We report fixed point variations of a frequency comb generated by a passively mode-locked fiber laser. We measured the pump induced changes in the repetition frequency and the carrier-envelope offset frequency in slightly different intracavity polarization states. The responses of the two frequencies varied by changing the polarization state. Each frequency had a specific polarization state in which it did not depend on the pump power. The fixed point for a pump induced change varied across ~1 PHz range. This study shows the possibility of realizing a robust and low-noise frequency comb.
2017 by The Institute of Electronics, Information and Communication Engineers