Dahua Zhou

Diode-pumped continuous wave and Q-switched operation of Nd:CaYAlO 4 crystal

The continuous wave (CW) and passively Q-switched performances of Nd:CaYAlO(4) crystal with both a- and c-cut were demonstrated. The CW output powers of 1.15 W and 1.26 W were obtained under the pump power of 8.96 W with slope efficiencies of 15.2% and 16.8% for a- and c-cut samples, respectively. As a result, new dual-wavelength all-solid-state lasers at 1080 nm and 1081 nm were achieved with c-cut crystal. By using Cr(4+):YAG wafer as saturable absorber, we performed Q-switching experiments. The highest average output powers and shortest pulse widths were measured to be 0.798 W, 10.6 ns and 0.537 W, 9.6 ns for a- and c-cut samples, respectively.

Spectral characterization and laser performance of a mixed crystal Nd:(Lu x Y 1-x ) 3 Al 5 O 12

An Nd-doped Lu(1.5)Y(1.5)Al(5)O(12) (Nd:LuYAG) crystal was obtained by Czochralski method. Absorption and emission spectra were recorded at low and room temperature. Continuous wave (CW) and passively Q-switched laser operations of Nd:LuYAG crystal were, to our knowledge, demonstrated for the first time. A CW output power of 1.67 W with slope efficiency of 39.8% was obtained. In the passively Q-switched operation, the shortest pulse width, largest pulse energy, and highest peak power were achieved to be 9.6 ns, 61.7µJ, and 6.4 kW, respectively, with Cr(4+):YAG crystals as the saturable absorbers.

Spectroscopic analysis and lasing of Er:Lu 1.5 Y 1.5 Al 5 O 12 crystals

A high optical quality erbium-doped LuYAG single crystal has been grown by the Czochralski technique. The segregation coefficient of Er3+ was measured to be 1.05. The absorption and emission spectra were measured at room temperature. The spectroscopic parameters were calculated using the Judd–Ofelt (J-O) theory, and the J-O parameters Ωt (t=2, 4, 6) were found to be 0.89×10−20, 1.64×10−20, 1.23×10−20 cm2, respectively. The emission cross section of the Er3+ 4I13/2→4I15/2 transition were calculated by the Fuchtbauer–Ladenburg formula, and the room-temperature fluorescence lifetime of the Er3+ 4I13/2→4I15/2 transition was measured to be 9.9 ms. Finally, promising laser performance with Er:Yb fiber laser pumping is described.