Passively-aligned fiber array to waveguide configuration

An interconnection arrangement providing passive alignment between an array of N optical fibers and an array of N optical waveguides, the interconnection arrangement comprising:

• a photonic integrated circuit (PIC) including
• an optical substrate having a top planar major surface and adjoining planar side edge surfaces;
• the array of N optical waveguides formed as an integrated element and disposed on the top planar major surface of the optical substrate, terminating at a selected adjoining planar side edge surface thereof, and
• a plurality of M extra-array alignment ridges disposed on the top planar major surface of the optical substrate and terminating at the selected adjoining planar side edge surface thereof, the plurality of M extra-array alignment ridges positioned beyond the extent of the array of N optical waveguides, where each extra-array alignment ridge exhibits a defined height h;
• and
• a fiber array substrate including
• an array of N fiber-supporting V-grooves formed in a top surface thereof, and
• a plurality of M extra-array alignment V-grooves disposed to engage with the plurality of M extra-array alignment ridges in a one-to-one relationship and provide passive alignment between the array of N optical waveguides and the array of N optical fibers, the fiber array substrate positioned over the top planar major surface of the PIC to overlap the plurality of M extra-array alignment ridges such that each extra-array alignment V-groove engages with its associated extra-array alignment ridge, with a pair of upper corners of each extra-array alignment ridge contacting inner sidewalls of the associated extra-array alignment V-groove at a location that creates alignment between a core region of an optical fiber supported within the associated V-groove and the optical waveguide integrated within the PIC so as to provide passive alignment between the array of N optical fibers and the array of N optical waveguides, with the alignment ridge height h selected to ensure that a gap spacing g remains between the top surface of the fiber array substrate and the top planar major surface of the PIC upon engagement of the plurality of M alignment V-grooves with the plurality of M extra-array alignment ridges.