New Co-containing glass ceramics saturable absorbers for 1.5 μm solid state lasers

摘要

New saturable absorber Q-switch for 1.54 μm Er:glass laser is presented The saturable absorber is transparent glass ceramic containing magnesium-aluminum spinel nanocrystallites doped with tetrahedrally coordinated Co~(2+) ions. Q-switched pulses of up to 5.5 mJ in energy and 80 ns in duration at 1.54 μm were achieved. Relaxation time of the ~4A_2→~4T_1(~4F) transition bleaching was measured to be (450+150) ns. Ground-state and excited-state absorption cross-sections at 1.54 μm wavelength were estimated to be (3.2+-0.4)xl0~(-19) cm~2 and (5.0+-0.6)xl0~(-20) cm~2, respectively. Results of study of absorption and luminescence spectra of different glass ceramics on the base of magnesium-aluminum, zink-aluminum, lithium-aluminum spinel nanocrystallites doped with tetrahedrally coordinated Co~(2+) ions are also analyzed.