A vertical micro-scale light guiding silicon dioxide tube array for optical neurostimulator

In this paper, we present out-of-plane micro-scale diameter light guiding silicon dioxide tube arrays for use in optical stimulation of neurons. An optical propagation through the dioxide tube was calculated by using finite-difference time-domain (FDTD) simulation. Based on the calculated result, we designed and fabricated 3-μm-inner diameter 24-μm-height silicon dioxide tube arrays with the wall thickness of 0.5 μm, using selective vapor-liquid-solid (VLS) growth of silicon microwire, followed by microfabricating processes. The optical transmission capability of the fabricated tube was experimentally confirmed by using light of 470 nm, 525 nm, and 595 nm in wavelength.