Adjustable beam characteristics

1. An optical beam delivery system, comprising:

an optical fiber including:

a first length of fiber comprising a first refractive index profile (RIP) formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof; and

a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within two or more cores wherein the first RIP and the second RIP are different; and

an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more beam characteristics.

2. The optical beam delivery system of claim 1 , further comprising a first process fiber coupled between a first process head and the optical system, wherein the first process fiber is configured to receive the optical beam comprising the modified one or more beam characteristics.

3. The optical beam delivery system of claim 2 , wherein the first process fiber comprises a third RIP configured to preserve at least a portion of the modified one or more beam characteristics of the optical beam within the two or more cores of the first process fiber.

4. The optical beam delivery system of claim 1 , wherein at least a portion of the free-space optics are configured to further modify the modified one or more beam characteristics of the optical beam.

5. The optical beam delivery system of claim 1 , wherein the one or more beam characteristics include beam diameter, divergence distribution, BPP, intensity distribution, luminance, M 2 value, NA, optical intensity, power density, radial beam position, radiance, or spot size, or any combination thereof.

6. The optical beam delivery system of claim 1 , wherein the optical system is a fiber-to-fiber coupler, a fiber-to-fiber switch or a process head, or a combination thereof.

7. An optical beam delivery system, comprising:

an optical fiber including:

a first length of fiber comprising a first refractive index profile (RIP) formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof; and

a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions wherein the first RIP and the second RIP are different;

an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more beam characteristics; and

a first process fiber coupled between a first process head and the optical system, wherein the first process fiber is configured to receive the optical beam comprising the modified one or more beam characteristics, wherein the first process fiber comprises a third RIP configured to preserve at least a portion of the modified one or more beam characteristics of the optical beam within one or more second confinement regions of the first process fiber.

8. The optical beam delivery system of claim 7 , wherein the third RIP is the same as the second RIP.

9. The optical beam delivery system of claim 7 , wherein the third RIP is different from the second RIP, wherein the third RIP is configured to further modify the modified one or more beam characteristics of the optical beam.

10. The optical beam delivery system of claim 9 , wherein at least one of the one or more second confinement regions includes at least one divergence structure configured to modify a divergence profile of the optical beam.

11. The optical beam delivery system of claim 10 , wherein the at least one divergence structure comprises an area of lower-index material than that of the second confinement region.

12. The optical beam delivery system of claim 7 , further comprising a second process fiber having a fourth RIP that is coupled between the optical system and a second process head, wherein the second process fiber is configured to receive the optical beam comprising the modified one or more beam characteristics within one or more third confinement regions of the second process fiber.

13. The optical beam delivery system of claim 12 , wherein the first process fiber or the second process fiber or a combination thereof is configured to further modify the modified one or more beam characteristics of the optical beam.

14. The optical beam delivery system of claim 12 , wherein the second process fiber includes at least one divergence structure configured to modify a divergence profile of the optical beam.

15. The optical beam delivery system of claim 14 , wherein the second process fiber comprises a central core surrounded by at least one of the one or more third confinement regions, wherein the central core and at least one third confinement region are separated by a cladding structure having a first refractive index that is lower than a second refractive index of the central core and a third refractive index of the at least one third confinement region, wherein the at least one third confinement region includes the at least one divergence structure.

16. The optical beam delivery system of claim 15 , wherein the at least one divergence structure comprises an area of lower-index material than that of the third confinement region.

17. The optical beam delivery system of claim 12 , wherein the second RIP is different from the third RIP or the fourth RIP or a combination thereof.

18. The optical beam delivery system of claim 12 , wherein the second RIP is the same as the third RIP or the fourth RIP or a combination thereof.

19. The optical beam delivery system of claim 12 , wherein the one or more beam characteristics include beam diameter, divergence distribution, BPP, intensity distribution, luminance, M 2 value, NA, optical intensity, power density, radial beam position, radiance, or spot size, or any combination thereof.

20. The optical beam delivery system of claim 12 , wherein at least a portion of the free-space optics are configured to further modify the modified one or more beam characteristics of the optical beam.

21. The optical beam delivery system of claim 20 , further comprising a first process fiber coupled between a first process head and the optical system, wherein the first process fiber is configured to receive the optical beam comprising twice modified one or more beam characteristics.

22. The optical beam delivery system of claim 21 , wherein the first process fiber has a third RIP configured to preserve at least a portion of the twice modified one or more beam characteristics of the optical beam within one or more second confinement regions of the first process fiber.

23. The optical beam delivery system of claim 21 , wherein the third RIP is different from the second RIP, wherein the third RIP is configured to further modify the twice modified one or more beam characteristics of the optical beam.

24. The optical beam delivery system of claim 21 , wherein the first process fiber includes a divergence structure configured to further modify the twice modified one or more beam characteristics of the optical beam.

25. The optical beam delivery system of claim 21 , further comprising a second process fiber coupled between the optical system and a second process head, wherein the second process fiber is configured to receive the twice modified one or more beam characteristics.

26. The optical beam delivery system of claim 25 , wherein the first process fiber or the second process fiber or a combination thereof is configured to further modify the twice modified one or more beam characteristics of the optical beam.

27. The optical beam delivery system of claim 25 , wherein the first process fiber or the second process fiber or a combination thereof includes at least one divergence structure configured to further modify the twice modified one or more beam characteristics of the optical beam.