OPTICAL WAVEGUIDE TYPE POLARIZATION SEPARATING ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide the small-sized optical waveguide type polarization separating element which can be integrated with an optical element. SOLUTION: This optical waveguide type polarization separating element has a substrate 4, two optical waveguides which are provided on the main surface of the substrate almost in parallel to each other and has two cores having the same refractive index, and a coupling layer 7 which couples the said two optical waveguides optically with each other; and the optical waveguides and coupling layer 7 are formed of materials which are optically anisotropic or birefringent materials, and the coupling layer 7 is smaller in refractive index to light having a specific plane of polarization than the cores 6a and 6b of the optical waveguides and larger in refractive index to light having the other plane of polarization than the cores 6a and 6b of the optical waveguides. When light is guided to one of the two optical waveguides, the light having the specific plane of polarization is guided in one optical waveguide and the light having the other plane of polarization move from one optical waveguide to the other optical waveguide through the coupling layer 7.