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Colloquium: Femtosecond Optical Frequency Combs



S T. Cundiff, Jun Ye


Recently there has been a remarkable synergy between the technology of precision laser stabilization and modelocked ultrafast lasers. This has resulted in control of the frequency spectrum produced by modelocked lasers, which consists of a regular comb of sharp lines. Thus such a controlled modelocked laser is a femtosecond optical frequency comb generator. For a sufficiently broad comb, it is possible to determine the absolute frequencies of all of the comb lines. This has revolutionized optical frequency metrology and synthesis. It has also served as the basis for the recent demonstrations of atomic clocks that utilize an optical frequency transition. In addition, it is having an impact on time-domain applications, including synthesis of a single pulse from two independent lasers. In this colloquium, we first review the frequency domain description of a modelocked laser and the connection between the pulse phase and frequency spectrum. This provides the basis for understanding how the absolute frequencies can be determined and controlled. Using this understanding, applications in optical frequency metrology and synthesis and optical atomic clocks are discussed. This is followed by a brief overview of how the comb technology is affecting and will affect time domain experiments.
Reviews of Modern Physics


carrier-envelope phase, optical frequency metrology, ultrafast lasers


Cundiff, S. and Ye, J. (2021), Colloquium: Femtosecond Optical Frequency Combs, Reviews of Modern Physics (Accessed April 24, 2024)
Created October 12, 2021