Bragg cell spectral analyzer with a prism expansion system

US4626102A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Eckhard Storck · Munich, DE
• Ulrich Wolff · Munich, DE

Key dates

• Filing date: Feb 6, 1985
• Grant date: Dec 2, 1986
• Expiry date: Feb 6, 2005

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/58
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A Bragg cell spectral analyzer with a prism expansion system for a laser beam, which has a Gaussian cross-sectional distribution of light intensity, is generally superimposed with stray light, and is conducted along a path through the system to a Bragg cell characterized by an aperture diaphragm being positioned in the path before the prism expansion system with the diameter of the aperture being selected to be larger than the half-width value of the Gaussian cross-sectional distribution. The prism expansion system only expands the laser beam to such a degree that the half-width value of the Gaussian cross-sectional distribution is smaller than the diameter of an aperture of the Bragg cell. As a result thereof, the diffraction side lobes of the spectrum can be reduced by apodization relative to the principal maximum of the spectrum and stray light contained in the laser beam can be blanked out.