POLARIZED WAVE SEPARATION TYPE SINGLE MODE OPTICAL FIBER COUPLER

摘要

PURPOSE:To demultiplex and multiplex two polarized wave components by selecting structure parameters and in-use wavelength so that a specific relation is established between two polarization modes as basic modes of two single mode optical fibers. CONSTITUTION:Elliptic core type constant-polarization fibers A and B are used as two signal-mode optical fiber type waveguides and polished from the long-axis side and short-axis side of the ellipsed to their cores almost by the long core diameter and short diameter respectively, and the polished surfaces of both fibers are brought into contact with each other to form a coupling part C. At this time, when propagation constants of the fibers A and B in polarization modes HE11x and HE11y as the basic mode of the fibers A and B are denoted as Bax and Bay, and Bbx and Bby, structure parameters such as the core diameters of, diffraction index difference between, core noncircularity of the fibers A and B, etc., and in-use wavelength lambda are so selected that expressions hold. thus, the two polarized wave components are demultiplexed and multiplexed.