Polarized single transverse mode Yb-doped fiber laser generating up to 200 µJ/6 W with flexible pulse parameters

Tim Lauterborn, Stefan Heinemann and A. Galvanauskas

Fraunhofer USA, Center for Laser Technology, 46025 Port Street, Plymouth, MI 48170, P: 734 354 6300 x. 203, F: 734 354 3335, tlauterborn@clt.fraunhofer.com  

Abstract:

We demonstrate a polarized, pulsed single transverse mode Yb-doped fiber laser that can be operated in a wide range of pulse lengths and repetition rates.  The pulsed 1064 nm beam of a single mode diode laser is amplified by a three stage fiber amplifier. Polarization maintaining fibers are used throughout the system. It consists of two pre-amplification stages that incorporate single-mode fibers. The third stage employs a LMA fiber with 30 µm diameter core and 0.06 NA. A monolithic setup is achieved by a taper between the 6 µm core of the pre-amplification stages and the 30 µm core LMA fiber of the third stage exciting only the fundamental mode in the LMA fiber.  Variable pulse regimes were investigated with a maximum output energy of 200 µJ at 8 ns pulse length and 10 kHz repetition rate. An average output power of 6 W was measured at 8 ns pulse length and 100 kHz repetition rate.