Description
Integrated photonic technologies provide a scalable route towards high-density neural interfaces capable of delivering engineered light fields for neuron stimulation. Compared with conventional fibre-based and LED-based approaches, integrated photonic circuits offer compact form factors, improved optical routing, reduced power consumption, and the ability to address large arrays of independently controlled stimulation sites using standard semiconductor fabrication techniques. These advantages position silicon photonics as a promising platform for next-generation implantable and in vitro neurophotonic systems.
Here we present the design, fabrication, packaging, and experimental validation of an integrated silicon nitride (SiN) photonic platform for optical stimulation of living, transfected neurons. Central to the platform are inverse-designed grating couplers engineered for broadband operation, polarization insensitivity, and beam profiles tailored for single neuron excitation. These designs were realized using a GPU-accelerated gradient-based topology optimization framework that mitigates the computational bottleneck of full 3D FDTD simulations.
The fabricated photonic chips integrate low-loss SiN waveguides with individually addressable stimulation sites and were packaged for compatibility with widefield fluorescence microscopy and live-cell experiments. Device performance was validated through optical characterization and biological experiments in protein-functionalized neuronal cultures, confirming localized optical excitation and efficient light delivery from individual inverse-designed couplers
These results demonstrate that inverse-designed integrated photonics can provide highly efficient, scalable, and manufacturable optical neural interfaces. The presented architecture establishes a foundation for high-density photonic stimulation arrays and highlights the potential of integrated silicon nitride photonics for neurotechnology, biomedical sensing, and future chip-scale optical interfaces with living tissue.
| I am the presenting author | Yes |
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