Dispersion-shifted fiber for optical parametric amplifier

• US 7,242,834 B2
• Filed: 07/30/2004
• Issued: 07/10/2007
• Est. Priority Date: 11/22/2003
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Hyun Jae, Park, Heuk, Lee, Won Kyoung
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US10/903,056
• Publication Number:
  US 20050111802A1
• Time in Patent Office: 1,075 Days
• Field of Search: 385/123, 385/126, 385/144
• US Class Current: 385/123
• CPC Class Codes: G02B 6/02028 Small effective area or mode field radius, e.g. for allowing nonlinear effects non-linear optical waveguide devices G02F1/365
• CPC Class Codes: G02B 6/02276 Dispersion shifted fibres, i.e. zero dispersion at 1550 nm
• CPC Class Codes: G02B 6/0281 Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core G02B6/0288, G02B6/0286 take precedence
• CPC Class Codes: G02B 6/03633 arranged - -
• CPC Class Codes: G02B 6/03644 arranged - + -
• CPC Class Codes: G02F 1/392 Parametric amplification
• CPC Class Codes: G02F 1/395 in optical waveguides

Abstract

Provided is a dispersion-shifted fiber for an optical parametric amplifier. The dispersion-shifted fiber is a silica-based optical fiber and has a large nonlinear coefficient and a small effective area. The dispersion-shifted fiber also reduces a bending loss and a splice loss due to a mode field diameter difference between it and a conventional single mode fiber. For this, the dispersion-shifted fiber comprises a rectangular core with a very small radius and a high refractive index, a depressed inner clad, and an outer clad with a ring. The core and/or the inner clad are/is doped with a heavy metal.

Claims

1. A dispersion-shifted fiber for an optical parametric amplifier, which comprises a core, an inner clad, and an outer clad, and has a nonlinear coefficient of 80 W⁻

1 km<sup>−

1</sup> or more, and a zero-dispersion wavelength of 1,530 to 1,620 nm wherein the core has a constant refractive index regardless of the radius of the core.

2. The dispersion-shifted fiber of claim 1, wherein the fiber has an effective area of 10.5 μ

m² or less.

3. The dispersion-shifted fiber of claim 1, wherein the core is doped with a heavy metal selected from bismuth (Bi), lead (Pb), and a mixture thereof.

4. The dispersion-shifted fiber of claim 3, wherein the core is doped with a Pb of 35 cation % or more.

5. The dispersion-shifted fiber of claim 3, wherein the core is doped with a Bi of 80 cation % or more.

6. The dispersion-shifted fiber of claim 5, wherein the heavy metal doped on the inner clad is used in a less amount than the heavy metal doped on the core.

7. The dispersion-shifted fiber of claim 1, wherein the inner clad is doped with a heavy metal selected from Bi, Pb, and a mixture thereof.

8. The dispersion-shifted fiber of claim 2, wherein the outer clad further comprises a ring.

9. The dispersion-shifted fiber of claim 8, wherein a relative refractive index difference between the core and the outer clad is 2% or less, and a relative refractive index difference between the inner clad and the outer clad is 1.5% or less and is higher than a relative refractive index difference between the ring and the outer clad.

10. The dispersion-shifted fiber of claim 8, wherein a thickness of the ring is 0.3–

0.8 times of a thickness of the core and a thickness of the inner clad is 6–

7 times of the thickness of the core.