Chen Fu-Der, Sharma Ankita, Xue Tianyuan, Jung Youngho, Govdeli Alperen, Mak Jason C C, Chameh Homeira Moradi, Movahed Mandana, Brunk Michael G K, Luo Xianshu, Chua Hongyao, Lo Patrick Guo-Qiang, Valiante Taufik A, Sacher Wesley D, Poon Joyce K S
Max Planck Institute of Microstructure Physics, Halle, Germany.
Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada.
Commun Eng. 2024 Dec 18;3(1):182. doi: 10.1038/s44172-024-00328-8.
In brain activity mapping with optogenetics, patterned illumination is crucial for targeted neural stimulation. However, due to optical scattering in brain tissue, light-emitting implants are needed to bring patterned illumination to deep brain regions. A promising solution is silicon neural probes with integrated nanophotonic circuits that form tailored beam patterns without lenses. Here we propose neural probes with grating-based light emitters that generate a single steerable beam. The light emitters, optimized for blue or amber light, combine end-fire optical phased arrays with slab gratings to suppress higher-order sidelobes. In vivo experiments in mice demonstrated that the optical phased array provided sufficient power for optogenetic stimulation. While beam steering performance in tissue reveals challenges, including beam broadening from scattering and the need for a wider steering range, this proof-of-concept demonstration illustrates the design principles for realizing compact optical phased arrays capable of continuous single-beam scanning, laying the groundwork for advancing optical phased arrays toward targeted optogenetic stimulation.
在利用光遗传学进行脑活动图谱绘制时，图案化照明对于靶向神经刺激至关重要。然而，由于脑组织中的光散射，需要发光植入物将图案化照明传递到脑深部区域。一种有前景的解决方案是具有集成纳米光子电路的硅神经探针，其无需透镜即可形成定制光束图案。在此，我们提出了带有基于光栅的发光器的神经探针，该发光器可产生单个可控光束。这些针对蓝光或琥珀光进行优化的发光器，将端射光学相控阵与平板光栅相结合，以抑制高阶旁瓣。在小鼠体内进行的实验表明，光学相控阵为光遗传学刺激提供了足够的功率。虽然组织中的光束转向性能显示出一些挑战，包括散射导致的光束展宽以及对更宽转向范围的需求，但这一概念验证演示阐明了实现能够连续单光束扫描的紧凑型光学相控阵的设计原则，为将光学相控阵推进到靶向光遗传学刺激奠定了基础。
