An extended cavity femtosecond Cr:LiSAF laser pumped by low cost diode lasers.

We describe an extended cavity femtosecond Cr:LiSAF laser pumped by inexpensive single spatial mode diodes. Using a multi-pass cavity (MPC) to lower the repetition rate and a saturable Bragg reflector (SBR) for mode-locking, pulse energies of 0.75 nJ at a repetition rate of 8.6 MHz are achieved with durations of 39 fs and bandwidths of 20 nm in a prismless configuration. Pulse energies of 0.66 nJ at a repetition rate of 8.4 MHz with durations of 43 fs and bandwidths of 18.5 nm are generated using prisms for dispersion compensation. This laser offers performance approaching that of standard Ti:sapphire lasers at a fraction of the cost.