Time-Dependent Oscillations in a cw HF Chemical Laser Unstable Resonator

Abstract

The multi-line performance of a cw HF chemical laser was measured as a function of the SF6 and H2 flow rates, pressure and resonator type. The Blase II and MNORO3 cw chemical laser computer codes gave reasonable agreement with the experimental data as the flow rates and pressure were varied. Total power and beam diameter increased as the pressure decreased. The data indicate the occurrence of a near resonant energy transfer from v=2, J=3, 4 to v=2, J=14 with a subsequent rotational cascade to v=2, J=11. The amplitude, frequency and Fresnel number dependence of the time-dependent oscillations which were predicted to occur on lines whose saturated gain does not fill the unstable resonator were measured. The time-dependent oscillations had a period of abour 40 ns independent of flow rates, do not occur for Fresnel numbers less than 1.5 and their amplitudes increased as the fraction of the resonator filled by the saturated gain of the oscillating line decreased.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADA142966

Entities

People

  • S. W. Towsend

Organizations

  • Air Force Institute of Technology

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Amplitude Modulation
  • Analyzers
  • Chemical Kinetics
  • Chemical Lasers
  • Detectors
  • Energy Transfer
  • Frequency
  • Geometry
  • High Pressure
  • Laser Resonators
  • Lasers
  • Measurement
  • Optics
  • Optomechanics
  • Plastic Explosives
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Mathematics or Statistics
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers