An anti-resonant hollow core optical fiber preform that includes an outer cladding, a plurality of structural tubes, and a central support tube. The outer cladding has a length, a central longitudinal axis, and a hollow interior. The plurality of structural tubes are disposed within the hollow interior of the outer cladding, the plurality of structural tubes each having a length that extends the length of the outer cladding. And the central support tube is disposed within the hollow interior of the outer cladding such that the plurality of structural tubes are disposed radially outward of the central support tube, the central support tube having a length that extends along the central longitudinal axis of the outer cladding. Furthermore, the length of the central support tube is less than the length of the outer cladding.

The low magnetic sensitivity PM-PCF based on mechanical buffer is obtained by adding buffer structures in the cladding layer of the photonic crystal fiber. In the center of the fiber, the core region contains at least 3 layers of air-holes, enclosed by the cladding layer. The buffer structures are placed in the cladding layer. These buffer structures are formed by replacing silica of any shape by air, and are symmetrically located in X-axis and Y-axis directions to achieve mechanical isotropy. The buffer structures improve the fiber's performance in fiber coiling and stress conditions. Therefore, the fiber optic gyroscope using the PM-PCF can do without a magnetic shield, thus greatly reducing the weight of the fiber optic gyroscope and extending the scope of its application. Compared with the conventional commercial PCF, the PM-PCF provides the fiber optic gyroscope with lower temperature sensitivity and improved accuracy.

A waveguide is provided for transmitting electromagnetic waves, in particular for transmitting image information, from a proximal end to a distal end, along a transport direction running between the ends and a via a cross-section running transversely to the transport direction. The waveguide has a plurality of structural elements, wherein at least two different types of structural elements have a first type with a first refractive index and a second type with a second refractive index. Each of the structural dements extends along the transport direction and over a part of the cross-section of the waveguide such that a plurality of cross-sectional regions are defined in the cross-section of the waveguide, each cross-sectional region corresponding to the cross-section of an individual structural element.

An optical amplifying fiber includes: at least one single core portion doped with a rare-earth element; an inner cladding portion configured to enclose the at least one core portion, the inner cladding portion having a lower refractive index than maximum refractive index of each core portion; and an outer cladding portion configured to enclose the inner cladding portion, the outer cladding portion having a lower refractive index than refractive index of the inner cladding portion, wherein the inner cladding portion includes a plurality of air bubbles.

A delivery fiber assembly suitable for delivering broad band light and including a delivery fiber and a connector member. The delivery fiber has a length, an input end for launching light, and a delivery end. The delivery fiber includes along its length a core region and a cladding region surrounding the core region, the cladding region includes a cladding background material having a refractive index N.sub.bg and a plurality of microstructures in the form of inclusions of solid material having refractive index up to N.sub.inc and extending in the length of the longitudinal axis of the delivery fiber, wherein N.sub.inc<N.sub.bg. The plurality of inclusions in the cladding region is arranged in a cross-sectional pattern including at least two rings of inclusions surrounding the core region. The connector member is mounted to the delivery fiber at a delivery end section of the delivery fiber including the delivery end.

Disclosed is a Chinese knot-like porous fiber core ultra-high birefringence THz optical fiber. The optical fiber comprises a substrate, claddings and fiber cores, wherein the claddings and the fiber cores are arranged in the substrate, and the fiber cores are embedded in the centers of the claddings; and the fiber core comprises a first fiber core region, a second fiber core region and a third fiber core region, the center of the first fiber core region 4 serves as the origin of coordinates, and the first fiber core region 4 is composed of six regular hexagon units with overlapped boundaries in the x-axis direction. In the present disclosure, the fiber core comprises a first fiber core region, a second fiber core region and a third fiber core region, and the three regions jointly form a fiber core region of a Chinese knot-like porous fiber core.

Certain exemplary embodiments can provide a system, machine, device, and/or manufacture adapted for and/or resulting from, and/or a method for, activities that can include and/or relate to, providing a photonic crystal fiber that includes an elongated solid core that extends a length of the photonic crystal fiber and defines a fiber longitudinal axis and an elongated annular cladding extending the length of the photonic crystal fiber and is co-axial with the core.

An interferometric optical fibre sensor comprises optical fibre defining an optical circuit configured to propagate a first optical wave via an environment in which the optical fibre can be exposed to a stimulus that modifies the first optical wave, and a second optical wave, and to combine the first optical wave and the second optical wave to create an interference signal containing information about the stimulus, wherein optical fibre propagating either or both of the first optical wave and the second optical wave comprises hollow core optical fibre configured to propagate the optical wave or waves by an antiresonant optical guidance effect.

An optical fiber having an axial direction and a cross section perpendicular to the axial direction, and a method and preform for producing such an optical fiber. The optical fiber is adapted to guide light at a wavelength λ, and includes a core region, an inner cladding region surrounding said core region, and at least one of a first type of feature including a void and a surrounding first silica material. The core, the inner cladding region and the first type of feature extends along said axial direction over at least a part of the length of the optical fiber. The first silica material has a first chlorine concentration of about 300 ppm or less.

A microstructured multicore optical fibre (MMOF) includes a cladding in which a plurality of basic cells are formed that run along the MMOF. Each of the basic cells includes a core, and at least one of the basic cells is surrounded by a plurality of longitudinal areas that run parallel to the core along the MMOF and are arranged in a hexagonal arrangement around the core. The longitudinal areas are spaced by a lattice constant Λ. Sides of the hexagon can be shared with adjacent basic cells.