Accession Number:

ADA244056

Title:

Coherent Cooperative Radiation in Solids

Descriptive Note:

Final rept. 1 May 90-31 Oct 91,

Corporate Author:

MICHIGAN UNIV ANN ARBOR DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE

Personal Author(s):

Report Date:

1991-10-30

Pagination or Media Count:

43.0

Abstract:

Avalanche upconversion dynamics and associated nonlinear optical response was also reported for the first time in TmYALO crystals at room temperature. The avalanche mechanism involves a cooperative down conversion cross relaxation step and is a promising method of pumping rare earth lasers at entirely new diode compatible wavelengths, corresponding to excited state absorptions rather than ground state absorptions. Quantum theory describing the threshold for photo-darkening and the role of energy migration in avalanches was developed, and semi quantitative agreement obtained with preliminary measurements of nonlinear susceptibilities. Cooperative dynamics in general, and avalanche dynamics in particular, were shown to furnish a promising new mechanism not only for solid state lasers but for nonlinear optical interactions as well, opening the door to practical signal processing and switching applications exploiting the low intensity thresholds of avalanche processes.

Subject Categories:

  • Lasers and Masers
  • Quantum Theory and Relativity
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE