title: Improved stabilization of a 1.3 microm femtosecond optical frequency comb by use of a spectrally tailored continuum from a nonlinear fiber grating.
abstract: We report significant enhancement (+24 dB) of the optical beat note between a 657 nm cw laser and the second-harmonic generation of the tailored continuum at 1314 nm generated with a femtosecond Cr:forsterite laser and a nonlinear fiber Bragg grating. The same continuum is used to stabilize the carrier-envelope offset frequency of the Cr:forsterite femtosecond laser and permits improved optical stabilization of the frequency comb from 1.0 to 2.2 microm. Using a common optical reference at 657 nm, a relative fractional frequency instability of 2.0 x 10(-15) is achieved between the repetition rates of Cr:forsterite and Ti:sapphire laser systems in 10 s averaging time. The fractional frequency offset between the optically stabilized frequency combs of the Cr:forsterite and Ti:sapphire lasers is +/-(0.024 +/- 6.1) x 10(-17).
authors.affiliation: National Institute of Standards and Technology, Boulder, Colorado 80305, USA. kskim@boulder.nist.gov
authors.forename: K
authors.initials: K
authors.lastname: Kim
authors.forename: S A
authors.initials: SA
authors.lastname: Diddams
authors.forename: P S
authors.initials: PS
authors.lastname: Westbrook
authors.forename: J W
authors.initials: JW
authors.lastname: Nicholson
authors.forename: K S
authors.initials: KS
authors.lastname: Feder