Using cross phase modulation in optical fiber to transfer optical frequency combs to arbitrary center frequencies

Summary form only given. In optical frequency metrology, it is often necessary to precisely bridge THz frequency gaps. Optical frequency combs (OFC) are one technique that have recently attracted interest. Key characteristics of OFCs include consistency of comb line spacing, center wavelength, and comb width. Previous OFCs have been constructed by placing an electro-optic modulator inside a high-finesse optical cavity. Recently we have developed a second technique to generate an OFC using cross phase modulation (XPM) in optical fiber. By copropagating a frequency stabilized cw laser and a femtosecond (fs) pulse train through an optical fiber, a frequency comb with spacing equal to the repetition frequency of the pulse train is written onto the cw laser via XPM.