Graduate Student, Columbia University/Cornell University
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Abstract
Reconfigurable Visible Nanophotonics Platform for High Resolution In Vivo Optogenetics

Optogenetics has revolutionized the study of neural function and connectivity by using light to control the activation and inhibition of neural activity with millisecond precision. Conventionally, to overcome the light scattering within the brain, a single fiber is used to flood light into a large area with limited resolution. High spatial and temporal resolution deep-brain optical excitation would enable activation of specific neural populations and lead to more comprehensive studies of neural circuits that are currently not possible. The scalability and versatility of integrated nanophotonics could enable neural excitation over large areas with single-cell resolution on an implantable probe. However, active control of these optical circuits has yet to be demonstrated for visible wavelengths, including those specific to optogenetic excitation (400 – 600 nm). Here we demonstrate an active nanophotonics platform based on integrated microheaters for neural excitation, enabling control of multiple beams for deep-brain neural stimulation. We generate precise and repeatable complex spatiotemporal neural spike patterns in vivo with single-neuron resolution using a fully packaged device inserted into the mouse brain. The directly activated neurons show robust spike firing activities with low first-spike latency and small jitter. Active switching on a nanophotonic platform provides the reconfiguration capabilities necessary for highly-multiplexed optical circuits that could enable high-resolution optogenetics for deep brain regions.

Bio
Aseema Mohanty is a Ph.D. student in Professor Michal Lipson’s group at Columbia University (formerly at Cornell University) in the Electrical Engineering Department. She completed her Bachelor’s degree in the department of Electrical Engineering and Computer Science at Massachusetts Institute of Technology (MIT). Her undergraduate research focused on optoelectronic devices including organic photovoltaics and thermophotovoltaics for renewable energy applications. Her graduate research has focused on expanding the capabilities of the nanophotonic platform for visible wavelength applications including quantum information systems and optical neural interfaces. More specifically, she has been working on using integrated mode-division multiplexing techniques in the quantum regime and creating an active reconfigurable switching network for high spatio-temporal resolution optogenetic excitation.