A method of confirming an optical axis of a laser processing apparatus includes placing an image capturing unit so as to be movable in X-axis directions, removing a second mirror and capturing an image of a laser beam with the image capturing unit for receiving the laser beam reflected by a first mirror, installing the second mirror and capturing an image of the laser beam with the image capturing unit for receiving the laser beam reflected by a third mirror, and determining whether an optical axis of the laser beam reflected by the first mirror and an optical axis of the laser beam reflected by the third mirror exist in one XZ plane or not on the basis of the captured images and a reference line in the captured images.

There is provided an optical axis adjustment jig including a flat parallel-surface plate having an upper surface and a lower surface with reflective films disposed respectively thereon, and an image capturing unit disposed beneath the flat parallel-surface plate for capturing an image of a laser beam applied thereto. The flat parallel-surface plate is made of a material that is transmissive of a wavelength of the laser beam. The laser beam is applied through the flat parallel-surface plate to the image capturing unit. A tilt of the optical axis of the laser beam is detected on the basis of the shape of the beam spot of the laser beam whose image has been captured by the image capturing unit.

Determination device (2) for determining at least one parameter of an energy beam (4), in particular an energy beam (4) generated via an irradiation device of an apparatus (1) for additively manufacturing three-dimensional objects, which determination device (2) comprises two determination units (5, 6) arrangeable or arranged in succession in a beam path (3) of the energy beam (4), characterized in that each determination unit (5, 6) builds or comprises at least one complementary pattern element (15, 18, 21, 23, 24, 27, 30), wherein at least two pattern elements (15, 18, 21, 23, 24, 27, 30) of the two determination units (5, 6) complement each other to a superordinate pattern (32, 35).

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.

The invention relates to a method and an apparatus for the direct determination of spatial dimensions of a light beam with high precision and short measuring period, which are also suitable for the measuring of laser beams with high power in the range of the beam focus. For this purpose, an apparatus is proposed that includes a beam scanner, at least one light sensor, a movement device for the execution of a relative movement between the light beam and the beam scanner, and a device for the signal recording of a temporally variable signal of the light sensor. The beam scanner comprises at least one scanning body with at least three sampling areas, which extends along sampling lines. The sampling areas are configured for the extraction of linear or strip-shaped light samples from a cross-section of the light beam. Several scanning surfaces are defined by the sampling lines of the sampling areas, each spanned by a movement vector of the relative movement. At least three scanning surfaces have a non-zero distance from one another in the direction of the axis of the light beam. The light sensor is configured for the detection of at least a portion of the sampled light extracted by the sampling areas from the cross-section of the light beam.

A laser device includes: a laser resonator for emitting a laser beam; a condenser lens for collecting the laser beam emitted from the laser resonator; an optical fiber for transmitting the laser beam collected by the condenser lens; at least one light sensor opposing a light receiving surface of the condenser lens and outside an optical path of the laser beam, the at least one light sensor detecting an amount of return light from the condenser lens; and a controller for determining a presence of an abnormality when a value of the amount detected by the at least one light sensor is greater than a predetermined maximum threshold.

A method and an apparatus for beam analysis in an optical system are disclosed, wherein a plurality of beam parameters of a beam propagating along an optical axis are ascertained. The method includes: splitting the beam into a plurality of partial beams which have a focus offset in the longitudinal direction in relation to the optical axis; recording a measurement image produced by these partial beams; carrying out a forward simulation of the beam in the optical system on the basis of estimated initial values for the beam parameters in order to obtain a simulated image; and calculating a set of values for the beam parameters on the basis of the comparison between the simulated image and the measurement image.

A laser system includes an integrated fiber laser front-end, configured to generate and output a pre-amplified first pulsed laser beam having predefined beam characteristics corresponding to a user defined pulse shape and a user defined pulse width setting selection of a controller. The first pulsed laser beam is generated from a master oscillator which outputs a CW laser beam to a temporal pulse shaper, which modulates the CW laser beam to output the first pulsed laser beam in response to an electrical pulse from an arbitrary wave generator and a DC bias voltage from an automatic modulator bias control circuitry. The first pulsed laser beam is pre-amplified to an output pulsed laser beam for laser peening or laser bond inspection. A beam detector is used to monitor beam characteristics, and to generate an error signal to be sent back as a feedback signal to the controller for adjustments and corrections.

Laser welding is performed while moving irradiation positions of a laser beam and a measurement beam in forward, rightward, rearward and leftward directions, and the penetration depth of a weld portion is measured during laser welding in each of the directions. Then, a direction in which a value smaller than a reference value is measured is determined to be an optical axis deviation direction, and a correction value is added to the values measured during the laser welding when the laser welding is performed in the optical axis deviation direction.

A laser welding device is configured to switch an irradiation position of a measurement beam between a position of a keyhole coaxial with the optical axis of a laser beam and a position of a weld bead behind the center of an optical axis of the laser beam in a welding direction. The laser welding device determines whether there is a gap between an upper metal plate and a lower metal plate based on a measured value of a recess depth measured at the position of the weld bead.