SSC CHIP, FIBER ARRAY ATTACHED WITH SSC, PLC MODULE ATTACHED WITH SSC AND METHOD FOR MANUFACTURING SSC

• US 20100142900A1
• Filed: 11/25/2009
• Published: 06/10/2010
• Est. Priority Date: 11/26/2008
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Nara, Kazutaka, Uchida, Yasuyoshi
• Granted Patent: US 8,538,213 B2
• Time in Patent Office: Days
• US Class Current: 385/89
• CPC Class Codes: G02B 6/305 and having an integrated mode-size expanding section, e.g. tapered waveguide
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres

Abstract

There is provided a SSC chip whose yield may be improved and whose processing steps may be simplified as compare to those of a prior art PLC chip having a light waveguide circuit to which a spot-size converter (SSC) is added, a fiber array attached with the SSC chip, a PLC module attached with the SSC chip and a method for manufacturing the SSC chip. The SSC chip has four spot-size converters and is fabricated separately from a PLC chip. Each SSC has a straight waveguide having the same core width and height with an end of an input/output waveguide of the PLC chip, a horizontally tapered waveguide in which the core width is enlarged in a tapered shape in the horizontal direction from the core width of the straight waveguide, a vertically tapered waveguide in which the core height is enlarged in a tapered shape in the vertical direction from the core height of the horizontally tapered waveguide and a spot-size enlarged portion whose core width and core height are both enlarged. Because it is unnecessary to fabricate the SSC at the end of the input/output waveguide of the PLC chip, a yield of the PLC chip may be improved.

Claims

1. A spot-size converter (SSC) chip used by being coupled with a planar lightwave circuit (PLC) chip having a planar lightwave circuit and having one or a plurality of spot-size converters, said spot-size converter being a light waveguide composed of a clad and a core, comprising:

a straight waveguide whose core width and core height are constant;

a vertically tapered waveguide at least whose core height among the core width and core height is enlarged in a tapered shape in the vertical direction from the core height of the straight waveguide; and

a spot-size enlarged portion whose core height and core width are both enlarged.

2. The SSC chip according to claim 1, wherein said SSC chip is used for said PLC chip having no horizontally tapered waveguide whose core width is enlarged in a tapered shape in the horizontal direction at an end of an input/output waveguide of said planar lightwave circuit and said spot-size converter comprising, in an order formed:

a straight waveguide having the same core width and core height with the end of the input/output waveguide of said PLC chip;

a horizontally tapered waveguide whose core width is enlarged in a tapered shape in the horizontal direction from the core width of the straight waveguide;

the vertically tapered waveguide at least whose core height is enlarged in a tapered shape in the vertical direction from the core height of the straight waveguide; and

the spot-size enlarged portion whose core height and core width are both enlarged.

3. The SSC chip according to claim 1, wherein said SSC chip is used for said PLC chip having no horizontally tapered waveguide whose core width is enlarged in the tapered shape in the horizontal direction is formed at the end of the input/output waveguide of said planar lightwave circuit and said spot-size converter comprising, in an order formed:

the straight waveguide having the same core width and core height with the end of the input/output waveguide of said PLC chip;

a vertically and horizontally tapered waveguide whose core width and core height are enlarged in a tapered shape in the vertical and horizontal directions from the core width and core height of the straight waveguide; and

the spot-size enlarged portion whose core height and core width are both enlarged.

4. The SSC chip according to claim 1, wherein said SSC chip is used for said PLC chip having no horizontally tapered waveguide whose core width is enlarged in the tapered shape in the horizontal direction is formed at the end of the input/output waveguide of said planar lightwave circuit and said spot-size converter comprising, in an order formed:

the straight waveguide having the same core width and core height with the end of the input/output waveguide of said PLC chip;

the vertically tapered waveguide whose core height is enlarged in the tapered shape in the vertical direction from the core height of the straight waveguide;

the horizontally tapered waveguide whose core width is enlarged in the tapered shape in the horizontal direction from the core width of the straight waveguide; and

the spot-size enlarged portion whose core height and core width are both enlarged.

5. The SSC chip according to claim 1, wherein said SSC chip is used for said PLC chip in which the horizontally tapered waveguide whose core width is enlarged in the tapered shape in the horizontal direction is formed at the end of the input/output waveguide of said planar lightwave circuit and said spot-size converter comprising, in an order formed:

the straight waveguide having the same core width and core height with the input/output waveguide of said PLC chip;

the vertically tapered waveguide whose core height is enlarged in the tapered shape in the vertical direction from the core height of the straight waveguide; and

the spot-size enlarged portion whose core height and core width are both enlarged.

6. A fiber array attached with the SSC chip having the SSC chip of claim 1 and a fiber array in which a plurality of fibers is arrayed and disposed, wherein the end face of said SSC chip is coupled with the end face of the fiber array so that each spot-size enlarged portion of said plurality of spot-size converters is coupled with each end face of said plurality of fibers respectively with minimum coupling loss.

7. A PLC module attached with the SSC chip having the SSC chip of claim 1, the PLC chip having the planar lightwave circuit connected to the plurality of input/output waveguides and the fiber array in which the plurality of fibers is arrayed and disposed,

wherein the end face of said SSC chip is coupled with the end face of the PLC chip so that each end face of said straight waveguides of said plurality of spot-size converters is coupled with each end face of said plurality of input/output waveguides of said planar lightwave circuit respectively with minimum coupling loss;

and

the other end face of said SSC chip is coupled with the end face of the fiber array so that each spot-size enlarged portion of said plurality of spot-size converters is coupled with each end face of said plurality of fibers respectively with minimum coupling loss.

8. A method for manufacturing the SSC chip of claim 1, comprising steps of:

forming an under cladding layer on a substrate by means of flame hydrolysis deposition;

forming a first core layer on said substrate;

disposing a shadow mask having a plurality of openings at predetermined position on said first core layer to form a second core layer having a vertically tapered structure in which core height is enlarged in a tapered shape at the predetermined position on said first core layer by means of plasma chemical vapor deposition (CVD);

forming a plurality of waveguide patterns by means of photolithography and etching; and

forming an upper cladding layer on said plurality of waveguide patterns by means of the flame hydrolysis deposition.

9. The method for manufacturing the SSC chip according to claim 8, wherein the first core layer is formed by means of plasma CVD.

10. The method for manufacturing the SSC chip according to claim 8, wherein the first core layer is formed by means of flame hydrolysis deposition.