Static full-Stokes Fourier transform imaging spectropolarimeter capturing spectral, polarization, and spatial characteristics

Abstract

A static full-Stokes Fourier transform imaging spectropolarimeter incorporating a liquid-crystal polarization modulator (LPM) and birefringent shearing interferometer (BSI) is reported. It can decode the polarization information at each wavelength along the spatial dimension of a two-dimensional data array. The LPM has a high-speed time-division architecture and employs two ferroelectric liquid crystals and two wave plates to produce four polarization states, providing full-Stokes polarimetric information with a high signal-to-noise ratio. The BSI comprises two birefringent crystal plates and generates an optical path difference with good linear distribution for broadband interference, allowing a fast and high-precision spectral recovery. The optimized design of LPM and BSI are introduced in detail. Subsequently, the signal reconstruction is verified through simulations and experiments. The proposed scheme is highly efficient, exhibits a higher spectral resolution, and constitutes a compact technical approach to realize high-dimensional optical measurement.

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

“…According to the spectral decoupling method mentioned above, the polarization interference intensity data cube of the target's four polarization directions, I θ [x,y,Δ(m,n)], can be obtained. The polarization interference intensity sequences corresponding to the characteristic pixel point (10,6) of the polarization interference image unit selected at the central wavelength of 3970 nm are shown in Figure 10. In order to solve the problem of wavenumber drift of a spectral line caused by tilting and pitching errors generated during the processing and adjustment of a multi-stage micromirror, wavenumber calibration experiments were conducted.…”

“…In 2021, a static full-Stokes Fourier transform infrared spectrometer was proposed and built by the Shandong University of Technology, which includes a liquid crystal polarization modulator and a birefringent shear interferometer as the core devices. The 4D data cube containing spatial, spectral, and polarization information can be obtained synchronously, and the optical path difference and full-Stokes polarization information with good linear distribution can be obtained with a high signal-to-noise ratio [10]. Image and spectral information processing is one of the key technologies in the development of spectral imaging systems.…”

High Light Efficiency Spectral Polarization Imaging Method Based on Mach–Zehnder Structured Liquid Crystal Tunable Filters and Variable Retarders

“…However, the optical throughput of this type of SPI is limited by the structure of the slit. A static full-Stokes Fourier transform imaging spectropolarimeter incorporating a liquid crystal polarization modulator (LPM) and birefringent shearing interferometer (BSI) was designed by Bai et al [17], which is able to provide high SNR image data. Fourier transform SPI with no slits and moving parts brings the advantages of a high optical throughput and easy alignment, but using the scanning method takes a long acquisition time to detect 4D hyperspectral polarized image information.…”