Polarization Snapshot Imaging Spectrometer for Infrared Range

Abstract

Infrared imaging spectrometers detect and identify targets by collecting spectral and image information. However, when detecting small temperature differences and dynamic targets, the accuracy of infrared detection is reduced, the traditional scanning structure detection time is longer, the real-time performance is poor and it is easy to introduce motion artifacts. This paper proposes an infrared polarization snapshot spectral imaging system (PSIFTIS) based on a polarizer array, a lens array and a roof-shaped stepped micromirror. Polarized light can solve the problem of small-temperature-difference target recognition by characterizing the surface properties of materials. Lens arrays utilize multi-aperture imaging to achieve snapshot detection of targets. The system can obtain 4D data information, including polarization, in a single measurement cycle. This study completed the overall optical design of a PSIFTIS and an optical simulation experiment using it. Finally, a system prototype was built in the laboratory and a polarization spectrum detection experiment was carried out. The experimental results show that the PSIFTIS could accurately obtain the polarization spectrum information for the target, the spectral resolution reached 7.8 cm−1 and the Stokes measurement error was less than 5%.

Research on the Processing of Image and Spectral Information in an Infrared Polarization Snapshot Spectral Imaging System

“…The process of obtaining the reconstructed polarization spectrum and the polarization fusion image through the processing of the polarization interference image array data is shown in Figure 3. The process is divided into two processing routes: the first route includes image segmentation, optical path difference matching, and image registration of a polarization interference image array to obtain the polarization interference intensity cube datasets I 0 [x,y,Δ(m,n)], I 45 [x,y,Δ(m,n)], I 90 [x,y,Δ(m,n)], and I 135 [x,y,Δ(m,n)], in polarization directions of 0°, 45°, 90°, and 135°, where (x,y) represents the spatial coordinate axis, Δ represents the optical path difference axis, m and n are the step orders of the high-and low-step micro-mirrors, (m,n) is the position coordinates of the corresponding phase modulation unit, and Δ(m,n) represents the modulated optical path difference generated by the phase modulation unit [18,19]. The interference intensity corresponding to the polarization direction is:…”

“…With the array center as the zero point, the optical path difference increases in the horizontal and vertical directions. After addressing baseline correction and apodization, the polarization interference intensity data cube set I θ [x,y,Δ(m,n)] is subjected to two-dimensional discrete Fourier transform , 90 • , and 135 • , where (x,y) represents the spatial coordinate axis, ∆ represents the optical path difference axis, m and n are the step orders of the high-and low-step micromirrors, (m,n) is the position coordinates of the corresponding phase modulation unit, and ∆(m,n) represents the modulated optical path difference generated by the phase modulation unit [18,19]. The interference intensity corresponding to the polarization direction is:…”

Stray Light Analysis and Suppression for an Infrared Fourier Imaging Spectrometer

“…At present, in modern aviation-based high-tech warfare, methods to enable the rapid identification of camouflage and false targets have become an important research field and a major application direction for military reconnaissance [1,2]. With the increasing demand for the application of imaging spectrometers in a variety of fields, the development of the Fourier transform imaging spectrometer [3][4][5][6] has also become a research hot spot. The fundamental task of the Fourier transform imaging spectrometer is to detect and acquire the image signal and the spectral function of a specific target [7,8].…”

Analysis of Two-Color Infrared Polarization Imaging Characteristics for Target Detection and Recognition

“…Infrared polarization imaging technology combines the advantages of infrared imaging and polarization imaging, utilizing not only the intensity information from target scene radiation and reflection but also the polarization information from target scene radiation and reflection. This technology enhances the detection and identification capabilities of imaging systems in complex backgrounds and holds great potential for further development [5][6][7][8][9][10][11][12].…”