The polarization characteristics of electro-optical (EO) switches using fiber Sagnac interferometer (FSI) structures are theoretically investigated. Analytical solutions of output fields are presented when the twists and birefringence in a Sagnac loop are considered. Numerical calculations show that the twists of fiber, the orientation of the inserted phase retarder, and the splitting ratio of the coupler will influence both the output intensity and the output polarization properties of the proposed switch. A polarization-independent EO switch based on a Sagnac interferometer and a PLZT bar was experimentally implemented, which showed good coincidence with the analytical results. The experiment showed a switch with 22 dB extinction ratio and less than 31.1 ns switching time.
© 2006 Optical Society of America
(060.1810) Fiber optics and optical communications : Buffers, couplers, routers, switches, and multiplexers
(060.2310) Fiber optics and optical communications : Fiber optics
(230.5440) Optical devices : Polarization-selective devices
Original Manuscript: May 11, 2005
Manuscript Accepted: October 17, 2005
Feng Liu, Qing Ye, Fufei Pang, Jianxin Geng, Ronghui Qu, and Zujie Fang, "Polarization analysis and experimental implementation of PLZT electro-optical switch using fiber Sagnac interferometers," J. Opt. Soc. Am. B 23, 709-713 (2006)