Data processing and performance evaluation of a tempo-spatially mixed modulation imaging Fourier transform spectrometer based on stepped micro-mirror

Abstract

A novel tempo-spatially mixed modulation imaging Fourier transform spectrometer based on a stepped micro-mirror has the advantages of high throughput, compactness, and stability. In this paper, we present a method of image- and spectrum-processing and performance evaluation, which is utilized to obtain a high-quality reconstructed image without stitching gaps and a reconstructed spectrum with significantly reduced noise and side-lobe oscillation. A theoretical model of instrument line shape and signal-to-noise ratio is established to verify the effectiveness of non-uniformity sampling correction and spectral resolution enhancement. Meanwhile, the performance of the instrument was evaluated combined with experimental results.

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:…”

Polarization Snapshot Imaging Spectrometer for Infrared Range

“…Finally, the image on the roof-shaped stepped micromirror enters the rear imaging system through the beam splitter and is finally imaged on the detector. From this, we can obtain the polarization interference image array for the target object and the three-dimensional polarization interference intensity datasets I 0 (x,y,∆(m,n)), I 45 (x,y,∆(m,n)), I 90 (x,y,∆(m,n)) and I 135 (x,y,∆(m,n)) for the four polarization directions of the target by segmenting and registering the polarization interference image array [19,20]. ∆(m,n) is the optical path difference modulated by the phase modulation unit (m,n): ∆(m,n) = 2(Nn−m)d. Here, m and n are the position coordinates of the corresponding phase modulation unit, taking the center of the whole modulation unit as the zero point and increasing accordingly in the horizontal and vertical directions.…”

Chemical Gas Telemetry System Based on Multispectral Infrared Imaging

“…Infrared imaging gas detection technology has developed quickly due to its advantages of high detection efficiency, long detection distance, dynamic and intuitive images, and quick discovery of leakage sources [ 5 , 6 , 7 , 8 , 9 , 10 ]. Hyperspectral infrared imaging gas detection can accurately identify the type of a gas, and has the ability to detect the composition of a mixed gas [ 11 , 12 , 13 , 14 , 15 ]. However, hyperspectral infrared imaging gas detection systems are complex and require huge amounts of data processing.…”