Abstract: A modular and scalable high-power fiber laser system is configurable to generate 1 kW or more of laser output, and includes one or more separable pump modules separately disposed from each other, each pump module including a plurality of fiber-coupled component pump sources optically combined by one or more fiber-based pump module pump combiners, each pump module providing one or more pump module fiber outputs, and a gain module separately disposed from the one or more separable pump modules and including one or more gain module pump fiber inputs optically coupled to corresponding ones of the pump module fiber outputs, and including a gain fiber optically coupled to the one or more gain module pump fiber inputs, the gain fiber configured to generate a gain module fiber output power scalable in relation to the number and power of said pump module fiber outputs coupled to the gain fiber.

Abstract: Disclosed herein are methods, apparatus, and systems for perturbing a laser beam propagating within a first length of fiber to adjust one or more beam characteristics of the laser beam in the first length of fiber or a second length of fiber or a combination thereof, coupling the perturbed laser beam into a second length of fiber and maintaining at least a portion of one or more adjusted beam characteristics within a second length of fiber having.

Abstract: A method for forming an article includes: forming a melt pool; exposing the melt pool to an optical beam having at least one beam characteristic; forming a keyhole cavity in the melt pool, the keyhole cavity having at least one keyhole cavity property; and modifying the at least one beam characteristic in response to a change in the keyhole cavity property.

Abstract: A method of processing by controlling one or more beam characteristics of an optical beam may include: launching the optical beam into a first length of fiber having a first refractive-index profile (RIP); coupling the optical beam from the first length of fiber into a second length of fiber having a second RIP and one or more confinement regions; modifying the one or more beam characteristics of the optical beam in the first length of fiber, in the second length of fiber, or in the first and second lengths of fiber; confining the modified one or more beam characteristics of the optical beam within the one or more confinement regions of the second length of fiber; and/or generating an output beam, having the modified one or more beam characteristics of the optical beam, from the second length of fiber. The first RIP may differ from the second RIP.

Abstract: An apparatus for heat deposition in additive manufacturing may include: a first optical beam source configured to generate a first optical beam; a second optical beam source configured to generate a second optical beam; and/or an optical system. The optical system may be configured to move the generated first optical beam over a target area. The optical system may be further configured to move the generated second optical beam over the target area so that a path of the second optical beam moving over the target area is dithered about a path of the first optical beam moving over the target area. The optical system may be configured to focus the generated first optical beam at a plane of a target area. The optical system may be further configured to focus the generated second optical beam at the plane of the target area.

Abstract: A method for forming an article includes providing a material having a first material property; forming a melt pool by exposing the material to an optical beam having at least one beam characteristic, wherein the melt pool has at least one melt pool property determinative of a second material property of the material; and modifying the at least one beam characteristic in response to a change in the melt pool property.

Abstract: An optical apparatus includes one or more pump sources situated to provide laser pump light, and a gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber. Methods of pumping a fiber sources include generating pump light from one or more pump sources, coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding, and generating a single-mode output beam from the gain fiber.

Abstract: A method of making a three-dimensional object. The method comprises: a) positioning a layer of particles over a build plate; b) exposing the layer of particles to a first laser beam having a first set of beam characteristics, thereby heating the layer sufficiently to fuse at least a portion of the particles together to form a build layer; c) exposing a first region of one of i) the layer of particles or ii) the build layer to a second laser beam having a second set of beam characteristics to provide a first temperature profile for the first region; and d) exposing a second region of one of i) the layer of particles or ii) the build layer to a third laser beam having a third set of beam characteristics to provide a second temperature profile for the second region, the second temperature profile being different than the first temperature profile, wherein both the first region and the second region are in the layer of particles or both the first region and the second region are in the build layer.

Abstract: A method of making a porous three-dimensional object.

Abstract: Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions.

Abstract: Disclosed herein are methods, apparatus, and systems for perturbing an optical beam propagating within a first length of fiber to adjust one or more beam characteristics of the optical beam in the first length of fiber or a second length of fiber or a combination thereof, coupling the perturbed optical beam into a second length of fiber and maintaining at least a portion of one or more adjusted beam characteristics within a second length of fiber having.

Abstract: Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery device, comprising a first length of fiber comprising a first RIP formed to enable modification of one or more beam characteristics of an optical beam by a perturbation device and a second length of fiber having a second RIP coupled to the first length of fiber, the second RIP formed to confine at least a portion of the modified beam characteristics of the optical beam within one or more confinement regions.

Abstract: Beam combining optical systems include a fiber beam combiner having multiple inputs to which output fibers of laser diode sources are spliced. Cladding light stripping regions are situated at the splices, and include exposed portions of fiber claddings that are at least partially encapsulated with an optical adhesive or a polymer. A beam combiner fiber that is optically downstream of a laser source has an exposed cladding secured to a thermally conductive support with a polymer or other material that is index matched to the exposed cladding. This construction permits attenuation of cladding light propagating toward a beam combiner from a splice.

Abstract: A system includes an optical fiber situated to propagate a laser beam received from a laser source to an output of the optical fiber, a first cladding light stripper optically coupled to the optical fiber and situated to extract at least a portion of forward-propagating cladding light in the optical fiber, and a second cladding light stripper optically coupled to the optical fiber between the first cladding light stripper and the optical fiber output and situated to extract at least a portion of backward-propagating cladding light in the optical fiber.

Abstract: An apparatus includes a plurality of input fibers including one or more signal fibers and one or more beam dump fibers, a signal combiner having an input end coupled to the plurality of input fibers so as to couple portions of one or more signal beams respectively propagating in one or more of the signal fibers to form a combiner beam, an output fiber coupled to an output end of the signal combiner so as to receive the combiner beam, and a beam dump coupled to at least one of the one or more beam dump fibers so as to receive a light beam propagating from the output fiber that is associated with the combiner beam.

Abstract: An optical apparatus includes one or more pump sources situated to provide laser pump light, and a gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber. Methods of pumping a fiber sources include generating pump light from one or more pump sources, coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding, and generating a single-mode output beam from the gain fiber.

Abstract: A fiber connector, comprising a housing comprising a region extending in a lengthwise direction an optical fiber disposed in the region, a first portion of the optical fiber comprising an inner core, a cladding layer surrounding the core, and a first outer polymer layer surrounding the cladding layer and a second portion of the optical fiber comprising the inner core, the cladding layer surrounding the core and a second outer polymer layer that is different from the first polymer layer.

Abstract: A method of spectrally multiplexing diode pump modules to increase brightness includes generating one or more pump beams from respective diode lasers at a first wavelength in a diode laser package, generating one or more pump beams from respective diode lasers at a second wavelength different from the first wavelength in the diode laser package, wavelength combining at least one of the pump beams at the first wavelength with at least one of the pump beams at the second wavelength to form one or more combined pump beams, and receiving the combined pump beams in a pump fiber coupled to the diode laser package. Laser systems can include multi-wavelength pump modules and a gain fiber having a core actively doped so as to have an absorption spectrum corresponding to the multiple wavelength, the gain fiber situated to receive the pump light and to produce an output beam at an output wavelength.

Abstract: An example apparatus includes an optical fiber including a core and cladding, the core being situated to propagate an optical beam along a propagation axis associated with the core, and at least one fiber Bragg grating (FBG) situated in the core of the optical fiber, the fiber Bragg grating including a plurality of periodically spaced grating portions situated with respect to the propagation axis so that light associated with Raman scattering is directed out of the core so as to reduce the generation of optical gain associated with stimulated Raman scattering (SRS).

Abstract: An apparatus includes a camera, a dark field illumination source, and a fiber inspection housing including a fiber connector input situated to receive an optical fiber connector so that an optical fiber output end of the optical fiber connector is removably insertable into an interior region of the fiber inspection housing and securable at a predetermined location in the interior region, a camera input situated to receive and secure the camera so that the camera is in optical communication with the interior region and the optical fiber output end, and a dark field illumination source input situated to receive the dark field illumination source so that light emitted from the dark field illumination source is received by the optical fiber output end at a dark field illumination angle and is scattered by contamination or defects associated with the optical fiber output end so as to be detectable by the camera.