| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical phase modulation evaluating apparatus capable of more accurately evaluating a modulation state of an optical phase modulation signal than the prior art. <P>SOLUTION: An optical phase modulation evaluation module 10 is equipped with a bit retarder 15 which gives an optical path length corresponding to one-bit delay of a symbol rate on optical paths of third light 103 and fifth light 105, and an optical phase difference setter 16 which gives delay of a predetermined optical phase, other than zero, to at least one of ninth light 109 and tenth light 110. The optical phase difference setter 16 is equipped with a translucent plate 16a provided on an optical path of the ninth light 109 and a translucent plate 16b provided on an optical path of the tenth light 110. <P>COPYRIGHT: (C)2008,JPO&INPIT |
