A method for manufacturing an optical device includes: a laser irradiation step of condensing pulsed first laser light and pulsed second laser light to the inside of a glass member including germanium and titanium; and a condensing position movement step of moving condensing positions relatively to the glass member. Each of the first laser light and the second laser light has a repetition frequency of 10 kHz or greater. The first laser light is condensed to a dot-shaped condensing region, and the second laser light is condensed to an annular condensing region surrounding the condensing region of the first laser light. A central wavelength of the first laser light is greater than 400 nm and equal to or less than 700 nm, and a central wavelength of the second laser light is equal to or greater than 800 nm and equal to or less than 1100 nm.

The present disclosure relates to a laser based system for laser peening a workpiece. The system has a pulse laser configured to generate laser pulses and a controller for controlling operation of the pulse laser. The controller is further configured to control the pulse laser to cause the pulse laser to generate at least one of the laser pulses with a spatio-temporally varying laser fluence over a duration of the at least one of the laser pulses.

In various embodiments, workpieces are processed, e.g., via welding or cutting, while the shape and/or one or more other parameters of the laser processing beam are altered. The shape and/or one or more other parameters of the laser processing beam may be varied based on one or more characteristics of the workpiece.

Laser welding methods include focusing laser radiation onto a first metal sheet disposed on a metal part, optionally with one or more intervening metal sheets therebetween. The laser radiation is steered to trace at least one spiral path to spot-weld together the metal parts. The laser radiation includes a center beam and an annular beam to maintain a stable keyhole. One method is tailored to weld aluminum parts, e.g., with high gas content and/or dissimilar compositions, and the laser radiation traces first an outward spiral path and then an inward spiral path. The center beam is pulsed during one segment of the inward spiral path. Another method is tailored to weld steel or copper parts having a coating at an interface therebetween, and the laser radiation traces an inward spiral path. The interface may be a zero-gap interface, or a non-zero gap may exist.

The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprise at least one first laser device, each providing at least one first optical feed fiber with a first laser beam; at least one second laser device, each providing at least one second optical feed fiber with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam for welding a workpiece; wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular shape concentric to the first output laser beam. The second laser device is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and the second output laser beam comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam has spectrum width of least 10 nanometers.

Apparatus for laser processing a material (11), which apparatus comprises an optical fibre (2), at least one squeezing mechanism (3), and a lens (4), wherein: the optical fibre (2) is a multimode optical fibre; the optical fibre (2) is such that laser radiation (13) is able to propagate along the optical fibre (2) in a first optical mode (21) and in a second optical mode (22); the squeezing mechanism (3) comprises at least one periodic surface (6) defined by a pitch (7); and the periodic surface (6) is located adjacent to the optical fibre (2); and the apparatus is characterized in that: the pitch (7) couples the first optical mode (21) and the second optical mode C(22) together; the first optical mode (21) is defined by a first mode order (24), and the second optical mode (22) is defined by a second O mode order (25) which is higher than the first mode order (24); the squeezing mechanism (3) is configured to squeeze the periodic surface (6) and the optical fibre (2) together with a squeezing force (12), thereby coupling the first optical mode (21) to the second optical mode (22); the lens (4) is defined by a front focal plane (14) and a rear focal plane (15); the first optical mode (21) is defined by a Rayleigh length (217); and the lens (4) is located within two of the Rayleigh lengths (217) from the distal end (16) of the optical fibre (2).

A welding method includes: arranging a workpiece containing copper in a region to be irradiated with laser light; and irradiating the workpiece with the laser light to melt and weld an irradiated portion of the workpiece. Further, the laser light is formed of a main beam and a plurality of sub beams, and a ratio of power of the main beam to total power of the plurality of sub beams is 72:1 to 3:7.

A method for laser processing a transparent workpiece includes focusing a pulsed laser beam output by a pulsed laser beam source into a pulsed laser beam focal line directed into the transparent workpiece, thereby forming a pulsed laser beam spot on the transparent workpiece and producing a defect within the transparent workpiece, directing an infrared laser beam output onto the transparent workpiece to form an annular infrared beam spot that circumscribes the pulsed laser beam spot at the imaging surface and heats the transparent workpiece. Further, the method includes translating the transparent workpiece and the pulsed laser beam focal line relative to each other along a separation path and translating the transparent workpiece and the annular infrared beam spot relative to each other along the separation path synchronous with the translation of the transparent workpiece and the pulsed laser beam focal line relative to each other.

An additive manufacturing device includes: an inner light beam radiation device of radiating an inner light beam; an outer light beam radiation device of radiating an outer light beam; and a control device. when a molten pool is irradiated with the outer light beam, the control device controls a power density of the outer light beam representing an output per unit area such that a cooling rate of the molten pool representing a temperature drop per unit time is 540 C./s or less at a freezing point of a carbide binder included in the molten pool, the molten pool being formed by irradiating a material including a hard material and a carbide binder with the inner light beam to melt the material. According to the present disclosure, the additive manufacturing device can prevent cracking and additively manufacture a high-quality shaped object with a simple configuration.

The device comprises a welding unit with a tube (3), a laser radiation unit (1) radiating in direction of the tube axis (3.0), and a mandrel (4) which is connected to the tube (3) via a holding unit which is formed, e.g., by two spacer elements (5.1) and which is coaxially arranged relative to and in the tube (3). The tube (3) and the circumferential surface of the mandrel (4) are reflective of the laser radiation of the laser radiation unit (1) such that through multiple reflections between the tube (3) and the mandrel (4) the laser radiation is deflected toward the beam output-side tube end (3.2) and is shaped annularly.