Almeida, D.; Lourenco, P.; Fantoni, A.; Costa, J.; Vieira, M. Grating Coupler Design for Low-Cost Fabrication in Amorphous Silicon Photonic Integrated Circuits. Preprints2024, 2024070689. https://doi.org/10.20944/preprints202407.0689.v1
APA Style
Almeida, D., Lourenco, P., Fantoni, A., Costa, J., & Vieira, M. (2024). Grating Coupler Design for Low-Cost Fabrication in Amorphous Silicon Photonic Integrated Circuits. Preprints. https://doi.org/10.20944/preprints202407.0689.v1
Chicago/Turabian Style
Almeida, D., João Costa and Manuela Vieira. 2024 "Grating Coupler Design for Low-Cost Fabrication in Amorphous Silicon Photonic Integrated Circuits" Preprints. https://doi.org/10.20944/preprints202407.0689.v1
Abstract
Photonic circuits find applications in biomedicine, manufacturing, quantum computing and communications. Photonic waveguides are crucial components, typically having cross-sections orders of magnitude inferior compared with other photonic components (e. g. optical fibers, light sources and photodetectors). Several light coupling methods exist, consisting of either on-plane (e. g. adiabatic and end-fire coupling) or off-plane methods (e. g. grating and vertical couplers). The grating coupler is a versatile light transference technique which can be tested at wafer level, not requiring specific fiber terminations or additional optical components, like lenses, polarizers or prisms. This study focuses on fully-etched grating couplers without bottom reflector, made from hydrogenated amorphous silicon (a-Si:H), deposited over a silica substrate. Different coupler designs were tested, of these we highlight two: superimposition of two lithographic masks with different periods and an offset between them to create a random distribution and a technique based on the quadratic refractive index variation along the device’s length. Results were obtained by 2D-FDTD simulation. The designed grating couplers achieve coupling efficiencies for the TE-like mode over -8 dB (mask overlap) and -3 dB (quadratic variation), at a wavelength of 1550 nm. The coupling scheme considers a 220 nm a-Si:H waveguide and an SMF-28 optical fiber.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
