A preform for making a vortex optical fiber comprises a glass cylinder formed substantially of silicone dioxide that defines a core portion along a longitudinal axis of the glass cylinder and a cladding portion surrounding the core portion. The glass cylinder further defines a plurality of holes running parallel to the longitudinal axis from a first end of the glass cylinder to a second end of the glass cylinder.

An integrated device and related instruments and systems for analyzing samples in parallel are described. The integrated device may include sample wells arranged on a surface of where individual sample wells are configured to receive a sample labeled with at least one fluorescent marker configured to emit emission light in response to excitation light. The integrated device may further include photodetectors positioned in a layer of the integrated device, where one or more photodetectors are positioned to receive a photon of emission light emitted from a sample well. The integrated device further includes one or more photonic structures positioned between the sample wells and the photodetectors, where the one or more photonic structures are configured to attenuate the excitation light relative to the emission light such that a signal generated by the one or more photodetectors indicates detection of photons of emission light.

An optical fiber design method according to the present invention is a design method of a photonic crystal fiber having a plurality of holes arranged in the optical fiber along a longitudinal direction, in which a required effective cross-sectional area is calculated from a light wavelength, a transmission distance, and output power such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding, and a fiber structure (hole diameter and hole interval) corresponding to the effective cross-sectional area is calculated.

The invention relates to a method of manufacturing an active optical fiber having a cladding and a doped core, as well as the active optical fiber equipped with the cladding and the doped core. The active optical fiber according to the invention is adapted to conduct and generate radiation having a wavelength and is provided with a cladding and a core containing at least one active dopant, characterized in that the core comprises elongate elements made of a first type of glass having a first refractive index n.sub.1 and elongate elements of a second type of glass having a second refractive index n.sub.2, oriented along the optical fiber and forming a compact bundle, wherein transverse dimensions of the elongate core elements are smaller than of the wavelength . Such optical fibers are used in laser generation and in amplification techniques.

A photonic crystal fiber according to the present invention has a plurality of holes arranged in the optical fiber along a longitudinal direction, in which the holes are arranged such that, in a cross section, a hole ratio which is an area of the holes per unit area is larger in a central side than in an outer side in a portion corresponding to a cladding and that a wide core area can be obtained while the number of modes that can be propagated is limited to several. Moreover, in a high-power optical transmission system according to the present invention, the amount of axis misalignment between the central axis of a laser oscillator and the central axis of the photonic crystal fiber is less than or equal to a certain amount.

The invention relates to a method of manufacturing an active optical fibre having a cladding and a doped core, as well as the active optical fibre equipped with the cladding and the doped core. The active optical fibre according to the invention is adapted to conduct and generate radiation having a wavelength and is provided with a cladding and a core containing at least one active dopant, characterised in that the core comprises elongate elements made of a first type of glass having a first refractive index n.sub.1 and elongate elements of a second type of glass having a second refractive index n.sub.2, oriented along the optical fibre and forming a compact bundle, wherein transverse dimensions of the elongate core elements are smaller than of the wavelength . Such optical fibres are used in laser generation and in amplification techniques.

An optical fiber for an optical fiber sensor and a chemical sensor using the same are disclosed. The optical fiber includes a core area, and a suspended cladding area formed around the core area and having at least one cladding hole. The core area has at least one core hole for reducing an effective refractive index of the core area. The optical fiber and the chemical sensor using the same may have improved measurement sensitivity by increasing an evanescent field fraction of existing suspended core fibers.

Embodiments are directed to an optical fiber cable assembly. The optical fiber cable assembly is a polarization maintaining optical fiber assembly. The assembly includes an optical core located within a cladding. Also within the cladding is a stress rod. The stress rod can be centered within the cladding, with the optical fiber eccentrically located within the cladding. There can also be a second optical fiber eccentrically located within the cladding. The optical fiber can be centered within the cladding, with the stress rod eccentrically located within the cladding.

A hollow-core photonic crystal fiber gas cell and method for preparing the same. The hollow-core photonic crystal fiber gas cell comprises a single-mode fiber, a fiber splicing protection sleeve, a hollow-core photonic crystal fiber, and a photoelectric detector. One end of the single-mode fiber is fusion spliced with one end of the hollow-core photonic crystal fiber to form a fusion splice and seal one end of the hollow-core photonic crystal fiber gas cell. The fiber splicing protection sleeve covers and protects the fusion splice. The other end of the hollow-core photonic crystal fiber is processed into an output end by fusion sealing, and the surface of the output end faces, but is not parallel to, a detection surface of the photoelectric detector.

A hollow-core photonic crystal fiber gas cell and method for preparing the same. The hollow-core photonic crystal fiber gas cell comprises a single-mode fiber, a fiber splicing protection sleeve, a hollow-core photonic crystal fiber, and a photoelectric detector. One end of the single-mode fiber is fusion spliced with one end of the hollow-core photonic crystal fiber to form a fusion splice and seal one end of the hollow-core photonic crystal fiber gas cell. The fiber splicing protection sleeve covers and protects the fusion splice. The other end of the hollow-core photonic crystal fiber is processed into an output end by fusion sealing, and the surface of the output end faces, but is not parallel to, a detection surface of the photoelectric detector.