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Spectral imaging is an imaging technique that introduces spectral filters in the imaging link to simultaneously obtain target spectral and spatial information. Among the spectral filters, liquid-crystal (LC) filters exhibit technical advantages of fast response speed, low power consumption, and large aperture. As a highly efficient electrically tunable microcavity interference filter structure, the miniaturized liquid-crystal Fabry-Pérot (LC-FP) is generally composed of a LC layer sandwiched by two highly reflective mirrors. By adjusting the applied voltage signals, the high spectral resolution spectrum selection and adjustment of transmitted beam is implemented. Generally, the birefringence difference of the LC material used determines the phase modulation capability, which in turn affects the device performance. In this paper, an electrically tunable LC-FP filter (ET LC-FP) with high-birefringence nematic LC mixture is proposed. The deviced ET LC-FP is constructed using a kind of high-birefringence nematic LC mixture (HB-45800) for achieving the typical electrically selecting and adjusting and jumping of spectral lightbeam outfrom the ET LC-FP filter. The electro-optical parameters of HB-45800 are: Δn = 0.385 at 589.3nm, the clear point is 95.1℃. The transmission spectral characteristics (1.5~15μm) of the ET LC-FP device were analyzed using a Fourier transform infrared spectrometer. Experiments demonstrate that an electrically tunable spectral resolution of better than 5nm is reached in the infrared domain of 1.5~3μm.
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