Adaptive polarization adjustment apparatus for controlling polarization of light inputted to polarization-maintaining waveguide components

摘要

A nonlinear birefringent waveguide is used for four wave mixing, wavelength conversion, Raman amplification, etc. In order to adjust the polarization of the input light to such waveguide (14), a polarization controller (10) is provided. And at the output side of the waveguide (14), a power divider (20) and a polarization selective unit (22) are provided. The power of the light passed by the polarization selective unit (22) is detected at photodiode (13). The detection signal of the photodiode (13) is fed back to the polarization controller (10). The polarization controller (10) controls the polarization input light so that the power of light detected at the photodiode (13) is minimized.