Waveguide structure, waveguide coupling structure, and production method

Patent metadata

Field	Value
Publication number	US-9746606-B2
Application number	US-201615152831-A
Country	US
Kind code	B2
Filing date	May 12, 2016
Priority date	Nov 13, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

The present invention provides three waveguide structures, including a protruding-type waveguide structure, a buried-type waveguide structure, and a redeposited-type waveguide structure, the protruding-type waveguide structure includes two axisymmetrically disposed first ends, and the first end is sequentially divided into a first region, a second region, and a third region in a direction toward an axis of symmetry; and the waveguide structure includes a first silicon substrate layer, a second silicon substrate layer, a first silicon dioxide layer, a second silicon dioxide layer, and a first silicon waveguide layer. The waveguide structure and the waveguide coupling structure that are provided in the present invention have advantages of a small size, low polarization dependence, and low temperature sensitivity, and a crosstalk value is greater than 25 dB, which meets a requirement of a passive optical network system, and provides feasibility for commercialization of the arrayed waveguide grating.

First claim

What is claimed is:

1. A waveguide structure for use with a straight waveguide part of an arrayed waveguide in a silicon-on-insulator-based arrayed waveguide grating, the waveguide structure comprising:
two axisymmetrically disposed first ends each sequentially divided into a first region, a second region, and a third region in a direction toward an axis of symmetry;
a first silicon substrate layer, a second silicon substrate layer, a first silicon dioxide layer, a second silicon dioxide layer, and a first silicon waveguide layer;
in the first region, the first silicon substrate layer, the second silicon substrate layer, the first silicon dioxide layer, the second silicon dioxide layer, and the first silicon waveguide layer are sequentially disposed, wherein a width of the first silicon waveguide layer is a constant value and an optical signal is transmitted at the first silicon waveguide layer;
in the second region, the second silicon substrate layer is etched as a first air layer, the first silicon substrate layer, the first air layer, the first silicon dioxide layer, the second silicon dioxide layer, and the first silicon waveguide layer are sequentially disposed, a width of the first silicon waveguide layer gradually decreases in the direction toward the axis of symmetry, and the optical signal is gradually transmitted from the first silicon waveguide layer to a first ridge silicon dioxide waveguide layer that comprises the first silicon dioxide layer and the second silicon dioxide layer; and
in the third region, the second silicon substrate layer is etched as the first air layer, the first silicon substrate layer, the first air layer, the first silicon dioxide layer, and the second silicon dioxide layer are sequentially disposed, wherein a width of the first silicon waveguide layer is 0 and the optical signal is transmitted at the first ridge silicon dioxide waveguide layer that comprises the first silicon dioxide layer and the second silicon dioxide layer.

2. The waveguide structure according to claim 1 , wherein:
the first silicon dioxide layer comprises:
multiple parallel first silicon dioxide layer units that are arrayed at intervals, and
a uniform first trench is disposed between the adjacent first silicon dioxide layer units;

the second silicon dioxide layer comprises:
multiple second silicon dioxide layer units, the second silicon dioxide layer units correspondingly cover surfaces of the first silicon dioxide layer units, and wherein the first silicon dioxide layer units and the second silicon dioxide layer units are comprised in the first ridge silicon dioxide waveguide layer; and

the first silicon waveguide layer comprises:
multiple first silicon waveguide layer units, the first silicon waveguide layer units correspondingly cover surfaces of the second silicon dioxide layer units.

3. A method for producing the waveguide structure according to claim 1 , the method comprising:
providing a first silicon-on-insulator wafer;
producing a first silicon waveguide layer on a surface of the first silicon-on-insulator wafer;
producing, on the surface of the first silicon-on-insulator wafer, a first ridge silicon dioxide waveguide layer that comprises a first silicon dioxide layer and a second silicon dioxide layer;
producing a first trench on the surface of the first silicon-on-insulator wafer to shape the first silicon dioxide layer units; and
shaping a second silicon substrate layer into a first air layer to obtain the waveguide structure by means of production.

4. A waveguide structure for use with a straight waveguide part of an arrayed waveguide in a silicon-on-insulator-based arrayed waveguide grating, the waveguide structure comprising:
two axisymmetrically disposed first ends each divided into a first region, a second region, and a third region in a direction toward an axis of symmetry;
a third silicon substrate layer, a third silicon dioxide layer, a second silicon waveguide layer, a first waveguide layer, and a second waveguide layer that are sequentially disposed, wherein a coverage area of the second silicon waveguide layer is less than a coverage area of the third silicon dioxide layer, the second silicon waveguide layer is partially buried in the first waveguide layer, a coverage area of the first waveguide layer is greater than a coverage area of the second waveguide layer, and refractive indexes of the first waveguide layer and the second waveguide layer both lie between a refractive index of the second silicon waveguide layer and a refractive index of the third silicon dioxide layer;
in the first region, the third silicon substrate layer, the third silicon dioxide layer, and the second silicon waveguide layer are sequentially disposed, wherein a width of the second silicon waveguide layer is constant and the optical signal is transmitted at the second silicon waveguide layer;
in the second region, the third silicon substrate layer, the third silicon dioxide layer, the second silicon waveguide layer, the first waveguide layer, and the second waveguide layer are sequentially disposed, wherein a width of the second silicon waveguide layer gradually decreases in the direction toward the axis of symmetry and the optical signal is gradually transmitted from the second silicon waveguide layer to a ridge waveguide layer that comprises the first waveguide layer and the second waveguide layer; and
in the third region, the third silicon substrate layer, the third silicon dioxide layer, the first waveguide layer, and the second waveguide layer are sequentially disposed, wherein a width of the second silicon waveguide layer is decreased to 0 and the optical signal is transmitted at the ridge waveguide layer that comprises the first waveguide layer and the second waveguide layer.

5. The waveguide structure according to claim 4 , wherein:
the first waveguide layer comprises multiple parallel first waveguide layer units that are arrayed at intervals;
the second waveguide layer comprises multiple second waveguide layer units, the second waveguide layer units correspondingly cover surfaces of the first waveguide layer units, and the first waveguide layer units and the second waveguide layer units are comprised in the ridge waveguide layer; and
the second silicon waveguide layer comprises multiple second silicon waveguide layer units, and the second silicon waveguide layer units are correspondingly buried in the first waveguide layer units.

6. The waveguide structure according to claim 4 , wherein materials of the first waveguide layer and the second waveguide layer are the same, and both comprise silicon nitride or polymethyl methacrylate.

7. A production method for producing the waveguide structure according to claim 4 , the method comprising:
providing a second silicon-on-insulator wafer;
producing a second silicon waveguide layer on a surface of the second silicon-on-insulator wafer;
producing a first waveguide layer and a second waveguide layer on the surface of the second silicon-on-insulator wafer; and
producing a ridge waveguide layer that comprises the first waveguide layer and the second waveguide layer.

Assignees

• Huawei Tech Co Ltd

Inventors

• Hu Jing
• Zhou Xiaoping

Classifications

• G02B6/12026

  characterised by means for reducing the temperature dependence · CPC title

• G02B6/12023

  characterised by means for reducing the polarisation dependence, e.g. reduced birefringence · CPC title

• G02B6/12011 Primary

  characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section · CPC title

• G02B2006/12061

  Silicon · CPC title

• G02B6/1228

  Tapered waveguides, e.g. integrated spot-size transformers (for coupling with fibres G02B6/305) · CPC title