Patent ID: 6882760
Filing Date: 2005-04-19
Classification: G02F,H04B

Abstract:
1. A polarization dispersion compensation apparatus comprising: polarization control means for controlling a polarization state of an optical signal so that a polarization axis of the optical signal substantially coincides with an optical axis of an optical transmission line; polarization beam splitter means for splitting an optical signal output from said polarization control means, and outputting optical signals having polarized components perpendicular to each other; optical delay means including two optical transmission lines having lengths different from each other, and causing a difference in delay between the polarized components of the optical signal output from said polarization beam splitter means; and polarization beam combiner means for combining the polarized components of the optical signal output from said optical delay means, and outputting a combined optical signal, wherein said polarization beam combiner means comprises a second symmetric Mach-Zehnder interferometer having optical transmission lines in third and fourth arm portions, and at least one of the third and fourth arm portions comprising second refractive index control means for controlling refractive index for the optical signal propagating through the optical transmission line of the arm portion and second birefringence means for causing birefringence in the optical signal propagating through the optical transmission line of the arm portion.