Efficient 1 GHz Ti:sapphire laser with improved broadband continuum in the infrared

We demonstrate a 1 GHz prismless femtosecond Ti:sapphire ring laser that emits 890 mW for 7.6 W of pump power over a continuum extending from 585 to 1200 nm at -20 dB below the maximum. A broadband continuum is obtained with the net cavity group delay dispersion having -50 to 100 fs2 oscillations from 700 to 900 nm. Further broadening is obtained by use of a slightly convex cavity mirror that increases self-phase modulation. Approximately 17% (75%) of the intracavity (output) power is generated in single pass through the crystal, outside the cavity bandwidth, and concentrated in the low-gain IR from 960 to 1200 nm.