Patent ID: 9069194
Filing Date: 2015-06-30
Classification: G02B,G02F

Abstract:
1. A polarization control device comprising: a multi-mode interference device having a primary-side end face including a first port, a second port and a third port located between the first port and the second port, a secondary-side end face including a port, a first side face, and a second side face; a first phase shifter optically coupled to the first port in the primary-side end face of the multi-mode interference device; a first optical waveguide optically coupled via the first phase shifter to the first port in the primary-side end face of the multi-mode interference device; a second optical waveguide optically coupled to the second port in the primary-side end face of the multi-mode interference device; a third optical waveguide optically coupled to the third port in the primary-side end face of the multi-mode interference device; and a tapered waveguide having one end and an other end, the one end being optically coupled to the port in the secondary-side end face of the multi-mode interference device, wherein the first port in the primary-side end face and the second port in the primary-side end face are located on a first axis and a second axis, respectively, in the primary-side end face, the port in the secondary-side end face is located on a third axis in the secondary-side end face, the third axis being located between the first axis and the second axis, the third port in the primary-side end face is located on the third axis in the primary-side end face, the first axis, the second axis, and the third axis extend in a direction from the primary-side end face to the secondary-side end face of the multi-mode interference device, and the tapered waveguide has a width decreasing in a direction from the one end to the other end of the tapered waveguide.