Abstract: A method for laser marking a metal surface (5) with a desired color, which method comprises forming at least one first pattern (41) on the metal surface (5) with a first laser beam (42) having a first pulse fluence (43), forming at least one second pattern (51) on the metal surface with a second laser beam (52) having a second pulse fluence (53), characterized by causing the second pattern (51) to overlay the first pattern (41), arranging the first pulse fluence (43) to be at least five times greater than the second pulse fluence (53), the color being given by the first and second pulse fluences (43, 53) and spot spacings (48) in the first and second patterns (41, 51), and selecting the first and second pulse fluences (43, 53) and the spot spacings (48) to form the desired color.

Abstract: An optical amplifier includes at least one pump source and an optical fiber cable which includes an amplifying optical fiber and a pump optical fiber that are defined by respective lengths. The amplifying optical fiber and the pump optical fiber are coated with a common coating along a portion of their respective lengths, and the fibers are in optical contact with each other along a coating length within the common coating. The common coating has a refractive index which is lower than a refractive index of a cladding material of the pump optical fiber. The fibers are made substantially from glass. The amplifying optical fiber includes a core and a cladding, and is doped with a rare earth dopant. The pump optical fiber is defined by a first end and a second end, the first end of the pump optical fiber being connected to the pump source.

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: An optical fiber arrangement has at least two optical fiber sections, each optical fiber section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fiber arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fiber. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fiber and a first multiplexer connected to the input fiber. Each amplifier is configured such that at least one of the amplifying optical fibers is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.

Abstract: Provided herein is an apparatus for optically isolating a light beam from a laser, comprising an optical isolator configured to isolate a light beam having a beam quality; a reference plane; an output connector disposed at the output of the optical isolator, wherein the output connector is configured with a common collimator interface to connect to a collimator which is capable of being mechanically referenced to the reference plane; a first lens arrangement disposed proximal to a distal end of the output connector, wherein the first lens arrangement is selected to provide an output light beam having a predetermined divergence. The laser can be selected from the group consisting of a fiber laser, a disk laser and a rod laser. Also provided herein are a system, a plurality of lasers, and a method of providing a light beam that has a consistent divergence and distance from a reference plane.

Abstract: In one embodiment, a photo-darkening resistant optical fiber includes a waveguide having a numerical aperture less than 0.15. The waveguide includes a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the fiber includes a first cladding having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3. The core includes silica, a concentration of alumina of between approximately 0.3 to 0.8 mole percent, a concentration of phosphate of substantially 15 mole percent, a concentration of ytterbium substantially in the range 20000 to 45000 ppm. The pedestal can include silica, phosphate and germania. The core can have substantially zero thulium dopant.

Abstract: An optical fiber arrangement has at least two optical fiber sections, each optical fiber section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fiber arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fiber. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fiber and a first multiplexer connected to the input fiber. Each amplifier is configured such that at least one of the amplifying optical fibers is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.

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: An optical fiber arrangement has at least two optical fiber sections, each optical fiber section defining an outside longitudinally extending surface. The outside longitudinally extending surfaces are in optical contact with each other. The invention further provides for an amplifying optical device have an optical fiber arrangement as just described, and a pump source. The amplifying optical device is configured such that the pump source illuminates the amplifying optical fiber. A amplifying arrangement is also disclosed. The amplifying arrangement includes a plurality of amplifying optical devices as just described, and each amplifier also has at least one input fiber and a first multiplexer connected to the input fiber. Each amplifier is configured such that at least one of the amplifying optical fibers is connected to the first multiplexer. The amplifying arrangement also has a second multiplexer connected to each of the first multiplexers.

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: Apparatus for dispersion compensating a signal (18) that propagates along a signal path (19), which apparatus comprises a grating (1) and a tuning means (2). The grating (1) is characterized by a wavelength operating range (3) and a group delay (4) that varies with wavelength (5), wherein the group delay (4) is equal at a plurality of pairs of wavelengths (6), (7) that are separated within the wavelength operating range (3), and wherein the grating (1) reflects each wavelength pair (6) from the same region (8) of the grating (1), and different wavelength pairs (7) from different regions (9) of the grating (1).