a pattern is maximum. The slit 3A and illumination mirrors 5A are incorporated in a conventional dark field microscope, which is usable in combination with a light field microscope according to the combination.

Interaction of the strong light field of a dye laser radiation with a two-level system

Abstract: The paper reports an investigation of the changes that occur in the generation spectrum of a dye laser with atomic-barium vapor in the cavity resonator near the resonance absorption line (lambda = 553.5 nm). It is shown that the changes in the generation spectrum are determined by the nature of the interaction between the strong light field of the radiation and the two-level system. The nonresonance and resonance interactions between the radiation and the two-level system are studied. It is shown that in the case of the nonresonance interaction the changes in the generation spectrum are due to the formation of a nonlinear frequency-dependent lens. In the case of the resonance interaction, it is found that the absorption line splits up into two components, and that the splitting increases linearly with increasing intensity of the light-wave field. There occurs between these components a spectral intensity amplification, which is interpreted as amplification, without population inversion, of the dye-laser radiation in the atomic-barium layer.

Multiphoton ionization in chaotic fields with a non-Lorentzian spectrum

Abstract: The effect of the band shape of a light field on the multiphoton ionization is studied by use of the Karhunen-Loeve expansion of the Gaussian process. As an example, exact results are given for the non-Markovian chaotic field, which corresponds to a square spectrum. It is shown that the band shape of the field significantly alters ionization signals.