Study of Efficiency Improvement of Optically Pumped Ca5(PO4)3F:Nd and Ca5(PO4)3F:Ho, Cr.
Abstract
The report covers a years effort devoted mainly to the investigation of Ca5(PO4)3F doped with Ho(+3) and Cr as a potential laser material in the 2.07 microns region of the spectrum. Four level laser action was attained with thresholds of approximately 20-25 joules at 77K. The laser wavelength is estimated to be 2.075 microns based on spontaneous emission spectroscopy. Spectroscopic data are presented which show Cr to have a very broad absorption extending from approximately 0.45 microns to 1.4 microns. Absorption of pump radiation throughout this band results in efficient transfer of energy from Cr to Ho. This very broad sensitizer excitation band should result in efficient utilization of pump energy. A total of three Ho, Cr doped crystals were grown for laser tests. All of them showed laser action at about the same threshold. In subordinate efforts, a large, 7 inch by 0.4 inch single crystal of Ca5(PO4)3F was grown, doped with Nd. A 6 x 0.3 inch rod fabricated from this crystal gave a slope efficiency of 6.6% at 1.06 microns. Attempts to prepare sensitized Ca5(PO4)3F:Nd rods were unsuccessful. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1969
- Accession Number
- AD0862967
Entities
People
- K. B. Steinbruegge
- N. T. Melamed
- R. H. Hopkins
- R. Mazelsky
- W. E. Kramer