Fluctuating polarization state-of-light in the optical loop is an important factor that seriously influences the output performance of a multi-carrier source based on re-circulating frequency shifter (RFS). The reason for output spectrum instability when no polarization controller (PC) is present in the loop is analyzed theoretically. Numerical simulations for the output spectra of the multi-carrier source with and without PC are conducted, and the trajectories of the several frequency components polarization states on the Poincare sphere with and without PC are compared. The results show that the performance of multi-carrier source based on a RFS can be improved effectively by adjusting the PC in the configuration properly.
© 2012 Chinese Optics Letters
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.2630) Fiber optics and optical communications : Frequency modulation
(230.5440) Optical devices : Polarization-selective devices
Fiber Optics and Optical Communications
Hao Zhou, Lixia Xi, Jianping Li, Xiaoguang Zhang, and Na Liu, "Theoretical analysis of polarization control for the stable output of multi-carrier source based on a re-circulating frequency shifter," Chin. Opt. Lett. 10, 100602-100602 (2012)