A 16-site neural probe integrated with a waveguide for optical stimulation

In this paper, we report a neural probe which can selectively stimulate target neurons optically from an integrated optical waveguide and also monitor extracellular neural signals in electrical recording sites. The waveguide is composed of SU-8 core and oxide cladding layer to guide a light from optical source. A U-groove has been formed at the end of the waveguide for easy alignment with an optical fiber. The coupling loss between the optical fiber and waveguide has been measured below -3.7 dB with a waveguide loss of -0.22 dB/mm. We have successfully transmitted a light of 470nm in wavelength through the integrated polymer waveguide on the neural probe.