title: Near-infrared imaging of liquid mixtures utilizing multi-channel photonic crystal wavelength filters.
abstract: We demonstrate a near-infrared (NIR) spectroscopy-based real-time imaging system of aqueous alcohol solutions (ethanol containing water). The system obtains a set of NIR images by the combination of an InGaAs area sensor and four-channel patterned photonic crystal wavelength filters. Acquired pictures were decomposed into a set of NIR images and processed by principal component analysis (PCA). According to a preliminary experiment for water/ethanol mixture samples, we confirmed that the system was capable of identifying the mixture ratio with accuracy of the order of a few percentage points at a frame rate of approximately 24 frames per second (fps).
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mitsuhashi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohtera
authors.forename: Hirohito
authors.initials: H
authors.lastname: Yamada