POLARIZATION-ADJUSTED AND SHAPE-ADJUSTED BEAM OPERATION FOR MATERIALS PROCESSING
In various embodiments, laser delivery systems feature variable polarizers and beam shapers for altering the polarization and/or shape of the output beam for processing of various materials. The polarization and/or shape of the beam may be varied based on one or more characteristics of the workpiece.
1 .- 26 . (canceled)
27 . A system for processing a workpiece, the system comprising:
a beam emitter;
a laser-delivery head for delivering a beam to the workpiece;
an optical fiber having an input end coupled to the beam emitter and an output end coupled to the laser-delivery head;
a positioning device for varying a position of the beam delivered from the laser-delivery head with respect to the workpiece;
disposed within the laser-delivery head, a variable polarizer for varying a polarization of the beam delivered from the laser-delivery head;
disposed within the laser-delivery head, a beam shaper for varying a shape of the beam delivered from the laser-delivery head; and
a controller, coupled to the positioning device, the polarizer, and the beam shaper, configured to cause the beam from the laser-delivery head to cut through the workpieces while traversing a path across at least a portion of the workpiece, and to vary the polarization and the shape of the beam delivered to the workpiece, along the path, based at least in part on one or more properties of the workpiece.
28 . The system of claim 27 , wherein the controller is configured to maintain a linear polarization of the beam having a polarization direction approximately parallel to the path as the beam traverses the path.
29 . The system of claim 27 , wherein the path includes at least one directional change.
30 . The system of claim 27 , wherein the beam emitter comprises:
a beam source emitting a plurality of discrete input beams;
focusing optics for focusing the plurality of input beams onto a dispersive element;
the dispersive element for receiving and dispersing said beams; and
a partially reflective output coupler positioned to receive said beams, transmit a portion of said beams therethrough as the beam of the beam emitter, and reflect a second portion of said beams back toward the dispersive element,
wherein the beam of the beam emitter is composed of multiple wavelengths.
31 . The system of claim 30 , wherein the dispersive element comprises a diffraction grating.
32 . The system of claim 27 , wherein the one or more properties of the workpiece comprise a composition and/or a thickness of the workpiece.
33 . The system of claim 27 , wherein the one or more properties of the workpiece comprise a composition and a thickness of the workpiece.
34 . The system of claim 27 , wherein the variable polarizer comprises a wave plate and a rotation element.
35 . The system of claim 27 , wherein the variable polarizer comprises a compensator plate, a fixed birefringent wedge disposed over the compensator plate, a movable birefringent wedge disposed over the fixed birefringent wedge, and a translation element.
36 . The system of claim 27 , wherein the beam shaper comprises:
a collimating lens for collimating the beam;
a focusing lens for receiving the collimated beam and focusing the beam toward the workpiece;
disposed optically upstream of the collimating lens, an optical element for receiving the beam and altering the shape thereof; and
a lens manipulation system for changing a position of the optical element within a path of the beam.
37 . The system of claim 36 , wherein the optical element comprises a meniscus lens.
38 . The system of claim 36 , further comprising a second optical element disposed optically downstream of the focusing lens.
39 . The system of claim 38 , wherein the second optical element comprises a lens having (i) a first surface having the shape of a truncated cone, and (ii) opposite the first surface, a second surface that is substantially planar.
40 . The system of claim 38 , wherein the second optical element comprises a lens having (i) a first surface having the shape of a truncated sphere, and (ii) opposite the first surface, a second surface that is substantially planar.
41 . The system of claim 38 , wherein the second optical element comprises a meniscus lens.
42 . The system of claim 27 , wherein the beam shaper comprises:
a collimating lens for collimating a beam received from the beam emitter;
a focusing lens for receiving the collimated beam and focusing the beam toward the workpiece;
disposed optically upstream of the collimating lens, first and second optical elements for receiving the beam and altering the shape thereof; and
a lens manipulation system for changing at least one of (i) a position of the first optical element within a path of the beam, (ii) a position of the second optical element within the path of the beam, or (iii) a distance between the first and second optical elements.
43 . The system of claim 42 , wherein the first optical element comprises a lens having (i) a first surface having the shape of a truncated cone, and (ii) opposite the first surface, a second surface that is substantially planar.
44 . The system of claim 42 , wherein the first optical element comprises a lens having (i) a first surface having the shape of a truncated sphere, and (ii) opposite the first surface, a second surface that is substantially planar.
45 . The system of claim 42 , wherein the first optical element comprises a meniscus lens.
46 . The system of claim 42 , wherein the lens manipulation system is configured to displace at least one of the first optical element or the second optical element laterally with respect to the path of the beam.