Stabilizing the frequency of femtosecond Ti:sapphire comb laser by a novel scheme

We demonstrated a novel scheme for scanning the absolute frequencies of a femtosecond Kerr-lens mode-locked Ti:sapphire laser with the repetition rate unaffected, where the carrier-envelop phase of the pulse was controlled by slightly shifting pump beam and the repetition rate was phase locked to a stable radio-frequency oscillator. Since it was the first time to stabilize the frequency of a mode-locked laser by referring directly to the frequency of cesium two-photon-transition (TPT) stabilized diode laser, we evaluated the frequency instability and the frequency accuracy that showed the characteristic of being a comb laser. The feature of the comb laser in this report will be significant for multi-photon spectroscopy where the frequency difference between comb lines plays a key role. PACS  06.30.+v; 42.60.By