title: Reference-free, high-resolution measurement method of timing jitter spectra of optical frequency combs.
abstract: Timing jitter is one of the most important properties of femtosecond mode-locked lasers and optical frequency combs. Accurate measurement of timing jitter power spectral density (PSD) is a critical prerequisite for optimizing overall noise performance and further advancing comb applications both in the time and frequency domains. Commonly used jitter measurement methods require a reference mode-locked laser with timing jitter similar to or lower than that of the laser-under-test, which is a demanding requirement for many laser laboratories, and/or have limited measurement resolution. Here we show a high-resolution and reference-source-free measurement method of timing jitter spectra of optical frequency combs using an optical fibre delay line and optical carrier interference. The demonstrated method works well for both mode-locked oscillators and supercontinua, with 2 × 10-9fs2/Hz (equivalent to -174 dBc/Hz at 10-GHz carrier frequency) measurement noise floor. The demonstrated method can serve as a simple and powerful characterization tool for timing jitter PSDs of various comb sources including mode-locked oscillators, supercontinua and recently emerging Kerr-frequency combs; the jitter measurement results enabled by our method will provide new insights for understanding and optimizing timing noise in such comb sources.
authors.affiliation: School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
authors.forename: Dohyeon
authors.initials: D
authors.lastname: Kwon
authors.affiliation: School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
authors.forename: Chan-Gi
authors.initials: CG
authors.lastname: Jeon
authors.affiliation: School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
authors.forename: Junho
authors.initials: J
authors.lastname: Shin
authors.affiliation: Center for Time and Frequency, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea.
authors.forename: Myoung-Sun
authors.initials: MS
authors.lastname: Heo
authors.affiliation: Center for Time and Frequency, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea.|Science of Measurements Program, University of Science and Technology (UST), Daejeon 34114, Korea.
authors.forename: Sang Eon
authors.initials: SE
authors.lastname: Park
authors.affiliation: School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Youjian
authors.initials: Y
authors.lastname: Song
authors.affiliation: School of Mechanical and Aerospace Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
authors.forename: Jungwon
authors.initials: J
authors.lastname: Kim