Fiber-based output couplers for wavelength beam combining laser systems
View Patent ↗In various embodiments, wavelength beam combining laser systems incorporate optical fibers and partially reflective output couplers or partially reflective interfaces or surfaces utilized to establish external lasing cavities.
1. A laser system comprising:
an array of beam emitters each emitting a beam;
focusing optics for focusing the beams toward a dispersive element;
the dispersive element for receiving and dispersing the focused beams, thereby forming a multi-wavelength beam;
an optical fiber for receiving the multi-wavelength beam; and
disposed within the optical fiber, a fiber Bragg grating for receiving the multi-wavelength beam, reflecting a first portion thereof back toward the dispersive element, and transmitting a second portion thereof as an output beam composed of multiple wavelengths,
wherein a portion of the optical fiber is disposed within an external lasing cavity established between the array of beam emitters and the fiber Bragg grating.
2. The laser system of claim 1 , wherein (i) the optical fiber comprises one or more cores at least partially surrounded by one or more cladding layers, and (ii) at least a portion of the fiber Bragg grating is disposed within at least one core of the optical fiber.
3. The laser system of claim 1 , wherein the dispersive element comprises a diffraction grating.
4. The laser system of claim 1 , wherein the focusing optics comprises at least one of a cylindrical lens or a cylindrical mirror.
5. The laser system of claim 1 , further comprising a first end cap attached to the optical fiber and disposed optically upstream of the fiber Bragg grating.
6. The laser system of claim 1 , further comprising a second end cap attached to the optical fiber and disposed optically downstream of the fiber Bragg grating.
7. The laser system of claim 1 , further comprising, disposed optically upstream of the dispersive element, second optics for rotating at least one of the beams.
8. The laser system of claim 1 , wherein the focusing optics comprise one or more spherical lenses and/or one or more spherical mirrors.
9. The laser system of claim 1 , further comprising a second fiber Bragg grating disposed within the optical fiber.
10. The laser system of claim 1 , further comprising, disposed optically downstream of the array of beam emitters, at least one of a slow-axis collimation lens, an optical twister, or a fast-axis collimation lens.
11. A laser system comprising:
an array of beam emitters each emitting a beam;
focusing optics for focusing the beams toward a dispersive element;
the dispersive element for receiving and dispersing the focused beams, thereby forming a multi-wavelength beam;
a first optical fiber for receiving the multi-wavelength beam;
a second optical fiber disposed optically downstream of the first optical fiber; and
disposed between the first and second optical fibers, a partially reflective output coupler for receiving the multi-wavelength beam, reflecting a first portion thereof back toward the dispersive element, and transmitting a second portion thereof as an output beam composed of multiple wavelengths.
12. The laser system of claim 11 , further comprising a first end cap and/or a first focusing lens disposed between the first optical fiber and the partially reflective output coupler.
13. The laser system of claim 12 , further comprising a second end cap and/or a second focusing lens disposed between the partially reflective output coupler and the second optical fiber.
14. The laser system of claim 11 , further comprising a second end cap and/or a second focusing lens disposed between the partially reflective output coupler and the second optical fiber.
15. The laser system of claim 11 , wherein the dispersive element comprises a diffraction grating.
16. The laser system of claim 11 , wherein the focusing optics comprise one or more cylindrical lenses, one or more cylindrical mirrors, one or more spherical lenses, and/or one or more spherical mirrors.
17. The laser system of claim 11 , wherein the first optical fiber comprises a core at least partially surrounded by one or more cladding layers.
18. The laser system of claim 11 , wherein the first optical fiber comprises multiple cores each at least partially surrounded by one or more cladding layers.
19. The laser system of claim 11 , wherein the second optical fiber comprises a core at least partially surrounded by one or more cladding layers.
20. The laser system of claim 11 , wherein the second optical fiber comprises multiple cores each at least partially surrounded by one or more cladding layers.
21. The laser system of claim 11 , further comprising, disposed optically upstream of the dispersive element, second optics for rotating at least one of the beams.
22. A laser system comprising:
an array of beam emitters each emitting a beam;
focusing optics for focusing the beams toward a dispersive element;
the dispersive element for receiving and dispersing the focused beams, thereby forming a multi-wavelength beam;
an optical fiber for receiving the multi-wavelength beam; and
disposed optically downstream of the optical fiber, a partially reflective output coupler for receiving the multi-wavelength beam from the optical fiber, reflecting a first portion thereof back through the optical fiber and toward the dispersive element, and transmitting a second portion thereof as an output beam composed of multiple wavelengths.
23. The laser system of claim 22 , wherein the partially reflective output coupler is disposed within a laser processing head detachable from at least a portion of the optical fiber.
24. The laser system of claim 23 , further comprising one or more focusing lenses disposed within the laser processing head.
25. The laser system of claim 22 , further comprising one or more focusing lenses disposed optically downstream of the optical fiber and optically upstream of the partially reflective output coupler.
26. The laser system of claim 22 , wherein the dispersive element comprises a diffraction grating.
27. The laser system of claim 22 , wherein the focusing optics comprise one or more cylindrical lenses, one or more cylindrical mirrors, one or more spherical lenses, and/or one or more spherical mirrors.
28. The laser system of claim 22 , wherein the optical fiber comprises a core at least partially surrounded by one or more cladding layers.
29. The laser system of claim 22 , wherein the optical fiber comprises multiple cores each at least partially surrounded by one or more cladding layers.
30. The laser system of claim 22 , further comprising, disposed optically upstream of the dispersive element, second optics for rotating at least one of the beams.