Low reflection lateral output fiber probe
A system and method which integrates a mirror at the fiber tip to the fiber tip and uses a tilted flat at the exit plane to prevent astigmatism caused by the cylindrical curvature of the fiber wall and minimize reflection.
1. A reduced reflection, lateral output optical fiber comprising:
an optical emitting fiber having a core and a cladding;
a mirror positioned to deflect light from the core laterally through the cladding; and
a tilted flat formed on the cladding around an exit plane of the deflected light, wherein the tilted flat is tapered or flared with respect to a planar surface parallel to an axial centerline of the optical emitting fiber.
2. The optical fiber of claim 1 , wherein the mirror is formed at an end of the optical emitting fiber and is adjacent to the tilted flat.
3. The optical fiber of claim 2 , wherein the mirror is formed at an angle of about 45° as measured from a planar surface perpendicularly intersecting an axial centerline of the optical emitting fiber.
4. The optical fiber of claim 2 , wherein the mirror deviates from a 45° angle to reduce reflection from a tilted flat having a tilt angle greater than about 20°.
5. The optical fiber of claim 1 , wherein the tilted flat provides a flat surface through which the deflected light exits the optical emitting fiber.
6. The optical fiber of claim 1 , wherein the tilted flat has a tilt angle such that reflectivity of the tilted flat back into the optical emitting fiber is lower than reflectivity from a flat with no tilt angle and/or having no anti-reflective coating.
7. The optical fiber of claim 1 , wherein the tilted flat has an angle of about 4° to about 65° measured from the planar surface parallel to the axial centerline and tangent to an outermost surface of the optical emitting fiber.
8. The optical fiber of claim 1 , wherein the tilted flat has an angle of about 4° to about 20° measured from the planar surface parallel to the axial centerline and tangent to an outermost surface of the optical emitting fiber.
9. The optical fiber of claim 1 , wherein the tilted flat has an angle of about 8° measured from the planar surface parallel to the axial centerline and tangent to an outermost surface of the optical emitting fiber.
10. The optical fiber of claim 1 , further comprising a covering over the tilted flat.
11. The optical fiber of claim 1 , further comprising a lens over the tilted flat.
12. The optical fiber of claim 1 , further comprising an anti-reflection coating on the tilted flat.
13. The optical fiber of claim 1 , wherein a substantial portion of light reflected from the optical emitting fiber is not recaptured by the fiber core.
14. The optical fiber of claim 1 , wherein light exiting the optical emitting fiber is substantially free of astigmatism.
15. The optical fiber of claim 1 , wherein the optical fiber is used in an optical probe LCI system for stent deployment.
16. A method for making a reduced reflection, lateral output optical fiber comprising:
providing an optical emitting fiber having a core and a cladding;
forming a mirror at an end of the optical emitting fiber, said mirror being positioned to deflect light from the core laterally through the cladding; and
forming a tilted flat on the cladding at an exit plane for light deflected by the mirror wherein the tilted flat is tapered or flared with respect to a planar surface parallel to an axial centerline of the optical emitting fiber.
17. The method of claim 16 , wherein the step of forming a tilted flat comprises removing a portion of the cladding to provide a flat surface at the exit plane.
18. The method of claim 16 , wherein the exit plane is at about 90° measured from the axial centerline of the optical emitting fiber.
19. The method of claim 16 , wherein the tilted flat has a tilt angle of about 8° measured from the planar surface parallel to the axial centerline and tangent to an outermost surface of the optical emitting fiber.
20. The method of claim 16 , further comprising attaching a lens to the tilted flat.
21. The method of claim 16 , further comprising coating the tilted flat with an anti-reflective coating.
22. A method for reducing reflection and astigmatism of light exiting an optical emitting fiber at an angle other than 0° comprising:
forming a mirror at an end of the optical emitting fiber, said mirror being positioned to deflect light from the core laterally through the cladding; and
forming a tilted flat on the cladding at an exit plane for light deflected by the mirror, wherein the tilted flat is tapered or flared with respect to a planar surface parallel to an axial centerline of the optical emitting fiber.
23. The method of claim 22 , wherein the step of forming a tilted flat comprises removing a portion of the cladding to provide a flat surface at the exit plane.
24. The method of claim 22 , wherein the tilted flat has a tilt angle of about 8° measured from the planar surface parallel to the axial centerline and tangent to an outermost surface of the optical emitting fiber.