VERTICAL DIRECTIONAL COUPLER SWITCH AND FABRICATION METHOD THEREOF

摘要

PURPOSE: A vertical directional coupler switch and a fabrication method thereof are provided, which have an extinction ratio of cross and bar states above 30 dB. CONSTITUTION: The vertical directional coupler switch includes the first and the second waveguide(32,34) having a switching operation induced section(SOIS) arranged symmetrically with equal refractive indexes in cross state and bar state respectively, and also having an extinction ratio enhanced section(ERES) arranged asymmetrically with difference refractive indexes in the above cross state and the above bar state respectively. The vertical directional coupler switch also includes a cladding layer which is inserted between two waveguides and includes a refractive index. The refractive index of the extinction ratio enhanced section is controlled independently by a current injection or an electro-optic effect.