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.