In an example embodiment, a system includes a first grating-coupled laser (GCL) that includes a first laser cavity optically coupled to a first transmit grating coupler configured to redirect horizontally-propagating first light, received from the first laser cavity, vertically downward and out of the first GCL. The system also includes a second GCL that includes a second laser cavity optically coupled to a second transmit grating coupler configured to transmit second light vertically downward and out of the second GCL. The system also includes a photonic integrated circuit (PIC) that includes a first receive grating coupler optically coupled to a first waveguide and configured to receive the first light and couple the first light into the first waveguide. The PIC also includes a second receive grating coupler optically coupled to a second waveguide and configured to receive the second light and couple the second light into the second waveguide.

In an example embodiment, a system includes a first grating-coupled laser (GCL) that includes a first laser cavity optically coupled to a first transmit grating coupler configured to redirect horizontally-propagating first light, received from the first laser cavity, vertically downward and out of the first GCL. The system also includes a second GCL that includes a second laser cavity optically coupled to a second transmit grating coupler configured to transmit second light vertically downward and out of the second GCL. The system also includes a photonic integrated circuit (PIC) that includes a first receive grating coupler optically coupled to a first waveguide and configured to receive the first light and couple the first light into the first waveguide. The PIC also includes a second receive grating coupler optically coupled to a second waveguide and configured to receive the second light and couple the second light into the second waveguide.

A surface-relief structure comprises a surface-relief grating including a first material characterized by a first refractive index, a first layer of a second material having a second refractive index conformally deposited on surfaces of the surface-relief grating, and a second layer of a third material having a third refractive index conformally deposited on the first layer. The effective refractive index of the combination of the first layer and the second layer is less than, equal to, or greater than the first refractive index, thereby increasing the duty cycle and/or modifying the overall refractive index of the surface-relief structure. The first layer and the second layer are deposited using, for example, atomic layer deposition techniques.

A multilayer waveguide coupler comprising a first grating and a second grating is provided. Each first copropagating waveguide of the first grating has a first periodically modulated width. Each second copropagating waveguide of the second grating has a second periodically modulated width. The second grating is positioned so that a phase offset is present between the first periodically modulated width of the first copropagating waveguides and the second periodically modulated width of the second copropagating waveguides. The grating spaced distance and phase offset are selected so that light diffracted out of the first copropagating waveguides and the second copropagating waveguides in the first direction interferes constructively to form the first light beam and light diffracted out of the first copropagating waveguides and the second copropagating waveguides in the second direction interferes destructively.

An optical coupling method and apparatus are disclosed. The optical coupling method improve the speed of optical alignment between an optical fiber and a grating coupler (GC) of an optical coupling apparatus for a characteristic test of a silicon photonic integrated circuit (Si-PIC) chip by using a reflective grating couplers disposed on the Si-PIC chip.

An optical coupling method and apparatus are disclosed. The optical coupling method improve the speed of optical alignment between an optical fiber and a grating coupler (GC) of an optical coupling apparatus for a characteristic test of a silicon photonic integrated circuit (Si-PIC) chip by using a reflective grating couplers disposed on the Si-PIC chip.

A method and system for generating a physical layout for a grating coupler integrated in a photonically-enabled circuit are disclosed herein. In some embodiments, the method receives a parametrized wavelength, a parametrized first refractive index, a parametrized second refractive index, a parametrized taper length, a parametrized width, a parametrized grating length, and a parametrized incident angle of the optical beam incident onto the grating coupler and generates a physical layout for the grating coupler based on the received parametrized inputs, the generating of the physical layout is according to a predefined model, and outputs the physical layout of the grating coupler for manufacturing under a semiconductor fabrication process.

An optical grating coupler includes a primary layer formed of a material having a first refractive index. A first plurality of scattering elements is formed within the primary layer. The first plurality of scattering elements has a second refractive index that is different than the first refractive index. A secondary layer is formed over the primary layer. The secondary layer is formed of a material having a third refractive index. A second plurality of scattering elements is formed within the secondary layer. The second plurality of scattering elements has a fourth refractive index that is different than the third refractive index. The fourth refractive index is different than the second refractive index. At least some of the second plurality of scattering elements at least partially overlap corresponding ones of the first plurality of scattering elements.

Structures including a grating coupler and methods of forming a structure that includes a grating coupler. The grating coupler includes segments that are spaced along a longitudinal axis. Each segment is inclined relative to the longitudinal axis. Each segment includes a first curved section having a first curvature and a second curved section having a second curvature that is inverted relative to the first curvature.

Structures including a grating coupler and methods of forming a structure that includes a grating coupler. The grating coupler includes segments that are spaced along a longitudinal axis. Each segment is inclined relative to the longitudinal axis. Each segment includes a first curved section having a first curvature and a second curved section having a second curvature that is inverted relative to the first curvature.