title: Fractional-length sync-pumped degenerate optical parametric oscillator for 500-MHz 3-μm mid-infrared frequency comb generation.
abstract: We demonstrate a mid-IR frequency comb centered at 3120 nm with 650-nm (20-THz) bandwidth at a comb-teeth spacing of 500 MHz. The generated comb is based on a compact ring-type synchronously pumped optical parametric oscillator (SPOPO) operating at degeneracy and pumped by a mode-locked Er-doped 1560 nm fiber laser at a repetition rate of 100 MHz. We achieve high-repetition rate by using a fractional-length cavity with a roundtrip length of 60 cm, which is one-fifth of the length dictated by conventional synchronous pumping.
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Ingold
authors.forename: Alireza
authors.initials: A
authors.lastname: Marandi
authors.forename: Charles W
authors.initials: CW
authors.lastname: Rudy
authors.forename: Konstantin L
authors.initials: KL
authors.lastname: Vodopyanov
authors.forename: Robert L
authors.initials: RL
authors.lastname: Byer