Neuromorphic Biophotonic Sensor Based on Near Infrared Optical Reflectometry

A biophotonic image sensor has been demonstrated by depositing a thin Au (gold) film on the single optical fiber by sputtering process to incorporate a self-contained reference plane, as well as to be sustainable for different contact interfacial medium. This side-viewing optical probe has been polished for 43°-49° angle in order to unilaterally reflect the beam to be focused with a micro dome-shape lens simply formed by high-energy melting process at the distal end of the standard single-mode fiber. The all fiber interferometric optics using a low (partial) coherence double-sided autocorrelator performing as a high-precision optical reflectometer at 1300 nm range noninvasively conducted a direct profiling of the depth information inside a biological tissue and for diagnosing brain tumors, as well as imaging subsurface depth profile for other turbid organic/inorganic samples. The optical probing imager, which normally operates in low power of 3 mW-7 mW has ~35 dB signal-to-noise ratio (SNR) and a ~15 μm axial resolution (3-dB width of the reflected peak curve).