Adaptive optic beamshaping in laser processing systems
AssigneeElectro Scientific Industries, Inc.
InventorsMark A. Unrath, Peter Pirogovsky, Leo Baldwin
Life of this patent
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Abstract
A laser processing system quickly and flexibly modifies a processing beam to determine and implement an improved or optimum beam profile for a particular application (or a subset of the application). The system reduces the sensitivity of beam shaping subsystems to variations in the laser processing system, including those due to manufacturing tolerances, thermal drift, variations in component performance, and other sources of system variation. Certain embodiments also manipulate lower quality laser beams (higher M2 values) to provide acceptable shaped beam profiles.
Claims20
A method for processing a workpiece using a laser beam with a selectively shaped spatial intensity profile, the method comprising:
- associating a first portion of the workpiece with a first set of processing characteristics and a second portion of the workpiece with a second set of processing characteristics;
- associating a first spatial intensity profile with the first set of characteristics and a second spatial intensity profile with the second set of characteristics, the first and second spatial intensity profiles corresponding to respective shapes of an output laser beam substantially incident on a focal plane of an objective lens;
- modulating at least one of the phase and the amplitude of an input laser beam to generate an output laser beam having the first spatial intensity profile, wherein the modulation is performed by one or more adaptive optic elements;
- processing the first portion of the workpiece using the output laser beam having the first spatial intensity profile;
- dynamically switching, within a predetermined switching time, from the first spatial intensity profile of the output laser beam to the second spatial intensity profile of the output laser beam by adjusting the modulation of the input laser beam using the one or more adaptive optic elements;
- and
- processing the second portion of the workpiece using the output laser beam having the second spatial intensity profile.
A laser processing system using a selectively shaped spatial intensity profile, the system comprising:
- a laser source to generate an input laser beam;
- a spatial filter to spatially separate the input laser beam into a first beam component having a low-order transverse mode and a second beam component having a higher-order transverse mode as compared to that of the first beam component;
- a first adaptive optic element to modulate at least one of the phase and the amplitude of the first beam component;
- a second adaptive optic element to modulate at least one of the phase and the amplitude of the second beam component;
- and
- optics to recombine the modulated first beam component and the modulated second beam component into an output laser beam for processing a workpiece.
A method for processing a workpiece using a laser beam with a selectively shaped spatial intensity profile, the method comprising:
- spatially filtering an input laser beam into a first beam component having a low-order transverse mode and a second beam component having a higher-order transverse mode as compared to that of the first beam component;
- modulating at least one of the phase and the amplitude of the first beam component using a first set of modulation characteristics;
- modulating at least one of the phase and the amplitude of the second beam component using a second set of modulation characteristics that are independent of the first set;
- recombining the modulated first beam component and the modulated second beam component into an output laser beam with a first spatial intensity profile substantially located at a focal plane of an objective lens;
- and
- processing a first portion of the workpiece with the output laser beam.
A laser processing system comprising:
- a laser source to generate an input laser beam;
- an adaptive optic element to modulate at least one of the phase and the amplitude of the input laser beam, the modulation to correct one or more characteristics of the input laser beam;
- and
- a diffractive optic element to shape the corrected input laser beam so as to generate an output laser beam having a selected spatial intensity profile substantially located at a focal plane of an objective lens.
Dependencies are inferred from the claim text.