Accession Number:

ADA550619

Title:

Implementing Digital Feedback Controls for the Multiple Simultaneous Ring Cavities in the FASOR-X System

Descriptive Note:

Corporate Author:

AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE

Report Date:

2011-09-01

Pagination or Media Count:

9.0

Abstract:

Precision tuned high power 50W 589nm generation for use in laser sodium guidestar generation is a key capability in todays modern adaptive optical systems. The approached used is Sum-Frequency Generation SFG of 1319nm and 1064nm lines of NdYAG in an LBO crystal. High power narrow line sources are not commercially available, so low power narrow-band NPRO sources are mated with resonantly tuned high power ring lasers to achieve high power pumps. Efficient conversion of 589nm requires high pump intensities within the LBO crystal, therefore a doubly-resonant ring cavity is used. Four implementations of the Pound-Drever-Hall method are applied to achieve these. Finally, precision wavelength tuning is required to generate the correct wavelength as measured by a Wavemeter and verified by a low pressure Na-cell. These multiple control loops are all interconnected, to some degree, with various physical requirements, constraints, and caveats. Like any worthwhile project, the systems integration of the control systems has been an educational endeavor.

Subject Categories:

  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE