In various embodiments, a workpiece is processed utilizing one or more output beams emitted from a step-core optical fiber and formed from one or more input beams that may have non-circular beam shapes. In various embodiments, an input beam may be a variable-power laser beam having a laser-beam numerical aperture (NA) that varies as a function of the power of the laser beam. The step-core optical fiber may have an outer core NA that is greater than or equal to the laser-beam NA at a laser power of approximately 100%, an inner core NA that is less than or equal to the outer core NA, and an inner core NA that is greater than or equal to the laser-beam NA at a power of 50%.

A direct metal laser melting (DMLM) system includes a rotatable base, and a build plate mounted on and supported by the rotatable base, where the build plate includes a build surface. The DMLM system also includes a first actuator assembly, a first powder dispenser disposed proximate the build plate and configured to deposit a weldable powder on the build surface of the build plate. In addition, the DMLM system includes a first powder spreader disposed proximate the build plate and configured to spread the weldable powder deposited on the build surface of the build plate, and a first laser scanner supported by the first actuator assembly in a position relative to the build plate, such that at least a portion of the build surface is within a field of view of the first laser scanner. The first laser scanner is configured to selectively weld the weldable powder. The first laser scanner is further configured to translate axially relative to the build surface on the first actuator assembly.

A method and apparatus particularly for additively manufacturing materials that are susceptible to hot cracking. The additive manufacturing process may include a leading energy beam (16) for liquefying a raw material to form a melt pool (20), and a trailing energy beam (17) directed toward a trailing region of the melt pool. The trailing energy beam may be configured to enhance agitation and/or redistribution of liquid in the melt pool to prevent hot cracking, reduce porosity, or improve other characteristics of the solidified part. The method and apparatus also may improve processing parameters, such as adjusting vacuum level to prevent volatilization of alloying agents, or providing a chill plate to control interpass temperature. The process may be used to form new articles, and also may be used to enhance tailorability and flexibility in design or repair of pre-existing articles, among other considerations.

A method of forming a build in a powder bed includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array onto the powder bed, the selected fibers of the array corresponding to a pattern of a layer of the build; and simultaneously melting powder in the powder bed corresponding to the pattern of the layer of the build. An apparatus for forming a build in a powder bed includes a diode laser fiber array including a plurality of diode lasers and a plurality of optical fibers corresponding to the plurality of diode lasers, each optical fiber configured to receive a laser beam from a respective diode laser and configured to emitting the laser beam; a support configured to support a powder bed or a component configured to support the powder bed at a distance from ends of the optical fibers; and a controller configured to control the diode laser fiber array to emit a plurality of laser beams from selected fibers of the diode laser fiber array onto the powder bed, the selected fibers of the array corresponding to a pattern of a layer of the build and simultaneously melt the powder in the powder bed corresponding to the pattern of the layer of the build.

A method for laser processing a transparent workpiece includes forming a contour line that includes defects, by directing a pulsed laser beam output by a beam source through an aspheric optical element positioned offset in a radial direction from the beam pathway and into the transparent workpiece such that the portion of the pulsed laser beam directed into the transparent workpiece generates an induced absorption within the transparent workpiece that produces a defect within the transparent workpiece. The portion of the pulsed laser beam directed into the transparent workpiece includes a wavelength λ, an effective spot size w.sub.o,eff, and a non-axisymmetric beam cross section having a minimum Rayleigh range Z.sub.Rx,min in an x-direction and a minimum Rayleigh range Z.sub.Ry,min in a y-direction. Further, the smaller of Z.sub.Rx,min and Z.sub.Ry,min is greater than $F_D=\frac{\pi w_{0,\mathrm{eff}}^2}{\lambda },$
where F.sub.D is a dimensionless divergence factor comprising a value of 10 or greater.

A laser machining device includes a laser machining head and a control unit. The laser machining head applies laser for machining an object to be machined, and includes a first laser light source for first laser, a second laser light source for second laser having a different pulse width different from the first laser, a condensing optical system provided between the object and the laser light sources to condense at least the lasers on the object, a switch mechanism provided between the condensing optical system and the laser light sources so that the switch mechanism is movable to a position that at least one of the lasers enters the condensing optical system, and an irradiation angle change mechanism provided between the condensing optical system and the switch mechanism to change an irradiation angle of the first laser. The control unit controls the laser machining head.

Laser beam welding a workpiece includes: generating first and second beam areas on the workpiece by first and second laser beams, respectively. The beam areas are guided in a feed direction relative to the workpiece. Centroids of the beam areas are not coinciding. The first beam area runs ahead of the second beam area. A length of the first beam area, measured transversely to the feed direction, is greater than or equal to that of the second. A surface area of the first beam area is greater than that of the second. A width of the first beam area, measured in the feed direction, is greater than or equal to that of the second. A laser power of the first laser beam is greater than that of the second. The second laser beam is irradiated into a weld pool generated by the first laser beam.

An additive manufacturing apparatus includes a platform, a dispenser configured to deliver a plurality of successive layers of feed material onto the platform, at least one light source configured to generate a first light beam and a second light beam, a polygon minor scanner, an actuator, and a galvo minor scanner. The polygon minor scanner is configured to receive the first light beam and reflect the first light beam towards the platform. Rotation of the first polygon mirror causes the light beam to move in a first direction along a path on a layer of feed material on the platform. The actuator is configured to cause the path to move along a second direction at a non-zero angle relative to the first direction. The galvo mirror scanner system is configured to receive the second light beam and reflect the second light beam toward the platform.

A system that uses a scalable array of individually controllable laser beams that are generated by a fiber array system to process materials into an object. The adaptive control of individual beams may include beam power, focal spot width, centroid position, scanning orientation, amplitude and frequency, piston phase and polarization states of individual beams. Laser beam arrays may be arranged in a two dimensional cluster and configured to provide a pre-defined spatiotemporal laser power density distribution, or may be arranged linearly and configured to provide oscillating focal spots along a wide processing line. These systems may also have a set of material sensors that gather information on a material and environment immediately before, during, and immediately after processing, or a set of thermal management modules that pre-heat and post-heat material to control thermal gradient, or both.

A laser welding method includes a welding process of irradiating a multiple laser beam so as to weld together a first member and a second member at a boundary. The multiple laser beam includes a first beam that is advanced while forming a first molten pool in which the first member is melted, a second beam that is advanced while forming a second molten pool in which the second member is melted, and a main beam that is advanced subsequently to the first beam and the second beam and irradiated to an integrated molten pool formed by integration of the first molten pool and the second molten pool. The first beam and the second beam do not swing, while the main beam swings with respect to the boundary.