| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve such a problem that the polarization dependence which means the propagation loss in a light beam entering an optical waveguide depends on a polarization plane is decreased in a light beam propagating in an upper side of the core, however, a conventional variable optical attenuator blocks a light beam propagating in an upper side of the core where influences of polarization dependence are less but transmits a lower part of the light much propagating the core strongly influenced by the polarization dependence. <P>SOLUTION: The variable optical attenuator has an input reflector that attenuates a light beam to couple an input core through a connection core to an output core. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
