Femtosecond Cr:LiSAF and Cr:LiCAF lasers pumped by tapered diode lasers
U. Demirbas1,4, M. Schmalz1, B. Sumpf2, G. Erbert2, G.S. Petrich3, L.A. Kolodziejski3, J.G. Fujimoto3, F.X. Kärtner3, and A. Leitenstorfer1
Published in:
Opt. Express, vol. 19, no. 21, pp. 20444-20461 (2011).
Abstract:
We report compact, low-cost and efficient Cr:Colquiriite lasers that are pumped by high brightness tapered laser diodes. The tapered laser diodes provided 1 to 1.2 W of output power around 675 nm, at an electricalto- optical conversion efficiency of about 30%. Using a single tapered diode laser as the pump source, we have demonstrated output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% from continuous wave (cw) Cr:LiSAF and Cr:LiCAF lasers, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetition rates around 100 MHz. Upon pumping the Cr:Colquiriite lasers with two tapered laser diodes (one from each side of the crystal), we have observed scaling of cw powers to 850 mW in Cr:LiSAF and to 650 mW in Cr:LiCAF. From the double side pumped Cr:LiCAF laser, we have also obtained ~220 fs long pulses with 5.4 nJ of pulse energy at 77 MHz repetition rate. These are the highest energy levels reported from Cr:Colquiriite so far at these repetition rates. Our findings indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of Cr:Colquiriite systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region (750-1000 nm).
1 Department of Physics and Center for Applied Photonics, University of Konstanz, D-78464 Konstanz, Germany
2 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
3 Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
4 Department of Electrical and Electronics Engineering, International Antalya University, 07190 Antalya, Turkey
OCIS codes:
(140.3460) Lasers; (140.4050) Mode-locked lasers; (140.3580) Lasers, solid-state; (140.3480) Lasers, diode pumped; (140.5680) Rare earth and transition metal solid-state lasers.
© 2011 Optical Society of America. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the Optical Society of America.
Full version in pdf-format.