Compact geometry for diode-pumped Cr:LiSAF femtosecond laser

A novel geometry for dispersion compensation in femtosecond lasers without specific cut of optical parts in a flat/Brewster angle or Gires-Tournots mirrors is demonstrated for attaining a compact diode-pumped Cr:LiSAF femtosecond pulse laser. In this geometry, the laser medium lies between the dispersion-compensation prism pair. This approach enables the laser to operate at variable repetition rates from 163 to 235 MHz keeping the pulsewidth less than 90 fs, where the value of the time-bandwidth product are not larger than 0.34. An 89 fs pulse duration generated at the 235 MHz repetition rate is, to our knowledge, the shortest pulse achieved in an all-solid-state Kerr-lens mode-locked laser operating above the 200 MHz repetition rate.