CW lasing in Yb{sup 3+} : GGG crystals pumped at 0.925 {mu}m

Single-mode cw lasing was obtained for the first time in Yb{sup 3+} : GGG crystals at room temperature at 1.030 and 1.037 {mu}m upon pumping Yb{sup 3+} ions by a 0.925-{mu}m neodymium-doped fibre laser. Lasing was observed at the transitions between the lower Stark sublevel of the {sup 2}F{sub 5/2} level and the upper Stark sublevels of the {sup 2}F{sub 7/2} ground state of Yb{sup 3+} ions. The study of lasing characteristic showed that lasing occurs according to the four-level scheme. The lasing threshold with respect to the absorbed power was 85 mW and the slope lasing efficiency was 20%. Upon 1.7-W pumping, the output power of 310 mW was achieved with the output resonator mirror with the transmission coefficient of 1%. The effective cross section of the lasing transition was 0.9x10{sup -20} cm{sup 2}. (special issue devoted to the 90th anniversary of a.m. prokhorov)