Signal beam

About: Signal beam is a research topic. Over the lifetime, 1881 publications have been published within this topic receiving 20717 citations.

Methods and systems for analyzing data

Abstract: A method and system for searching for a given sequence in a data base having a multitude of reference sequences stored or identified therein. In accordance with this method, a light beam is modulated with patterns representing the reference sequences, and with a pattern representing the given sequence, and a correlation signal is generated representing the correlation of the reference and given sequences. Optical diffraction patterns may be used to represent the given and reference sequences. In one embodiment, a multitude of first diffraction patterns, each one representing the given sequence, are formed in an optical medium, and a light beam is modulated with each of those multitude of diffraction patterns to form a multi-channel signal beam. Each channel of that beam is then modulated with a respective one second diffraction pattern representing one of the reference sequences to form a multi-channel correlation beam. The intensity of each channel of the correlation beam is then measured to determine whether the given sequence correlates with any of the reference sequences.

Bistable optical photorefractive crystal device

Abstract: An optical bistable photorefractive crystal device is provided in which a photorefractive crystal disposed between two mirrors is uniformly illuminated by a light beam, a signal beam being focused on a given portion of the crystal to cause bistable switching of this portion inside the crystal.

Parametric reflection upon cascade interaction of focused optical beams

Abstract: The parametric reflection of a signal beam in the waist of the reference pump beam upon mismatched three-frequency interaction in a quadratically nonlinear medium is discussed The critical angle of total internal reflection from the induced defocusing channel is found as a function of the beam waist parameters It is shown that when the reference beam is focused, this angle increases and some distortions are introduced into the reflected wave due to a finite length of the waist The modification of the cross section of a wave reflected from a convex parametric mirror is analysed The optimal beam focusing geometry is found at which the distortions of the shape and divergence of the reflected wave are minimal Under certain conditions, the signal wave also flows around a cylindrical inhomogeneity produced by the axially symmetric pump beam The results of theoretical analysis and numerical simulation are in good agreement

Process and apparatus for generating at least three light bundles of different wavelength, especially for displaying color images

Abstract: In a process and an apparatus for generating at least three light bundles of different wavelength for displaying color images, one of these light bundles having a longest wavelength and another of the light bundles having a shortest wavelength, which light bundles are obtained by an OPO and further nonlinear optical component elements from a signal beam and/or idler beam of the OPO and/or a primary light bundle, from which a beam exciting the OPO is also derived, it is provided that at least a partial light bundle is separated from the primary light bundle for exciting the OPO, in that the light bundle with the longest wavelength and the light bundle with the shortest wavelength are obtained from the signal beam and/or idler beam of the OPO by way of frequency multiplication and/or frequency mixing with another partial light bundle of the primary light bundle by excluding components of light bundles other than the generated light bundles with the shortest and longest wavelengths for image display.

A phase feature extraction technique for terahertz reflection spectroscopy

Abstract: We present a phase feature extraction technique for weakly polarized organic compounds in THz-RTDS by taking the second derivative of the phase of the signal beam with respect to frequency. In nitrogen purged environment this method doesn't require any reference. In real scenarios, a reference beam is applied only to remove the influence of atmospheric attenuation. This method offers a straightforward and speedy way to retrieve the absorption features in the reflection spectrum without the presence of the amplitude of the THz pulse or the settlement of a reference surface. It opens the pathways for the application of a more un-conventional THz emission mechanism and extends the capability of THz sensing technology into more practical sensing and imaging situations.