The present disclosure relates to an apparatus for additively manufacturing a product in a layer-by-layer sequence, wherein the product is formed using powder particles deposited on an interface layer of a substrate. A laser generates first and second beam components. The second beam component has a higher power level and a shorter duration than the first beam component. A mask creates a 2D optical pattern in which only select portions of the second beam components can irradiate the powder particles. The first beam component heats the powder particles close to a melting point, where the particles experience surface tension forces relative to the interface layer. While the particles are heated, the second beam component further heats the particles and also melts the interface layer before the surface tension forces can act on and distort the particles, enabling the particles and the interface layer are able to bond together.

An article includes a ceramic material and features a machined surface that is characteristic of cold ablation laser machining, and the machined surface exhibits no visible oxidation. A laser machining apparatus and technique is based on cold-ablation, but is modified or augmented with an inert assist gas to minimize deleterious surface modifications and mitigate oxide formation associated with laser machining.

Separation lines are formed in a glass plate having first and second main surfaces by irradiating with laser light. The separation lines are configured of a product line corresponding to an outline of a glass article to be separated; and a release line. The product line includes a first in-plane void array configured of in-plane voids arranged on the first main surface; and internal void arrays for product line, each having an in-plane void. The release line includes internal void arrays for release line. A maximum length of the internal void array for product line L.sub.1max is equal to a maximum length of the internal void array for release line L.sub.2max, and a minimum length of the internal void array for product line L.sub.1min is greater than a minimum length of the internal void array for release line L.sub.2min; or the length L.sub.1max is greater than the length L.sub.2max.

Separation lines are formed in a glass plate having first and second main surfaces by irradiating with laser light. The separation lines are configured of a product line corresponding to an outline of a glass article to be separated; and a release line. The product line includes a first in-plane void array configured of in-plane voids arranged on the first main surface; and internal void arrays for product line, each having an in-plane void. The release line includes internal void arrays for release line. A maximum length of the internal void array for product line L.sub.1max is equal to a maximum length of the internal void array for release line L.sub.2max, and a minimum length of the internal void array for product line L.sub.1min is greater than a minimum length of the internal void array for release line L.sub.2min; or the length L.sub.1max is greater than the length L.sub.2max.

A method for separating and releasing a closed-form piece from a workpiece made of a brittle material is disclosed. A first pulsed laser-beam creates defects along the outline of the closed-form piece. A second laser-beam selectively heats the closed-form piece for a first time that is sufficient to initiate cracking between the defects. The heating is stopped for a period sufficiently long for the cracks to propagate completely between the defects. The second laser-beam is applied for a second time that causes melting and deformation of the closed-form piece. The deformation opens a gap between the closed-form piece and the rest of the workpiece, thereby allowing release of the closed-form piece.

A method for separating and releasing a closed-form piece from a workpiece made of a brittle material is disclosed. A first pulsed laser-beam creates defects along the outline of the closed-form piece. A second laser-beam selectively heats the closed-form piece for a first time that is sufficient to initiate cracking between the defects. The heating is stopped for a period sufficiently long for the cracks to propagate completely between the defects. The second laser-beam is applied for a second time that causes melting and deformation of the closed-form piece. The deformation opens a gap between the closed-form piece and the rest of the workpiece, thereby allowing release of the closed-form piece.

A system and method is disclosed for forming a graded index (GRIN) on a substrate. In one implementation the method may involve applying a metal layer to the substrate. A fluence profile of optical energy applied to the metal layer may be controlled to substantially ablate the metal layer to create a vaporized metal layer. The fluence profile may be further controlled to control a size of metal nanoparticles created from the vaporized metal layer as the vaporized metal layer condenses and forms metal nanoparticles, the metal nanoparticles being deposited back on the substrate to form a GRIN surface on the substrate.

A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam is reduced, motion of the focused beams is stopped, the power of the center beam is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.

A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam is reduced, motion of the focused beams is stopped, the power of the center beam is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.

A method for shaping a thin-film photovoltaic cell module from a photovoltaic cell sheet according to a predetermined contour of the module, where the cell sheet includes a flexible substrate based on a polymer or metal foil and a photovoltaic stack including one or more photo-active layers arranged on a front surface of the substrate. The method includes: providing the cell sheet, directing a laser beam towards a rear surface of the substrate; creating, by the laser beam, a trench in the rear surface, the trench shaped according to the contour such that the cell sheet is “divided” in a first portion within the contour and a second portion outside the contour; affixing a handling tool to one of the portions of the cell sheet on the rear surface of the substrate; selectively separating the portions by displacing the handling tool and one portion relative to the other portion.