Optical waveguide and electronic device

Patent metadata

Field	Value
Publication number	US-9151888-B2
Application number	US-201113819600-A
Country	US
Kind code	B2
Filing date	Aug 26, 2011
Priority date	Aug 27, 2010
Publication date	Oct 6, 2015
Grant date	Oct 6, 2015

Abstract

An optical waveguide including a first cladding layer; a core layer, including first and second core sections with cladding sections on sides thereof in the in-layer direction; and a second cladding layer. A refractive index distribution in the in-layer direction in the core layer, from the first core section to an adjacent cladding section, has a continuous change and a region with a first peak, a first dip, and a second peak in this order; the first peak at a position of the first core section, the second peak with a maximum value of refractive index smaller than of the first peak, at a position of the cladding section, and a portion, from the first cladding layer to the first core section, corresponded to a refractive index distribution in the layer-stacking direction, discontinuously changing at the boundary between the first cladding layer and first core section.

First claim

The invention claimed is:

1. An optical waveguide comprising:
a first cladding layer;
a core layer provided over the first cladding layer and having a cladding section, a first core section, a cladding section, a second core section, and a cladding section aligned in an order of the cladding section, first core section, cladding section, second core section and cladding section in the in-layer direction; and
a second cladding layer provided over the core layer,
wherein the core layer has a refractive index distribution W in the in-layer direction in a portion which ranges from the first core section to the cladding section such that the refractive index distribution W has a continuous change and a region in which a first peak, a first dip, and a second peak are aligned in an order of the first peak, first dip and second peak, the first core section and the second core section are in contact with the first cladding layer and with the second cladding layer, the first peak in the refractive index distribution W is at the position corresponding to the first core section, the second peak in the refractive index distribution W has a maximum value of refractive index smaller than a maximum value of refractive index of the first peak and is at the position corresponding to the cladding section, the first cladding layer and the first core section have a refractive index distribution T in the layer-stacking direction in a portion which ranges from the first cladding layer to the first core section such that refractive index distribution T has a discontinuous change at the boundary between the first cladding layer and the first core section, and a difference between the maximum value of refractive index of the first core section and the maximum value of refractive index of the first cladding layer is larger than a difference between the maximum value of refractive index of the first core section and the maximum value of refractive index of the cladding section.

2. The optical waveguide according to claim 1 , wherein the first cladding layer, core layer and second cladding layer have a refractive index distribution P in the layer-stacking direction in a portion which ranges from the first cladding layer through the cladding section to the second cladding layer such that the refractive index distribution P appears differently in a portion located at the first cladding layer and a portion located at the cladding section.

3. The optical waveguide according to claim 1 , wherein the refractive index distribution T in the layer-stacking direction in the portion which ranges from the first cladding layer to the first core section is different from the refractive index distribution W.

4. The optical waveguide according to claim 1 , further comprising a second core layer provided over the second cladding layer, wherein the second core layer has a third core section located above the first core section in the layer-stacking direction.

5. The optical waveguide according to claim 1 , wherein the refractive index at the bottom of the first dip is smaller than the average refractive index of the cladding sections.

6. The optical waveguide according to claim 1 , wherein the refractive index distribution W shows the apex of the second peak at a portion other than the vicinity of the boundary between the first core section and the cladding section.

7. The optical waveguide according to claim 1 , wherein the refractive index distribution W shows the apex of the second peak at the center portion of the cladding section and has a region in which the refractive index continuously decreases from the apex of the second peak towards the first dip.

8. The optical waveguide according to claim 1 , wherein a difference between the refractive indices of the first core section and the first cladding layer in the refractive index distribution T is larger than a difference between the refractive indices at the bottom of the first dip and at the apex of the first peak in the refractive index distribution W.

9. The optical waveguide according to claim 1 , further comprising a space provided so as to extend across the first core section and the first cladding layer, with an inner surface thereof being configured as a reflective surface on which light which propagates through the core section is reflected.

10. The optical waveguide according to claim 1 , wherein a difference between the refractive indices at the bottom of the first dip and the average refractive index of the cladding section is 3 to 80% of a difference between the refractive indices at the bottom of the first dip and at the apex of the first peak.

11. The optical waveguide according to claim 1 , wherein a difference between the refractive indices at the bottom of the first dip and at the apex of the first peak is 0.005 to 0.07.

12. The optical waveguide according to claim 1 , wherein, in the refractive index distribution W, defining a in μm to be the width of a region of the first peak, over which the refractive index is not smaller than the average refractive index of the cladding section, and defining b in μm to be the width of a region of the first dip, over which the refractive index is smaller than the average refractive index of the cladding section, then b is 0.01a to 1.2a.

13. An electronic device comprising the optical waveguide of claim 1 .

14. An optical waveguide comprising:
a first cladding layer;
a core layer provided over the first cladding layer and having a cladding section, a first core section, a cladding section, a second core section, and a cladding section aligned in an order of the cladding section, first core section, cladding section, second core section and cladding section in the in-layer direction; and
a second cladding layer provided over the core layer,
wherein the core layer has a refractive index distribution W in the in-layer direction in a portion which ranges from the first core section to the cladding section such that the refractive index distribution W has a continuous change and a region in which a first peak, a first dip, and a second peak are aligned in an order of the first peak, first dip and second peak, the first core section and the second core section are in contact with the first cladding layer and with the second cladding layer, the first peak in the refractive index distribution W is at the position corresponding to the first core section, the second peak in the refractive index distribution W has a maximum value of refractive index smaller than a maximum value of refractive index of the first peak and is at the position corresponding to the cladding section, the first cladding layer and the first core section have a refractive index distribution T in the layer-stacking direction in a portion which ranges from the first cladding layer to the first core section such that refractive index distribution T has a discontinuous change at the boundary between the first cladding layer and the first core section, and a difference between the refractive indices of the first core section and the first cladding layer in the refractive index distribution T is larger than a difference between the refractive indices at the bottom of the first dip and at the apex of the first peak in the refractive index distribution W.

15. The optical waveguide according to claim 14 , wherein the first cladding layer, core layer and second cladding layer have a refractive index distribution P in the layer-stacking direction in a portion which ranges from the first cladding layer through the cladding section to the second cladding layer such that the refractive index distribution P appears diff

Assignees

• Mori Tetsuya
• Moriya Kimio
• Sumitomo Bakelite Co

Inventors

• Mori Tetsuya
• Moriya Kimio

Classifications

• G02B6/1221 Primary

  made from organic materials · CPC title

• G02B6/138

  by using polymerisation · CPC title

• G02B6/4214

  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 title

• G02B6/028 Primary

  with core or cladding having graded refractive index {(G02B6/02033, G02B6/02295 take precedence)} · CPC title