Observation of Polarization Switching and Pulse Break-Up in Spun Fiber

Abstract
The nonlinear directional coupler (NLDC) [1] is a promising element for ultra-fast all-optical signal processing. The experiments have demonstrated self-switching of light in fiber-optic NLDC's, such as dual-core fibers [2-3], birefringent fibers [4], and periodically twisted birefringent filters [5]. Fiber-optic nonlinear couplers exhibit an istantaneous Kerr-law response, which permits femtosecond pulse switching [3]. Whereas with fiber-optic switches the switching power is relatively high, owing to the weakness of the fused quartz nonlinearity.