Optical fiber, optical fiber cable and communication equipment

1. An optical fiber, comprising:

a core; and

at least one cladding layer formed on a periphery of the core,

wherein the cladding layer comprises a polymer having a repeating unit (A) derived from 2-(perfluorohexyl)ethyl methacrylate.

2. The optical fiber according to claim 1 , wherein the polymer forming the cladding layer further contains a repeating unit (B) derived from a fluoroalkyl (meth)acrylate represented by formula (3) below:

wherein in formula (3), p is an integer of 1 or 2, q is an integer of 1 to 4, R is a hydrogen atom or a methyl group, and X is a hydrogen atom or fluorine atom.

3. The optical fiber according to claim 1 , wherein the polymer forming the cladding layer further comprises a repeating unit (C) derived from an alkyl (meth)acrylate that does not include a fluorine atom.

4. The optical fiber according to claim 1 , wherein the polymer forming the cladding layer further comprises a repeating unit (D) derived from a hydrophilic monomer.

5. The optical fiber according to claim 2 , wherein the polymer forming the cladding layer comprises the following relative to 100 mass % of the polymer:

15 to 60 mass % of the repeating unit (A) derived from 2-(perfluorohexyl)ethyl methacrylate,

20 to 70 mass % of the repeating unit (B) derived from fluoroalkyl (meth)acrylate represented by formula (3),

10 to 30 mass % of a repeating unit (C) derived from alkyl (meth)acrylate that does not include a fluorine atom, and

0.1-10 mass % of a repeating unit (D) derived from a hydrophilic monomer.

6. The optical fiber according to claim 1 , wherein the polymer to form the cladding layer comprises the following relative to 100 mass % of the polymer:

10 to 50 mass % of the repeating unit (A) derived from 2-(perfluorohexyl)ethyl methacrylate,

40 to 80 mass % of a repeating unit (C) derived from alkyl (meth)acrylate that does not include a fluorine atom, and

0.1 to 10 mass % of a repeating unit (D) derived from a hydrophilic monomer.

7. The optical fiber according to claim 4 , wherein the polymer forming the cladding layer comprises at least 1.5 mass % of the repeating unit (D) derived from a hydrophilic monomer relative to 100 mass % of the polymer.

8. The optical fiber according to claim 1 , wherein the polymer forming the cladding layer has a glass transition temperature (Tg) (° C.) and a refractive index (n) that satisfy formula (4) below:

Tg≧ 375× n− 455  (4).

9. The optical fiber according to claim 1 , comprising only one cladding layer.

10. The optical fiber according to claim 1 , comprising two or more cladding layers.

11. The optical fiber according to claim 1 , comprising one core.

12. The optical fiber according to claim 1 , comprising multiple cores.

13. An optical fiber cable, comprising:

the optical fiber according to claim 1 ; and

a jacket layer formed on a periphery of the optical fiber.

14. The optical fiber cable according to claim 13 , wherein the jacket layer comprises 50 mass % or greater of a polyolefin resin or a chlorinated polyolefin resin.

15. A communication equipment device, comprising the optical fiber according to claim 1 .

16. The optical fiber cable according to claim 4 , wherein a monomer forming the repeating unit (D) is selected from the group consisting of (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and glycidyl (meth)acrylate.

17. The optical fiber cable according to claim 10 , wherein the cladding layer comprises:

a first inner layer containing a cladding material comprising the polymer having a repeating unit derived from 2-(perfluorohexyl)ethyl methacrylate, and

a second layer containing a cladding material having a refractive index lower than that of the first layer.