All in fiber optical frequency metrology by selective Brillouin amplification of single peak in an optical comb.

Suitable use of stimulated Brillouin amplification (SBA) effect for selective single peak amplification in an optical frequency comb is demonstrated to provide high accuracy in optical frequency metrology. A pump wave generated by a tunable laser source (TLS) is used to stimulate SBA of such optical comb along an optical fiber and selectively amplify only one single peak of the comb. Nature of SBA preserves both linewidth and absolute wavelength position of the selected comb peak. All of these features result in a simple, robust and compact all in fiber system. Relative optical frequency accuracy in the order of Hz is confirmed.