Accession Number : ADD013925

Title :   Incoherent Laser System for Producing Smooth and Controllable Spatial Illumination Profiles.

Descriptive Note : Patent, Filed 5 Jun 87, patented 13 dec 88,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Lehmberg, Robert H

Report Date : 13 Dec 1988

Pagination or Media Count : 6

Abstract : A technique called echelon-free ISI produces smooth, controllable target beam profiles with large KrF fusion lasers. The technique projects the desired time-averaged spatial profile F(r) onto the target via a laser system, using partially coherent broadband light. The information needed to reproduce F(r) is transported through the system by a multitude of independent coherence zones, whose diameters are small compared to scalelengths of linear aberration and gain nonuniformities; as a result F(r) remains relatively insensitive to these effects. Under conditions applicable to large KrF lasers, perturbations due to linear aberration, self-focusing, gain saturation, and diffraction, will result in a small broadening and smoothing of F(r), whose functional form should be controllable to within a few percent. Patents. (JHD)

Descriptors :   *LASER BEAMS, *PATENTS, *BEAM FORMING, BROADBAND, COHERENCE, COHERENT OPTICAL RADIATION, DISTORTION, GAIN, PERTURBATIONS, SATURATION, EXCIMERS, FOCUSING

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE