Amorphous silicon alloy based integrated spot-size converter

• US 20030165293A1
• Filed: 08/12/2002
• Published: 09/04/2003
• Est. Priority Date: 02/28/2002
• Status: Active Grant

• Current Assignee: Sarnoff Corporation (SRI International, Inc.)
• Original Assignee: Sarnoff Corporation (SRI International, Inc.)
• Inventors: Abeles, Joseph H., Maley, Nagendranath, Yang, Liyou, Whaley, Ralph Doud Jr.
• Granted Patent: US 6,888,984 B2
• Time in Patent Office: Days
• US Class Current: 385/33
• CPC Class Codes: G02B 3/0087 with index gradient
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies

Abstract

A photonic device suitable for being optically coupled to at least one optical fiber having a first spot-size, the device including: at least one photonic component; and, a graded index lens optically coupled between the at least one photonic component and the at least one optical fiber; wherein, the graded index lens is adapted to convert optical transmissions from the at least one photonic component to the first spot size.

Claims

1. A photonic device suitable for being optically coupled to at least one optical fiber having a first spot-size, said device comprising:

at least one photonic component; and

,

a graded index lens optically coupled between said at least one photonic component and said at least one optical fiber;

wherein, said graded index lens is adapted to convert optical transmissions from said at least one photonic component to said first spot size.

2. The device of claim 1, wherein said first spot-size is ≧

approximately 5 μ

m.

3. The device of claim 2, wherein said photonic component has a second spot-size≦

approximately 1 μ

m.

4. The device of claim 3, wherein said at least one photonic component comprises at least one type III-V semiconductor compound based photonic component.

5. The device of claim 4, wherein, said graded index lens is further adapted to convert optical transmissions from said optical fiber to said second spot size.

6. The device of claim 1, wherein said graded index lens has an index profile that varies quadratically as a function of transverse position.

7. The device of claim 6, wherein a refractive index at an outermost edge of said graded index lens is less than a refractive index at at least one other transverse position.

8. The device of claim 1, wherein said graded index lens comprises at least one amorphous silicon based alloy material.

9. The device of claim 8, wherein said amorphous silicon based alloy material comprises at least one a-Si:

H or a-Si;

F based alloy.

10. The device of claim 8, wherein said at least one amorphous silicon based alloy material comprises at least one material selected from the group consisting essentially of:

a-SiC_x where 0<

x<

1, a-SiN_y where 0<

y<

1.33, a-SiO_z where O<

z<

2 and a-SiGe_w where 0<

w<

1.

11. The device of claim 1, further comprising at least one waveguide optically coupled to said graded index lens.

12. The device of claim 11, wherein said graded index lens includes first and second refractive indices and said waveguide has a refractive index greater than said first refractive index of said graded index lens and less than said second refractive index of said graded index lens.

13. The device of claim 11, wherein said graded index lens has a refractive index profile and said waveguide has a refractive index approximately equal to an average of said refractive index profile of said graded index lens.

14. The device of claim 11, wherein said graded index lens and waveguide each comprise at least one amorphous silicon based alloy material.

15. The device of claim 11, wherein said graded index lens and waveguide each comprise at least one a-Si:

H or a-Si;

F based alloy.

16. The device of claim 15, wherein said at least one amorphous silicon based alloy material comprises at least one material selected from the group consisting essentially of:

a-SiC_x where 0<

x<

1, a-SiN_y where 0<

y<

1.33, a-SiO_z where 0<

z<

2 and a-SiGe_w where 0<

w<

1.

17. The device of claim 1, wherein said graded index lens comprises a quadratic graded index lens.

18. The device of claim 1, further comprising cladding adjacent to at least said graded index lens.

19. The device of claim 18, wherein said graded index lens has a refractive index n(x) as a function of transverse position where:

n²(x)=n²(0)(1−

(gx)²), n(0) is the central index, and g is the lens curvature

20. The device of claim 1, wherein said graded index lens is at least partially laterally tapered.

21. A method for optically coupling at least one photonic device having a first spot-size to at least one optical fiber having a second spot-size, said method comprising forming a graded index lens adapted to convert optical transmissions from said first spot size to said second spot-size so as to be integrated with said at least one photonic device;

wherein, said graded index lens is adapted to be optically coupled between said at least one photonic device and optical fiber.

22. The method of claim 21, wherein said forming comprises using at least one amorphous silicon based alloy material.

23. The method of claim 21, wherein said amorphous silicon based alloy material comprises at least one a-Si:

H or a-Si;

F based alloy.

24. The method of claim 22, wherein said at least one amorphous silicon based alloy material comprises at least one material selected from the group consisting essentially of:

a-SiC_x where 0<

x<

1, a-SiN_y where 0<

y<

1.33, a-SiO_z where 0<

z<

2 and a-SiGe_w where 0<

w<

1.

25. The method of claim 22, wherein said forming comprises plasma enhanced chemical vapor depositing said amorphous silicon based alloy material in a varying manner.

26. The method of claim 21, wherein said at least one graded index lens is at least partially laterally tapered.

27. The method of claim 21, wherein said forming comprises plasma enhanced chemical deposition processing using:

at least a first gas to provide at least one baseline refractive index for said graded index lens; and

,

at least a second gas to vary said at least one baseline refractive index as a function of transverse position.