Cobalt-doped transparent glass ceramic as a saturable absorber Q switch for erbium:glass lasers

摘要

A new saturable absorber Q switch for 1.54-μm Er:glass lasers is presented. The saturable absorber is a transparent glass ceramic that contains magnesium-aluminum spinel nanocrystallites doped with tetrahedrally coordinated Co~(2+) ions. We obtained Q-switched pulses of up to 5.5 mJ in energy and 80 ns in duration at 1.54 μm. The relaxation time of ~(4)A_(2)→~(4)T_(1)(~(4)F) 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)×10~(-19) cm~(2) and (5.0±0.6)×10~(-20) cm~(2), respectively.