摘要 |
An optical de-polarizer is implemented by using an optical fiber, and/or a beam splitter coupled with output of said optical fiber. An optical fiber is longer than a predetermined length so that equation ¦t1-t2¦>tc is satified where t1 is polarization mode dispersion in a first optical fiber, t2 is a polarization mode dispersion in a second optical fiber which is coupled with output of the first optical fiber, and tc is coherence time of a beam defined by an optical source. According to the present invention, one of the conditions (1) an angle between polarization axis of the first optical fiber and polarization axis of the second optical fiber is 45 DEG , and (2) an angle between polarization axis of the optical fiber and polarization axis of the beam splitter is 45 DEG , is satisfied. |