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.

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.

An optical fibre (10) which has a first refractive index profile (61) that can be changed by heating to a second refractive index profile (62), at least one first dopant (7) for providing the first refractive index profile, at least one concealed dopant (8), and at least one mobile dopant (9), wherein the mobile dopant has a molar refractivity and is present in a concentration (19) such as to balance a change (146) in the first refractive index profile induced by the concealed dopant, and has a diffusion constant (16) greater than a diffusion constant (15) of the concealed dopant, so that heating of the optical fibre causes the mobile dopant to diffuse more quickly than the concealed dopant, thereby allowing the concealed dopant and the mobile dopant to change the first refractive index profile to the second refractive index profile.

In various embodiments, the beam parameter product and/or beam shape of a laser beam is adjusted by coupling the laser beam into an optical fiber of a fiber bundle and directing the laser beam onto one or more in-coupling locations on the input end of the optical fiber. The beam emitted at the output end of the optical fiber may be utilized to process a workpiece.

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.

A method of producing a capillary tube from glass includes zonally softening a tubular preform having an outer diameter D.sub.OD, an inner diameter D.sub.ID and a diameter ratio D.sub.relwith D.sub.rel=D.sub.OD/D.sub.IDin a heating zone heated to a draw temperature T.sub.draw and drawing off continuously from the softened region a capillary strand having an outer diameter d.sub.AD, an inner diameter d.sub.ID and a diameter ratio d.sub.relwith d.sub.rel=d.sub.OD/d.sub.IDat a draw speed v.sub.draw and cutting the capillary to length therefrom. For cost-effective production of a thick-walled capillary by drawing from a preform without strict requirements for the geometry and dimensional accuracy of the preform, the capillary bore is subjected in the heating zone to a shrinkage process based on the action of draw temperature T.sub.draw and surface tension, such that the diameter ratio d.sub.rel of the capillary strand is adjusted to a value greater than the diameter ratio D.sub.rel of the preform by at least a factor of 5.