Anti-resonant hollow-core fibers featuring support structures

An optical fiber fabrication method comprising:

• fabricating a nested-element preform by:
• fabricating a cladding preform including a hollow interior preform region;
• and
• fabricating one or more nested AR (anti-reflective) preform elements (distributed around walls of the hollow interior preform region;
• and
• drawing the nested-element preform into an AR hollow-core optical fiber (AR-HCF), wherein the AR-HCF comprises:
• a cladding structure associated with the cladding preform, wherein the cladding structure extends along a fiber length of the AR-HCF and provides a hollow interior fiber region;
• and
• one or more nested AR elements associated with the one or more nested AR preform elements, wherein the one or more nested AR elements are configured to guide light along the fiber length in a central portion of the hollow interior fiber region based on optical anti-resonance, wherein at least one of the one or more nested AR elements comprises:
• a first AR element formed as a wall extending along the fiber length and located entirely within the hollow interior fiber region, wherein the wall of the first AR element, in a cross-sectional plane orthogonal to the fiber length, fully surrounds an interior region and further has a non-uniform thickness profile between the interior region and an outer perimeter of the first AR element, wherein the non-uniform thickness profile forms one or more support structures with a solid shape in the cross-sectional plane;
• and
• a second AR element located within the interior region of the first AR element and exclusively in contact with the support structure.

An optical fiber preform comprising:

• a cladding preform extending along a fiber length providing a hollow interior fiber region;
• and
• a plurality of anti-resonant (AR) preform elements formed as walled structures with walls extending along the fiber length, wherein the plurality of AR preform elements includes at least one nested set of AR elements comprising:
• a first AR preform element formed as a wall extending along the fiber length and located entirely within the hollow interior fiber region, wherein the wall of the first AR preform element, in a cross-sectional plane orthogonal to the fiber length, fully surrounds an interior region and further has a non-uniform thickness profile between the interior region and an outer perimeter of the first AR preform element, wherein the non-uniform thickness profile forms one or more support structure preform elements with a solid shape in the cross-sectional plane;
• and
• a second AR preform element located within the interior region of the first AR element and exclusively in contact with the support structure preform;
• wherein the optical fiber preform is configured to guide light along the fiber length in a central portion of the hollow interior fiber region based on optical anti-resonance when drawn into an AR hollow-core optical fiber (AR-HCF).