Preform holey optical fibre, a holey optical fibre, and a method for their production
AssigneeCrystal Fibre A/S
InventorsWilliam John Wadsworth, Brian Joseph Mangan, Timothy Adam Birks, Jonathan Cave Knight, Philip St. John Russell
Life of this patent
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Abstract
A holey optical fibre for supporting propagation of light of a wavelength λ,comprises a plurality of cylinders (10) each having a longitudinal axis, the cylinders (10) being separated from each other by regions of a matrix material (20) and having their longitudinal axes substantially parallel to each other. Each cylinder (10) has a diameter, in the plane perpendicular to the longitudinal axis, that is small enough for the composite material of the ensemble of cylinders and matrix material to be substantially optically homogenous in respect of light of wavelength λ.
Claims61
A composite material for supporting propagation of light of a wavelength λ, comprising a plurality of elongate regions comprising solid cylinders separated from each other by regions of a solid matrix material and defining a longitudinal axis, the composite material being arranged to support propagation of light in a direction substantially parallel to said longitudinal axis, wherein each cylinder is made from material differing from a neighbouring region of matrix material in an optical property, and each cylinder having a transverse cross-sectional area that is sufficiently small for the composite material to be substantially optically homogeneous in respect of light of wavelength λ, and wherein said regions are solid.
A method of providing a selected optical property in a composite material for supporting propagation of light of a wavelength λcomprising:
- (i) providing a plurality of rods each having a longitudinal axis;
- (ii) forming a bundle of the rods, in which the rods have their longitudinal axes substantially parallel to each other,
- (iii) drawing an elongate, fused rod from the bundle;
- cutting the fused rod into a plurality of lengths;
- and
- (iv) repeating steps (ii) and (iii) at least once by forming the bundle from the lengths of fused rod and drawing a further, elongate fused rod from the bundles,
- wherein steps (i)–(iv) are arranged to provide that the further, elongate fused rod produced at the end of step (iv) comprises a plurality of elongate regions comprising solid cylinders each having a longitudinal axis, the cylinders being separated from each other by regions of a solid matrix material and the cylinders having their longitudinal axes substantially parallel to each other, wherein each cylinder is made from material differing from a neighbouring region of matrix material in an optical property, and each cylinder having a transverse cross-sectional area that is sufficiently small for the composite material to be substantially optically homogeneous in respect of light of wavelength λ, and wherein said regions are solid.
Dependencies are inferred from the claim text.