LASER AND ABSORPTION SATURATION MEASUREMENTS OF CR4-BAND PULSED 940 NM RADIATION( CRYSTALS, PUMPED BY BROAD)

The characteristics of a 940 nm pumped Cr4+:forsterite laser have been investigated using a pulsed colour centre laser as the excitation sou rce, Laser threshold, slope efficiency and temporal behaviour have bee n determined for high and low Cr4+ doped material. 940 nm pumping is f ound to be more efficient than 532 and 730-770 nm excitation. Discrepa ncies with 1064 nm pumping are attributed to excited state absorption. Absorption saturation measurements have been used to assess the poten tial applications of Cr4+:forsterite, Cr4+:YAG and Cr4+:Lu3Al5O12 (LuA G) as passive Q-switches for Nd lasers in the 940 nm region. (C) 1998 Elsevier Science Ltd. All rights reserved.