| 摘要 |
PROBLEM TO BE SOLVED: To make level difference small as much as possible of two orthogonal polarization components at a subsequent stage of an optical transmission module, used in a digital coherent transmission communication system and the like.SOLUTION: Output from an optical transmission module 11 is led to a polarization holding type optical fiber 12 so that two orthogonal polarization components will be maintained. A parallel flat glass 14 is tilted by a prescribed angle relative to an optic axis such that it is rotated around a polarization direction of one of the polarization components. The light which went through the parallel flat glass 14 is led to an optical fiber 16. The level difference of the two orthogonal polarization components can be adjusted by setting the angle of incidence &thetas; corresponding to the level difference of the two orthogonal polarization components. |
