VARIABLE OPTICAL ATTENUATOR

摘要

PROBLEM TO BE SOLVED: To provide a small-sized variable optical attenuator wherein a polarization dependent loss (PDL) is suppressed, especially the PDL in a region where an attenuation factor is high is improved. SOLUTION: The total attenuation factor is made to be a desired attenuation factor by adopting a multiple stage type variable optical attenuator formed by serially connecting variable optical attenuators each having the PDL which is non-linearly increased associated with increase of the attenuation factor as basic variable optical attenuator elements and by using each variable optical attenuator in a region where the PDL is small. Integration and miniaturization are made possible by adopting a Mach-Zehnder interferometer type variable optical attenuator as the basic variable optical attenuator element. COPYRIGHT: (C)2006,JPO&NCIPI