Optical waveguide element and optical axis adjustment method

An optical waveguide element comprising:

• a waveguide configured to propagate light;
• a clad including an upper clad whose lower surface is in contact with one surface of the waveguide and a lower clad whose upper surface is in contact with the other surface of the waveguide;
• both side surfaces provided on both sides of the upper clad and the lower clad;
• an incident end surface provided at one end of the waveguide and the clad;
• and
• an emission end surface provided at the other end of the waveguide and the clad, wherein
• one of a flat upper surface of the upper clad and a flat lower surface of the lower clad is formed in a uniform inclined surface with respect to the waveguide, and the other is formed in a uniform parallel surface with respect to the waveguide, wherein
• a thickness of the clad in a direction perpendicular to the waveguide is thinner on a side of the emission end surface than on a side of the incident end surface, and a distance between the flat upper surface of the upper clad and the flat lower surface of the lower clad uniformly and gradually decreases from the incident end surface to the emission end surface.

An optical waveguide element comprising:

• a waveguide configured to propagate light;
• a clad including an upper clad whose lower surface is in contact with one surface of the waveguide and a lower clad whose upper surface is in contact with the other surface of the waveguide;
• both side surfaces provided on both sides of the upper clad and the lower clad;
• an incident end surface provided at one end of the waveguide and the clad;
• and
• an emission end surface provided at the other end of the waveguide and the clad, wherein
• both a flat upper surface of the upper clad and a flat lower surface of the lower clad are formed in uniform inclined surfaces with respect to the waveguide, wherein
• a thickness of the clad in a direction perpendicular to the waveguide is thinner on a side of the emission end surface than on a side of the incident end surface, and a distance between the flat upper surface of the upper clad and the flat lower surface of the lower clad uniformly and gradually decreases from the incident end surface to the emission end surface.