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Title: High power, high beam quality regenerative amplifier

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct themore » beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.« less
Authors:
 [1] ;  [1]
  1. (Livermore, CA)
Publication Date:
OSTI Identifier:
868898
Report Number(s):
US 5239408
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Patent
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Country of Publication:
United States
Language:
English
Subject:
power; beam; quality; regenerative; amplifier; regenerative; laser; amplifier; generates; peak; power; energy; pulse; output; beams; enabling; generation; x-rays; x-ray; lithography; manufacturing; integrated; circuits; laser; amplifier; shaped; optical; path; limited; components; including; polarizer; passive; 90; degree; phase; rotator; plurality; mirrors; relay; telescope; medium; components; placed; close; image; plane; relay; telescope; reduce; diffraction; phase; perturbations; limit; peak; intensity; spiking; beam; makes; passes; medium; transit; optical; path; increase; amplifier; loss; ratio; beam; input; makes; passes; diverted; sbs; phase; conjugator; proceeds; sbs; phase; conjugator; equal; opposite; direction; passes; reducing; phase; perturbations; master; oscillator; inputs; beam; isolation; cell; faraday; pockels; transmits; beam; polarization; rotation; isolation; cell; rotates; polarization; beams; proceeding; direct; beams; amplifier; diffraction; limited; quality; input; beam; preserved; amplifier; power; output; beam; nearly; diffraction; limited; quality; produced; sbs phase; sbs phase; beam quality; pulse output; output beams; shaped optical; image plane; input beam; x-ray lithography; opposite direction; power output; output beam; output beam; optical path; optical path; laser amplifier; laser amplifier; integrated circuits; integrated circuit; peak power; diffraction limited; diffraction limited; master oscillator; components including; regenerative amplifier; regenerative laser; peak intensity; phase conjugator; phase conjugator; degree phase; enabling generation /359/372/