| Popis: |
A mid-infrared spectroscopic imager needs to be portable and tough for the identification of dyestuffs used for murals in ancient tombs during archaeological on-site analysis. Meanwhile, an extremely compact and tough hyperspectral camera with mass less than 2 kg is required for mounting on drones to observe nutritive components like nitrogen and phosphorus. We proposed a near-common-path wavefront-division phase-shift interferometer as an imaging-type twodimensional Fourier spectrometer. Because the proposed interferometer has strong robustness against mechanical vibrations, a palm-sized Fourier spectroscopic imager can be realized without an anti-mechanical vibration system. We developed a palm-sized (80-mm cube weighing 0.5 kg) and tough hyperspectral camera for mid-infrared light (wavelength of 8–14 μm) that can be operated using only a notebook personal computer. Furthermore, the field of view of a conventional hyperspectral camera is narrow (e.g., 6.4 deg × 5.1 deg). However, employing a proposed field angle correlation method and using a fisheye lens as the objective lens, the field of view can be expanded to 180 deg. The total price of the mid-infrared two-dimensional spectroscopic imager is no more than several thousand USD because a lowprice microbolometer (Vision Sensing, VIM-80G2, wavelength range: 8-14 μm, 80 × 80 pixels, price: 300 USD) is used. Additionally, a long-stroke (10 mm) and high-resolution (Optical encoder resolution: 100 nm) impact-drive actuator (Technohands XCWT70-10 weighing 30 g) is introduced as a low-price (1000 USD) and tough phase-shift stage with cross-roller linear-motion guides. |
