Low attenuation optical waveguide

• US 6,282,354 B1
• Filed: 08/17/2000
• Issued: 08/28/2001
• Est. Priority Date: 09/12/1997
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Jones, Peter C., Smith, David K., Ma, Daiping
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US09/641,019
• Time in Patent Office: 376 Days
• Field of Search: 385/122-128
• US Class Current: 385/124
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/02009 Large effective area or mode field radius, e.g. to reduce nonlinear effects in single mode fibres
• CPC Class Codes: G02B 6/02238 Low dispersion slope fibres
• CPC Class Codes: G02B 6/02242 having a dispersion slope <0.06 ps/km/nm2
• CPC Class Codes: G02B 6/02276 Dispersion shifted fibres, i.e. zero dispersion at 1550 nm
• CPC Class Codes: G02B 6/0285 Graded index layer adjacent to the central core segment and ending at the outer cladding index
• CPC Class Codes: G02B 6/0286 Combination of graded index in the central core segment and a graded index layer external to the central core segment G02B6/0288 takes precedence
• CPC Class Codes: G02B 6/03611 Highest index adjacent to central axis region, e.g. annular core, coaxial ring, centreline depression affecting waveguiding
• CPC Class Codes: G02B 6/03627 arranged - +
• CPC Class Codes: G02B 6/03633 arranged - -
• CPC Class Codes: G02B 6/03644 arranged - + -
• CPC Class Codes: G02B 6/0365 arranged - - +
• CPC Class Codes: G02B 6/03672 arranged - - + -
• CPC Class Codes: G02B 6/03694 Multiple layers differing in properties other than the refractive index, e.g. attenuation, diffusion, stress properties

Abstract

Disclosed is a single mode optical waveguide fiber having a core refractive index profile in which the profile parameters are selected to provide an attenuation minimum. A set of profiles having the same general shape and dimensions is shown to have a group of profiles contained in a sub-set which exhibit a minimum of attenuation as compared to the remaining members of the set. The members of the sub-set have been found to have the lowest effective group index, n_geff, and the lowest change in β² under waveguide fiber bending.

Claims

1. A single mode optical waveguide fiber optimized to have low attenuation comprising:

a core glass region having a refractive index profile;

an annular clad glass layer surrounding and in contact with the core glass region, the clad glass layer having a refractive index profile, wherein at least a portion of the core index profile is greater than at least a portion of the clad layer index profile;

wherein, said core region includes,

a center segment having an outer radius r₁, a relative index Δ

₁%, and a centerline having a relative index,

a first annular segment, surrounding and in contact with the center segment, having a relative index Δ

₂ %, and,

a second annular segment, surrounding and in contact with the first annular segment, having a center radius r₃, a relative index Δ

₃ %, and a width w₃;

wherein,

Δ

₁ %>

Δ

₃ %≧

Δ

₂ %≧

0; and

Δ

₁ % is in the range 0.77% to 1.30%, r₁ is in the range 2.04 μ

m to 3.41 μ

m, Δ

₂ % is in the range 0 to 0.16%, Δ

₃ % is in the range 0 to 0.51%, r₃ is in the range 5.53 μ

m to 10.21 μ

m, and w₃ is in the range 0 to 5.76 μ

m.

2. The single mode waveguide of claim 1 wherein total dispersion slope ≦

0.10 ps/nm²-km, diameter in the range 7.9 μ

m to 9.1 μ

m and cut off wavelength ≦

1500 nm.

3. The single mode waveguide of claim 2 wherein mode field diameter >

7.9 μ

m.

4. The single mode waveguide of claim 3 wherein said single mode waveguide is characterized by induced attenuation under pin array bending conditions and the pin array bending induced attenuation is less than or equal to 8 dB.

5. The single mode waveguide of claim 4 wherein zero dispersion wavelength is in the range of 1575 nm to 1595 nm.

6. The single mode waveguide of claim 2 further characterized by an inner and an outer profile volume wherein the inner volume is about 3.02 units and the outer volume is about 3.9 units;

and wherein,

the combinations of profile parameters selected from the prescribed ranges provide a single mode waveguide having attenuation at 1550 nm less than or equal to 0.19 dB/km.

7. The single mode waveguide of claim 1 further characterized by an inner and an outer profile volume wherein the inner volume is in the range 2.67 units to 3.62 units and the outer volume is in the range 1.00 units to 7.85 units;

and wherein,

the combinations of profile parameters selected from the prescribed ranges provide a single mode waveguide having attenuation at 1550 μ

m less than or equal to 0.203 dB/km.

8. A single mode optical waveguide fiber optimized to have low attenuation comprising:

a core glass region having a refractive index profile;