Accession Number : AD0862967

Title :   Study of Efficiency Improvement of Optically Pumped Ca5(PO4)3F:Nd and Ca5(PO4)3F:Ho, Cr.

Descriptive Note : Final technical rept., 10 Dec 67-30 Dec 68,

Corporate Author : WESTINGHOUSE RESEARCH LABS PITTSBURGH PA

Personal Author(s) : Melamed, N. T. ; Steinbruegge, K. B. ; Mazelsky, R. ; Kramer, W. E. ; Hopkins, R. H.

Report Date : JUL 1969

Pagination or Media Count : 98

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)

Descriptors :   *INFRARED RADIATION), (*LASERS, (*HOLMIUM, LASERS), PHOSPHATES, FLUORIDES, CALCIUM COMPOUNDS, NEODYMIUM, DOPING, CRYSTAL GROWTH, FLUORESCENCE, CHROMIUM, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA.

Subject Categories : Lasers and Masers
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE