Optical integrated device and optical control device

• US 7,529,455 B2
• Filed: 08/09/2006
• Issued: 05/05/2009
• Est. Priority Date: 08/11/2005
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Sakai, Atsushi, Suzuki, Shuichi
• Primary Examiner(s): Connelly-Cushwa; Michelle R.
• Assistant Examiner(s): CHU, CHRIS H
• Application Number:
  US11/501,050
• Publication Number:
  US 20070036500A1
• Time in Patent Office: 1,000 Days
• Field of Search: 385/129
• US Class Current: 385/129
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12119 Bend
• CPC Class Codes: G02B 2006/12147 Coupler
• CPC Class Codes: G02B 2006/12164 Multiplexing; Demultiplexing
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/1223 high refractive index type, i.e. high-contrast waveguides
• CPC Class Codes: G02B 6/1228 Tapered waveguides, e.g. integrated spot-size transformers for coupling with fibres G02B6/305
• CPC Class Codes: G02B 6/305 and having an integrated mode-size expanding section, e.g. tapered waveguide

Abstract

An optical integrated device having multiple optical waveguides connected on the same substrate and each including a core and a cladding is disclosed. Adjacent two of the optical waveguides are different in the refractive index difference between the core and the cladding.

Claims

1. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding,

wherein two adjacent optical waveguides are different in a refractive index difference between the core and the cladding;

wherein the cores of the two adjacent optical waveguides have a same refractive index;

wherein a first one of the two adjacent optical waveguides has a greater relative index difference than a second one of the two adjacent optical waveguides; and

wherein the first one of the two adjacent optical waveguides has a curved part having a smaller radius of curvature than the second one of the two adjacent optical waveguides.

2. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding,

wherein two adjacent optical waveguides are different in a refractive index difference between the core and the cladding;

wherein the cores of the two adjacent optical waveguides have a same refractive index;

wherein a first one of the two adjacent optical waveguides has a greater relative index difference than a second one of the two adjacent optical waveguides;

wherein the cladding of the second one of the two adjacent optical waveguides includes a first cladding part and a second cladding part between which the core is sandwiched; and

wherein a refractive index of a material forming the second one of the two adjacent optical waveguides is controlled by applying voltage between the first cladding part and the second cladding part.

3. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding,

wherein two adjacent optical waveguides are different in a refractive index difference between the core and the cladding;

wherein the cores of the two adjacent optical waveguides have a same refractive index;

wherein a first one of the two adjacent optical waveguides has a greater relative index difference than a second one of the two adjacent optical waveguides;

wherein the cladding of the first one of the two adjacent optical waveguides includes a first cladding part and a second cladding part between which the core is sandwiched; and

wherein a refractive index of a material forming the first one of the two adjacent optical waveguides is controlled by applying voltage between the first cladding part and the second cladding part.

4. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, wherein:

a first one of three adjacent optical waveguides and a second one of the three adjacent optical waveguides are equal in a refractive index difference between the core and the cladding;

a third one of the three adjacent optical waveguides sandwiched between the first one and the second one thereof is different in the refractive index difference between the core and the cladding from the first one and the second one; and

wherein the cores of the three adjacent optical waveguides have a same refractive index.

5. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, the optical integrated device comprising:

an optical coupling part configured to couple two adjacent optical waveguides different in a refractive index difference between the core and the cladding, the optical coupling part including an optical waveguide having a core and a cladding wherein;

the cladding of the optical coupling part comprises at least two types of cladding materials;

a first one of the two adjacent optical waveguides has a greater relative index difference than a second one of the two adjacent optical waveguides;

a first one of the cladding materials forming the cladding of the optical coupling part is equal to a cladding material forming the cladding of the first one of the two adjacent optical waveguides; and

a second one of the cladding materials forming the cladding of the optical coupling part is equal to a cladding material forming the cladding of the second one of the two adjacent optical waveguides.

6. The optical integrated device as claimed in claim 5, wherein the optical coupling part comprises a cladding layer formed of the second cladding material;

and

a width of the cladding layer is reduced toward the first one of the two adjacent optical waveguides from the second one of the two adjacent optical waveguides.

7. The optical integrated device as claimed in claim 5, wherein the cores of the first one and the second one of the two adjacent optical waveguides and the core of the optical coupling part have a same cross-sectional shape.

8. The optical integrated device as claimed in claim 5, wherein the cores of the first one and the second one of the two adjacent optical waveguides and the core of the optical coupling part have a same cross-sectional size.

9. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, the optical integrated device comprising:

an optical coupling part configured to couple two adjacent optical waveguides different in a refractive index difference between the core and the cladding, the optical coupling part including an optical waveguide having a core and a cladding,

wherein the cores of the first one and the second one of the two adjacent optical waveguides and the core of the optical coupling part have a same refractive index.

10. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, the optical integrated device comprising:

an optical coupling part configured to couple two adjacent optical waveguides different in a refractive index difference between the core and the cladding, the optical coupling part including an optical waveguide having a core and a cladding, wherein;

the core of the second one of the two adjacent optical waveguides has a greater width than the core of the first one of the two adjacent optical waveguides;

the optical coupling part is coupled to the first one and the second one of the two adjacent optical waveguides at a first end and a second end, respectively, of the optical coupling part, and the core of the optical coupling part is equal in width to the core of the first one of the two adjacent optical waveguides at the first end of the optical coupling part and to the core of the second one of the two adjacent optical waveguides at the second end of the optical coupling part; and

a width of the core of the optical coupling part is reduced toward the first one of the two adjacent optical waveguides from the second one of the two adjacent optical waveguides.

11. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, the optical integrated device comprising:

an optical coupling part configured to couple two adjacent optical waveguides different in a refractive index difference between the core and the cladding, the optical coupling part including an optical waveguide having a core and a cladding; and

a cladding layer provided on each of the cores of the first one and the second one of the two adjacent optical waveguides and the optical coupling part, the cladding layers having a same refractive index,

wherein the cladding layer is equal in width to the core in each of the first one and the second one of the two adjacent optical waveguides and the optical coupling part.

12. The optical integrated device as claimed in claim 11, wherein the refractive index of the cladding layers is equal to a refractive index of the substrate.

13. An optical integrated device having a plurality of optical waveguides connected on a same substrate and each including a core and a cladding, the optical integrated device comprising:

an optical coupling part configured to couple two adjacent optical waveguides different in a refractive index difference between the core and the cladding, the optical coupling part including an optical waveguide having a core and a cladding; and

a buffer layer formed of one of a dielectric thin film, a metal thin film, and a combination thereof, the buffer layer being provided on at least one of a first surface and a second surface of the substrate, the first surface facing away from the second surface.