Broadband grating coupler
AssigneeVTEC Lasers & Sensors Ltd
InventorsKrishnaKant Rana, Jan Mink
Life of this patent
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Abstract
One illustrative device disclosed herein includes a waveguide structure positioned at the left and right portion of the structure, mirror, and buffer layer. In this example, the device also includes an apodized grating structure wherein the grating structure comprises a plurality of grating elements whose pitch changes along the length of the grating, which is able to couple in multiple wavelength and diffract out a broadband spectrum depending on the positioning of the source.
Claims20
A broadband grating coupler apparatus comprising:
- an input coupling comprising an input waveguide layer, the input coupling configured to receive a broadband signal source;
- an input grating structure on the input coupling;
- an output coupling comprising an output waveguide layer, the output coupling configured to output discrete wavelengths;
- and
- an output grating structure on the output coupling,
- wherein at least one of the input grating structure and the output grating structure is an apodized grating structure, the apodized grating structure comprising a plurality of grating elements whose pitch changes along a length of the at least one input grating structure and output grating structure.
A method comprising:
- receiving a broadband signal source, by a broadband grating coupler,
- the broadband grating coupler comprising:
- an input coupling comprising an input waveguide layer, the input coupling configured to receive the broadband signal source;
- an input grating structure on the input coupling;
- an output coupling comprising an output waveguide layer, the output coupling configured to output discrete wavelengths;
- and
- an output grating structure on the output coupling,
- wherein at least one of the input grating structure and the output grating structure is an apodized grating structure, the apodized grating structure comprising a plurality of grating elements whose pitch changes along a length of the at least one input grating structure and output grating structure;
- diffracting the broadband signal source through the input grating structure resulting in an emitted beam;
- projecting the emitted beam on a reflection target, wherein the reflection target is above the input coupling and the output coupling;
- receiving, by the output grating structure, a reflected beam from the reflection target, resulting in an output signal;
- guiding the output signal through the output waveguide layer of the output coupling;
- and
- emitting the output signal from the output coupling.
A method of manufacturing an apodized grating coupler, comprising:
- depositing an insulator layer above a substrate layer through plasma-enhanced chemical vapor deposition (PECVD);
- depositing a metal in a reflector layer;
- stacking the reflective layer above the insulator layer;
- depositing silicon nitride above the reflector layer, using low-pressure chemical vapor deposition (LPCVD), to form a waveguide layer;
- spin-coating a negative photoresist above the waveguide layer;
- patterning the spin-coated negative photoresist using E-beam lithography;
- and
- etching a grating pattern into a top of the waveguide layer to form an apodized grating structure on the apodized grating coupler.
Dependencies are inferred from the claim text.