1 Department of Photonics Engineering, Technical University of Denmark2 Fiber Sensors and Supercontinuum Generation, Department of Photonics Engineering, Technical University of Denmark3 Risø National Laboratory for Sustainable Energy, Technical University of Denmark4 Fraunhofer Gesellschaft
Gain-switching of a CW fiber laser is a simple and cost-effective approach to generate pulses using an all-fiber system. We report on the construction of a narrow bandwidth (below 0.1 nm) gain-switched fiber laser and optimize the pulse energy and pulse duration under this constraint. The extracted pulse energy is 20 μJ in a duration of 135 ns at 7 kHz. The bandwidth increases for a higher pump pulse energy and repetition rate, and this sets the limit of the output pulse energy. A single power amplifier is added to raise the peak power to the kW-level and the pulse energy to 230 μJ while keeping the bandwidth below 0.1 nm. This allows frequency doubling in a periodically poled lithium tantalate crystal with a reasonable conversion efficiency.
Optics Express, 2013, Vol 21, Issue 10, p. 12302-12308