Optical fiber for use in Bragg grating and fiber Bragg grating using the same

• US 6,233,386 B1
• Filed: 06/22/1999
• Issued: 05/15/2001
• Est. Priority Date: 06/24/1998
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Oh, Kyung-hwan, Paek, Un-chul
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/337,417
• Time in Patent Office: 693 Days
• Field of Search: 385/37, 385/123, 385/124, 385/125, 385/126, 385/127, 385/128, 385/141, 385/142, 385/144
• US Class Current: 385/123
• CPC Class Codes: G02B 6/0219 based on composition of fibre materials
• CPC Class Codes: G02B 6/03627 arranged - +

Abstract

An optical fiber for use in a fiber Bragg grating and a fiber Bragg grating using the same are provided. The optical fiber includes a core made of a material obtained by adding germanium oxide (GeO₂) to silica (SiO₂), for guiding light, and a cladding made by adding a material having a negative thermal expansion coefficient to silica (SiO₂), the cladding having a refractive index lower than that of the core. Therefore, the change in Bragg wavelength depending on temperature can be minimized by forming the optical fiber using a material having a negative thermal expansion coefficient.

Claims

1. An optical fiber, comprising:

a core comprising GeO₂—

SiO₂, for guiding light; and

a cladding surrounding the core and having a value of refractive index lower than that of the core, said cladding being a glass comprising SiO₂ and further comprising a first additive selected from the group consisting of TiO₂ and ZrO₂.

2. The optical fiber of claim 1, said cladding further comprising a second additive selected from the group consisting of fluorine and boron.

3. The optical fiber of claim 1, said first additive being TiO₂.

4. The optical fiber of claim 3, said cladding consisting essentially of SiO₂ and TiO₂.

5. The optical fiber of claim 2, said first additive being TiO₂.

6. The optical fiber of claim 1, said first additive being ZrO₂.

7. The optical fiber of claim 6, said cladding consisting essentially of SiO₂ and ZrO₂.

8. The optical fiber of claim 2, said first additive being ZrO₂.

9. The optical fiber of claim 1, said optical fiber further characterized in that said cladding has a negative value of the thermal coefficient of expansion.

10. The optical fiber of claim 2, said optical fiber further characterized in that said cladding has a negative value of the thermal coefficient of expansion.

11. The optical fiber of claim 1, further comprising:

a region of the optical fiber having a pattern spacing of refractive index change, for use as a Bragg grating.

12. The optical fiber of claim 2, further comprising:

a region of the optical fiber having a pattern spacing of refractive index change, for use as a Bragg grating.

13. A double-cladding optical fiber, comprising:

a core comprising GeO₂—

SiO₂, for guiding light;

an inner cladding surrounding the core and having a refractive index lower than that of the core, said inner cladding being a glass comprising SiO₂; and

an outer cladding surrounding the inner cladding and having a value of refractive index less than that of the core, said outer cladding being a glass comprising SiO₂ and further comprising a first additive selected from the group consisting of TiO₂ and ZrO₂;

said outer cladding further comprising a second additive selected from the group consisting of fluorine and boron.

14. The optical fiber of claim 13, said first additive being TiO₂.

15. The optical fiber of claim 13, said first additive being ZrO₂.

16. The optical fiber of claim 13, said optical fiber further characterized in that said outer cladding has a negative value of the thermal coefficient of expansion.

18. The optical fiber of claim 13, further comprising:

a region of the optical fiber having a pattern spacing of refractive index change, for use as a Bragg grating.

19. The optical fiber of claim 13, said outer cladding further having a value of refractive index higher than that of said inner cladding.

17. A double-cladding optical fiber, comprising:

a core comprising GeO₂—

SiO₂, for guiding light;

an inner cladding surrounding the core and having a refractive index lower than that of the core, said inner cladding being a glass comprising SiO₂; and

an outer cladding surrounding the inner cladding and having a value of refractive index less than that of the core, said outer cladding being a glass comprising SiO₂ and further comprising a first additive selected from the group consisting of TiO₂ and ZrO₂;

said optical fiber further comprising;

a region of the optical fiber having a pattern spacing of refractive index change, for use as a Bragg grating.

20. An optical fiber apparatus, comprising:

an optical fiber having a pattern spacing of refractive index change, said optical fiber comprising;

a core comprising GeO₂—

SiO₂, for guiding light; and

an outer cladding surrounding the core and having a value of refractive index lower than that of the core, said outer cladding being a glass comprising SiO₂ and further comprising an additive, said additive having a negative value of the thermal coefficient of expansion.

21. The apparatus of claim 20, further comprising:

an inner cladding interposed between said core and outer cladding, said inner cladding having a value of refractive index lower than that of the core, and said inner cladding being made of a glass comprising SiO₂.

22. The apparatus of claim 21, said outer cladding further having a value of refractive index higher than that of said inner cladding.