Precise control of femtosecond Ti:sapphire laser frequency comb

Phase controlled Femtosecond Ti:sapphire laser frequency comb have been widely used in measurement of absolute optical frequency, which is the revolutionary progress in the optical metrology. In this paper, based on the home-made 90MHz femtosecond Ti:sapphire laser, we firstly broadened the spectrum output directly from the laser to more than one octave with a piece of photonic crystal fiberthen locked precisely both the repetition rate and the carrier-envelope phase offset frequency to the same Cs clock with the stability of 6×1014 by use of two sets of different phase-locked loops. As a result, we obtained the phase controlled Femtosecond laser frequency comb with the stability of the Cs clock.