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 optically isolating a laser (1) from external reflections, which apparatus comprises a mode filter (19) and a first optical fibre (1), wherein: the first optical fibre (1) is a multimode optical fibre that supports a fundamental mode (3) and at least one higher order mode (4); the mode filter (19) is defined by an optical attenuation which is higher for the higher order mode (4) than for the fundamental mode (3); the mode filter (19) is configured to pass the fundamental mode (3) into the first optical fibre (1); and the apparatus being characterized in that: the first optical fibre (1) comprises a long period grating (10); and the long period grating (10) is defined by a period (13) selected to couple the fundamental mode (3) to the higher order mode (4) of the first optical fibre (1); whereby if the fundamental mode (3) and the higher order mode (4) are reflected back into the first optical fibre (1) as back-reflected fundamental and higher order modes (25), (26), then the mode filter (19) opt

Abstract: Apparatus for optically isolating a laser (1) from external reflections, which apparatus comprises a mode filter (19) and a first optical fibre (1), wherein: the first optical fibre (1) is a multimode optical fibre that supports a fundamental mode (3) and at least one higher order mode (4); the mode filter (19) is defined by an optical attenuation which is higher for the higher order mode (4) than for the fundamental mode (3); the mode filter (19) is configured to pass the fundamental mode (3) into the first optical fibre (1); and the apparatus being characterized in that: the first optical fibre (1) comprises a long period grating (10); and the long period grating (10) is defined by a period (13) selected to couple the fundamental mode (3) to the higher order mode (4) of the first optical fibre (1); whereby if the fundamental mode (3) and the higher order mode (4) are reflected back into the first optical fibre (1) as back-reflected fundamental and higher order modes (25), (26), then the mode filter (19) opt

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: Apparatus for controlling laser piercing of a remote material (10), which apparatus comprises: at least one piercing laser (1) for emitting laser radiation (2) for piercing the remote material (10), which laser radiation (2) is characterized by a first wavelength (16); a probe laser (3) for emitting a probe signal (4) for monitoring the piercing of the remote material (10); beam delivery optics (5) configured to direct the laser radiation (2) and the probe signal (4) onto the material (10); at least one detector (6) for detecting optical radiation (7) that is emitted or reflected by the material (10) in response to the probe signal (4); and an electronic filter (8) for filtering an electronic signal (9) emitted by the detector (6) in response to the detector (6) detecting the optical radiation (7); and the apparatus being characterized in that the probe laser (3) is configured such that the probe signal (4) is able to be modulated by a modulation signal (13); and the electronic filter (8) comprises a phase se

Abstract: A weld (3) between a first material (1) and a second material (2), the first material (1) being a first metallic material, and the second material (2) being a second metallic material, the weld (3) has a width (4) between 0.5 mm and 7 mm, the weld (3) comprises at least one microweld (8), the microweld (8) forms a welding pattern (5) defined parallel to a surface (6) of the first material (1), and the microweld (8) has a characteristic feature size (7) of between 20 ?m and 400 um.

Abstract: Laser apparatus (1) comprising a reference source (2), a reference fiber (3), and at least one laser diode (4), wherein the reference fiber (3) comprises a core (5) having a refractive index n1 and a first cladding (6) having a refractive index n2, the first cladding (6) is surrounded by a second cladding (7) having a refractive index n3, the refractive index n1 is greater than the refractive index n2, the refractive index n2 is greater than the refractive index n3, the laser diode (4) emits laser radiation (8) that is guided through the first cladding (6) of the reference fiber (3), the reference source (2) emits reference radiation (9) that has a predetermined wavelength ?R (10), the reference radiation (9) is guided through the core (5) of the reference fiber (3) to the laser diode (4), and the reference radiation (9) that is guided through the core (5) of the reference fiber (3) to the laser diode (4) has a power (11) at the predetermined wavelength ?R (10), which power is greater than an injection lockin

Abstract: Apparatus for combining laser radiation (1) 5 which apparatus comprises a seed laser (2), a splitter (3), a plurality of amplifier chains (4), a reference amplifier chain (7), detection means (5). demodulator means (6), and phase control means (12), wherein each of the amplifier chains (4) comprises at least one optical amplifier (11), optical radiation (17) emitted from the seed laser (2) is split into the plurality of amplifier chains (4) by the splitter (3).

Abstract: A method for determining the effectiveness of a sterilization and/or disinfection process is disclosed.

Abstract: Laser apparatus (1) comprising a reference source (2), a reference fibre (3), and at least one laser diode (4), wherein the reference fibre (3) comprises a core (5) having a refractive index n1 and a first cladding (6) having a refractive index n2, the first cladding (6) is surrounded by a second cladding (7) having a refractive index n3, the refractive index n1 is greater than the refractive index n2, the refractive index n2 is greater than the refractive index n3, the laser diode (4) emits laser radiation (8) that is guided through the first cladding (6) of the reference fibre (3), the reference source (2) emits reference radiation (9) that has a predetermined wavelength ?R (10), the reference radiation (9) is guided through the core (5) of the reference fibre (3) to the laser diode (4), and the reference radiation (9) that is guided through the core (5) of the reference fibre (3) to the laser diode (4) has a power (11) at the predetermined wavelength ?R (10), which power is greater than an injection lockin

Abstract: Apparatus for the industrial processing of a material by a fiber laser, which fiber laser emits optical radiation, the apparatus configured such that the optical radiation forms an optical power distribution on a surface of the material, including first and second optical powers which are located at respective first and second radii from a center of the optical power distribution and which are of substantially higher intensity than a third optical power which is located at a third radius from the center of the optical power distribution and which is smaller than the first and the second radii.

Abstract: Apparatus for providing optical radiation (10) comprising a pump array (8) for providing pump radiation (7), a first pump combiner (1), and a waveguide (3), wherein the pump radiation (7) from the pump array (8) is coupled into the waveguide (3) via the first pump combiner (1), and wherein the waveguide (3) comprises a pump guide (4) for guiding the pump radiation (7), and a gain medium (5) which emits the optical radiation (10) when it is pumped by the pump radiation (7).

Abstract: Apparatus for providing optical radiation includes a pump source and at least one first amplifying waveguide. The first amplifying waveguide emits optical radiation in excess of 1400 nm when pumped by the pump source. In one embodiment, the pump source can include a plurality of laser diodes and a plurality of second amplifying waveguides. In this arrangement the first amplifying waveguide is pumped by the second amplifying waveguides, the second amplifying waveguides are pumped by the laser diodes, and the second amplifying waveguides are configured to improve the beam quality of radiation emitted by the laser diodes.

Abstract: Apparatus for providing optical radiation, which apparatus comprises an optical fibre (5) having a core (3), a first cladding (1) and a second cladding (2), in which the first cladding (1) has a substantially constant diameter (9) in its cross-section. The first cladding (1) can be non-circular. Advantages include more reliable cleaving, joining and splicing.

Abstract: Apparatus for providing optical radiation (10) comprising a pump array (8) for providing pump radiation (7), a first pump combiner (1), and a waveguide (3), wherein the pump radiation (7) from the pump array (8) is coupled into the waveguide (3) via the first pump combiner (1), and wherein the waveguide (3) comprises a pump guide (4) for guiding the pump radiation (7), and a gain medium (5) which emits the optical radiation (10) when it is pumped by the pump radiation (7).

Abstract: An optical fibre including a waveguide and at least one stress applying region is described. The waveguide is defined by a numerical aperture, and the stress applying region is defined by a depressed refractive index. The optical fibre is configured such that the waveguide supports at least two polarised fundamental modes, two polarized first second-order modes, and two polarised second second-order modes. The waveguide includes comprises a gain medium. The stress applying region, the waveguide and the disposition of the gain medium are such as to provide preferential guidance to at least one of the modes at an operating wavelength.

Abstract: A system and method for the remote measurement of physical parameters, comprising an optical fiber cable adapted to measure a physical parameter in a remote location, a conduit extending to the remote location and configured to accommodate the optical fiber cable, a cable installation mechanism configured to install the optical fiber cable through the conduit and place the optical fiber cable at the remote location, the cable installation mechanism including means for propelling a fluid along the conduit, and a seal between the optical fiber cable and the conduit.

Abstract: A system and method for the remote measurement of physical parameters, comprising an optical fiber cable adapted to measure a physical parameter in a remote location, a conduit extending to the remote location and configured to accommodate the optical fiber cable, a cable installation mechanism configured to install the optical fiber cable through the conduit and place the optical fiber cable at the remote location, the cable installation mechanism including means for propelling a fluid along the conduit, and a seal between the optical fiber cable and the conduit.

Abstract: Methods and apparatus for the remote measurement of physical parameters are described. The apparatus includes a sensor, sensor instrumentation, a carbon coated optical fiber cable for extending between the sensor and the sensor instrumentation, a conduit for extending to a measurement location and configured to accommodate the optical fiber cable and the sensor, and a cable installing device configured to install the sensor and the optical fiber cable through the conduit and place the sensor at the measurement location. The cable installation device includes an apparatus for propelling a fluid along the conduit, such as a pump, a compressor, and the like. In the method, a sensor is installed at a measurement location by pumping the sensor and a carbon-coated optical fiber cable through a conduit, forming a seal around the cable where it enters the conduit, and connecting the cable to sensor instrumentation.