Design and performance of an automated video-based laser beam alignment system

Conference · Tue Jul 14 04:00:00 EDT 1992

OSTI ID:6366229

Rundle, W J ^[1]; Kartz, M W ^[2]; Bliss, E S; English, Jr, R E; Peterson, R L; Thompson, G R; Uhlich, D M ^[3]

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1. Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
2. KMI Energy, Inc., Livermore, CA (United States)
3. Lawrence Livermore National Lab., CA (United States)

This paper describes the design and performance of an automated, closed-loop, laser beam alignment system. Its function is to sense a beam alignment error in a laser beam transport system and automatically steer mirrors preceding the sensor location as required to maintain beam alignment. The laser beam is sampled by an optomechanical package which uses video cameras to sense pointing and centering errors. The camera outputs are fed to an image processing module, which includes video digitizers and uses image storage and software to sense the centroid of the image. Signals are sent through a VMEbus to an optical device controller'' (ODC), which drives stepper-motor actuators on mirror mounts preceding the beam-sampling location to return the beam alignment to the prescribed condition. Photodiodes are also used to extend the control bandwidth beyond that which is achievable with video cameras. This system has been operated at LLNL in the Atomic Vapor Laser Isotope Separation (AVLIS) program to maintain the alignment of copper and dye laser beams, the latter to within [plus minus]2 [mu]r in pointing and less than 1 mm in centering. The optomechanical design of the instrumented package, which includes lens, mirror, and video mounts in a rigid housing, the automated control system architecture, and the performance of this equipment is described.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6366229
• Report Number(s): UCRL-JC-109276; CONF-920792--57; ON: DE93012571
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
070100* -- Physical Isotope Separation
440600 -- Optical Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
ALIGNMENT
AUTOMATION
BEAM TRANSPORT
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
DESIGN
ELECTROMAGNETIC RADIATION
ISOTOPE SEPARATION
LASER ISOTOPE SEPARATION
LASER RADIATION
MIRRORS
ON-LINE CONTROL SYSTEMS
ON-LINE SYSTEMS
PERFORMANCE
RADIATIONS
SEPARATION PROCESSES