An optical coupler includes N members. A Kth (K is an integer of 1 to N) member includes a MCF including P (P is an integer of N or greater) cores, and a marker disposed at a position closest to a first core, and at least one SCF. A core of the SCF of the Kth member is coupled to a coupled core other than the first core. Cores of the MCF of an Mth (M is an integer of 1 to N−1) member are connected to cores of the MCF of an (M+1)th member. A total number of SCF included in the N members is P. Each of P cores of the MCFs configured through the connection of the N members is connected to a core of one of the SCFs.

A cable holder (10) attaches to a cable (1) with a plurality of cores (2). The cable holder (10) has a receiving body (11) with a plurality of receiving chambers (12). The chambers (12) extend in a cable longitudinal direction (L). An insertion opening (13) is formed at least on one side of the receiving chamber for inserting an end of a core (2). A fastening portion (14) is connected to the receiving chamber (12). The fastening portion (14) fastens the cable holder (10) to the outer sheath of the cable (1) by a fastening device (3) engaging around the cable (1).

Methods and systems for generating a laser beam with different beam profile characteristics are provided. In one aspect, a method includes coupling an input laser beam into one fiber end of a multi-clad fiber, in particular a double-clad fiber and emitting an output laser beam from the other fiber end of the multi-clad fiber. To generate different beam profile characteristics of the output laser beam, the input laser beam is electively coupled either at least into the inner fiber core of the multi-clad fiber or at least into at least one outer ring core of the multi-clad fiber, or a first sub-beam of the input laser beam is coupled into at least into the inner fiber core of the multi-clad fiber and a second, different sub-beam of the input laser beam is coupled at least into the at least one outer ring core of the multi-clad fiber.

In an example, a tandem pumped fiber amplifier may include a seed laser, one or more diode pumps, and a single or plural active core fiber. The single or plural active core fiber may include a first section to operate as an oscillator and a second different section to operate as a power amplifier. The one or more diode pumps may be optically coupled to the first section of the single or plural active core fiber, and the seed laser may be optically coupled to the single active core or an innermost core of the plural active core fiber.

The invention concerns an apparatus and a method for laser processing. There is provided at least one first laser beam from at least one first optical feed fiber connected to at least one first laser device and at least one second laser beam from at least one second optical feed fiber connected to at least one second laser device. Said first and second laser beams are combined in a multi-core optical fiber. Said first core of said multi-core optical fiber has a circular cross-section, and said second core has an annular shape concentric to said first core. A composite laser beam comprising first and second output beams is directed from said multi-core optical fiber to a workpiece with overlapping elements to be welded.

Systems and methods of aligning multicore fiber optic cables are provided. A method for aligning a first multicore fiber (MCF) and a second multicore fiber (MCF), the first MCF and second MCF each comprising a plurality of cores and a marker, the method including: producing a brightness profile for the first and second MCFs; determining rotational orientations of the first and second MCFs from the brightness profile; rotating at least one of the first and second MCFs until each of the plurality of cores of the first MCF and the second MCF are aligned; determining if the markers of the first MCF and second MCF are aligned in view of a region of the brightness profile associated with the markers; and splicing the first MCF and the second MCF together if the cores and marker of the first MCF are aligned with the cores and marker of the second MCF.

A system and method for determining the length of a non-shape-sensed interventional device (102) which includes a shape-sensed guidewire (106) that is received in the lumen (103) of the device. A hub (107) is configured to secure a position of the shape-sensed guidewire and interventional device. A registration module (124) is configured to register a position of the distal tip (117) of the non-shape-sensed interventional device to a position of the shape-sensed guidewire. A determination module (126) determines the length of the non-shape-sensed interventional device using a known position of the device in the hub and the position of the distal tip of the device. The system includes a detection module (146) that receives curvature data from the shape-sensed guidewire and is configured to determine the state of the shape-sensed guidewire with respect to an interventional device.

Certain aspects of the present disclosure provide a thermally robust laser probe assembly comprising a cannula, wherein one or more optical fibers extend at least partially through the cannula for transmitting laser light from a laser source to a target location. The probe assembly further comprises a lens housed in the cannula and a protective component press-fitted to the distal end of the cannula, wherein the lens is positioned between the one or more optical fibers and the protective component.

It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.

Optical fiber structures for generating a single mode, saddle shaped output beam include first and second lengths of fiber. The first length of fiber has a first input end configured to receive a single mode gaussian beam. The second length of fiber has a second input end coupled to an output end of the first length of fiber. The second length of fiber includes a centrally located anti-guiding core and an annular guiding region coaxially encompassing the centrally located anti-guiding core.