OPTICAL WAVEGUIDE SUBSTRATE, METHOD OF MANUFACTURING OPTICAL WAVEGUIDE SUBSTRATE, AND METHOD OF REPAIRING OPTICAL WAVEGUIDE SUBSTRATE

• US 20190324207A1
• Filed: 04/09/2019
• Published: 10/24/2019
• Est. Priority Date: 04/20/2018
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Choraku, Kohei, MATSUI, AKIKO, HIROSHIMA, YOSHIYUKI, TAKAHASHI, Kazuki, Yamada, Tetsuro
• Granted Patent: US 10,877,216 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/138 by using polymerisation
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections

Abstract

An optical waveguide substrate includes a substrate that includes a recess, a buffer layer disposed on a bottom surface and a wall surface of the recess, and an optical waveguide disposed inside the recess with the buffer layer interposed therebetween and having a cladding layer disposed on the buffer layer and a core layer disposed inside the cladding layer.

Claims

1. An optical waveguide substrate comprising:

a substrate that includes a recess;

a buffer layer disposed on a bottom surface and a wall surface of the recess; and

an optical waveguide disposed inside the recess with the buffer layer interposed therebetween and having a cladding layer disposed on the buffer layer and a core layer disposed inside the cladding layer.

2. The optical waveguide substrate according to claim 1,

wherein the buffer layer includes:

a first portion disposed along the bottom surface; and

a second portion disposed to rise up from the first portion along the wall surface.

3. The optical waveguide substrate according to claim 1,

wherein a coefficient of thermal expansion of the buffer layer is between a coefficient of thermal expansion of the substrate and a coefficient of thermal expansion of the cladding layer.

4. The optical waveguide substrate according to claim 1,

wherein the buffer layer includes:

a first layer disposed inside the recess and being in contact with the substrate; and

a second layer disposed inside the recess and being in contact with the optical waveguide.

5. The optical waveguide substrate according to claim 4,

wherein the buffer layer further includes:

a third layer having a tab portion extended from an interposed portion disposed between the first layer and the second layer inside the recess and pulled out of the recess.

6. A method of manufacturing an optical waveguide substrate, comprising:

forming a buffer layer on a bottom surface and a wall surface of a recess disposed in a substrate; and

forming an optical waveguide inside the recess with the buffer layer interposed therebetween, the optical waveguide having a cladding layer disposed on the buffer layer and a core layer disposed inside the cladding layer.

7. The method of manufacturing an optical waveguide substrate according to claim 6,

wherein in the forming a buffer layer, the buffer layer is formed by

supplying a buffer material with fluidity onto the wall surface, causing part of the supplied buffer material to remain on the wall surface, and causing other part of the buffer material to flow from the wall surface onto the bottom surface;

and

curing the part and the other part of the supplied buffer material.

8. A method of repairing an optical waveguide substrate comprising:

from an optical waveguide substrate including;

a substrate having a recess;

a first buffer layer disposed on a bottom surface and a wall surface of the recess; and

a first optical waveguide disposed inside the recess with the first buffer layer interposed therebetween and having a first cladding layer disposed on the first buffer layer and a first core layer disposed inside the first cladding layer, removing the first optical waveguide;

forming a second buffer layer on the bottom surface and the wall surface of the recess from which the first optical waveguide has been removed; and

forming a second optical waveguide inside the recess with the second buffer layer interposed therebetween, the second optical waveguide having a second cladding layer disposed on the second buffer layer and a second core layer disposed inside the second cladding layer.

9. The method of repairing an optical waveguide substrate according to claim 8,

wherein the first buffer layer includes:

a first layer disposed inside the recess and being in contact with the substrate;

a second layer disposed inside the recess and being in contact with the first optical waveguide, and

a third layer having a tab portion extended from an interposed portion disposed between the first layer and the second layer inside the recess and pulled out of the recess,

in the removing the first optical waveguide, the third layer, the second layer, and the first optical waveguide are removed by pulling the tab portion upward of the recess.