Grating-based optical fiber-to-waveguide interconnects
View Patent ↗Embodiments of the present invention are directed to optical waveguide-to-fiber interconnects. In one aspect, an optical fiber-to-waveguide interconnect includes a grating coupler ( 102 ) located at the end of a waveguide, and a grating layer ( 110 ) disposed on the end of an optical fiber ( 112 ). The optical fiber includes a core ( 118 ) and the grating layer includes a planar, non-periodic, sub-wavelength grating ( 116 ). Light carried by the waveguide into the grating coupler is output and coupled into the core via the sub-wavelength grating, and light transmitted along the core to the grating layer is directed by the sub-wavelength grating into the grating coupler for transmission in the waveguide.
1. An optical fiber-to-waveguide interconnect comprising:
a grating coupler ( 102 ) located at the end of a waveguide; and
a grating layer ( 110 ) disposed on the end of an optical fiber ( 112 ), the optical fiber including a core ( 118 ) and the grating layer including a planar, non-periodic, sub-wavelength grating ( 116 ), wherein light carried by the waveguide into the grating coupler is output and coupled into the core via the sub-wavelength grating, and light transmitted along the core to the grating layer is directed by the sub-wavelength grating into the grating coupler for transmission in the waveguide.
2. The interconnect of claim 1 , wherein the grating coupler further comprises a tapered waveguide ( 106 ) attached to the waveguide, and a grating block attached to the tapered waveguide.
3. The interconnect of claim 2 , wherein the grating coupler further comprises the waveguide, tapered waveguide, and grating block composed of an integral material.
4. The interconnect of claim 1 , wherein the sub-wavelength grating further comprises a one-dimensional grating pattern ( 300 ).
5. The interconnect of claim 1 , wherein the sub-wavelength grating further comprises a two-dimensional grating pattern ( 310 , 318 ).
6. The interconnect of claim 1 , wherein the sub-wavelength grating further comprises a grating pattern configured to couple light output from the grating coupler and incident on the sub-wavelength at a particular angle of incidence into the core.
7. The interconnect of claim 1 , wherein the sub-wavelength grating further comprises a grating pattern configured to couple light output from the core into the grating block at a particular angle of incidence.
8. The interconnect of claim 1 , wherein the grating coupler and the grating layer are separated by air space.
9. The interconnect of claim 1 , wherein the optical fiber and the grating coupler further comprise the optical fiber oriented approximately perpendicular to the plane of the grating coupler.
10. The interconnect of claim 1 , wherein the optical fiber further comprises a multimode fiber.
11. The interconnect of claim 1 , wherein the optical fiber further comprises a single mode fiber.