A 2 μm, gain-switched Tm-doped fiber laser and an amplifier system with an output average power of 9 W at 50 kHz

Abstract

We demonstrate a gain-switched thulium-doped fiber laser and amplifier system (TDFL&A) operating at a wavelength of 1994.7nm. A pulsed fiber Master Oscillator Power Amplifier (MOPA) at 1.55μm was used to gain-switch the Tm fiber laser via in-band pumping. In the next step, the gain-switched pulses were amplified in a cladding-pumped Tm-doped fiber amplifier pumped by up to 30 W at 793nm. For the pulse repetition frequency (PRF) of 100kHz, the laser system delivered the maximum average output power as high as 9.03W with a slope efficiency of 36.4%. For the PRF of 50 kHz, stable 25-ns pulses with energy of 0.18mJ corresponding to a peak-power of 6.8kW were achieved. The performance of the laser system is described. © 2013 Photonics Society of Poland.