TRANSIENT RADIATION EFFECTS ON RUBY LASERS.
Abstract
The report describes ionizing radiation effects on a ruby laser. Both transient and permanent radiation effects are discussed. The transient cut-off observed in a ruby laser when irradiated is attributed to a transient optical absorption center associated with a O(-) ion trapped at a charge deficient cation site in the Al2O3 lattice. The center has a lifetime of about 10 msec at room temperature. The permanent radiation effects are a reduction of or cessation of laser output. This effect has three causes, color center formation in the pump bands, loss of Cr(3+) by valence change, and a permanent absorption at the R lines. The important effect at the level of 10,000 rad (ruby) is color center formation in the pump bands. A worse case estimate is, ignoring flash lamp bleaching, for a 0.05% Cr(3+), 0.25 inch. diam. rod of 60 deg orientation, (a typical ruby laser rod), that a dose of 10,000 rad (ruby) will reduce the optical pumping by 10%. This means that 10,000 rad (ruby) will shut off a laser operating at 110% threshold. The defects producing the color centers are isolated, remotely charge compensated defects in the lattice. Locally charge compensated defects which involve a Cr(3+) ion are also observed and account for most of the Cr(3+) loss on irradiation. The maximum Cr(3+) loss observed, independent of concentration was 10%. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 20, 1970
- Accession Number
- AD0704069
Entities
People
- Francis J. Campbell
- Joseph J. Halpin
- Richard F. Wenzel
Organizations
- United States Naval Research Laboratory