Devices, systems, and methods for optical signal processing

A system for optical signal processing, the system comprising:

• a first optical fiber configured to transmit one or more optical signals using a light beam;
• and
• a photonic die configured to process the one or more optical signals, the photonic die comprising:
• a first layer formed from a material transparent to the light beam;
• a first lens formed within a silicon portion of the first layer and adjacent to a top surface of the first layer, the first lens being associated with the first optical fiber and comprises a plurality of anti-reflective coating (ARC) layers formed above a curved surface;
• a second layer located underneath the first layer and adjacent to another surface of the first layer, the second layer formed from the material transparent to the light beam;
• a waveguiding layer located underneath the second layer, and configured to waveguide the light beam transmitted in the waveguiding layer;
• and
• a first grating coupler associated with the first lens and formed over the waveguiding layer, wherein the first lens is configured to receive, from one of the grating coupler or a light-guiding element, the light beam, and focus the light beam towards another one of the light-guiding element or the grating coupler.

A method for fabricating a semiconductor device, comprising:

• providing a substrate layer;
• forming a first oxide layer over the substrate layer;
• forming a waveguiding layer for waveguiding a light beam transmitted in the waveguiding layer over the first oxide layer, wherein a grating coupler is disposed over the waveguiding layer;
• forming a second oxide layer transparent to the light beam with a target wavelength over the waveguiding layer;
• forming a semiconductor layer transparent to the light beam over the second oxide layer, wherein the second oxide layer is underneath the semiconductor layer and adjacent to a surface of the semiconductor layer;
• and
• forming a lens disposed within a silicon portion of the semiconductor layer and adjacent to another surface of the semiconductor layer, wherein the lens comprises a plurality of anti-reflective coating (ARC) layers formed above a curved surface and is configured to receive, from one of the grating coupler or a light-guiding element, the light beam, and focus the light beam towards another one of the light-guiding element or the grating coupler.