Methods, apparatus, and systems comprising a fiber-coupled laser and time-varying beam characteristics. A laser may generate an optical beam that is launched into one or more lengths of fiber, at least one of which comprises a confinement region that is optically coupled to an output. A perturbation device may modulate, through action upon the one or more lengths of fiber, a beam characteristic over a time period during which the laser is energized. A controller may cause the perturbation device to act upon the one or more lengths of fiber to impart a time-averaged beam characteristic and/or to induce a continuous variation in one or more beam characteristics during system use. A process monitor may sense a metric external to the optical system, and a feedback signal from the process monitor may be coupled into the controller. Dynamic beam characteristics may be modulated based on the feedback signal.

Disclosed herein are methods, apparatus, and systems for a multi-operation optical beam delivery device having a laser source to generate the optical beam. A beam characteristic conditioner that, in response to a control input indicating a change between the different laser process operations, controllably modifies the beam characteristics for a corresponding laser process operation of the different laser process operations. A delivery fiber has an input end coupled to the beam characteristic conditioner and an output end coupled to a process head for performing the corresponding laser process operation.

An all-fiber optical beam switch mechanism includes a first length of fiber through which an incident optical beam having beam characteristics propagates along a first propagation path and which has a first refractive index profile (RIP). The first RIP enables, in response to an applied perturbation, modification of the optical beam to form an adjusted optical beam that is movable to propagate along a second propagation path. A second length of fiber is coupled to the first length of fiber and formed with multiple spaced-apart, non-coaxial confinement cores. A selected state of applied perturbation moves the second propagation path of the adjusted optical beam to a position of a selected corresponding one of the multiple confinement cores to confine and thereby direct the adjusted optical beam to a corresponding beam output location at the output of the second length of fiber.

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.

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.

Additive manufacturing systems and methods for fabricating an article are provided. The additive manufacturing system may include a substrate and a layering device configured to fabricate a first layer of the article on the substrate. The layering device may include an optical beam source configured to generate an optical beam and a variable beam characteristics (VBC) fiber operably coupled with the optical beam source and configured to modify one or more beam characteristics, such as a wavelength, of the optical beam.

An optical beam delivery device is configured to generate, from an optical beam, selectable intensity profiles. The device has a first length of fiber having a first refractive index profile (RIP), and a second length of fiber having second RIP that is different from the first RIP. The second length of fiber includes coaxial confinement regions arranged to confine at least a portion of an adjusted optical beam. The confined portion corresponds to an intensity distribution of different intensity distributions. The intensity distribution is established by a corresponding state of different states of perturbation that is applied to the device such that the confined portion is configured to provide, at an output of the second length of fiber, a selected intensity profile of the selectable intensity profiles.

Systems and methods for modifying an optical beam and adjusting one or more beam characteristics of an optical beam are provided. The system may include a first length of fiber operably coupled with an optical beam source and configured to receive an optical beam therefrom. The system may also include a perturbation device operably coupled with the first length of fiber and configured to modify the optical beam traversing therethrough, and a second length of fiber operably coupled with the first length of fiber and configured to receive the modified optical beam therefrom. The system may further include a beam shaping assembly configured to receive the modified optical beam from the second length of fiber, adjust one or more beam characteristics of the modified optical beam, and direct the adjusted optical beam to a downstream process.

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.

An optical beam delivery device establishes, from an optical beam, an optical trap that is moveable to different optical trap locations. The device has a first length of fiber through which the optical beam propagates along a propagation path and which has a first refractive index profile (RIP) enabling modification of the propagation path to form an adjusted optical beam movable to propagate along different propagation paths in response to different states of applied perturbation. The device also has a second length of fiber coupled to the first length of fiber and having confinement cores defining a second RIP. The confinement cores occupy different positions in, and correspond to the different optical trap locations at an output of, the second length of fiber.