Abstract: A curved and one-sidedly open waveguide for plastic welding, especially for laser transmission welding, includes a first reflecting element having a reflecting surface by means of which laser light can be reflected. The reflecting surface defines a receiving end at which laser light from a laser light source, in particular a light guide or a plurality of light guides, is receivable, and an output end at which laser light is directable into a laser light transmitting work piece. The reflecting surface is defined by a curve between the receiving end and the output end so that the reflecting surface of the first reflecting element has a continuously curved concave shape when viewed in cross-section. Further, the first reflecting element is not opposed by a second reflecting element so that the waveguide is open in the direction normal to the reflecting surface.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.