title: Polarization-independent optical directional coupler based on slot waveguides.
abstract: A polarization-independent optical directional coupler based on slot waveguides is proposed and analyzed by using rigorous full-vectorial analysis methods based on a finite-element scheme. Properly choosing materials and structural parameters makes the coupling length for quasi-TE modes become equal to that for quasi-TM modes. Tolerances to operating wavelength and structural parameters are also discussed. The proposed coupler can be used for highly integrated optical circuits without polarization diversity schemes.
authors.affiliation: Division of Media and Network Technologies, Hokkaido University, Sapporo 060-0814, Japan. fujisawa@dpo7.ice.eng.hokudai.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Koshiba