The relative effectiveness of the major absorption bands in producing fluorescence of the neodymium ion in glass was investigated. The chief result was that the conversion efficiency, the number of fluorescence photons per absorbed photon, was nearly independent of the absorption band pumped. For 5% Nd in barium crown glass, the conversion efficiency was 0.43 for the total fluorescence, and 0.26 for the 1.06-µ fluorescence.
L. G. DESHAZER and L. G. KOMAI, "Fluorescence Conversion Efficiency of Neodymium Glass," J. Opt. Soc. Am. 55, 940-941 (1965)