title: Direct comparison of optical frequency combs using a comb-injection-lock technique.
abstract: This paper demonstrates a direct comparison of optical frequency combs (OFCs) with different repetition rates without a stable intermediate laser using a single-mode comb-injection-lock technique. Two OFCs based on Ti:Sapphire mode-locked lasers were compared utilizing a single-mode diode laser for the selection and the amplification of one mode of an OFC by comb-injection, which makes the direct comb comparison possible. The frequencies of the two combs were found to agree within 0.019 Hz at 352 THz with the uncertainty of 0.25 Hz (7.1 x 10(-16) ). This is one of the best results among the comparisons of combs referenced to a microwave frequency. This technique simplifies the comb comparison utilities and can be applied even when repetition rates differ.
authors.affiliation: Division of physical Metrology, Korea Research Institute of Standards and Science,1 Doryong-Dong, Yuseong-Gu, Daejeon 305-340, Korea.
authors.forename: E B
authors.initials: EB
authors.lastname: Kim
authors.forename: W K
authors.initials: WK
authors.lastname: Lee
authors.forename: C Y
authors.initials: CY
authors.lastname: Park
authors.forename: D H
authors.initials: DH
authors.lastname: Yu
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: S E
authors.initials: SE
authors.lastname: Park
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D004867:Equipment Design; D007834:Lasers; D008872:Microwaves; D055095:Optics and Photonics; D015203:Reproducibility of Results; D014025:Titanium / Q000737:chemistry
chemical_list: D014025:Titanium; D000537:Aluminum Oxide