Abstract: A gas-flow nozzle for laser welding includes a central opening to transmit a laser beam from a top of the central opening to a workpiece at a bottom of the central opening. The central opening is bounded by two inward-facing opposite sides of the gas-flow nozzle. The gas-flow nozzle further includes (a) one or more lower gas-flow channels to direct a lower gas flow to the workpiece from both of the two sides bounding the central opening, (b) one or more upper gas-flow channels to direct an upper gas flow to the workpiece from both of the two sides bounding the central opening, and (c) one or more middle gas-flow channels to exhaust gas from both of the two sides of the central opening. The gas-flow nozzle is useful for laser welding prismatic battery cases. In this scenario, the upper gas flow helps prevent burning of battery-terminal insulator material.

Abstract: 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.

Abstract: A method for laser welding a pair of metal pins delivers a laser beam to a work-side of the pair of metal pins where a respective pair of surfaces of the metal pins are adjacent to each other and face in the same direction. The laser beam first traces a first path on the work-side to form a melt pool by keyhole welding. The first path crosses an interface between the metal pins. After tracing the first path, the laser beam is switched to trace a second path on the work-side with the laser beam at a delivered rate of energy per unit path length that is less than the one used for the first path. The second path crosses the interface and is within the first path. The method is well-suited for welding of hairpin and I-pin stators.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention concerns an apparatus and a method for laser processing. There is provided at least one first laser beam from at least one first optical feed fiber connected to at least one first laser device and at least one second laser beam from at least one second optical feed fiber connected to at least one second laser device. Said first and second laser beams are combined in a multi-core optical fiber. Said first core of said multi-core optical fiber has a circular cross-section, and said second core has an annular shape concentric to said first core. A composite laser beam comprising first and second output beams is directed from said multi-core optical fiber to a workpiece with overlapping elements to be welded.

Abstract: A method for laser welding a pair of metal pins delivers a laser beam to a work-side of the pair of metal pins where a respective pair of surfaces of the metal pins are adjacent to each other and face in the same direction. The laser beam first traces a first path on the work-side to form a melt pool by keyhole welding. The first path crosses an interface between the metal pins. After tracing the first path, the laser beam is switched to trace a second path on the work-side with the laser beam at a delivered rate of energy per unit path length that is less than the one used for the first path. The second path crosses the interface and is within the first path. The method is well-suited for welding of hairpin and I-pin stators.

Abstract: 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.

Abstract: The invention concerns an apparatus and its use for laser processing. The invention also concerns a method and an optical component. According to the invention, at a first laser device, providing a first optical feed fiber and a second laser device providing a second optical feed fiber is provided. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed.

Abstract: An apparatus and its use for laser processing along with a method and an optical component. A first laser device provides a first optical feed fiber and a second laser device provides a second optical feed fiber. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed. A control unit individually controls the power density of the output laser beams.

Abstract: A pump reflector for efficiently recycling unabsorbed pump radiation in a diode-pumped fiber laser includes a core for guiding a laser beam, a pump cladding, and a tapered capillary tube. Pump radiation is adiabatically guided in the tapered capillary tube, which includes a mirror that is reflective for the pump radiation. The pump reflector may be packaged as a fiber component for co-propagating or counter-propagating fiber laser amplifiers and resonators.

Abstract: The invention relates to a method and apparatus for processing substrates, such as glass and semiconductor wafers. The method comprises directing to the substrate from a laser source a plurality of sequential focused laser pulses having a predetermined duration, pulsing frequency and focal spot diameter, the pulses being capable of locally melting the substrate, and moving the laser source and the substrate with respect to each other at a predetermined moving velocity so that a structurally modified zone is formed to the substrate. According to the invention, the pulse duration is in the range of 20-100 ps, pulsing frequency at least 1 MHz and moving velocity adjusted such that the distance between successive pulses is less than ? of the diameter of the focal spot. The invention can be utilized, for example, for efficient dicing, scribing and welding of materials which are normally transparent.

Abstract: The invention concerns a method of fusing and electrically contacting a first insulating substrate (28A) having at least one first conductive layer (29A) thereon with at least one second insulating substrate (28B) having at least one second conductive layer (29B) thereon, the method comprising: stacking the first and second substrates (28A, 28B) such that an interface zone is formed between them, the interface zone comprising an electrical contacting zone where at least one first conductive layers (29A) faces and is at least partially aligned with at least one second conductive layer (29B), and a substrate fusing zone where the insulating substrates (28A, 28B) directly face each other; focusing to the interface zone of the substrates (28A, 28B) through one of the substrates (28A, 28B) a plurality of sequential focused laser pulses from a laser source, the pulse duration, pulse frequency and pulse power of the laser light being chosen to provide local melting the substrate (28A, 28B) materials and the conducti

Abstract: The present invention provides a packaging for a fiber optic component, such as an optical fiber, wherein the heating induced strain to the fiber optic component is minimized, where the packaging comprises a first support member having a first coefficient of thermal expansion (k1). The packaging further comprises a second support member, which is resiliently mounted to the first support member for minimizing transfer of thermal expansion induced strain of the first support member to the second support member. The second support member comprises a longitudinal groove open at least on one side of the second support member for receiving a fiber optic component, wherein the second support member has a tensile strength considerably higher than that of the fiber optic component.

Abstract: The invention concerns a fiber-optic component, in particular a fiber coupler, and method for manufacturing thereof. The component comprises a housing (25), at least one first optical element (21) capable of guiding light and having an output end, the first optical element (21) being affixed to said housing (25) at a mounting zone (26A), and at least one second optical element (22, 23) optically coupled to the first optical element (21) at a coupling zone (27) for receiving light from the output end of the first optical element (21). According to the invention, the component comprises at least one zone (29) of light-scattering material arranged in the vicinity of the first optical element (21) at a region between the coupling zone (27) and the mounting zone (26A). By means of the invention, the effect potentially harmful reverse radiation in fiber-optic components can be mitigated.

Abstract: The invention concerns a method of fusing and electrically contacting a first insulating substrate (28A) having at least one first conductive layer (29A) thereon with at least one second insulating substrate (28B) having at least one second conductive layer (29B) thereon, the method comprising: stacking the first and second substrates (28A, 28B) such that an interface zone is formed between them, the interface zone comprising an electrical contacting zone where at least one first conductive layers (29A) faces and is at least partially aligned with at least one second conductive layer (29B), and a substrate fusing zone where the insulating substrates (28A, 28B) directly face each other; focusing to the interface zone of the substrates (28A, 28B) through one of the substrates (28A, 28B) a plurality of sequential focused laser pulses from a laser source, the pulse duration, pulse frequency and pulse power of the laser light being chosen to provide local melting the substrate (28A, 28B) materials and the conducti

Abstract: The invention relates to a method and apparatus for processing substrates, such as glass and semiconductor wafers. The method comprises directing to the substrate from a laser source a plurality of sequential focused laser pulses having a predetermined duration, pulsing frequency and focal spot diameter, the pulses being capable of locally melting the substrate, and moving the laser source and the substrate with respect to each other at a predetermined moving velocity so that a structurally modified zone is formed to the substrate. According to the invention, the pulse duration is in the range of 20-100 ps, pulsing frequency at least 1 MHz and moving velocity adjusted such that the distance between successive pulses is less than ? of the diameter of the focal spot. The invention can be utilized, for example, for efficient dicing, scribing and welding of materials which are normally transparent.