Optical fiber
An object of the present disclosure is to provide an optical fiber having a simple structure, as well as attaining removal of loss components generated in an electric field part oozing out to a core-clad interface or a clad region and reduction in scattering loss generated from an interface with the clad region. The present disclosure relates to an optical fiber including a core for propagating light, a cladding disposed around the core, an air layer between the core and the cladding, and two or more bridges for supporting the core in the air layer.
1 . An optical fiber comprising:
a core for propagating light,
a cladding disposed around the core;
an air layer between the core and the cladding; and
two or more bridges for supporting the core in the air layer;
wherein a refractive index of the cladding is lower than a refractive index of the core; and
wherein, given that the number of propagation modes is (n+1), the refractive index of the cladding is lower than an effective refractive index of an n-th order mode and higher than an effective refractive index of an (n+1)-th order mode.
2 . The optical fiber according to claim 1 , wherein a thickness of the air layer is equal to or less than 1.6 μm.
3 . An optical fiber comprising:
a core for propagating light,
a cladding disposed around the core;
an air layer between the core and the cladding; and
two or more bridges for supporting the core in the air layer, wherein a relative refractive index difference Δ of the core to the cladding is as follows:
0.0748
a
-
1.962
<
Δ
<
0.18
a
-
1.941
[
Math
.
4
]
where a is a radius of the core.
4 . The optical fiber according to claim 3 , wherein a refractive index of the cladding is lower than a refractive index of the core.
5 . The optical fiber according to claim 4 , wherein, given that the number of propagation modes is (n+1), the refractive index of the cladding is lower than an effective refractive index of an n-th order mode and higher than an effective refractive index of an (n+1)-th order mode.
6 . The optical fiber according to claim 3 , wherein a thickness of the air layer is equal to or less than 1.6 μm.