Patent ID: 8179931
Filing Date: 2012-05-15
Classification: G02F,H01S

Abstract:
1. A wavelength tunable filter comprising: a semiconductor substrate; a first optical waveguide which is mounted on the semiconductor substrate and provided with a first core layer; and a second optical waveguide which is mounted on the semiconductor substrate and provided with a second core layer, wherein the first optical waveguide is positioned along the second optical waveguide in an in-plane direction of the semiconductor substrate, wherein a grating is formed in one or more of the optical waveguides, wherein the first core layer is positioned close to a p-type conductive semiconductor and an n-type conductive semiconductor and structured to be capable of injecting a current or applying a voltage, wherein the second core layer is positioned close to either the p-type conductive semiconductor or the n-type conductive semiconductor, and wherein the distance between the first optical waveguide and the second optical waveguide is longer at an end of the second optical waveguide than at the center thereof.