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This study proposes a polychromatic interferometric illumination and polarimetric sensor-based imaging method for spectrum, polarization, and 3D shape, which are significant physical parameters of feature analysis for target detection. 5D-fusion sensing refers to the joint detection and fusion of the above 5D information, which is currently a great challenge. The method generates a polychromatic interference pattern using a Sagnac lateral shearing interferometer and projects it to the target. Then, interferograms modulated by the target are acquired during scanning. Fast Fourier transform (FFT) is performed on the interferograms to obtain their frequency spectra. The spectral and polarization information is extracted from the moduli of the frequency spectra. The 3D shape is recovered from the phase of the frequency spectra using the calibration data. The theory of 5D-fusion sensing is investigated, and verification experiments are then performed. The experiments indicate that the proposed method can fulfill 5D-fusion sensing in one scanning and with FFT using only one device compared with other separate methods. Consequently, the proposed method can improve the sensing and recognition ability of optical imaging technology, which provides great application potential in biomedicine, food safety, material analysis, criminal investigation, archeology, and other fields.

A new Fourier transform imaging spectrometer based on a focal plane birefringent interferometer (FPBI) is presented. The FPBI, located in front of the detector, is capable of performing spectral imaging measurements. It mainly consists of a birefringent plate and a birefringent wedge. The ordinary and extraordinary rays—with an optical path difference—are split by the FPBI and interfere on the focal plane. The spectral image of the target can be acquired via scene scanning and spectral recovery. The principle of interferometric imaging of the FPBI is investigated, and verification experiments are then performed. The experiments indicate that the FPBI not only provides effective spectral imaging measurements, but also presents the advantages of being ultra-compact and lightweight. As a result, it can be effectively applied in situations such as outdoor surveillance and airborne remote sensing.