Tubular anti-resonant hollow core fiber with low viscosity cladding material

An anti-resonant hollow core optical fiber, comprising:

• a cladding having an outer circumferential surface and an inner circumferential surface that defines a first interior volume, wherein at least part of the cladding is made of a cladding material;
• an assembly hollow tube arranged within the first interior volume and coupled to the inner circumferential surface of the cladding, wherein the assembly hollow tube defines a second interior volume;
• and
• a plurality of non-contacting tubes arranged within the second interior volume, in a ring formation, wherein the plurality of non-contacting tubes are coupled to an interior surface of the assembly hollow tube and define a hollow core,
• wherein the plurality of non-contacting tubes are separated by gaps such that no non-contacting tube is in contact with another non-contacting tube,
• wherein the plurality of non-contacting tubes are made of a tube material that is different from the cladding material.

A method of manufacturing an anti-resonant hollow core optical fiber, the method comprising:

• providing an assembly hollow tube having a first interior volume;
• forming a plurality of capillary tubes, the plurality of capillary tubes being made of a tube material;
• inserting the plurality of capillary tubes into the first interior volume of the assembly hollow tube to form a tube assembly, wherein the plurality of capillary tubes are coupled to an interior surface of the assembly hollow tube in an initial ring formation, and wherein the plurality of capillary tubes are separated by initial gaps such that no capillary tube is in contact with another capillary tube;
• providing a cladding having an outer circumferential surface with an initial outer circumferential dimension and an initial inner circumferential surface with an initial inner circumferential dimension, wherein the initial inner circumferential surface defines a second interior volume, and wherein at least part of the cladding is made of a cladding material that has a lower viscosity at a drawing temperature than the tube material;
• inserting the tube assembly into the second interior volume to form a fiber preform;
• and
• drawing the fiber preform from a furnace at the drawing temperature and at a drawing tension to form the anti-resonant hollow core optical fiber,
• wherein, in the anti-resonant hollow core optical fiber, the plurality of capillary tubes are arranged in a final ring formation to define a hollow core configured to confine light.

An anti-resonant hollow core optical fiber, comprising:

• a cladding having an outer circumferential surface and an inner circumferential surface that defines an interior volume, wherein at least part of the cladding is made of a cladding material;
• and
• a plurality of circular capillary tubes arranged within the interior volume, in a ring formation, wherein the plurality of circular capillary tubes are coupled to the inner circumferential surface of the cladding and define a hollow core,
• wherein the plurality of circular capillary tubes are made of a tube material that is different from the cladding material.