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Saturable absorber Q-switching of the 1.54 μm Er:glass laser using U4+:SrF2 has been obtained for the first time. Q-switched pulses of 3 mJ, 60 nanoseconds FWHM were achieved using a 2.69 mm thick Q-switch in a 14 cm long flat-flat cavity, with a 3 x 50 mm Kigre QE-7S Englass rod. Pulses of 40 mJ, 64 nanoseconds have been obtained using a 4 x 76 mm Er:glass laser rod. The high absorption cross-section of U4+:SrF2 at 1.54 μm resulted in efficient Q-switched operation (without intracavity focussing) in agreement with the theoretical predictions.

New saturable absorber as magnesium-aluminum-silicate glass ceramic containing tetrahedrally coordinated Co2+ ions for Er:glass laser is presented. Q-switched pulses of 5.5 mJ in energy and 80 ns in duration at 1.54 µm were obtained. Bleaching relaxation time was measured to be ~450 ns. Ground-state absorption cross-section at 1.54 µm was estimated to be 3.3×l0−19 cm2.

Room temperature Er:YAG (0.5, 1, 2 and 4%) lasers at 1 644μ were demonstrated by pumping with an Er glass laser at 1.535 μ. An end pumped arrangement was utilized simulating diode laser pumping. The characteristics ot these low threshold and efficient lasers are described.

The upconversion pumped solid state laser was first reported by L. F. Johnson and H. J. Guggenheim in 1971 with Yb3+ − Er3+ and Yb3+ − Ho3+ in a BaY2F8 crystal.1 Recently, upconversion pumped laser action was obtained by Pollack et. al. on the 4I11/2 → 4I13/2 transition of Er3+ in CaF22 and in SrF2, YAG and YLF.3