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.

A stimulated Raman scattering (SRS) spectrometer for real-time, high-resolution molecular analysis of gases is based on two hollow-core fibres illuminated by a single high-power, short-pulse laser pump. The first fibre is prefilled with high-concentration target gases. Interaction of each target gas inside the first fibre, with the laser pump, generates Raman signals corresponding to the target gases. The combined beam of the Raman signals and the pump laser beam is directed into the second fibre containing the measured target gases. Interaction of each target gas with the combined beam generates the Stimulated Raman Growth (SRG), i.e., amplification of the Raman signal, which is proportional to the corresponding target gas concentration. A receiver subsystem receives the beam from the second fibre, spectrally separates it to wavelengths corresponding to each target gas, extracts the SRG value corresponding to each target gas and calculates the concentration of each target gas.

A mounted hollow-core fiber arrangement includes a hollow-core fiber having a microstructure, and a mount arrangement including a plurality of mounting contacts configured to apply a force to an outer layer of the hollow-core fiber. A portion of the hollow-core fiber is located in a receiving region of the mount arrangement. The plurality of mounting contacts are positioned around the receiving region. The mounting contacts are distributed around the receiving region, the distribution of the mounting contacts corresponding to a distribution of features of the microstructure of the hollow-core fiber. The mounted hollow core fiber can be used in a radiation source apparatus for providing broadband radiation.

Described herein are systems, methods, and articles of manufacture for reducing coupling loss between optical fibers, more particularly, to reducing coupling loss between a hollow-core optical fiber (HCF) and another fiber, such as solid core fibers (SCF), through the use of mismatched mode field diameter (MFD) and optical connector assemblies for low latency patchcords. According to one embodiment, an article is configured to reduce a coupling loss between multiple optical fibers, wherein the article includes an HCF supporting the propagation of a first mode and an SCF coupled to the HCF. According to a further embodiment, a method is described for reducing the coupling loss or splicing loss between optical fibers, such as an exemplary HCF and a solid core SMF. These exemplary articles and methods may include coupling/splicing an exemplary HCF to an exemplary SMF with significantly smaller MFD as well as a splice-on-connector (SOC) assembly including a bridge fiber spliced between the HCF and the SCF, wherein the bridge fiber has a third MFD that is greater than the second MFD and smaller than the first MFD. Additional embodiments may feature a SCF having a second MFD at the proximal end and a third MFD at the distal end, wherein the second MFD is greater than the third MFD, and the third MFD is no greater than 90% of the first MFD of the HCF.

An apparatus and method of use are provided; the apparatus having at least a degasser, a hollow core fiber HCF, an optical mechanism, a detector, and circuitry. The degasser enables gasses to permeate out of a liquid into the degasser interior. The propagator establishes a low-pressure area that helps to pull the gas from the degasser interior into the HCF interior, where the optical mechanism delivers electromagnetic radiation EMR that interacts with the gas. The detector determines EMR absorption, producing output signals which are sent to the circuitry. Circuitry controls the optical mechanism and analyzes the output signals to quantify the concentration of gas in the HCF and in the liquid.

A Concentrating PhotoVoltaic (CPV) system employs an inflatable non-imaging CPC concentrator to concentrate sunlight to realize extremely low cost and a synergistically combined photonic crystal waveguide solar spectrum splitter and perovskite integrated circuitry solar cell package to realize ultra-high conversion efficiency of solar radiation. The corporation of band gap variable perovskite materials into the integrated circuit solar cell not only reduces the cost and raises the efficiency of the photovoltaic package as the receiver, but also addresses the unstable issue of the perovskite materials through sealing the perovskite materials into package to prevent moisture, reducing the heat generation to low the temperature, and filtering the UV light and channel to other elemental solar made of broader band gap photovoltaic materials.

Methods are known for producing an anti-resonant hollow-core fiber which has a hollow core extending along a fiber longitudinal axis and an inner jacket region that surrounds the hollow core, said jacket region comprising multiple anti-resonant elements. The known methods have the steps of: providing a cladding tube that has a cladding tube inner bore and a cladding tube longitudinal axis along which a cladding tube wall extends that is delimited by an interior and an exterior; providing a number of tubular anti-resonant element preforms; arranging the anti-resonant element preforms at target positions of the interior of the cladding tube wall, thereby forming a primary preform which has a hollow core region and an inner jacket region; and further processing the primary preform in order to form a secondary preform, including a process of elongating the primary preform in order to directly form the hollow-core fiber or to form the secondary preform. The aim of the invention is to achieve a high degree of precision and an exact positioning of the anti-resonant elements in a sufficiently stable and reproducible manner on the basis of the aforementioned methods. This is achieved in that a primary preform with an outer diameter ranging from 20 to 70 mm is used for the elongation process.

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.

Methods, devices, and systems for welding optical fibers and perforated elements by pulsed laser beam are provided. In one aspect, a method includes focusing a pulsed laser beam onto a region of a joining surface formed by an outer circumference of an optical fiber and an inner circumference of a hole of a perforated element, a beam direction of the pulsed laser beam running in an axial direction of the joining surface, and moving a laser focus of the pulsed laser beam in the region axially in or counter to the beam direction to produce at least one weld seam in the region. The optical fiber and the perforated element are locally melted in the region by the pulsed laser beam focused into a material of the optical fiber and a material of the perforated element and are thereby welded to one another.

Described herein are systems, methods, and articles of manufacture for reducing coupling loss between optical fibers, more particularly, to reducing coupling loss between a hollow-core optical fiber (HCF) and another fiber, such as solid core fibers (SCF), through the use of mismatched mode field diameter (MFD). According to one embodiment, an article is configured to reduce a coupling loss between multiple optical fibers, wherein the article includes an HCF supporting the propagation of a first mode and an SCF coupled to the HCF. According to a further embodiment, a method is described for reducing the coupling loss or splicing loss between optical fibers, such as an exemplary HCF and a solid core SMF. These exemplary methods may include coupling/splicing an exemplary HCF to an exemplary SMF with significantly smaller MFD.