Co2+-Doped Glass Ceramic as Saturable Absorber Q Switch for 1.54 µm Er-Glass Laser

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.