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Updated: Sep 16, 2026

Multi-Fiber Photometry to Record Neural Activity in Freely-Moving Animals
Published on: October 20, 2019
M3-RGB: An Imaging Sensor System Using Multicore, Multimode Optical Fiber and Neural Networks
Seigo Ito1, Isamu Takai1, Akari Kawasaki1
1Toyota Central R&D Labs., Inc., 41-1, Yokomichi, Nagakute 480-1192, Aichi, Japan.
Abstract:
Conventional image acquisition requires an electrically powered image sensor to be placed directly behind the camera lens, constraining camera placement. To overcome this issue, we introduce M3-RGB as an incoherent-light fiber imaging system in which a multicore, multimode optical fiber passively relays lens images to a remotely located image sensor. Unlike conventional approaches, M3-RGB is designed to operate directly on incoherent light and requires no electrical power or active components at the sensing interface. Because propagation through the fiber yields spatially scrambled patterns, a neural network is used to reconstruct the original scene by exploiting the spatial locality preserved by the multicore structure. In a controlled optical bench setup, where a liquid crystal display monitor displays road-scene images, we construct a paired dataset of scrambled and ground-truth images and quantitatively evaluate reconstruction performance across different fiber core counts, fiber lengths, and calibration settings, utilizing the peak signal-to-noise ratio and structural similarity index measure as performance metrics. By decoupling imaging electronics from the sensing point, this passive remote image relay approach may expand sensor placement options for potential applications such as all-around perception for mobile robots and autonomous vehicles, surveillance, and inspection in confined spaces. Evaluations in real outdoor environments constitute future work.
