Methods for welding an optical fiber to a photonic integrated circuit
Multiple methods are provided for fiber optic welding on a photonic integrated circuit (PIC). An example method includes providing a PIC, forming an attachment surface on the PIC configured to receive an optical fiber. The method further includes disposing at least a portion of the optical fiber on the attachment surface. The method may then include welding the optical fiber to secure the optical fiber with respect to the attachment surface. The attachment surface may be comprised of substantially the same material as an outer portion of the optical fiber and may result in a homogenous weld securing and connecting the optical fiber to the PIC.
1 . A method for attaching an optical fiber to a photonic integrated circuit (PIC), the method comprising:
providing the PIC;
forming an attachment surface on the PIC configured to receive the optical fiber, wherein the attachment surface of the PIC comprises substantially the same material as an outer portion of the optical fiber;
disposing at least a portion of the outer portion of the optical fiber onto the attachment surface; and
heating an outer surface of the portion of the outer portion of the optical fiber and the attachment surface of the PIC to a melting point of the material to form a homogenous weld securing the optical fiber with respect to the attachment surface of the PIC.
2 . A method according to claim 1 , wherein the attachment surface comprises a V-shaped groove defined by the PIC.
3 . A method according to claim 2 further comprising disposing optical beads within the V-shaped groove, wherein the optical beads are configured to facilitate formation of the homogenous weld.
4 . A method according to claim 1 , wherein the PIC defines a V-shaped groove, wherein forming the attachment surface comprises disposing a silicon dioxide passivation layer onto the V-shaped groove.
5 . A method according to claim 1 , wherein the PIC defines a V-shaped groove, wherein forming the attachment surface comprises applying at least one mirror to a surface of the V-shaped groove, wherein the at least one mirror is configured to focus the heating of the optical fiber within the V-shaped groove.
6 . A method according to claim 1 further comprising cleaving the optical fiber to correspond to a shape of the attachment surface.
7 . A method according to claim 1 further comprising affixing a glass slab to the optical fiber, wherein the glass slab is configured to extend an area of the optical fiber for engagement with the attachment surface to facilitate formation of the homogenous weld.
8 . A method according to claim 1 , wherein the PIC defines a groove having a curved cross-section, wherein the attachment surface is a surface of the groove.
9 . A method according to claim 1 , wherein the attachment surface comprises a passivation layer comprising silicon dioxide.
10 . A method according to claim 9 further comprising welding a silicon dioxide chip to the outer portion of the optical fiber, wherein welding the optical fiber onto the attachment surface comprises welding the silicon dioxide chip to the passivation layer.
11 . A method according to claim 10 wherein the silicon dioxide chip comprises a silicon nitride waveguide.
12 . A method according to claim 9 further comprising affixing an extension to the optical fiber, wherein welding the optical fiber comprises welding the extension to the attachment surface.
13 . A method according to claim 12 , wherein affixing the extension to the optical fiber comprises affixing the extension to an end of the optical fiber, and wherein the extension is a glass slab.
14 . A method according to claim 12 , wherein the extension is a prism.
15 . A method according to claim 14 , wherein the prism comprises a lens.
16 . A method according to claim 14 further comprising disposing an intermediate material between the optical fiber and the passivation layer.
17 . A method according to claim 16 , wherein the intermediate material comprises a lens, and wherein the prism is configured to direct an optical signal from the optical fiber into a waveguide of the PIC via the lens.
18 . A method according to claim 1 further comprising affixing an optical glass substrate to the optical fiber, wherein welding the optical fiber comprises welding the optical glass substrate to the attachment surface, wherein the optical glass substrate defines an angled end configured to be welded to the attachment surface such that a predetermined working distance and angle for coupling is achieved.
19 . A method for attaching an optical fiber to a photonic integrated circuit (PIC), the method comprising:
providing the PIC;
defining a groove in the PIC wherein the groove comprises an attachment surface configured to receive the optical fiber, wherein the attachment surface of the PIC comprises substantially the same material as an outer portion of the optical fiber;
disposing a passivation layer of silicon dioxide on the attachment surface;
disposing at least a portion of the outer portion of the optical fiber for receipt by the attachment surface; and
heating an outer surface of the portion of the outer portion of the optical fiber and the attachment surface of the PIC to a melting point of the material to form a homogenous weld securing the optical fiber with respect to the attachment surface of the PIC.
20 . A method according to claim 19 wherein the groove is a V-shaped groove or has a curved cross section.