Narrow linewidth optical source from a femtosecond comb and O-E-O frequency conversion pair

Single-longitudinal-mode, narrow-linewidth laser has many applications such as coherent optical communication and long distance optical sensing. One traditional way to generate this laser is using long fiber (e.g. several kilometers or even above) cavity combing stimulated Brillouin scattering (SBS) effect [1]. But this structure exists some intrinsic problems such as being sensitive to environment and too small longitudinal-mode interval, which may degrade the performance (e.g. frequency drifting, mode-hop or multi-longitudinal-mode operation). Another way to generate this laser is based on active feedback control, but a high-stable cavity, a high-precise algorithm and a large-bandwidth feedback loop [2] must be satisfied simultaneously. Moreover, the traditional ways can't tune lasing wavelength in wide waveband.