title: Femtosecond laser pumped by high-brightness coherent polarization locked diodes.
abstract: We demonstrate, for the first time to our knowledge, the use of a coherent polarization locked diode as the high-brightness pump source for a femtosecond laser. Four diode emitters are coherently locked to produce more than 5 W linearly polarized, narrow linewidth, and single-lobed pump beam. This gives >10× brightness improvement over the conventional diode array. The diode beam is then used to pump a Yb:KYW laser to obtain 2 W output with 57% slope efficiency in cw laser operation. By using a saturable absorber mirror, we achieved cw mode-locking operation with a 177 fs pulse width at an average power of 0.55 W.
authors.affiliation: Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553, Singapore.
authors.lastname: Purnawirman
authors.forename: P B
authors.initials: PB
authors.lastname: Phua