Systems and methods for laser systems with variable beam parameter product utilizing thermo-optic effects
In various embodiments, a beam-parameter adjustment system and focusing system alters a spatial power distribution of a radiation beam, via thermo-optic effects, before the beam is coupled into an optical fiber or delivered to a workpiece.
1. A beam-parameter adjustment system and focusing system for receiving and altering a spatial power distribution of a radiation beam from a beam source and focusing the radiation with the altered spatial power distribution onto a workpiece, the system comprising:
a thermo-optic element for receiving the radiation beam and propagating the radiation beam toward the workpiece;
spaced apart from the thermo-optic element, a heat source for heating portions of the thermo-optic element to alter refractive indices thereof, thereby forming an optical distortion pattern within the thermo-optic element;
one or more first optical elements for receiving heat from the heat source and directing the heat to the thermo-optic element, whereby the optical distortion pattern is formed within the thermo-optic element;
focusing optics for receiving the radiation beam from the thermo-optic element and focusing the radiation beam on the workpiece; and
a controller for controlling the thermo-optic element and/or the heat source to achieve a target altered spatial power distribution on the workpiece, the target altered spatial power distribution resulting at least in part from interaction between the radiation beam and the optical distortion pattern within the thermo-optic element.
2. The system of claim 1 , further comprising a second optical element for directing the radiation beam onto the thermo-optic element.
3. The system of claim 2 , wherein the second optical element comprises one or more lenses and/or one or more mirrors.
4. The system of claim 2 , wherein at least one said first optical element is disposed within an optical path between the second optical element and the thermo-optic element.
5. The system of claim 4 , wherein the at least one said first optical element comprises a dichroic mirror positioned to receive heat from the heat source and the radiation beam from the second optical element.
6. The system of claim 1 , wherein the thermo-optic element comprises fused silica.
7. The system of claim 1 , wherein the workpiece comprises an end face of an optical fiber.
8. The system of claim 1 , wherein the workpiece comprises a metallic object.
9. The system of claim 1 , wherein the focusing optics comprise one or more lenses.
10. The system of claim 1 , wherein the heat source comprises a plurality of individually controllable heating elements.
11. The system of claim 1 , wherein the one or more optical elements comprises a dichroic mirror.
12. The system of claim 1 , wherein at least one said first optical element is disposed within an optical path between the beam source and the thermo-optic element.
13. The system of claim 12 , wherein the at least one said first optical element comprises a dichroic mirror positioned to receive heat from the heat source and the radiation beam from the beam source.
14. The system of claim 1 , wherein the one or more first optical elements comprise a plurality of first optical elements, each first optical element positioned to receive heat from the heat source and direct the heat onto a different area of the thermo-optic element.
15. A method of manipulating a radiation beam from a beam source, the method comprising:
generating heat at a heat source different from the beam source and spaced away from a thermo-optic element;
directing at least a portion of the heat from the heat source to the thermo-optic element, thereby forming an optical distortion pattern within the thermo-optic element;
receiving the radiation beam from the beam source with the thermo-optic element, a spatial power distribution of the radiation beam being altered in response to the optical distortion pattern within the thermo-optic element; and
focusing the radiation beam with the altered spatial power distribution toward a workpiece.
16. The method of claim 15 , wherein the at least a portion of the heat is directed to the thermo-optic element along at least a portion of a beam path from the beam source to the thermo-optic element.
17. The method of claim 15 , wherein the heat source comprises a plurality of individually controllable heating elements.
18. The method of claim 15 , wherein the at least a portion of the heat is directed to the thermo-optic element by a dichroic mirror.
19. The method of claim 15 , wherein the at least a portion of the heat is directed to the thermo-optic element by a plurality of optical elements, each optical element positioned to receive heat from the heat source and direct the heat onto a different area of the thermo-optic element.
20. The method of claim 15 , wherein focusing the radiation beam with the altered spatial power distribution toward the workpiece comprises coupling the radiation beam with the altered spatial power distribution into an optical fiber disposed optically downstream of the thermo-optic element.
21. The method of claim 20 , wherein the radiation beam is emitted from the optical fiber onto the workpiece.
22. The method of claim 15 , wherein the at least a portion of the heat is directed to the thermo-optic element along a heating path, at least a portion of the heating path not extending along a beam path from the beam source to the thermo-optic element.
23. The method of claim 15 , further comprising cutting the workpiece with the radiation beam.