Optical Coupler Provided With a Structuration

Patent metadata

Field	Value
Publication number	US-2016170147-A1
Application number	US-201414904809-A
Country	US
Kind code	A1
Filing date	Jul 11, 2014
Priority date	Jul 15, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

The invention relates to an optical coupler ( 10 ) in a vertical configuration, capable of working for a wavelength and comprising a first waveguide ( 12 ) and a second waveguide ( 14 ). The second waveguide ( 14 ) has a patterning ( 33 ) in the form of a series of patterns ( 36 ), the patterns ( 36 ) extending along a transverse direction (X) perpendicular to the longitudinal direction (Z), being parallel to each other and orthogonal to the general direction of the first waveguide ( 12 ), each pattern ( 36 ) being arranged both in the core ( 30 ) and the cladding ( 32 ) of the second waveguide ( 14 ) and having parameters influencing the evanescent wave coupling between the first waveguide ( 12 ) and the second waveguide ( 14 ), said parameters being chosen such that the coupling (C) is greater than 15%.

First claim

1 . An optical coupler in a vertical configuration, capable of working for a wavelength and comprising:
a first waveguide extending in the longitudinal direction and capable of propagating a first propagation mode of the light having a first effective index, a second waveguide distinct from the first waveguide, parallel to the first waveguide, having a core and a cladding and capable of propagating a second propagation mode of the light having a second effective index, the second effective index being different from the first effective index, the second waveguide having a patterning, the patterning having a period along the longitudinal direction below the ratio between the wavelength at which the optical coupler is capable of operating and the product of two by the second effective index, the patterning being in the form of a series of patterns, the patterns extending along a transverse direction perpendicular to the longitudinal direction, being parallel to each other and orthogonal to the general direction of the first waveguide, each pattern having parameters influencing the evanescent wave coupling between the first waveguide and the second waveguide, said parameters being chosen such that the coupling is greater than 15%.

2 . The optical coupler according to claim 1 , wherein the patterns are chosen from the group made up of:
openings made in the second waveguide, and blades.

3 . The optical coupler according to claim 1 , wherein the patterns have a dimension along the transverse direction larger than the dimension of the core of the second waveguide along the transverse direction.

4 . The optical coupler according to claim 1 , wherein the core of the second waveguide having an optical index, the second effective index is greater than the first effective index and the patterns are made from a material having an optical index below the optical index of the core of the second waveguide.

5 . The optical coupler according to claim 1 , wherein the patterning has a fill factor, the patterns are made from a material having an optical index, the parameters influencing the evanescent wave coupling between the first waveguide and the second waveguide being the fill factor of the patterning, the optical index of the material from which the patterns are made, and the spacing along the longitudinal direction between each pattern.

6 . The optical coupler according to claim 1 , wherein each pattern is arranged both in the core and the cladding of the second waveguide.

7 . The optical coupler according to claim 1 , wherein each waveguide includes a cladding and a core, the optical index of the core of the first waveguide being below the optical index of the cladding of the second waveguide.

8 . The optical coupler according to claim 1 , wherein the spacing along the longitudinal direction between the patterns is variable in the longitudinal direction.

9 . The optical coupler according to claim 1 , wherein the first waveguide includes a core made from a material belonging to column III of the periodic table formed with a material from column V of the periodic table and two lower and upper layers surrounding the core.

10 . The optical coupler according to claim 1 , wherein the core of the second waveguide has a variable dimension in the transverse direction.

11 . The optical coupler according to claim 1 , wherein the optical coupler includes a substrate, made from a first material, in which the second waveguide is buried, the first waveguide being arranged in contact with the substrate and formed from a material different from the first material.

12 . The optical coupler according to claim 1 , wherein the optical coupler includes a third waveguide distinct from the first and second waveguides and extending parallel to the first and second waveguides, the third waveguide being arranged between the first waveguide and the second waveguide and being capable of propagating a third light propagation mode having a third effective index.

13 . The optical coupler according to claim 1 , including a thermal insulation zone of the first waveguide in which the patterning is arranged.

14 . An optical component comprising an optical coupler according claim.

15 . A method for determining an optical coupler in a vertical configuration, capable of working for a wavelength and comprising:
a first waveguide extending in the longitudinal direction and capable of propagating a first propagation mode of the light having a first effective index, a second waveguide distinct from the first waveguide, parallel to the first waveguide, having a core and a cladding and capable of propagating a second propagation mode of the light having a second effective index, the second effective index being greater than the first effective index, the second waveguide ( 14 ) having a patterning, the patterning having a period along the longitudinal direction below the ratio between the wavelength at which the optical coupler is capable of operating and the product of two by the second effective index, the patterning being in the form of a series of patterns having parameters influencing the evanescent wave coupling between the first waveguide and the second waveguide, the patterns extending along a transverse direction perpendicular to the longitudinal direction, being parallel to each other and orthogonal to the general direction of the first waveguide, each pattern having parameters influencing the evanescent wave coupling between the first waveguide and the second waveguide, the method comprising a step for: choosing a desired evanescent wave coupling between the first waveguide and the second waveguide, the desired coupling being greater than or equal to 15%, modifying the parameters of the patterning to obtain the desired evanescent wave coupling between the first waveguide and the second waveguide.

16 . A method for manufacturing an optical coupler according to claim 1 , wherein the manufacturing method comprises steps for manufacturing waveguides and the patterning involving techniques for deposition, epitaxy, polishing, gluing and material removal by etching.

Assignees

• Commissariat Energie Atomique
• Alcatel Lucent

Inventors

• Boutami Salim
• Brun Mickaël
• Labeye Pierre
• Nicoletti Sergio
• Maisons Grégory

Classifications

• G02B6/29331 Primary

  operating by evanescent wave coupling · CPC title

• G02B6/14

  Mode converters · CPC title

• G02B2006/12147

  Coupler · CPC title

• G02B6/122

  Basic optical elements, e.g. light-guiding paths · CPC title

• G02B6/13

  Integrated optical circuits characterised by the manufacturing method · CPC title