Integrated photonics waveguide grating coupler

摘要

A photonic integrated device comprises a waveguide embedded in a photonic substrate. The waveguide has a waveguide radiation exit surface and the waveguide is optically connected to a two dimensional grating. The photonic integrated device also comprises a two dimensional grating having a plurality of curved elongate scattering elements. The two dimensional grating is adapted for diffracting radiation received from the waveguide toward a direction out of the photonic substrate and the curved elongate scattering elements are oriented with respect to the waveguide such that, for points of the scattering elements which can be irradiated by radiations stemming from the waveguide, normal lines to at least the curved elongate scattering element closest to the waveguide radiation exit surface do not substantially intersect with the waveguide radiation exit surface of the waveguide.

主权项

1. A photonic integrated device, the photonic integrated device comprising:
a waveguide embedded in a photonic substrate, the waveguide having a waveguide radiation exit surface and the waveguide being optically connected to a two dimensional grating, said two dimensional grating having a plurality of curved elongate scattering elements, said two dimensional grating being configured for diffracting radiation received from the waveguide toward a direction out of said photonic substrate, wherein the curved elongate scattering elements are oriented with respect to the waveguide such that, for points of the scattering elements which can be irradiated by radiations stemming from the waveguide, normal lines to at least the curved elongate scattering element closest to the waveguide radiation exit surface do not substantially intersect with said waveguide radiation exit surface of said waveguide, and wherein at least one of the plurality of elongate scattering elements forms at least a part of an ellipse having a first focus point substantially positioned on said waveguide radiation exit surface and having a major axis forming an angle different from 0° with a longitudinal axis of the waveguide, wherein said angle is larger than a half of the sum of a divergence angle of light emanating from said waveguide and the ratio of a maximum diameter of a waveguide end surface over a focal distance between a grating surface and the waveguide radiation exit surface.