Bent optical waveguide

Patent metadata

Field	Value
Publication number	US-9778417-B2
Application number	US-201314436093-A
Country	US
Kind code	B2
Filing date	Oct 15, 2013
Priority date	Oct 18, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An optical multi-mode HIC (high index contrast) waveguide ( 102, 104, 201, 301 ) for transporting electromagnetic radiation in the optical waveband, the waveguide comprising a guiding core portion ( 204 ) with higher refractive index, and cladding portion ( 206 ) with substantially lower refractive index configured to at least partially surround the light guiding core in the transverse direction to facilitate confining the propagating radiation within the core, the waveguide being configured to support multiple optical modes of the propagating radiation, wherein the waveguide incorporates a bent waveguide section ( 202 ) having bend curvature that is configured to at least gradually, preferably substantially continuously, increase towards a maximum curvature of said section from a section end.

First claim

The invention claimed is:

1. An optical multi-mode HIC (high index contrast) waveguide, for transporting electromagnetic radiation in an optical waveband, the waveguide comprising:
a guiding core portion of a first refractive index,
a cladding portion of a refractive index lower than the first refractive index, the cladding portion configured to at least partially surround the guiding core portion in a transverse direction to facilitate confining the propagating radiation within the guiding core,
a bent waveguide section defined by section ends corresponding bent portions of the guiding core portion and the cladding portion, the bent waveguide section including a bend curvature that is configured to gradually increase towards a maximum curvature value from one of the section end within said waveguide section in the direction of another section end,
the waveguide being configured to support multiple optical modes of the transported electromagnetic radiation, and,
wherein the relative refractive index contrast between said guiding core and said cladding, portion is about 25% or higher.

2. The waveguide of claim 1 , wherein the bend curvature increases from at least local minima at the section ends towards the maximum between the section ends.

3. The waveguide of claim 1 , wherein the section ends are substantially straight.

4. The waveguide of claim 1 , wherein the bent section, contains two substantially mirror-symmetric sub-sections, said waveguide optionally further comprising another adjacent, bent waveguide section with similar mirror-symmetric sub-sections to establish a predetermined double symmetric structure.

5. The waveguide of claim 1 , wherein the curvature is substantially linearly varying with the bend length between the section end and the point of maximum curvature.

6. The waveguide of claim 1 , wherein the minimum radius of curvature is substantially on the order of magnitude of the waveguide width, which is at least approximately two times the waveguide width or smaller.

7. The waveguide of claim 1 , wherein the core portion defines a substantially planar core layer.

8. The waveguide, of claim 1 , wherein the relative refractive index contrast between said core portion and said cladding portion is approximately at least 50%.

9. The waveguide of claim 1 , wherein the guiding core portion comprises dielectric material.

10. The waveguide of claim 1 , wherein the core portion comprises at least one material selected from the group consisting of: semiconductor, Si, Ge, GaAs, InP, CdTe, ZnTe, Si3N4, doped or undoped silicon oxide, TiO2, diamond, and their compounds.

11. The waveguide of claim 1 , wherein the cladding portion comprises at least one material selected from the group consisting of: air, silica-containing glass, and polymer.

12. The waveguide of claim 1 , wherein the waveguide width is at least substantially on the order of magnitude of microns or less.

13. The waveguide of claim 1 , selected from the group consisting of: electronic devices, optoelectronic devices, photonic devices, optical circuits, integrated optical circuits, microring elements, microring resonators, interferometers, multi-stage cascaded Mach-Zehnder interferometers, delay lines, reflectors, multi-mode interference reflectors, communications devices, SOI (silicon-on-insulator) devices, and sensors.

Assignees

• Teknologian Tutkimuskeskus Vtt Oy

Inventors

• Cherchi Matteo
• Aalto Timo

Classifications

• G02B6/02047

  Dual mode fibre (G02B6/105 takes precedence) · CPC title

• G02B6/262 Primary

  Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements · CPC title

• G02B6/125 Primary

  Bends, branchings or intersections · CPC title

• G02B6/1223 Primary

  high refractive index type, i.e. high-contrast waveguides · CPC title

• G02B6/122

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