Spectral asymmetry by group velocity dispersion and self-phase modulation in hybridly mode-locked Rh6G dye laser with a pair of Brewster prisms

摘要

In a hybridly mode-locked continuous-wave dye laser with a Rh6G saturable gain and a 3,3'-diethyloxadicarbocyanine iodide saturable absorber, a pair of Brewster prisms were used to control the group velocity dispersion (GVD), Chirped spectra induced by GVD were dominant in the case of excess GV'D compensations. The spectral asymmetry between excess positive and negative GVD compensation cases, whs observed. Meanwhile, up-chirp due to the self-phase modulation was dominant in case of proper GVD compensation. We also described the behaviour of linear chirped spectra and fitted the measured spectra with a linear chirp parameter.