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Title: Generation of low-divergence laser beams

Abstract

Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonatormore » cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.« less

Inventors:
 [1]
  1. (108 Independent Blvd., Aiken, SC 29801)
Issue Date:
Research Org.:
WESTINGHOUSE SAVANNAH RIVER CO
OSTI Identifier:
868924
Patent Number(s):
5245619
Assignee:
Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801) SRS
DOE Contract Number:  
AC09-89SR18035
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
generation; low-divergence; laser; beams; apparatus; transforming; conventional; beam; coherent; light; gaussian; energy; distribution; relatively; divergence; approximates; single; non-zero-order; bessel; function; comprises; zone; plate; transmitting; reflecting; zones; defined; pattern; interference; produced; combination; concentric; array; multiple; annuli; preferably; recorded; hologram; form; photo-etching; portions; layer; deposited; material; containing; approximately; 50; incident; passing; reflected; redirected; direction; parallel; transmitted; alternatively; filter; similar; placed; resonator; cavity; front; mirror; rear; axially; aligned; mirrors; inside; generate; source; interference pattern; axially aligned; laser beams; apparatus comprises; laser beam; light beam; light beams; beam energy; energy distribution; laser source; layer deposited; incident beam; reflected beam; coherent light; resonator cavity; apparatus comprise; gaussian beam; containing approximately; reflecting layer; axially align; low-divergence laser; conventional laser; /372/359/

Citation Formats

Kronberg, James W. Generation of low-divergence laser beams. United States: N. p., 1993. Web.
Kronberg, James W. Generation of low-divergence laser beams. United States.
Kronberg, James W. Fri . "Generation of low-divergence laser beams". United States. https://www.osti.gov/servlets/purl/868924.
@article{osti_868924,
title = {Generation of low-divergence laser beams},
author = {Kronberg, James W.},
abstractNote = {Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1993},
month = {1}
}

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