Optical circuit, and optical switch using same

Patent metadata

Field	Value
Publication number	US-10248002-B2
Application number	US-201615561135-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 30, 2015
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

In an optical circuit using a Mach-Zehnder-type element, it is difficult to obtain an optical circuit which has a less wavelength dependence and is suitable for achieving high integration. Accordingly, an optical circuit according to the present invention includes: a first Mach-Zehnder-type element including a first branch waveguide, a first branching/combining unit connected to one end of the first branch waveguide, and a second branching/combining unit connected to another end of the first branch waveguide and having a branch configuration different from that of the first branching/combining unit; and a second Mach-Zehnder-type element including a second branch waveguide, a third branching/combining unit connected to one end of the second branch waveguide, and a fourth branching/combining unit connected to another end of the second branch waveguide and having a branch configuration different from that of the third branching/combining unit. The first branch waveguide and the second branch waveguide each include a phase difference adjustment means. In the second branching/combining unit and the third branching/combining unit, light coupling between two basic modes with a phase inverted and a higher-order mode, is smaller than that in the first branching/combining unit and the fourth branching/combining unit. The first Mach-Zehnder-type element and the second Mach-Zehnder-type element are connected with each other through the second branching/combining unit and the third branching/combining unit.

First claim

What is claimed is:

1. An optical circuit comprising:
a first Mach-Zehnder-type component including a first branch waveguide, a first branching/combining unit connected to one end of the first branch waveguide, and a second branching/combining unit connected to another end of the first branch waveguide and having a branch configuration different from that of the first branching/combining unit; and
a second Mach-Zehnder-type component including a second branch waveguide, a third branching/combining unit connected to one end of the second branch waveguide, and a fourth branching/combining unit connected to another end of the second branch waveguide and having a branch configuration different from that of the third branching/combining unit,
wherein the first branch waveguide and the second branch waveguide each include a thermo-optical phase difference adjuster,
wherein in the second branching/combining unit and the third branching/combining unit, light coupling between two basic modes with a phase inverted and a higher-order mode is smaller than that in the first branching/combining unit and the fourth branching/combining unit,
wherein the first Mach-Zehnder-type component and the second Mach-Zehnder-type component are connected with each other through the second branching/combining unit and the third branching/combining unit,
wherein an OFF state of the optical circuit is provided by an absence of current applied to the thermo-optical phase difference adjuster for setting a phase difference of π between arms of the first and the second Mach-Zehnder type components, and
wherein an ON state of the optical circuit is provided by a presence of current applied to the thermo-optical phase difference adjuster for setting a phase difference of 0 between arms of the first and the second Mach-Zehnder type components.

2. The optical circuit according to claim 1 , wherein the first branching/combining unit and the fourth branching/combining unit are 1×2-type branching/combining units, and
wherein the second branching/combining unit and the third branching/combining unit are 2×2-type branching/combining units.

3. The optical circuit according to claim 1 , wherein all of an optical waveguide, constituting each of the first branch waveguide, the second branch waveguide, the first branching/combining unit, the second branching/combining unit, the third branching/combining unit, and the fourth branching/combining unit, is a silicon optical waveguide including a core having a silicon material as a principal component and a clad having a silica material as a principal component.

Assignees

• Nec Corp

Inventors

• Nakamura Shigeru

Classifications

• G02B6/3542

  Non-blocking switch, e.g. with multiple potential paths between multiple inputs and outputs, the establishment of one switching path not preventing the establishment of further switching paths · CPC title

• G02F1/225

  in an optical waveguide structure · CPC title

• H04Q11/00

  Selecting arrangements for multiplex systems (multiplex systems H04J) · CPC title

• G02F2203/04

  wavelength independent · CPC title

• G02B6/3596

  With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate · CPC title