Detection Of Polarization Research Articles

Polarization detection in miniature

Polarization detection in miniature

Polarization‐Sensitive Momentum‐Matching Interlayer Excitons for Infrared Photodetection

Abstract2D materials hold potential for developing low‐cost, high‐performance broadband polarized infrared photodetectors. However, the development of 2D broadband polarized infrared photodetectors is largely constrained by the fixed bandgap spectral (cutoff wavelength) limitations of available semiconductors. Here, an approach is presented that leverages anisotropic interlayer excitons (IEXs) within a type‐II van der Waals heterojunction, achieving polarization photoresponse beyond the intrinsic bandgap spectral limits of its constituent semiconductors. By constructing heterojunctions using CrPS4 and ReS2, a unique type‐II band alignment, enabling strong anisotropic optical excitation is achieved through the interlayer sub‐bandgap, which is lower than the intrinsic bandgaps of both CrPS4 and ReS2. The heterojunction exhibits a responsivity of 0.3 A W−1 and a polarization ratio of 1.3 at an incident photon energy of 0.8 eV, comparable to naturally anisotropic materials with intrinsic bandgaps. Additionally, the potential of anisotropic IEXs is demonstrated for dual‐band polarization detection by introducing a ReS2/CrPS4/MoS2 heterojunctions with distinct inte rlayer sub‐bandgaps. This flexible design of IEXs offers a new platform for multi‐dimensional optical sensing and on‐chip optoelectronic applications.

Image Dehazing Enhancement Strategy Based on Polarization Detection of Space Targets

In view of the fact that the technology of polarization detection performs better at identifying targets through clouds and fog, the recognition ability of the space target detection system under haze conditions will be improved by applying the technology. However, due to the low ambient brightness and limited target radiation information during space target detection, the polarization information of space target is seriously lost, and the advantages of polarization detection technology in identifying targets through clouds and fog cannot be effectively exerted under the condition of haze detection. In order to solve the above problem, a dehazing enhancement strategy specifically applied to polarization images of space targets is proposed. Firstly, a hybrid multi-channel interpolation method based on regional correlation analysis is proposed to improve the calculation accuracy of polarization information during preprocessing. Secondly, an image processing method based on full polarization information inversion is proposed to obtain the degree of polarization of the image after inversion and the intensity of the image after dehazing. Finally, the image fusion method based on discrete cosine transform is used to obtain the dehazing polarization fusion enhancement image. The effectiveness of the proposed image processing strategy is verified by carrying out simulated and real space target detection experiments. Compared with other methods, by using the proposed image processing strategy, the quality of the polarization images of space targets obtained under the haze condition is significantly improved. Our research results have important practical implications for promoting the wide application of polarization detection technology in the field of space target detection.

2D Multifunctional Phototransistor Based on MoTe2/Graphene/SnS0.25Se0.75 Heterostructure with High Photogain and Reconfigurable Polarized Detection

Abstract2D van der Waals (vdWs) heterojunctions exhibit facile fabrication process and tunable optoelectronic properties. However, suppressing interfacial charge traps and multifunctional photoresponse remain significant challenges. Here, the study designs a 2D multifunctional phototransistor based on ambipolar MoTe2/graphene (Gr)/p‐type SnS0.25Se0.75 double vdWs vertical heterostructure via alloy engineering. The middle Gr interlayer is pivotal in reducing interfacial charge traps, facilitating vertical photocarrier transportation, and enhancing light absorption coefficient. Under photogating effect, the trapped electrons in SnS0.25Se0.75 promote the photogating effect, resulting in the maximum photogain of 8084 and specific detectivity (D*) of 8.2 × 1012 Jones. Under photoconductive effect, a high responsivity (R) of 36.9 A W−1 and D* of 7.17 × 1011 Jones are achieved. Under photovoltaic effect, the devices exhibit a remarkable R of 501 mA W−1, D* of 1.4 × 1011 Jones. Notably, a self‐driven photocurrent polarized ratio of 8 under 635 nm is achieved because of the anisotropic nature of SnS0.25Se0.75 and the effective double built‐in electric fields. By varying the gate voltage, the polarization ratio can be modulated from 1 to 2.5, enabling reconfigurable polarized‐sensitive detection. Above all, the designed heterojunction with multifunctional and reconfigurable polarization detection.

The First Detection of X-Ray Polarization in a Newly Discovered Galactic Transient Swift J151857.0-572147

We study the spectropolarimetric properties of a newly discovered black hole (BH) X-ray binary Swift J151857.0-572147 jointly using Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR observations during 2024 March. The analysis of IXPE data reports the first detection of X-ray with a polarization degree (PD) of 1.34 ± 0.27 and a polarization angle (PA) of −13.°69 ± 5.°85 using a model-independent approach, while the model-dependent analysis gives a PD of 1.18 ± 0.23 and a PA of −14.°01 ± 5.°80. The joint spectral analysis of the broadband data and NuSTAR analysis in isolation constrain the mass of the central BH between ∼9.2 ± 1.6 and 10.1 ± 1.7M ⊙ and a moderate spin parameter of ∼0.6 ± 0.1–0.7 ± 0.2 with a disk inclination of ∼35° ± 7°–46° ± 15°. The power-law photon index and cutoff energy are 2.19 ± 0.03–2.47 ± 0.06 and ∼36 ± 4–78 ± 10 keV, suggesting a transition to the soft spectral state. Additionally, a relatively lower corona size of 6 ± 1–9 ± 2r S , a low mass outflow rate ( <3%ṀEdd ), and the best-fitted halo accretion is less compared to the disk accretion rate further confirm the same state. The low PD detected in the soft state can be due to repeated scattering inside the dense corona, and the dominant emission from the disk agrees with the low spin and low disk inclination. The hydrogen column density obtained from the fit is relatively high at ∼4–5 × 1022 cm−2.

Probing the polarized emission from SMC X-1: The brightest X-ray pulsar observed by IXPE

Recent observations of X-ray pulsars (XRPs) performed by the Imaging X-ray Polarimetry Explorer (IXPE) have made it possible to investigate the intricate details of these objects in a new way, thanks to the added value of X-ray polarimetry. Here we present the results of the IXPE observations of SMC X-1, a member of the small group of XRPs displaying super-orbital variability. SMC X-1 was observed by IXPE three separate times during the high state of its super-orbital period. The observed luminosity in the 2–8 keV energy band of L ∼ 2 × 1038 erg s−1 makes SMC X-1 the brightest XRP ever observed by IXPE. We detect significant polarization in all three observations, with values of the phase-averaged polarization degree (PD) and polarization angle (PA) of 3.2 ± 0.8% and 97° ±8° for Observation 1, 3.0 ± 0.9% and 90° ±8° for Observation 2, and 5.5 ± 1.1% and 80° ±6° for Observation 3, for the spectro-polarimetric analysis. The observed PD shows an increase over time with decreasing luminosity, while the PA decreases in decrements of ∼10°. The phase-resolved spectro-polarimetric analysis reveals significant detection of polarization in three out of seven phase bins, with the PD ranging between ∼2% and ∼10%, and a corresponding range in the PA from ∼70° to ∼100°. The pulse-phase resolved PD displays an apparent anti-correlation with the flux. Using the rotating vector model, we obtain constraints on the pulsar’s geometrical properties for the individual observations. The position angle of the pulsar displays an evolution over time supporting the idea that we observe changes related to different super-orbital phases. Scattering in the wind of the precessing accretion disk may be responsible for the behavior of the polarimetric properties observed during the high-state of SMC X-1’s super-orbital period.

Van der Waals GeSe with Strain- and Gate-Tunable Linear Dichroism for Wearable Electronics.

The direct detection of light polarization poses a crucial challenge in the field of optoelectronics and photonics. Herein, the tunable linear dichroism (LD) in GeSe-based polarized photodetectors is presented through electronic and structural asymmetry modulation, and demonstrate their application prospects in wearable electronics. An improvement in the dichroic ratio up to 34% is achieved under a gate voltage of 20V, and the improvement reaches 44% by applying a tensile strain along the zigzag direction. Theoretical calculations reveal that the gate regulation of barrier height between GeSe and Au electrodes is responsible for the electrical-tunable LD, while the anisotropic optical absorption in response to strains leads to the strain-tunable LD. Moreover, flexible GeSe transistors are developed for wearable applications including motion sensors and glucose monitors. This study offers viable approaches for modulating the optical anisotropy of low-dimensional materials and emphasizes the versatility of van der Waals materials for practical applications in wearable electronic devices.

A Novel Near-Infrared Tricyanofuran-Based Fluorophore Probe for Polarity Detection and LD Imaging.

In this paper, LD-TCF, a targeting probe for lipid droplets (LDs) with a near-infrared emission wavelength and large Stokes shift, was fabricated for polarity detection by assembling a donor-π-acceptor (D-π-A) molecule with typical twisted intramolecular charge transfer (TICT) characteristics. Surprisingly, the fluorescence emission wavelength of the newly constructed probe LD-TCF was stretched to 703 nm, and the Stokes shift was amplified to 126 nm. Furthermore, LD-TCF could specifically answer the change in polarity efficiently and did not experience interference from other biologically active materials. Importantly, LD-TCF exhibited the ability to target lipid droplets, providing valuable insights for the early diagnosis and tracking of pathophysiological processes underlying LD polarity.

PdSe2/2H-MoTe2 Heterojunction Self-Powered Photodetector: Broadband Photodetection and Linear/Circular Polarization Capability.

In this research, we introduce a PdSe2/2H-MoTe2 heterojunction photodetector that exhibits both broadband self-powered photodetection and linear/circular polarization detection capabilities. It has a broad spectral response range (covering 375-2200 nm) and reaches a peak sensitivity at 532 nm, exhibiting a notable responsivity of 7.3 × 103 A/W and a substantial specific detectivity of 8.5 × 1012 Jones. Even in the near-infrared region of 1310 nm, it still has a high responsivity of 20 A/W. The self-powered photodetection capabilities of the PdSe2/2H-MoTe2 heterojunction are equally impressive, covering a broad range from 375 to 1550 nm, with a responsivity of 243 mA/W, a specific detectivity of 6.46 × 1010 Jones, a fill factor of 0.8, and an external quantum efficiency of 56.73%. Finally, simultaneous implementation of linear/circular polarization detection on the PdSe2/2H-MoTe2 heterojunction provides a powerful solution for near-infrared full-Stokes polarization detectors with high integration, miniaturization, and portability.

Infrared dual-band multi-focus full Stokes metalens for polarization detection

Infrared dual-band multi-focus full Stokes metalens for polarization detection

X-ray spectropolarimetric characterization of GX 340+0 in the horizontal branch: A highly inclined source?

We report the first detection of X-ray polarization in the horizontal branch for as obtained by the Imaging X-ray Polarimetry Explorer ( A polarization degree of 4.3&lt;!PCT!&gt;pm 0.4&lt;!PCT!&gt; at a confidence level of 68&lt;!PCT!&gt; is obtained. This value agrees with the previous polarization measurements of Z-sources in the horizontal branch. The spectropolarimetric analysis, performed using a broadband spectral model obtained by and quasi-simultaneous observations, allowed us to constrain the polarization for the soft and hard spectral components that are typical of these sources. The polarization angle for the two components differs by sim This result can be explained by a misalignment of the NS rotation axis with respect to the accretion disk axis. We compared the results with the polarization that is expected in different models. Theoretical expectations for the polarization of the disk and the Comptonization components favor a higher orbital inclination for than 60 as expected for Cyg-like sources. This is in contrast with the results we report for the reflection component based on the broadband spectrum.

Strained van der Waals Metallic Magnet for Photomagnetic Modulation and Spin Photodiode Application

AbstractAll‐optical magnetization reversal provides a low‐power approach for investigating spin state manipulation in 2D magnets. However, the ambient observation of photomagnetic coupling presents significant challenges due to the low Curie temperatures exhibited by most 2D magnets. Herein, a mixed‐dimensional heterostructure comprising a surface‐oxidized Fe3GeTe2 nanosheet with enhanced magnetic properties and individual semiconducting ZnO nanorod is proposed to explore proximity photomagnetic modulation and spin‐enhanced photodetection behaviors. The surface curvature of ZnO nanorod induces pronounced strains for Fe3GeTe2 nanosheet, leading to its anomalous Raman polarization and spin ordering at room temperature. Strain‐activated itinerant spin electrons are immobilized on the O‐2p orbitals of adjacent ZnO, thereby facilitating the optical demagnetization process in Fe3GeTe2 without aid of magnetic field. First‐principles calculations together with in situ characterization experiments further confirm that the primary charge transfer channel involves coupling between Fe3+ and oxygen vacancy defects anchored at heterointerfaces. The rapid establishment of magnetization by illumination in ZnO nanorod contributes to spin‐tunneling‐enhanced photocurrent, device response dynamics, polarization detection and ultraviolet imaging capability. These findings offer valuable insights to optimize the optoelectronic properties of conventional semiconductors and advance complex dimensional spin‐optoelectronic devices.

Polarized spectral bidirectional reflectance distribution function in visible band based on Cauchy’s empirical dispersion equation

The polarized bidirectional reflectance distribution function (pBRDF) can describe the changes between the Stokes vectors of incident and reflected light. The existing model can only describe the spatial distribution of the target’s polarization characteristics at a single wavelength, so further research is needed for the description of the target’s polarized spectral characteristics. In this paper, a modified three-component polarized spectral bidirectional reflectance distribution function (pSBRDF) is proposed, which combines Fresnel equation in the specular reflection component with Cauchy’s empirical dispersion equation, by introducing the wavelength variable and dispersion constants that do not change with wavelength. The degree of the linear polarization (DoLP) of two types of coated fabric samples was measured at three incident angles and 400 to 760 nm wavelength. The error of the model in describing the spectral and the spatial distribution of DoLP are controlled within 0.00743 and 0.0757 respectively, which proves the accuracy of the model. This research provides the model basis for analysis of the target’s polarization characteristics and the theoretical basis for the application of polarization detection.

Customizable Generation of Arbitrary‐Order Polarization Vortices by Spin‐Decoupled Geometric Phases

AbstractDue to nontrivial field topologies, polarization vortices carrying polarization singularities have attracted increasing interest in the fields of optics and photonics. However, the conventional methods for generation of polarization vortcies still suffer from the complexity and the heavy bulk. In this work, taking advantage of spin‐decoupled geometric phase in metasurfaces, a novel method is proposed to generate polarization vortices with customizable topological charges. By tailoring spin‐decoupled geometric phases generated by the metasurface, distinct helical phase profiles can be imparted to left‐ and right‐handed circularly polarized components. Consequently, two scalar vortices with different topological charges can be simultaneously generated in the two orthogonal circular polarization components, leading to the generation of the polarization vortices with the needed topological charges and the diverse morphologies. Both simulation and experimental results well demonstrate the method. Owing to the nondispersive feature of geometric phases, the designed metasurface works well in a wide frequency band. The proposed method contributes a reliable and feasible solution for customizing the generation of polarization vortices, which can be further transposed to other frequencies and applied to information encoding and polarization detection etc.

Polarization-selective dual-band infrared metamaterial perfect absorber

Abstract Metamaterial absorbers have significant effects and great potential for applications in a variety of important sciences and technologies, including infrared imaging, thermal emitters, electromagnetic shielding, and photodetectors. However, conventional absorbers with a single function are difficult to meet the growing demand of devices, especially for the situations where the absorption and polarization are simultaneously required in infrared detection. If the polarization absorption function is realized by integrating absorption and polarization elements, it will lead to a large overall system size and slow response time. To solve this problem, we propose a dual-band polarization-selective metamaterial perfect absorber, whose maximum absorptions at resonant wavelengths of λ1=2.824μm and λ2=7.622μm are 99.99% and 99.88%, respectively. The absorber exhibits strong polarization sensitivity, absorbing TM-polarized incident light and reflecting TE-polarized incident light at the two resonant wavelengths. The extinction ratios of the absorber at the two referred resonant wavelengths are 90.9 and 142.7, respectively. The proposed absorber would be beneficial for infrared polarization detection and imaging.

Polarization photodetectors with configurable polarity transition enabled by programmable ferroelectric-doping patterns

Advances in symmetry-breaking engineering of heterointerfaces for optoelectronic devices have garnered significant attention due to their immense potential in tunable moiré quantum geometry and enabling polarization light detection. Despite several proposed approaches to breaking the symmetry of low-dimensional materials, there remains a lack of universal methods to create materials with prominent polarization detection capabilities. Here, we introduce a reliable strategy for manipulating the symmetry of low-dimensional materials through a programmable ferroelectric-doping patterns technique. This method introduces a spontaneous photocurrent and enables the detection of linearly polarization light in isotropic 2H-MoTe2. The 2H-MoTe2 photodetector exhibits a significant short-circuit photocurrent intensity (Jsc = 29.9 A/cm2) and open-circuit voltage Voc of 0.12 V ( ~ 3 × 105 V/cm). Under a specific bias, the polarization ratio transitions from 1 to ∞/−∞, shifting from a positive state (unipolar regime) to a negative state (bipolar regime). These findings underscore the potential of ferroelectric-doping patterns as a promising approach to creating composite materials with artificial bulk photovoltaic effect and achieving high-performance polarization light detection.

High performance self-driven broadband photodetector for polarized imaging based on novel ZrS3/ReSe2 van der Waals heterojunction

The distinctive characteristics of anisotropic two-dimensional (2D) materials, including in-plane anisotropy of optical absorption and carrier mobility, render them exceptionally suitable for application in the field of polarization detection and as a novel platform for the polarization imaging. Meanwhile, the consolidation of diverse functionalities within a single photodetector is highly anticipated to meet the demands of some special scenarios. Herein, a novel ZrS3/ReSe2 van der Waals (vdWs) heterostructure device was successfully constructed to realize polarization-sensitive, self-powered, and broadband photodetection and imaging. Owing to the built-in electric field of the type-II band alignment within the heterojunction, the device achieves a self-powered photoresponse ranging from 300 to 980 nm, an ultralow dark currentt ∼1 pA, and a commendable rise/decay time of 0.35/0.28 ms. Additionally, it has been demonstrated that the self-driven photodetector possesses a polarization-sensitivity with a notable anisotropic ratio about 2.02 (1.98) under 490 nm (980 nm) light illumination with zero bias, coupled with an excellent repeatability and stability. Furthermore, we also demonstrate the polarization imaging capabilities of the device in visible and near-infrared spectrum, realizing a contrast-enhanced degree of linear polarization imaging. This work paves a new platform to develop heterojunction photodetectors for high performance polarization-sensitive photodetection and next-generation polarized imaging.

Tunable graphene plasmonic metadevice for infrared polarization resolved spectroscopy detection

Polarization-resolved spectroscopy imaging holds significant promise in various fields. However, conventional polarization-resolved spectroscopy imaging systems often reply on separate dispersion elements, polarization splitting components, and mechanical scanning or rotating structures, resulting in bulky systems with intricate designs. The pursuit of lightweight and seamlessly integrated polarization spectroscopy imaging systems presents a critical challenge. Here, we propose an integrated polarization spectroscopy detector operating in the mid-infrared range based on a tunable graphene metasurface. Within the graphene metasurface, plasmonic resonances of graphene are excited by a gold nano-grating, allowing simultaneous modulation of spectral and polarization transmission characteristics for infrared light by tuning the Fermi energy of graphene. With the help of neural network based recovery algorithms, this system achieves pixel-level spectral detection (with a resolution below 200 nm), multi-color polarization Stokes vector analysis (with a monochromatic angular error of less than 0.1 rad), and concurrent polarization and spectroscopy detection. This research paves the way for the development of the next generation integrated infrared polarization resolved spectroscopy imaging systems.

Probing Magnetic Fields in Young Supernova Remnants with IXPE

Synchrotron emission from the shocked regions in supernova remnants provides, through its polarization, crucial details about the magnetic field strength and orientation in these regions. This, in turn, provides information on particle acceleration in these shocks. Due to the rapid losses of the highest-energy relativistic electrons, X-ray polarization measurements allow for investigations of the magnetic field to be carried outvery close to the sites of particle acceleration. Measurements of both the geometry of the field and the levels of turbulence implied by the observed polarization degree thus provide unique insights into the conditions leading to efficient particle acceleration in fast shocks. The Imaging X-ray Polarimetry Explorer (IXPE) has carried out observations of multiple young SNRs, including Cas A, Tycho, SN 1006, and RX J1713.7−3946. In each, significant X-ray polarization detections provide measurements of magnetic field properties that show some common behavior but also considerable differences between these SNRs. Here, we provide a summary of results from IXPE studies of young SNRs, providing comparisons between the observed polarization and the physical properties of the remnants and their environments.

Optimal multi-spectrum polarization detection with full-Stokes in a single channel by using standard retarders

Polarization detection with full-Stokes is one of the important way to obtain spatial distribution and physical information on targets. However, the most full-Stokes multi-spectrum polarization detection system is relatively complex, as the traditional method is generally designed for multi-channel to adapt the different wavelength. In this paper, we propose an optimal polarization detection method to obtain the full-Stokes vector of the incident light in one channel for different wavelengths. This method utilizes two standard retarders for multi-spectrum full polarization modulation, which can obtain accurately the desired retardance to achieve optimal system performance at multi-wavelengths. The numeric analysis validates the feasibility of the dual-retarders detection system based on tunable polarization retardance method. Furthermore, in experiments, just two much more readily available quarter-wave plate (QWP) retarders are utilized, the various special retardance within 0.2° errors and high polarization measurement accuracy below 10-2 level at multi-wavelengths are achieved. This method, with a simple structure, has excellent application prospects in high-precision polarization detection, such as solar magnetic field detection.