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Title: System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)

Abstract

In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies ("colors") cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers.

Inventors:
 [1];  [1];  [1];  [1];  [2];  [3]
  1. Rochester, NY
  2. Honeoye Falls, NY
  3. Pittsford, NY
Publication Date:
Research Org.:
Univ. of Rochester, NY (United States)
OSTI Identifier:
867984
Patent Number(s):
US 5048029
Assignee:
University of Rochester (Rochester, NY)
DOE Contract Number:  
FC03-85DP40200
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
obtaining; smooth; laser; beams; intensity; variations; reduced; spectral; dispersion; light; ssd; smoothing; reduces; time-averaged; spatial; provide; uniform; illumination; fusion; target; electro-optic; phase; modulator; beam; passes; produces; broadband; output; imposing; frequency; modulated; bandwidth; grating; provides; angular; due; modulation; frequencies; colors; cycle; dispersed; amplified; converted; tripled; plurality; lines; distributed; plate; dpp; line; irradiated; spectrally; focused; pattern; produced; color; cycling; enhances; pulse; prevents; formation; spikes; damage; medium; power; amplifiers; beam line; frequency modulated; power amplifier; intensity variations; spectral dispersion; uniform intensity; beam passes; laser beams; output beam; laser pulse; laser beam; laser light; laser fusion; laser medium; phase plate; phase modulation; fusion target; provide uniform; uniform illumination; modulated laser; phase modulator; distributed phase; beam lines; /372/

Citation Formats

Skupsky, Stanley, Kessler, Terrance J, Short, Robert W, Craxton, Stephen, Letzring, Samuel A, and Soures, John. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD). United States: N. p., 1991. Web.
Skupsky, Stanley, Kessler, Terrance J, Short, Robert W, Craxton, Stephen, Letzring, Samuel A, & Soures, John. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD). United States.
Skupsky, Stanley, Kessler, Terrance J, Short, Robert W, Craxton, Stephen, Letzring, Samuel A, and Soures, John. 1991. "System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)". United States. https://www.osti.gov/servlets/purl/867984.
@article{osti_867984,
title = {System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)},
author = {Skupsky, Stanley and Kessler, Terrance J and Short, Robert W and Craxton, Stephen and Letzring, Samuel A and Soures, John},
abstractNote = {In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies ("colors") cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers.},
doi = {},
url = {https://www.osti.gov/biblio/867984}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1991},
month = {Tue Jan 01 00:00:00 EST 1991}
}