Tuning power spectrum of semiconductor and intracavity-etalon based modelocked laser via detuning

A report is presented on the tuning of the frequency envelope of a broadband comb source generated from a semiconductor-based modelocked ring laser with an intracavity high finesse Fabry-Pérot etalon (FPE). By deliberately adjusting the matching condition between FPE transmission peaks and lasing optical comb frequencies, ~ 7 nm tuning of more than 200 optical frequency comb lines spaced by 10 GHz is achieved.