Optical fiber combiner includes a plurality of input optical fibers having a core and a cladding surrounding the core, a bridge fiber having a portion that transmits a light beam entered from each of the input optical fibers, and a glass member fusion-spliced to an end face of the cladding and to a first end face of the bridge fiber. The end portions of the claddings of the plurality of input optical fibers are bundled on at least a first end face side, with the adjacent side surfaces of the claddings being in contact with each other. The glass member has an outer diameter greater than the diameter of the core and smaller than the outer diameter of the cladding. The adjacent glass members are in a non-fusion-spliced state.

As kilowatt class fiber laser and amplifier systems become more in demand, there are ongoing efforts to improve optical fiber laser and amplifier designs to maximize efficiency and further increase the capacity of these high-energy optical fiber lasers and amplifiers. The present disclosure provides a fiber laser or amplifier system configured to efficiently and conveniently generate and couple high numerical aperture and high-energy pump light into a fiber laser or amplifier system.

An optical fiber-based sensor is described that is suitable for operation in a gas-rich environment. The sensor comprises a chamber into which are mounted one or more segments of optical fiber, into which are inscribed a plurality of sensor gratings. Each of the plurality of sensor gratings is configured to have the same wavelength shift over time in response to a change in gas diffusion, such that gas diffusion parameters are excluded in the determination of the respective amount of change in temperature, applied strain, and gas diffusion. Also described is a fiber, and techniques for making same, comprising of cores extend through a common cladding. The cores are doped so as to create, in conjunction with the cladding, a plurality of waveguides having the same wavelength shift over time is response to a change in gas diffusion, but different wavelength shifts in response to changes in other parameters.

An apparatus for combining optical radiation, wherein the apparatus comprises a bundle of input optical fibres formed of glass, a taper, and an output optical fibre, wherein the taper is fused to the output optical fibre; and the apparatus comprises at least one cladding mode stripper to strip out higher order modes that would otherwise degrade a polymer coating on at least one of the input optical fibres and the output optical fibre.

Multimode beam combiners include at least one gradient-step index optical fiber in which a refractive index difference at a core/cladding interface is selected to provide a numerical aperture so as to provide stable, uniform beam output. One or more such fibers is formed into a tapered bundle than can be shaped to provide a selected illuminated aperture. The fibers in the bundle can be separated by respective tapered claddings so as to be optically coupled or uncoupled. Illumination systems can include a plurality of such fibers coupled to a plurality of laser diodes or other light sources.

A method is disclosed to provide improved fiber inline optical power monitoring that eliminates the need for micro-bending the fiber or for fabricating micro-reflector on the fiber. A subset of light is tapped through an offset at a fusion-spliced upstream and downstream optic fiber, and is guided out of the downstream fiber by a light guide to a reflector and photo-sensing measurement. The disclosed inline fiber monitoring is thus cost effective, wavelength independence, reliable, stable, and also causes less light transmission loss.

A laser component includes a pump-signal combiner, which includes a first capillary, a plurality of pump fibers, a second capillary, and a signal fiber. The plurality of pump fibers, the second capillary, and the signal fiber are arranged in a bundle configuration. The bundle configuration is disposed within an internal portion of the first capillary. A cross-section of the bundle configuration includes an outer area, in which the plurality of pump fibers are disposed, and an inner area, in which the second capillary and the signal fiber are disposed. The signal fiber is disposed within an internal portion of the second capillary.

Provided is a system for and a method of processing an optical fiber, such as tapering an optical fiber. The method includes receiving fiber parameters defining characteristics of an optical fiber, modeling an idealized fiber based on the fiber parameters to establish modeled data, and establishing processing parameters. A processing operation is performed on the optical fiber according to the processing parameters to produce a resultant fiber. Aspects of the resultant fiber are measured to establish measured data. The measured data and the modeled data are normalized to a common axis and a difference between the two is determined. The processing parameters are adjusted based on the differences.