| 摘要 |
The present invention includes a polarization beam splitter (111) that splits input signal light (Sig) into two different polarized waves (TM, TE); two variable optical attenuators (113, 114) that respectively adjust attenuation of and output signal light of the polarization states split by the polarization beam splitter (111); a single planar optical waveguide (102) on which the polarization beam splitter and the variable optical attenuators (113, 114) are disposed; and without attenuation differences of the polarization split signal light caused by polarization dependent loss, integrates variable optical attenuator function on the planar optical waveguide (102). |
