High-energy, high-brightness Q-switched TM3+-doped fiber laser using an electro-optic modulator

Q-switched operation of a 2 mum Tm3+-doped silica fiber laser using an electro-optic modulation (EOM) is described for the first time. A larger multimode core of 17 mum diameter is used to increase the laser gain volume and achieve higher pulse energy. Experimentally this laser produced pulses with a peak power of similar to3.3 kW at a low repetition rate of 70 Hz and a pulse energy up to 2.3 mJ, limited by excited state absorption with only slightly compromized spatial-mode quality (M-2 similar to 1.5). This approach using an EOM offers significant scope for extending the range of single-mode output powers and energies that are achievable from fiber lasers and amplifier systems. (C) 2003 Elsevier Science B.V. All rights reserved.