A theoretical and experimental investigation for wavelength switchable TmYAG laser modulated by Tm:YAG crystal length

Based on the analysis of the quasi-three-level side pumped Tm:YAG laser system, the oscillating conditions of this laser are predicted from the point of pump threshold. The laser oscillation at 2.02 mu m with larger stimulated emission sections is suppressed when the crystal length is larger than similar to 85 mm with a 5% output coupling and then an efficient side-diode-pumped rod Tm:YAG laser operating at 2.07 mu m is realized. Experimental results are reported from single-module and two-modules Tm:YAG laser and compared with the predictions obtained from the model. The experimental results show that the center wavelength of the Tm:YAG laser is shifted to 2.07 mu m when the Tm:YAG crystal length is switched from 69 mm to 138 mm, which is in well agreement with the predictions obtained from the model. (C) 2014 Elsevier Ltd. All rights reserved.