Dispersion-controlled optical fiber

• US 6,999,667 B2
• Filed: 03/19/2003
• Issued: 02/14/2006
• Est. Priority Date: 04/03/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Jeong-Sik, Choi, Sung-Wook, Do, Mun-Hyun, Jang, Yun-Geun, Han, Ju-Chang, Yang, Jin-Seong
• Primary Examiner(s): Ullah, Akm Enayet
• Assistant Examiner(s): Stein, James D.
• Application Number:
  US10/391,669
• Publication Number:
  US 20030190128A1
• Time in Patent Office: 1,063 Days
• Field of Search: 385/123, 385/124, 385/100, 385/127
• US Class Current: 385/124
• 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 6/02266 Positive dispersion fibres at 1550 nm
• CPC Class Codes: G02B 6/0228 Characterised by the wavelength dispersion slope properties around 1550 nm G02B6/02228 takes precedence
• CPC Class Codes: G02B 6/03627 arranged - +

Abstract

Disclosed is an optical fiber comprising a center core which forms a passageway for transmitting optical signals and has a refractive index N₁, and a cladding which encloses the center core and has a refractive index N₀. The optical fiber further comprises an upper core, which has a distribution of refractive indices increased starting from a refractive index N₂ (>N₀) at its outer circumference to the refractive index N₁ at its internal circumference, and a minutely depressed refractive index region, which is interposed between said upper core and cladding and has a refractive index N₃. The refractive index N₃ is lower than the refractive index N₀.

Claims

1. A dispersion-controlled optical fiber comprising:

a center core having a refractive index N₁ for forming a passageway for transmitting optical signals;

a cladding having a refractive index N₀ for enclosing said center core;

an upper core surrounding said center core and having a refractive index distribution increased starting from a refractive index N₂ at its outer circumference to the refractive index N₁ at its internal circumference; and

,

a minutely depressed refractive index region having a reflective index N₃ and interposed between said upper core and cladding, wherein the refractive index N₃ is lower than the refractive index N₀, wherein the internal radius a and external radius b of said upper core, and the internal radius c of said cladding meet with the relationships;

0.06≦

a/b≦

0.8 and 0.02≦

a/c≦

0.9.

2. The dispersion-controlled optical fiber in accordance with claim 1, wherein the internal circumference of said upper core conforms to the external circumference of said center core.

3. The dispersion-controlled optical fiber in accordance with claim 1, wherein the internal circumference of said upper core is spaced from the center of said center core by a predetermined distance.

4. The dispersion-controlled optical fiber in accordance with claim 1, wherein the refractive indices of said upper core linearly increase from N₂ to N₁.

5. The dispersion-controlled optical fiber in accordance with claim 1, wherein the internal radius a and external radius b of said upper core, and the internal radius c of said cladding meet with the relationships:

1.2≦

N₁/N₂≦

2.67 and −

8≦

N₁/N₃≦

1.6.

6. The dispersion-controlled optical fiber in accordance with claim 1, the optical fiber has a loss not exceeding 0.25 dB/km, a cutoff wavelength not exceeding 1400 nm, and a dispersion slope not exceeding 0.08 ps/nm²·

km at the wavelength of 1550 nm.

7. The dispersion-controlled optical fiber in accordance with claim 1, the optical fiber has a dispersion value not less than 0.1 ps/nm·

km at the wavelength of 1400 nm, and a dispersion value not exceeding 16 ps/nm·

km at the wave length of 1625 nm.

8. The dispersion-controlled optical fiber in accordance with claim 1, wherein the optical fiber has a mode-field diameter not less than 8.2 μ

m at the wavelength of 1550 nm.

9. The dispersion-controlled optical fiber in accordance with claim 1, wherein the optical fiber comprises suitable optical characteristics for wavelength-division multiplexing transmission using a wavelength band of 1400˜

1625 nm.

10. A dispersion-controlled optical fiber comprising:

a loss not exceeding 0.25 dB/km, a cutoff wavelength not exceeding 1400 nm, and a dispersion slope not exceeding 0.08 ps/nm²·

km at the wavelength of 1550 nm;

a dispersion value not less than 0.1 ps/nm·

km at the wavelength of 1400 nm;

a dispersion value not exceeding 16 ps/nm·

km at the wavelength of 1625 nm; and

a mode field diameter not less than 8.2 μ

m at the wavelength of 1550 nm, so that the optical fiber has suitable optical characteristics for wavelength-division multiplexing transmission using a wavelength band of 1400˜

1625 nm.

11. The dispersion-controlled optical fiber in accordance with claim 10, wherein the dispersion value at the wavelength of 1400 nm is between 0.1 and 4 ps/nm·

km, the optical fiber has a dispersion value at the wavelength of 1550 nm which is between 5 and 13 ps/nm·

km, and the dispersion value at the wavelength of 1625 nm is between 8 and 16 ps/nm·

km.