Thermally robust multi-spot laser probe
A laser probe includes a cannula, at least one optical fiber positioned within the cannula, and a lens positioned within the cannula at a distal end of the fiber. The lens is adapted to receive a laser beam from the optical fiber at a proximal end of the lens and to transmit the laser beam towards a distal end of the lens. The laser probe includes an optical element configured coupled to the cannula by a brazed joint and to receive the laser beam from the distal end of the lens and emit the laser beam from the probe. The brazed joint may form a hermetic or liquid-tight seal between the optical element and the cannula.
1. A laser probe, comprising:
a cannula;
at least one optical fiber positioned within the cannula;
a lens positioned within the cannula distal to the fiber, the lens configured to receive a laser beam from the optical fiber at a proximal end of the lens and to transmit the laser beam towards a distal end of the lens;
an optical element configured to receive the laser beam from the distal end of the lens and emit the laser beam from the probe;
wherein the optical element is coupled to the cannula by a brazed joint;
wherein the brazed joint forms a liquid-tight seal between the optical element and the cannula.
2. The laser probe of claim 1 , wherein the brazed joint comprises:
a first inter-molecular bond between a braze filler and an outer surface of the optical element; and
a second inter-molecular bond between the braze filler and an inner surface of the cannula.
3. The laser probe of claim 1 , wherein the brazed joint comprises:
a first inter-molecular bond between a braze filler and a metallic material deposited on an outer surface of the optical element; and
a second inter-molecular bond between the braze filler and an inner surface of the cannula.
4. The laser probe of claim 3 , wherein the metallic material deposited on the outer surface of the optical element comprises at least one of titanium and gold.
5. The laser probe of claim 1 , wherein the brazed joint forms a hermetic seal between the optical element and the cannula.
6. The laser probe of claim 1 , wherein the at least one optical fiber comprises a multi-core fiber.
7. The laser probe of claim 1 , wherein the at least one optical fiber comprises a plurality of optical fibers.
8. The laser probe of claim 1 , wherein:
a proximal end of the optical element is positioned within the cannula; and
a distal end of the optical element is flush with a distal end of the cannula.
9. The laser probe of claim 1 , wherein the lens comprises a GRIN (Gradient-index) lens or a spherical lens.
10. The laser probe of claim 1 , wherein the optical element comprises an optically clear material.
11. The laser probe of claim 1 , wherein the optical element comprises at least one of sapphire and fused silica.
12. The laser probe of claim 1 , wherein the cannula comprises at least one of stainless steel, nickel, titanium, nitinol, and platinum-iridium.
13. The laser probe of claim 1 , wherein:
a diameter of the cannula is in the range of 200-700 μm;
the optical element is cylindrically shaped;
a diameter of the optical element is in the range of 200-700 μm;
a length of the optical element is in the range of 200-700 μm;
the lens is cylindrically shaped;
a diameter of the lens is in the range of 200-700 μm;
a length of the lens is in the range of 200 μm to 1.5 mm (millimeters); and
a thickness of the brazed joint is no greater than 50 μm.
14. The laser probe of claim 1 , further comprising:
a body sized and shaped for grasping by a user; and
wherein the cannula is coupled to the body and is configured to be positioned within an eye of a patient.
15. The laser probe of claim 1 , wherein a proximal surface of the optical element abuts the distal surface of the lens.
16. The laser probe of claim 1 , wherein:
a distal surface of the optical fiber is pressed against a proximal surface of the lens; and
a distal surface of the lens is pressed against a proximal surface of the optical element, such that the optical element functions as a mechanical stop with respect to the lens.
17. A laser probe, comprising:
a cannula;
at least one optical fiber positioned within the cannula;
a lens positioned within the cannula distal to the fiber, the lens configured to receive a laser beam from the optical fiber at a proximal end of the lens and to transmit the laser beam towards a distal end of the lens;
an optical element configured to receive the laser beam from the distal end of the lens and emit the laser beam from the probe;
wherein the optical element is coupled to the cannula by a brazed joint;
a proximal end of the optical element is positioned within the cannula; and
a distal end of the optical element protrudes beyond a distal end of the cannula.
18. The laser probe of claim 17 , wherein the distal end of the optical element protrudes beyond the distal end of the cannula by a length in the range of 50-200 μm (micrometers).
19. A laser probe, comprising:
a body sized and shaped for grasping by a user;
a cannula coupled to the body and configured to be positioned within an eye of a patient;
a multi-core fiber positioned within the cannula;
a GRIN lens positioned within the cannula distal to the multi-core fiber, the GRIN lens configured to receive a laser beam from the multi-core fiber at a proximal end of the lens and to transmit the laser beam towards a distal end of the lens;
an optical element comprising an optically clear window configured to receive the laser beam from the distal end of the lens and emit the laser beam from the probe, wherein a proximal end of the optical element is positioned within the cannula, and a distal end of the optical element protrudes beyond a distal end of the cannula; and
a brazed joint coupling the optical element to the cannula, the brazed joint forming at least one of a hermetic seal and a liquid-tight seal between the optical element and the cannula.