Wavefront correction system based on an equilateral triangular arrangement of actuators
- Lawrence Livermore National Lab., CA (United States)
Atomic Vapor Laser Isotope Separation (AVLIS) requires the copropagation of multiple beams at different wavelengths and at average powers exceeding 1 kW. Although mirror coatings are used that absorb less than one part in 10{sup 5}, the beams still suffer from thermally induced phase distortions, both in the dye amplifiers and in transmissive optics, such as beam combiners and vacuum windows. These aberrations are 2nd-order and 3rd-order and can reach 5 waves peak-to-valley (p-v), which causes the beam to distort and break up when propagated over large distances. The magnitude of the aberrations scales with power, with time constants on the order of 30 seconds. Previous adaptive systems that have been developed corrected these thermally induced phase distortions of both 2nd-order and 3rd-order; however, these systems had limited spatial resolution and in some cases marginal stability. The authors have developed a new adaptive optics system where both the actuators of the deformable mirror and the lenslets of the Hartmann sensor are arranged with centers at the vertices of equilateral triangles. The wavefront sensor is a video Hartmann sensor that also uses an equilateral array of lenslets. The controller hardware uses a VME bus. The design minimizes the generation of reflected wavefronts higher than first order across each lenslet for large excursions of actuators from positions where the mirror is flat and, thus maximizes the precision of the slopes measured by the Hartmann sensor. The design is also immune to the waffle mode that is present in the reconstructors of adaptive optics systems where actuators are arranged in a square array.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 10172275
- Report Number(s):
- UCRL-JC-112655; CONF-930220-2; ON: DE93017219; TRN: 93:016694
- Resource Relation:
- Journal Volume: 1920; Conference: Conference on smart structures and materials, Albuquerque, NM (United States), 1-4 Feb 1993; Other Information: PBD: Feb 1993
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
LASER ISOTOPE SEPARATION
OPTICAL SYSTEMS
DESIGN
LASERS
RADIATION TRANSPORT
LASER RADIATION
LASER MIRRORS
VACUUM SYSTEMS
WINDOWS
CHROMATIC ABERRATIONS
CORRECTIONS
ACTUATORS
PERFORMANCE
CONTROL EQUIPMENT
MACH-ZEHNDER INTERFEROMETER
ALGORITHMS
COMPUTERIZED CONTROL SYSTEMS
DEFORMATION
070100
050500
PHYSICAL ISOTOPE SEPARATION
URANIUM ENRICHMENT