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Title: Apparatus and method for increasing the bandwidth of a laser beam

Abstract

A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a "signal beam") and a broadband laser that outputs a vertically polarized beam (a "pump beam") whose intensity varies rapidly. The two beam are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beam; however there is coupling between the two beams as a result of cross phase modulations, which induces a bandwidth change of the signal beam. The amount of bandwidth change is dependent upon the average intensity of the pump beam. The beams are coupled out from the birefringent material and the modulated signal beam is separated by a polarization selector. The modulated signal beam now has a wider bandwidth, and its shape remains smooth in time.more » This signal beam can be applied to incoherence inducing systems. The different bandwidths required by these different incoherence inducing systems can be obtained by varying the intensity of the pump beam. The United States Government has rights in this invention pursuant to Contract No. W7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.« less

Inventors:
 [1]
  1. Bolina, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
867808
Patent Number(s):
5015054
Assignee:
United States of America as represented by Department of Energy (Washington, DC)
Patent Classifications (CPCs):
G - PHYSICS G02 - OPTICS G02F - DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
apparatus; method; increasing; bandwidth; laser; beam; disclosed; provides; output; broad; intensity; smooth; time; varied; easily; varying; broadband; source; optical; modulation; comprising; narrowband; outputs; horizontally; polarized; signal; vertically; pump; varies; rapidly; coupled; birefringent; material; respective; polarizations; coincide; principal; axes; beams; travel; polarization; preserving; properties; maintain; coupling; result; phase; modulations; induces; change; amount; dependent; average; modulated; separated; selector; wider; shape; remains; applied; incoherence; inducing; systems; bandwidths; required; obtained; united; government; rights; pursuant; contract; w7405-eng-48; department; energy; university; california; operation; lawrence; livermore; national; laboratory; laser output; modulated signal; output beam; laser beam; signal beam; apparatus comprising; pump beam; polarized beam; broad band; broad bandwidth; laser material; phase modulation; average intensity; livermore national; national laboratory; intensity varies; lawrence livermore; vertically polarized; horizontally polarized; /385/359/372/

Citation Formats

Chaffee, Paul H. Apparatus and method for increasing the bandwidth of a laser beam. United States: N. p., 1991. Web.
Chaffee, Paul H. Apparatus and method for increasing the bandwidth of a laser beam. United States.
Chaffee, Paul H. Tue . "Apparatus and method for increasing the bandwidth of a laser beam". United States. https://www.osti.gov/servlets/purl/867808.
@article{osti_867808,
title = {Apparatus and method for increasing the bandwidth of a laser beam},
author = {Chaffee, Paul H},
abstractNote = {A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a "signal beam") and a broadband laser that outputs a vertically polarized beam (a "pump beam") whose intensity varies rapidly. The two beam are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beam; however there is coupling between the two beams as a result of cross phase modulations, which induces a bandwidth change of the signal beam. The amount of bandwidth change is dependent upon the average intensity of the pump beam. The beams are coupled out from the birefringent material and the modulated signal beam is separated by a polarization selector. The modulated signal beam now has a wider bandwidth, and its shape remains smooth in time. This signal beam can be applied to incoherence inducing systems. The different bandwidths required by these different incoherence inducing systems can be obtained by varying the intensity of the pump beam. The United States Government has rights in this invention pursuant to Contract No. W7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {1}
}

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