Patent ID: 9122003
Filing Date: 2015-09-01
Classification: G02B

Abstract:
1. A semiconductor optical device, comprising: a light receiving device; an optical waveguide having a mesa structure, the optical waveguide including a first waveguide portion, a second waveguide portion, a third waveguide portion, and a fourth waveguide portion, which are arranged along a waveguide axis; and a passivation layer provided on a side surface of the light receiving device, wherein the second waveguide portion is optically coupled to the first and third waveguide portions, the mesa structure in the second waveguide portion having a width increasing along the waveguide axis, the third waveguide portion is optically coupled to the second and fourth waveguide portions, the mesa structure in the third waveguide portion having a width decreasing along the waveguide axis, the fourth waveguide portion is optically coupled to the third waveguide portion and the light receiving device, the second waveguide portion includes a first region and a second region arranged along the waveguide axis, the first region being optically coupled to the first waveguide portion and the second region being optically coupled to the third waveguide portion, the passivation layer is provided on side surfaces of the mesa structure in the second region, the third waveguide portion, and the fourth waveguide portion, and the mesa structures in the first waveguide portion and the first region have side surfaces without the passivation layer.