title: Novel polarization diversity without switch duplication of a Si-wire PILOSS optical switch.
abstract: We demonstrate the compact polarization diversity based on the bidirectional full-port use of a path-independent-insertion-loss (PILOSS) optical switch. A polarization-diversity 4 × 4 strictly non-blocking optical switch is developed using a single thermooptic PILOSS Si-wire switch and fiber-based polarization beam splitters (PBSs) and combiners (PBCs). We measure characteristics of the switch and confirm that the proposed configuration demonstrates the performance in the insertion loss, polarization-dependent loss (PDL), and differential group delay (DGD) comparable with that of a conventional polarization-diversity 4 × 4 PILOSS switch using double switch elements. On the other hand, higher crosstalk is observed. The crosstalk increase is associated with the backward crosstalk at a waveguide intersection based on a directional coupler. The effect of the backward crosstalk on the total crosstalk is estimated, and future prospects are discussed.
authors.forename: Ken
authors.initials: K
authors.lastname: Tanizawa
authors.forename: Keijiro
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ikeda
authors.forename: Shu
authors.initials: S
authors.lastname: Namiki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kawashima