Branched optical waveguide and its method of use

• US 6,278,822 B1
• Filed: 04/30/1999
• Issued: 08/21/2001
• Est. Priority Date: 05/01/1998
• Status: Expired due to Fees

• Current Assignee: Bookham Incorporated (Oclaro (North America), Inc.)
• Original Assignee: Bookham Incorporated (Oclaro (North America), Inc.)
• Inventors: Dawnay, Emma Jane Clarissa
• Primary Examiner(s): Schuberg, Darren
• Assistant Examiner(s): ASSAF, FAYEZ G
• Application Number:
  US09/302,413
• Time in Patent Office: 844 Days
• Field of Search: 385/2, 385/3, 385/8-10, 385/37, 385/40, 385/50, 385/132
• US Class Current: 385/50
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/2257 the optical waveguides being made of semiconducting material
• CPC Class Codes: G02F 1/3133 the optical waveguides being made of semiconducting materials

Abstract

The device comprises an upper silicon layer (10) including two optically connected rib waveguides (3,4) formed in the upper silicon layer (10); a pair of dissimilar materials (6,7) each positioned between the two waveguides (3,4); and an electrical circuit (8,9,13) through the pair of dissimilar materials (6,7), so that an electrical current can be passed through the dissimilar materials (6,7) in both forward and reverse directions, so as to simultaneously heat one waveguide and cool the other waveguide by virtue of the Peltier effect.

Claims

1. A method of using an optoelectronic device comprising an upper silicon layer and two optically connected waveguides that form part of the upper silicon layer, the method comprising:

heating a first of the waveguides;

cooling a second of the waveguides, thereby introducing a refractive index difference between the two waveguides and, consequently, a relative phase shift between light passing through the first and second waveguides, wherein the steps of heating the first of the waveguides and cooling the second of the waveguides comprise;

(i) providing an electrical circuit comprising at least one pair of dissimilar materials, each of the dissimilar materials being positioned between the first and second waveguides, wherein each of the at least one pair of dissimilar materials comprises;

an n-doped region of a semiconductor, and

a p-doped region of a semiconductor, wherein the electrical circuit further comprises;

metal tracking provided in electrical contact with the n- and p-doped regions; and

dissimilar-material-junctions positioned at junctions between the metal tracking and each of the n- and p-doped regions, wherein the dissimilar-material-junctions are heated and cooled via the Peltier effect to bring about the heating and cooling of the waveguides; and

(ii) passing an electrical current around the electrical circuit, including through the dissimilar materials, thereby effecting the heating of the first waveguide and the cooling of the second waveguide via the Peltier effect; and

cooling the heated waveguide and heating the cooled waveguide such that the temperature of the waveguides is substantially equalized and substantially no relative phase shift exists between light passing through the first and second waveguides.

2. A method according to claim 1, wherein said metal tracking extends at least part way along each of the waveguides.

3. A method of using an optoelectronic device comprising an upper silicon layer and two optically connected waveguides that form part of the upper silicon layer, the method comprising:

heating a first of the waveguides;

cooling a second of the waveguides, thereby introducing a refractive index difference between the two waveguides and, consequently, a relative phase shift between light passing through the first and second waveguides; and

cooling the heated waveguide and heating the cooled waveguide such that the temperature of the waveguides is substantially equalized and substantially no relative phase shift exists between light passing through the first and second waveguides wherein the two optically connected waveguides comprise rib waveguides formed in the upper silicon layer and wherein the optoelectronic device further comprises metal tracks in contact with upper and side surfaces of the rib waveguides, and also in contact with parts of an upper surface of the upper silicon layer on opposing sides of the ribbed waveguides, wherein said metal tracks are adapted to effect said heating and cooling when an electrical current is passed through said metal tracks.

4. An optoelectronic device, comprising:

an upper silicon layer;

two optically connected rib waveguides formed in the upper silicon layer;

at least one pair of dissimilar materials positioned so that each dissimilar material is positioned between a first and second one of the rib waveguides;

means to complete an electrical circuit through the at least one pair of dissimilar materials, so that an electrical current can be passed through the dissimilar material in both forward and reverse directions;

metal tracking provided in electrical contact with the n- and p-doped regions; and

dissimilar-material-junctions positioned at junctions between the metal tracking and each of the n- and p-doped regions, wherein the dissimilar-material-junctions are heated and cooled via the Peltier effect to bring about the heating and cooling of the rib waveguides.

5. An optoelectronic device according to claim 4, wherein said metal tracking extends at least part way along each of the waveguides.

6. An optoelectronic device, comprising:

an upper silicon layer;

two optically connected rib waveguides formed in the upper silicon layer;

at least one pair of dissimilar materials positioned so that each dissimilar material is positioned between a first and second one of the rib waveguides; and

means to complete an electrical circuit through the at least one pair of dissimilar materials, so that an electrical current can be passed through the dissimilar material in both forward and reverse directions, wherein the at least one pair of dissimilar materials comprises a plurality of pairs of dissimilar materials positioned so that each dissimilar material of each pair is positioned between the first and second rib waveguides, and wherein the means to complete the electrical circuit is adapted to pass an electrical current in series between each pair of dissimilar materials in both forward and reverse directions.

7. An optoelectronic device, comprising:

an upper silicon layer;

two optically connected rib waveguides formed in the upper silicon layer;

at least one pair of dissimilar materials positioned so that each dissimilar material is positioned between a first and second one of the rib waveguides;

means to complete an electrical circuit through the at least one pair of dissimilar materials, so that an electrical current can be passed through the dissimilar material in both forward and reverse directions; and

metal tracks in contact with upper and side surfaces of the rib waveguides, and also in contact with parts of an upper surface of the upper silicon layer on opposing sides of the rib waveguides, wherein said metal tracks are adapted to effect said heating and cooling when an electrical current is passed through said metal tracks.