Optical waveguide and optical circuit base component

• US 6,785,454 B2
• Filed: 12/19/2001
• Issued: 08/31/2004
• Est. Priority Date: 12/20/2000
• Status: Expired due to Fees

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Abe, Shinichi
• Primary Examiner(s): Kim, Ellen E.
• Application Number:
  US10/033,828
• Publication Number:
  US 20020105000A1
• Time in Patent Office: 986 Days
• Field of Search: 385/123, 385/129-132
• US Class Current: 385/123
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12176 Etching
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/305 and having an integrated mode-size expanding section, e.g. tapered waveguide
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures

Abstract

In a conventional optical waveguide using a photonic crystal, loss of light occurs in the substrate therebelow. The invention provides an optical waveguide comprising a substrate, a core portion formed on the substrate, and clad portions arranged on the substrate so that the core portion is sandwiched therebetween. The clad portions each have a periodic structure which exhibits a periodic variation in refractive index in a direction perpendicular to a light propagation direction, and at least one of the periodic structures is inclined with respect to a surface of the substrate so that an interval between the periodic structures is gradually reduced toward the substrate. The slim, compact optical waveguide can be fabricated in a relatively simple and easy process, incurs lower loss, offers satisfactory light propagation characteristics, and has adequate mechanical strength.

Claims

1. An optical waveguide comprising:

a substrate;

a core portion formed on the substrate; and

clad portions arranged on the substrate so that the core portion is sandwiched therebetween, the clad portions each having a periodic structure which exhibits a periodic variation in refractive index in a direction perpendicular to a light propagation direction,

wherein at least one of the periodic structures is inclined with respect to a surface of the substrate so that an interval between the periodic structures is gradually reduced toward the substrate.

2. The optical waveguide of claim 1,

wherein at least one of the periodic structures is inclined an angle of 5 to 60 degree from a direction perpendicular the surface of the substrate.

3. The optical waveguide of claim 2,

wherein the two periodic structures make contact with each other at their lower ends.

4. The optical waveguide of claim 3,

wherein the periodic structure is configured as a columnar periodic structure.

5. The optical waveguide of claim 2,

wherein the periodic structure is configured as a columnar periodic structure.

6. The optical waveguide of claim 1,

wherein the two periodic structures make contact with each other at their lower ends.

7. The optical waveguide of claim 6,

wherein the periodic structure is configured as a columnar periodic structure.

8. The optical waveguide of claim 1,

wherein the periodic structure is configured as a columnar periodic structure.

9. The optical waveguide of claim 8,

wherein column components of the columnar periodic structure occupy 20 to 80 percent of a sectional area of the columnar periodic structure sectioned along a direction perpendicular to a length of the column component.

10. The optical waveguide of claim 1,

wherein a period of the periodic structure has a thickness corresponding to 20 to 60 percent of a wavelength of light propagating through the core portion.

11. The optical waveguide of claim 1,

wherein the periodic structure has five periods or more.

12. An optical circuit base component comprising:

a substrate;

an optical waveguide comprising a substrate, a core portion formed on the substrate, and clad portions arranged on the substrate so that the core portion is sandwiched therebetween, the clad portions each having a periodic structure which exhibits a periodic variation in refractive index in a direction perpendicular to a light propagation direction, at least one of the periodic structures being inclined with respect to a surface of the substrate so that an interval between the periodic structures is gradually reduced toward the substrate; and

a portion formed on the substrate, for mounting an optoelectronic conversion element which is optically coupled to the optical waveguide.

13. The optical circuit base component of claim 12,

wherein, in the optical waveguide, at least one of the periodic structures is inclined at an angle of 5 to 60 degree from a direction perpendicular to the surface of the substrate.

14. The optical circuit base component of claim 13,

wherein, in the optical waveguide, the two periodic structures make contact with each other at their lower ends.

15. The optical circuit base component of claim 14,

wherein, in the optical waveguide, the periodic structure is configured as a columnar periodic structure.

16. The optical circuit base component of claim 13,

wherein, in the optical waveguide, the periodic structure is configured as a columnar periodic structure.

17. The optical circuit base component of claim 12,

wherein, in the optical waveguide, the two periodic structures make contact with each other at their lower ends.

18. The optical circuit base component of claim 17,

wherein, in the optical waveguide, the periodic structure is configured as a columnar periodic structure.

19. The optical circuit base component of claim 12,

wherein, in the optical waveguide, the periodic structure is configured as a columnar periodic structure.