Methods of calibrating an irradiation device of an apparatus for additively manufacturing three-dimensional objects include arranging at least one calibration body in a beam guiding region in which an energy beam can be guided via an irradiation device, with the calibration body being at least partially permeable for the energy beam, guiding the energy beam to at least one position on the calibration body and/or in the volume of the calibration body, generating at least one calibration structure in the at least one position, determining at least one calibration parameter of the at least one calibration structure, determining a calibration status of the irradiation device dependent on the at least one calibration parameter, and calibrating the irradiation device based on the calibration status.

A controller includes a machining information obtaining unit that obtains, as machining information, a machining result of the workpiece, the machining result being obtained by emitting the laser beam; a target value obtaining unit that obtains a target value of the machining result; a reference command value calculation unit that calculates, as a reference command value, a command value of an operation command for the laser machining device, based on the target value; a compensation amount determination unit that determines, based on the machining information and the target value, an amount of compensation for the laser beam; a compensated command value determination unit that determines a compensated command value by compensating for the reference command value, based on the reference command value and the amount of compensation; and an execution control unit that controls the laser machining device to emit the laser beam in accordance with the compensated command value.

A laser irradiation apparatus (1) according to an embodiment includes an optical-system module (20) configured to apply laser light (L1) to an object to be irradiated, a shield plate (51) in which a slit (54) is formed, through which the laser light (L1) passes, and a reflected-light receiving component (61) disposed between the optical-system module (20) and the shield plate (51), in which the reflected-light receiving component (61) is able to receive, out of the laser light (L1), reflected light (R1) reflected by the shield plate (51).

Apparatus for optical isolation, which apparatus comprises a laser (1), a beam delivery system (91), and an output port (92), wherein: the beam delivery system (91) comprises an optical isolator (8) and an optical fibre (2); the laser (1) is defined by a peak power (21); the laser (1) emits laser radiation (13) at a signal wavelength (19); the laser radiation (13) is coupled from the laser (1) to the output port (92) via the beam delivery system (91); and the optical fibre (2) comprises an optical waveguide (100) defined by a core (101), a cladding (102), a mode field area (104) at the signal wavelength (19), a length (86), and a Raman wavelength (25); and the apparatus being characterised in that: the Raman wavelength (25) is longer than the signal wavelength (19); the beam delivery system (91) attenuates the laser radiation (13) at the signal wavelength (19) such that the power of the laser radiation (13) emitted by the laser (1) is more than the power of the laser radiation (13) at the output port (92); the apparatus does not include a pump for pumping the laser radiation (13) at the signal wavelength (19) as the laser radiation (13) propagates along the optical fibre (2); the optical isolator (8) has greater backward optical isolation (33) and greater forward transmission (28) at the signal wavelength (19) compared to the Raman wavelength (25); and the optical fibre (2) comprises a suppressing means (94) for suppressing stimulated Raman scattering.

A laser irradiation apparatus (1) according to an embodiment includes an optical-system module (20) configured to apply laser light (L1) to an object to be irradiated, a shield plate (51) in which a slit (54) is formed, through which the laser light (L1) passes, and a reflected-light receiving component (61) disposed between the optical-system module (20) and the shield plate (51), in which the reflected-light receiving component (61) is able to receive, out of the laser light (L1), reflected light (R1) reflected by the shield plate (51).

A laser machining method includes, before laser machining: calculating the amount of focus movement on the basis of a first measurement value measured with the external optical system warmed up and being the amount of energy of a laser beam passing through a small-diameter hole and a first reference value (database D1) predetermined depending on the type of contamination of the external optical system in relation to the first measurement value; and compensating the focus position in laser machining on the basis of the calculated amount of focus movement.

A laser processing apparatus includes a branching unit configured to branch a laser beam to a first optical path and a second optical path, a condenser configured to condense the branched laser beams on a processing face of a workpiece, an output power measuring unit configured to measure the output power of the laser beam emitted from a laser beam generation unit and having passed through the condenser, and a blocking member positioning mechanism disposed between the condenser and the output power measuring unit and capable of positioning a blocking member between a first laser beam blocking position at which the blocking member blocks only the laser beam of the first optical path from between the branched laser beams and a retracted position at which the blocking member blocks none of the laser beams.

Laser processing apparatus includes movable mirror for changing paths of laser light for processing and measurement light, and stage for changing an incident angle of measuring light. Furthermore, laser processing apparatus includes lens for condensing laser light for processing and measurement light on processing point, controller for controlling laser oscillator, movable mirror, and stage based on corrected data for processing, and measurement processor for measuring a depth of keyhole generated at processing point. The corrected data for processing is data corrected so as to a deviation of an arrival position of at least one of laser light for processing and measurement light caused by chromatic aberration of lens on the surface of workpiece. With this configuration, an accurate depth of keyhole can be measured.

A laser device, including multiple laser modules, includes a plurality of drive power units that drive the laser modules, a plurality of output detection units that detect laser outputs from the laser modules, and output detected values as first output signals, a coupled output detection unit that detects a total laser output after coupling of a plurality of the laser outputs, and outputs a detected value as a second output signal, a computing unit that sets multiple output correction factors for correspondingly controlling the laser modules using the plurality of first output signals and the second output signal, and a control unit that controls the plurality of drive power units using the multiple output correction factors. The multiple output correction factors are each set to allow the total laser output to be maintained at a constant value.

A laser beam irradiating unit of a laser processing apparatus includes a laser oscillator, a mirror configured to reflect a laser beam emitted from the laser oscillator and propagate the laser beam to a processing point, a power measuring unit configured to measure power of leakage light of the laser beam transmitted without being reflected by the mirror, and a condensing lens configured to condense the laser beam propagated by the mirror and irradiate a workpiece with the condensed laser beam. The control unit measures the power of the leakage light of the laser beam by the power measuring unit while irradiating the workpiece with the laser beam.