Self-Pumped Phase Conjugation in Barium Titanate with High Intensity Nanosecond Pulses,

Abstract

An investigation of self-pumped phase conjugation in barium titanate is made using nanosecond pulses (15 ns) derived from a repetitively pulsed (10 Hz) and frequency-doubled Nd:YAG laser system (532 nm wavelength). It is experimentally shown that high reflectivity (> 20 %) can be achieved. It is also shown that there is a progressive decrease in the reflectivity of both the corner-pumped and ring-passive geometries at pulse intensities of > 4 MW/sq.cm. At these intensity levels a high photo-carrier population is induced, altering the relative concentrations of Fe(2+) and Fe(3+) centres and leading to a strong intensity-dependent competition between hole and electron photoconductivity. For the corner-pumped geometry the intensity-dependence of the phase conjugate reflectivity is shown. The reflectivity increases with pulse intensity up to 20%. Small change in reflectivity occurs in the range 0.5 to 4 M/cm2 but a dramatic decrease in the reflectivity occurs at intensity > 4 MW/sq.cm.

Document Details

Document Type
Technical Report
Publication Date
May 22, 1992
Accession Number
ADP006782

Entities

People

  • M. J. Damzen
  • N. Barry

Organizations

  • Imperial College London

Tags

DTIC Thesaurus Topics

  • Barium
  • Barium Titanates
  • Geometry
  • Intensity
  • Materials
  • Nanosecond Time
  • Phase Conjugation
  • Photorefractive Materials
  • Reflectivity
  • Titanates
  • Yag Lasers

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Microelectronics