Patent ID: 11137548

Abstract:
A grating coupler reflector (retro reflector) is formed within a photonics chip and includes a vertical scattering region, an optical waveguide, and a reflector. The optical waveguide is optically coupled to the vertical scattering region. The reflector is positioned at an end of the optical waveguide. The reflector is configured to reflect light that propagates through the optical waveguide from the vertical scattering region back toward the vertical scattering region. The location of the grating coupler reflector on the photonics chip is determinable by scanning a light emitting active optical fiber over the chip and detecting when light is reflected back into the active optical fiber from the grating coupler reflector. The determined location of the grating coupler reflector on the photonics chip is usable as a reference location for aligning optical fiber(s) to corresponding optical grating couplers on the photonics chip.