METHOD AND DEVICE FOR POLARIZED INDEPENDENT OPTICAL DEMULTIPLEXING

摘要

PROBLEM TO BE SOLVED: To unnecessitate a strict mounting operation and the use of a long part of an expensive special fiber by reflecting separate mixed signals caused by polarization turning and combining the mixed signals at a polarization maintenance fiber part. SOLUTION: Both a signal to be demultiplexed and a control signal are divided into two orthogonally polarized components temporally separated by a polarized maintenance fiber 14, and four wave mixing along a dispersion- shifting fiber 15 generates a pair of pulses separated as much as time being equal to group delay of the two components. Two pulses going out of a filter 16 are sent to a Faraday mirror 17, reflected while turning those polarization by 90 degrees and sent toward a circulator 13 through the filter 16. When they are inputted to the circulator 13 again, the pulses corresponding to two polarization modes are recombined to be a simple pulse. The pulse goes out through the 2nd output port of the circulator 13 and is sent to a system receiver through a fiber 18.