Abstract: An apparatus for laser processing a material including an optical fibre, at least one squeezing mechanism, and a lens. The optical fibre is a multimode optical fibre in which laser radiation propagates in a first optical mode and in a second optical mode. The squeezing mechanism includes at least one periodic surface defined by a pitch. The periodic surface is located adjacent to the optical fibre. The pitch couples the first and second optical modes together. The first optical mode is defined by a first mode order. The second optical mode is defined by a second mode order which is higher than the first mode order. The squeezing mechanism squeezes the periodic surface and optical fibre together with a squeezing force thereby coupling the first optical mode to the second optical mode.

Abstract: Apparatus for laser processing a material (11), which apparatus comprises a laser (1), an optical fibre (2), and a coupler (125), wherein: the laser (1) is connected to the optical fibre (2); the optical fibre (2) is such that laser radiation (13) is able to propagate along the optical fibre (2) in a first optical mode (21) having a first mode order (24), a second optical mode (22) having a second mode order (25), and a third optical mode (23) having a third mode order (26); the third mode order (26) is higher than the second mode order (25); and the second mode order (25) is higher than the first mode order (24); the apparatus being characterized in that: the coupler (125) is configured to switch laser radiation propagating in the first optical mode (21) to the laser radiation propagating in the second order mode (22); and the coupler (125) is configured to switch the laser radiation propagating in the second optical mode (22) to laser radiation propagating in the third order mode (23).

Abstract: Apparatus for laser processing a material (11), which apparatus comprises an optical fibre (2), at least one squeezing mechanism (3), and a lens (4), wherein: the optical fibre (2) is a multimode optical fibre; the optical fibre (2) is such that laser radiation (13) is able to propagate along the optical fibre (2) in a first optical mode (21) and in a second optical mode (22); the squeezing mechanism (3) comprises at least one periodic surface (6) defined by a pitch (7); and the periodic surface (6) is located adjacent to the optical fibre (2); and the apparatus is characterized in that: the pitch (7) couples the first optical mode (21) and the second optical mode C(22) together; the first optical mode (21) is defined by a first mode order (24), and the second optical mode (22) is defined by a second O mode order (25) which is higher than the first mode order (24); the squeezing mechanism (3) is configured to squeeze the periodic surface (6) and the optical fibre (2) together with a squeezing force (12), ther

Abstract: An apparatus for combining optical radiation, wherein the apparatus comprises a bundle of input optical fibers formed of glass, a taper, and an output optical fiber, wherein the taper is fused to the output optical fiber; 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 fibers and the output optical fiber.

Abstract: An optical combiner (25), comprising a bundle of input fibers (24) spliced to an output fiber (26), the output fiber having a cladding and at least one high-index portion within the cladding, such that the high index portion has a diameter substantially equal to or less than the outer diameter of the input fiber bundle at the splice point.

Abstract: 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.

Abstract: An optical combiner (25), comprising a bundle of input fibres (24) spliced to an output fibre (26), the output fibre having a cladding and at least one high-index portion within the cladding, such that the high index portion has a diameter substantially equal to or less than the outer diameter of the input fibre bundle at the splice point.

Abstract: An optical assembly comprising a plurality of inputs comprising optical fibres which have a non-circular core cross-section, the fibres having a proximal end for receiving light from a respective diode emitter and a distal end, the fibres being combined at their distal ends and joined to a single output fibre which has a circular core cross-section, whereby in use light from a plurality of diode emitters is combined and output through the single output fibre.

Abstract: A termination for an optical fiber is disclosed, including an end cap optically connected to a delivery end of the fiber and tapering its towards its proximal end so as to expand the signal beam output by the fiber, a capillary having a bore mounted so that the end cap and an end portion of the delivery fiber are mounted within the bore, the capillary having an end which is angled so as to reflect undesired radiation within the capillary away from the fiber, and a cladding mode stripper arranged upstream of the delivery end.

Abstract: A fibre laser system is disclosed comprising an optical fibre, a part of which is doped with a rare earth to form an optical gain medium; at least one laser diode; means for applying pump radiation from the laser diode to the optical gain medium and for generating a laser beam and delivery fibre means for delivering a laser beam to a workpiece, wherein the fibre laser is provided with at least one means for protecting one or more components from damage caused by errant radiation. Several different means of protection are disclosed.

Abstract: A termination for an optical fibre is disclosed, including an end cap optically connected to a delivery end of the fibre and tapering its towards its proximal end so as to expand the signal beam output by the fibre, a capillary having a bore mounted so that the end cap and an end portion of the delivery fibre are mounted within the bore, the capillary having an end which is angled so as to reflect undesired radiation within the capillary away from the fibre, and a cladding mode stripper arranged upstream of the delivery end.

Abstract: A fibre laser system is disclosed comprising an optical fibre, a part of which is doped with a rare earth to form an optical gain medium; at least one laser diode; means for applying pump radiation from the laser diode to the optical gain medium and for generating a laser beam and delivery fibre means for delivering a laser beam to a workpiece, wherein the fibre laser is provided with at least one means for protecting one or more components from damage caused by errant radiation. Several different means of protection are disclosed.