Recently, lasers with cylindrical polarization have gained much interest, as the rotational symmetry of the state of polarization (i.e. radial or azimuthal polarization) leads to benefits in laser material processing. The ultra-short pulse regime at high average powers if of particular interest. Yb-doped YAG single crystalline waveguides, so-called “single crystal fibers” (SCF) have shown promising properties for the design of simple and highly efficient amplifier schemes for the amplification of ultra-short pulses to high average powers and high energies in recent publications.
As the amplification of radially and azimuthally polarized laser beams is demanding with common amplifier designs, experiments have been carried out at the IFSW in collaboration with the LCFIO and Fibercryst in order to investigate the use of SCF amplifiers for the amplification of cylindrically polarized laser beams. For both azimuthal and radial polarization, up to 100 W of output power (CW) have been demonstrated so far at a input powers of 32 W, which corresponds to a single-pass amplification factor of about 3. The low depolarization losses that were measured even at high pump powers of up to 515 W particularly underline the suitability of SCF amplifiers for the amplification to high average powers. Further experiments in order to investigate the performance of SCF-based amplifiers for radially and azimuthally polarized ultrashort pulses are under preparation.
S. Piehler, X. Délen, M. Rumpel, J. Didierjean, N. Aubry, T. Graf, F. Balembois, P. Georges, M. Abdou Ahmed, „ Amplification of cylindrically polarized laser beams in single crystal fiber amplifiers“, Optics Express 21, 9 (2013) 11376-11381 http://www.opticsinfobase.org/oe/viewmedia.cfm?URI=oe-21-9-11376&seq=0&origin=search
Spotlight on Optics: http://www.opticsinfobase.org/spotlight/summary.cfm?uri=oe-21-9-11376&ori
Contact: Dr. Marwan Abdou Ahmed