A method for laser keyhole welding a stack of metal foils to a metal tab is disclosed. The method independently adjusts power in a focused center beam and power in a focused annular beam to form a weld through all the foils and the tab. The annular beam provides sufficient power to heat the metal to about melting temperature, widen a mouth of a keyhole, and stabilize a melt pool. The center beam provides sufficient additional power to form the keyhole. The power of the annular beam is sustained for a longer time than the power of the center beam. A plurality of such welds is formed to provide mechanical strength and electrical conductivity.

A method for processing a transparent workpiece includes forming a first contour line, comprising a first plurality of defects, in the transparent workpiece; forming a second contour line, comprising a second plurality of defects, in the transparent workpiece, wherein the second contour line defines a second contour intersecting the first contour line at an intersection point, wherein the laser pulse energy of the second pulsed laser beam is increased from a first laser pulse energy to a second laser pulse energy at a first distance from the intersection point; and wherein the laser pulse energy of the second pulsed laser beam is decreasing from the second laser pulse energy to the first laser pulse energy at a second distance from the intersection point.

A laser processing device includes a laser oscillator, optical fiber (90), beam control mechanism (20), and a laser light emitting head. The laser oscillator includes first and second laser oscillation units that generate first and second laser light rays (LB1) and (LB2), respectively. Beam control mechanism (20) includes optical path changing and holding mechanism (40) that is disposed between second condenser lens (32) that condenses second laser light (LB2) and dichroic mirror (33) that multiplexes first and second laser light rays (LB1) and (LB2) and causes the multiplexed light to be incident on optical fiber (90).

Beam control mechanism (20) changes an incident position of second laser light (LB2) on optical fiber (90).

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%.

Forming holes in a material includes focusing a pulsed laser beam into a laser beam focal line oriented along the beam propagation direction and directed into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a defect line along the laser beam focal line within the material, and translating the material and the laser beam relative to each other, thereby forming a plurality of defect lines in the material, and etching the material in an acid solution to produce holes greater than 1 micron in diameter by enlarging the defect lines in the material. A glass article includes a stack of glass substrates with formed holes of 1-100 micron diameter extending through the stack.

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.

A system for laser marking a substrate includes a multi-emitter array (16) for directing radiation onto a substrate. The multi-emitter array has a radiation guide (19) defining a number of discrete emission channels (20) with emitting ends (20a) of the emission channels (20) arranged in an array. Each emission channel (20) is coupled at its opposing end with two or more laser diodes (18a, 18b). The laser diodes (18a, 18b) are operated at a maximum operational output power (P.sub.op) sufficiently below their rated maximum power (P.sub.m) to provide acceptable levels of reliability whilst providing a combined radiation (24) emitted from each channel (20) having a power high enough to achieve increased operational speeds. The multi-emitter array (19) may comprise a number of optical fibres (26) whose emitter ends are arranged in an array. The system is particularly suited for inkless printing on substrates susceptible to colour change when irradiated.

The invention relates to a method for fusing a solder material deposit by means of laser energy, in which laser radiation emitted from a first laser source is applied to the solder material deposit in a first application phase by means of a first laser device (11) and laser radiation emitted from a second laser source is applied to the solder material deposit in a second application phase by means of a second laser device (12), said first laser source having a lower laser power than the second laser source, a switch being made from the first application phase to the second application phase by means of a switching device (30) and said switch being triggered by a temperature sensor, by means of which the temperature of the solder material deposit is measured at least during the first application phase.

A laser processing apparatus of the present disclosure controls outputs of a blue laser oscillator and an infrared laser oscillator such that before a surface melting is detected on a workpiece, the workpiece is irradiated with at least blue laser light, and after the surface melting is detected on the workpiece, a power of infrared laser light with which the workpiece is irradiated is increased as compared to before the surface melting is detected.