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Multispectral image sensor attachable to low-cost microcomputers


Multi-spectral filter array composed of a wavy alternating dielectric multilayer was integrated on a CMOS image sensor of the Raspberry Pi HQ Camera. The filter array consists of 16-channel elementary filters exhibiting pseudo-random transmission characteristics. Each filter covers \(20\times 20\) CMOS pixels. The incoming spectrum is encoded as a set of 16 grayscale intensities and passed to principal component analysis (PCA) to classify the states of the target spectral characteristic. Preliminary demonstration for blood flow state identification in human peripheral revealed proposed device’s potential ability as a real-time monitoring tool in the near infrared.

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We are grateful for Mr. Shinsuke Kurata of Toyama Prefectural University for his effort and assistance in preparing the hyperspectral imaging system. This work has been in part supported by KAKENHI Grant no. 20K04520. EB lithography was carried out in the Micro Systems Integration Center of Tohoku University, Japan.

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Correspondence to Yasuo Ohtera.

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Ohtera, Y., Sato, A., Kawashima, T. et al. Multispectral image sensor attachable to low-cost microcomputers. Opt Rev 29, 140–152 (2022).

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  • Multi-spectral imaging
  • Raspberry Pi
  • Spectral encoding
  • Autocloning