Device and method for laser welding around a circumference of a workpiece. A fixed, non-movable unitary optical reflector is provided, which has a pair of optical reflecting surface portions on a first side surface and a second side surface, respectively, arranged at an obtuse angle relative to each other. A workpiece is positioned and fixed in an assembly that includes the unitary optical reflector. During setup, the vertical distance is adjusted between the unitary optical reflector and the workpiece along an axis that is transverse to a longitudinal axis of the workpiece without any adjustment of the reflecting surfaces, which remain fixed during setup. The first and second side surfaces define a curve that is transverse to the longitudinal axis. Once setup has been completed, a laser beam is directed so that it moves along the optical reflector to thereby produce a 360 degree circumferential weld around the workpiece.

Plastic parts are welded in a laser welding system. An infrared laser source in a laser chamber is controlled by a controller using closed-loop feedback control with a corrected feedback signal that is compensated for background infrared radiation in the laser chamber. Prior to the infrared laser source being turned on, the controller senses with the optical sensor an intensity of background infrared radiation in the laser chamber. Once the laser is on, the controller senses with the optical sensor an intensity of infrared laser radiation in the laser chamber. The controller calculates the corrected feedback signal by subtracting the intensity of the background infrared radiation sensed when the infrared laser source was off from the intensity of the infrared laser radiation sensed when the infrared laser source is on.

Sensors incorporated within a waveguide detect a laser light output from at least a laser delivery optical fiber to provide in situ feedback of the laser light intensity detected by the sensor. The sensors may detect laser light directly from the laser delivery optical fiber or as reflected back from a plurality of work pieces during a weld cycle. In various aspects, the feedback provided from the sensors is used to control the laser light intensity or to alert an operator that the laser light intensity is below a predetermined parameter.

A waveguide segment with two sub-segments including a first sub-segment with a first wall and a second wall, each having an inner face by which laser light can be reflected. The inner faces are opposite to each other and a depth of the sub-segment is defined by a distance between the first and the second inner face. Further, each wall has an exit side, and an opposite entry side, a height defined by the distance between the exit and the entry side and a width. At least part of the entry side of each wall extends in an angle to the height, for which applies: 0<<90. The second sub-segment may be formed complementary and the second sub-segment has a portion at the exit side of each wall. Laser light passing through the second sub-segment enters the first sub-segment between the first and the second portion.

A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

A method of welding a protective structure to a tip of a surgical laser fiber involves inserting the optical fiber into a length of tubing, and positioning the fiber and the tubing in a rotatable fixture arranged to simultaneously rotate the fiber and tubing while laser radiation is directed through a transparent material of the tubing, so that one or both contacting surfaces of the tubing and the fiber absorb the laser radiation and heat up to weld the tubing to the fiber. The tubing may be a length of polymer material.

The present invention relates to a method and to a device for assembling together two tubes (1, 2) comprising a tubular junction sleeve and an internal pipe liner tube made of thermoplastic materials by laser welding two contact surfaces of revolution (1-1, 2-1) pressed one against the other at the ends of the tubular sleeve of said liner tube overlapping coaxially.

A laser welding method and system for joining portions of first and second workpieces of thermoplastic material that is partially permeable to a laser beam but absorbs radiation from the laser beam. The first and second workpieces, which are made of material that absorbs radiation from a laser beam, are clamped together. A mask is placed on a first surface of the first workpiece, the first surface being opposite the surface engaging the second workpiece. The mask is impermeable to a laser beam and forms a slot for passing a laser beam to the portion of the first surface of the upper workpiece exposed by the slot, so that heating and melting of the material of the workpieces is limited to the width of the slot. A laser beam is directed onto the slot and moved in a manner to illuminate the slot to melt and join the workpieces.

A waveguide for plastic welding has an entry end, an exit end as well as a first and a second inner face arranged between the entry end and the exit end, which are arranged opposite to each other and by means of which laser light can be reflected. A first distance between the entry end and the exit end defines a length of the waveguide and a second distance between the first and the second inner face defines a thickness of the waveguide. The exit end may be arranged opposite to the entry end and a central plane of the waveguide may extend centrally from the entry end to the exit end. The first inner face comprises a continuously curved, concave shape so that a third distance between the first inner face and the central plane varies continuously from the entry end in the direction of the exit end.

A method for joining two components of a meltable material comprises the steps of providing a first component having a first border region and a second component having a second border region, placing the second component relative to the first component so as to form an overlap between the first border region and the second border region under a gap between the first border region and the second border region, continuously heating opposed sections of the first border region and the second border region at the same time through at least one energy source arranged in the gap at least partially, continuously providing a relative motion of the at least one energy source along the first border region and the second border region in the gap, and continuously pressing already heated sections of the first border region and the second border region onto each other.