High-power all fiber telescope
An optical fiber device may include an optical waveguide to guide a laser output from a first end of the optical waveguide to a second end of the optical waveguide. The optical fiber device may include a fiber telescope optically coupled to the second end of the optical waveguide to modify the laser output. The fiber telescope may include a first graded-index optical element, a first facet of the first graded-index optical element being fused to the second end of the optical waveguide; and a second graded-index optical element, a first facet of the second graded-index optical element being fused to a second facet of the first graded-index optical element.
1. A method comprising:
guiding a laser output from a first end of an optical waveguide to a second end of the optical waveguide; and
modifying the laser output by a fiber telescope coupled to the second end of the optical waveguide,
wherein the fiber telescope comprises a set of graded-index optical elements comprising:
a first graded-index optical element having a first core radius, and
a second graded-index optical element having a second core radius that is different from the first core radius,
wherein a diameter of the fiber telescope matches a diameter of the optical waveguide at the second end of the optical waveguide and
wherein the modifying includes at least one of:
a magnification of the laser output,
a demagnification of the laser output,
a shifting of an image plane relative to a caustic waist of the laser output, or
beam shaping of the laser output.
2. The method of claim 1 , wherein the first graded-index optical element and the second graded-index optical element have substantially parabolic refractive-index profiles.
3. The method of claim 1 , wherein a total length of the set of graded-index optical elements is greater than one-quarter pitch.
4. The method of claim 1 , wherein the set of graded-index optical elements includes a graded-index optical element in which a graded-index profile varies as a function of position along a fiber axis.
5. The method of claim 1 , wherein a first facet of the first graded-index optical element is fused to the second end of the optical waveguide.
6. The method of claim 1 , further comprising:
reducing a power density of the laser output via an endcap fused to the fiber telescope.
7. The method of claim 1 , wherein the fiber telescope comprises cladding surrounding the set of graded-index optical elements.
8. A method comprising:
guiding a laser output from a first end of an optical waveguide to a second end of the optical waveguide; and
modifying the laser output by a fiber telescope coupled to the second end of the optical waveguide,
wherein the fiber telescope comprises a set of graded-index optical elements comprising:
a first graded-index optical element having a first numerical aperture, and
a second graded-index optical element having a second numerical aperture that is different from the first numerical aperture,
wherein a diameter of the fiber telescope matches a diameter of the optical waveguide at the second end of the optical waveguide, and
wherein the modifying includes at least one of:
decreasing a spot size of the laser output,
increasing the spot size,
increasing a numerical aperture at an exit facet of the fiber telescope,
decreasing the numerical aperture,
shifting of an image plane relative to a caustic waist of the laser output, or
causing divergence of the laser output.
9. The method of claim 8 , wherein the first graded-index optical element and the second graded-index optical element have substantially parabolic refractive-index profiles.
10. The method of claim 8 , wherein the first graded-index optical element has a first core radius that is different from a second core radius of the second graded-index optical element.
11. The method of claim 8 , wherein at least one of the set of graded-index optical fibers is a non-quarter pitch graded-index lens.
12. The method of claim 8 , wherein the set of graded-index optical elements includes a graded-index element in which a graded-index profile varies as a function of position along a fiber axis.
13. The method of claim 8 , wherein a first facet of the first graded-index optical element is fused to the second end of the optical waveguide.
14. The method of claim 8 , wherein modifying the laser output comprises:
causing the numerical aperture to match a numerical aperture of an engine including a plurality of laser modules.
15. A method comprising:
guiding a laser output from a first end of an optical waveguide to a second end of the optical waveguide; and
modifying the laser output by a fiber telescope coupled to the second end of the optical waveguide,
wherein the fiber telescope comprises a set of graded-index optical elements comprising:
a first graded-index optical element having a first numerical aperture, and
a second graded-index optical element having a second numerical aperture that is different from the first numerical aperture,
wherein the fiber telescope comprises cladding surrounding the set of graded-index optical elements, and
wherein diameter of the fiber telescope is constant along its length; and
reducing a power density of the laser output by an endcap fused to at least one of the set of graded-index optical elements.
16. The method of claim 15 , wherein the set of graded-index optical elements includes a graded-index element in which a graded-index profile varies as a function of position along a fiber axis.
17. The method of claim 15 , wherein modifying the laser output includes at least one of:
magnifying the laser output,
demagnifying the laser output,
shifting an image plane relative to a caustic waist of the laser output, or
beam shaping the laser output.
18. The method of claim 15 , wherein modifying the laser output includes at least one of:
decreasing a spot size of the laser output,
increasing the spot size,
increasing a numerical aperture at an exit facet of the fiber telescope,
decreasing the numerical aperture,
shifting of an image plane relative to a caustic waist of the laser output, or
causing divergence of the laser output.
19. The method of claim 15 , wherein modifying the laser output includes:
causing a numerical aperture of a single module laser to match a numerical aperture of an engine including a plurality of laser modules.
20. The method of claim 15 , wherein modifying the laser output includes:
causing a numerical aperture of an engine of including a plurality of lasers to match a numerical aperture of a single laser module.