Jun Chen

In this paper, a high-throughput anti-phase snapshot imaging polarimeter (ASIP) based on polarization gratings is proposed, which can be classified into a linear polarimeter and a full-Stokes polarimeter according to the number of detectable polarization parameters. The two configurations differ only in the addition of an extra polarization grating pair and a quarter-wave plate. The ASIP utilizes polarization grating pairs to perform light beam shearing and polarization state modulation. Subsequently, a polarizing beam splitter splits the modulated beams into s-polarized and p-polarized light, and the two polarized light components are then detected separately by two detectors to acquire anti-phase interference images. Simple addition and subtraction operations on the data received by the two detectors enable the acquisition of full-resolution S ₀ and interference images of the remaining Stokes parameters, which are free from DC component interference. Meanwhile, the proposed ASIP eliminates the use of linear polarizers, which effectively improves the system throughput and the signal-to-noise ratio of frequency-domain channels, thereby significantly enhancing the demodulation accuracy of the measured Stokes parameters. In this paper, the theoretical models of the two ASIP configurations are derived in detail, simulation analyses are performed, and specific parameter designs are provided.

This paper presents a multi-grating-based cross-dispersed spatial heterodyne spectrometer (MGCDSHS). The principle of generation of two-dimensional interferograms for two cases, where the light beam is diffracted by one sub-grating or two sub-gratings, is given and equations for the interferogram parameters in these two cases are derived. An instrument design with numerical simulations is presented that demonstrates the spectrometer’s ability to simultaneously record separate interferograms corresponding to different spectral features with high resolution over a broad spectral range. The design solves the mutual interference problem caused by overlapping of the interferograms, and also provides the high spectral resolution and broad spectral measurement range that cannot be achieved using conventional SHSs. Additionally, by introducing cylindrical lens groups, the MGCDSHS solves the throughput loss and light intensity reduction problems caused by direct use of multi-gratings. The MGCDSHS is compact, highly stable, and high-throughput. These advantages make the MGCDSHS suitable for high-sensitivity, high-resolution, and broadband spectral measurements.

A Stokes white-light channeled imaging polarimeter using Savart plates and a polarization Sagnac interferometer (IPSPPSI) is presented, which provides an effective solution to the problem of channel aliasing in broadband polarimeters. The expression for the light intensity distribution and a method to reconstruct polarization information are derived, and an example design for an IPSPPSI is given. The results reveal that a complete measurement of the Stokes parameters in broad band can be achieved with a snapshot on a single detector. The use of dispersive elements like gratings suppresses broadband carrier frequency dispersion so the channels in the frequency domain do not affect each other, ensuring the integrity of information coupled across the channels. Furthermore, the IPSPPSI has a compact structure and does not employ moving parts or require image registration. It shows great application potential in remote sensing, biological detection, and other fields.