Fiber optic coupler array

Abstract

An assembly includes optical fibers each having a waveguide core, a photonic integrated circuit (IC) that includes in-plane waveguides corresponding to the optical fibers, and a substrate bonded to the photonic IC with grooves that support the optical fibers. The substrate and photonic IC can have metal bumps that cooperate to provide mechanical bonding and electrical connections between the substrate and photonic IC. Portions of the optical fibers supported by the substrate grooves can define flat surfaces spaced from the optical fiber cores. The photonic IC can include passive waveguide structures with a first coupling section that interfaces to the flat surface of a corresponding optical fiber (for evanescent coupling of optical signals) and a second coupling section that interfaces to a corresponding in-plane waveguide (for adiabatic spot-size conversion of optical signals).

Description

[0001] Cross References to Related Applications [0002] This application claims priority to US Provisional Application No. 61 / 736,768, filed December 13, 2013, which is incorporated herein by reference in its entirety. technical field [0003] This application relates to waveguide input and output couplers for optical integrated circuits. Background technique [0004] Waveguide input and output couplers have always been an important issue in the design of optical integrated circuits. Various coupling schemes have been proposed or demonstrated to overcome the low coupling efficiency between optical fibers and on-chip waveguides. Based on the direction in which light is coupled into or out of the waveguide, these schemes fall into one of two categories: vertical coupling (out-of-plane) and lateral coupling (in-plane). [0005] Vertical coupling is typically accomplished with a diffraction grating incorporated into the waveguide layer to provide conversion between the single...

AI Technical Summary

Problems solved by technology

Although lateral coupling has weak polarization dependence and is insensitive to the input bandwidth, it imposes stringent requirements on the vertical and lateral alignment of the fiber

Furthermore, SSC designs require excellent control over critical dimensions and often require lensed fibers or special fibers for nanowaveguides (especially when implemented for short wavelengths), which increases cost and complicates the fabrication and processing of integrated circuits. Complex packaging

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