WAVEGUIDE TYPE POLARIZATION COMPENSATOR AS WELL AS WAVEGUIDE TYPE RING RESONATOR AND WAVEGUIDE TYPE MACH-ZEHUNDER INTERFEROMETER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To prevent output power from varying according to the polarization state of input light by compensating the double refraction of a waveguide to align the resonance points of the (x) polarized light and(y)polarized light of a waveguide type ring resonator. ;SOLUTION: The waveguide is formed to the structure obtd. by embedding the circumference of a core 17 formed on a glass substrate 18 with a clad 16. A waveguide type polarization compensator 20 is formed in a part of the ring waveguide 10. The compensator 20 is constituted by forming multilayered films 21 periodically changed in refractive index in the evanescent region of the core 17 constituting the ring waveguide 10. Alternate layers of TiO₂ and SiO₂ are used for the multilayered films 21. The length of the waveguide type polarization compensator is set at 1=Δβ₀.πr/Δβ (Δβ₀; the difference in propagation constant between the (x) polarized light and (y) polarized light of the ring waveguide, Δβ; the difference in propagation constant between the (X) polarized light and (y) polarized light propagating in the waveguide part forming the compensator, r; a ring radius). As a result, Δβ₀ and Δβ are offset.;COPYRIGHT: (C)1997,JPO