The present disclosure provides a hollow-core microstructure optical fiber preform, an optical fiber, and a method for manufacturing thereof. An objective of the present disclosure is to introduce a support sheet into a nested structure unit of the hollow-core microstructure optical fiber preform, which not only increases the number of reflection surfaces without increasing the number of nested layers of glass tubes, but also achieves a more accurate positioning by the support sheet and improves manufacturing accuracy as compared to a tangential structure of nested glass tubes, such that the following technical problems, difficulty in controlling a curvature of reflection surfaces, low manufacturing accuracy, large difference between actual loss and theoretical loss, or poor batch consistency, in related anti-resonance optical fibers, caused by increasing the number of layers of nested microstructure units in order to increase the number of reflection surfaces, are solved.

The disclosure relates to an integrated hollow-core optical fiber preform, an optical fiber and a fabrication method thereof. Initially, holes are drilled to obtain a preform which is then subjected to a drawing process with gas fed into the drilled holes for pressurization control, resulting in an optical fiber with an anti-resonant ring structure. This method employs mechanical drilling to achieve precise positioning of the azimuth angle of the anti-resonant unit, ensuring axial uniformity and preventing any azimuthal shift during the drawing process. Furthermore, no additional materials are introduced for positioning the anti-resonant unit, thereby minimizing contamination from impurities and enhancing properties such as attenuation and strength of the optical fiber. Additionally, gas pressure control expands the anti-resonant unit during the drawing process, reducing its wall thickness and consequently lowering attenuation in this hollow-core optical fiber.

A method for producing a preform for an anti-resonant hollow-core fiber which comprises a hollow core extending along a longitudinal axis of the fiber and a sheath that surrounds the hollow core and through which hollow channels pass.

In a known method for fabricating a preform for an antiresonant hollow-core fiber with an ALIF design, tubular antiresonance element preforms (ARE preforms for short), that each comprise a primary tube and at least two secondary tubes, are evenly distributed around the inside of a cladding tube to form a primary preform. The primary preform is either drawn into a hollow-core fiber or further processed into a secondary preform.

A method of processing glass filament comprises: providing a length of glass filament from which a portion is to be separated from the remainder of the filament; directing energy onto the filament in order to cause a decrease in a width of the filament at a desired location for separation of the portion; and causing relative longitudinal movement between the portion and the remainder of the filament to separate the portion from the remainder of the filament at the desired location.

A method of manufacturing a preform for a hollow core optical fiber including: a redraw step including: (1) heating a workpiece including: (a) a cladding tube including (i) a cladding interior, (ii) a cladding outer surface at a cladding outer radius, and (iii) a cladding thickness; and (b) a capillary disposed within the cladding interior, the capillary including (i) a capillary interior, (ii) a capillary outer radius, (iii) a capillary inner radius, (iv) a capillary thickness, and (v) a capillary aspect ratio corresponding to the ratio of the capillary inner radius to the capillary outer radius, and (2) manipulating a gas pressure within the capillary interior or the cladding interior, via a source of gas or a vacuum, to vary the aspect ratio of the capillary. Both the cladding outer radius and the cladding thickness change during the redraw step by less than 20%.