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An acoustic delay line consisting of two Y – X -cut lithium niobate plates 0.2 mm thick placed on top of each other was experimentally investigated. An interdigital transducer is located at the edge of each plate. An rf voltage (pulsed or continuous-wave) is fed to one transducer, which excites a piezoelectrically active acoustic wave with transverse–horizontal polarization propagating in the first plate. The electric field of this wave penetrates the second plate to excite an acoustic wave therein, which is converted into an electrical signal using the second interdigital transducer. The phase and delay time of the output signal can be changed by varying the distance between the transducers by shifting one plate relative to the other.

We propose two new ocean wind retrieval models for right circular-vertical (RV) and right circular-horizontal (RH) polarizations respectively from the compact-polarimetry (CP) mode of the RADARSAT Constellation Mission (RCM), which is scheduled to be launched in 2019. For compact RV-polarization (right circular transmit and vertical receive), we build the wind retrieval model (denoted CoVe-Pol model) by employing the geophysical model function (GMF) framework and a sensitivity analysis. For compact RH polarization (right circular transmit and horizontal receive), we build the wind retrieval model (denoted the CoHo-Pol model) by using a quadratic function to describe the relationship between wind speed and RH-polarized normalized radar cross-sections (NRCSs) along with radar incidence angles. The parameters of the two retrieval models are derived from a database including wind vectors measured by in situ National Data Buoy Center (NDBC) buoys and simulated RV- and RH-polarized NRCSs and incidence angles. The RV- and RH-polarized NRCSs are generated by a RCM simulator using C-band RADARSAT-2 quad-polarized synthetic aperture radar (SAR) images. Our results show that the two new RCM CP models, CoVe-Pol and CoHo-POL, can provide efficient methodologies for wind retrieval.

The Valles Caldera (VC), one of the largest Quaternary silicic calderas in North America, formed by explosive rhyolitic eruptions. Seismic studies suggest a crustal magmatic reservoir beneath the caldera with low‐velocity anomalies, but resolving the detailed geometry of localized melt requires constraints from seismic anisotropy. To image P‐wave velocity and radial anisotropy using dense nodal array data, we develop a teleseismic tomography method that integrates an eikonal solver with the adjoint‐state approach. Our results reveal a pronounced low‐velocity anomaly (>20% reduction) extending laterally across the resurgent dome and down to 15–20 km depth, consistent with a crustal magma chamber. We also identify a colocated zone showing a previously unrecognized pattern of strong positive P‐wave radial anisotropy (up to 8%) where horizontally polarized P‐waves travel faster than vertically polarized ones. This anisotropy indicates a laterally extensive magmatic sill complex and provides new constraints on magma distribution and reservoir architecture beneath the VC.

In this study, the spatial mode evolution of a chiral polarized beam during reflection on an isotropic medium surface at Brewster angle is both theoretically and experimentally investigated. In this process, the topological charge of the reflection field’s horizontal component increases (decreases) by one, relative to the specific left (right) elliptical polarization incident beam. While incident l i -order vortex beam is in a certain polarization state, the intensity distribution of the reflection field’s horizontal component appears as the interference pattern of the l i ± 1 -order output vortex beams. The conversion occurs between the spin and orbital angular momentum and does not violate the conservation of the total angular momentum. We explain the physical mechanism of this phenomenon using phase shift theorem, and analyze the effect of ellipticity and polarization angle on this physical phenomenon.

Pulsed laser detection is widely utilized in various fields due to its high accuracy and excellent directionality. However, the presence of smoke and dust particles can interfere with laser detection, leading to misidentification or missed targets. Existing studies have indicated that smoke and dust particles can depolarize polarized light, providing a potential means for mitigating smoke interference. Despite this, current research lacks systematic analysis of the transmission characteristics of different polarization states in smoky environments, and methods for smoke interference resistance based on polarization characteristics have not been fully explored. With the Monte Carlo method and Stokes vector analysis this study establishes a multiple scattering simulation model for pulsed polarized lasers in smoke and dust, By examining the echo characteristics of various polarized lasers, significant differences are identified in the degrees of polarization of laser echoes under horizontally polarized light and 45° linearly polarized light, both with and without a target. As a result, a detection method to counteract smoke and dust interference is proposed, utilizing polarized lasers and differentiating based on variations in echo Stokes vectors and degrees of polarization.

FlexPES is a soft X‐ray beamline on the 1.5 GeV storage ring at MAX IV Laboratory, Sweden, providing horizontally polarized radiation in the 40–1500 eV photon energy range and specializing in high‐resolution photoelectron spectroscopy, fast X‐ray absorption spectroscopy and electron–ion/ion–ion coincidence techniques. The beamline is split into two branches currently serving three endstations, with a possibility of adding a fourth station at a free port. The refocusing optics provides two focal points on each branch, and enables either focused or defocused beam on the sample. The endstation EA01 at branch A (Surface and Materials Science) is dedicated to surface‐ and materials‐science experiments on solid samples at ultra‐high vacuum. It is well suited not only to all flavours of photoelectron spectroscopy but also to fast (down to sub‐minute) high‐resolution X‐ray absorption measurements with various detectors. Branch B (Low‐Density Matter Science) has the possibility to study gas‐phase/liquid samples at elevated pressures. The first endstation of this branch, EB01, is a mobile setup for various ion–ion and electron–ion coincidence techniques. It houses a versatile reaction microscope, which can be used for experiments during single‐bunch or multi‐bunch delivery. The second endstation, EB02, is based on a rotatable chamber with an electron spectrometer for photoelectron spectroscopy studies on primarily volatile targets, and a number of peripheral setups for sample delivery, such as molecular/cluster beams, metal/semiconductor nanoparticle beams and liquid jets. This station can also be used for non‐UHV photoemission studies on solid samples. In this paper, the optical layout and the present performance of the beamline and all its endstations are reported. A new versatile beamline for experiments with soft X‐ray absorption, photoelectron emission and electron–ion coincidence spectroscopies is available at MAX IV Laboratory, Sweden, serving user communities from ultra‐high‐vacuum surface science to materials science and low‐density matter research.

A newly developed four‐segmented APPLE‐II undulator enables arbitrary polarization control in the soft to tender X‐ray region. The undulator is installed at NanoTerasu BL13U, aiming for X‐ray absorption spectroscopy over a wide energy range, 180–3000 eV, with versatile photon polarizations. By adjusting the phase difference of the synchrotron radiation using electromagnetic phase shifters, arbitrary orientations of linear polarization were obtained from left and right circularly polarized radiation. Elliptically polarized radiation was also generated from vertical and horizontal linearly polarized radiation. In addition, the ellipticity angles were successfully controlled. Circularly polarized radiation in the tender X‐ray region is considered to be achieved by utilizing the third harmonic. Methods and performance of polarization control of the segmented APPLE‐II undulator using the phase shifters are presented. A four‐segmented APPLE‐II undulator was constructed, and its operation has started at NanoTerasu BL13U. The performance of arbitrary polarization control using phase shifters is demonstrated.

Using seismic recordings of event S1222a, we measure dispersion curves of Rayleigh and Love waves, including their first overtones, and invert these for shear velocity (VS) and radial anisotropic structure of the Martian crust. The crustal structure along the topographic dichotomy is characterized by a fairly uniform vertically polarized shear velocity (VSV) of 3.17 km/s between ∼5 and 30 km depth, compatible with the previous study by Kim et al. (2022), https://doi.org/10.1126/science.abq7157. Radial anisotropy as large as 12% (VSH > VSV) is required in the crust between 5 and 40 km depth. At greater depths, we observe a large discontinuity near 63 ± 10 km, below which VSV reaches 4.1 km/s. We interpret this velocity increase as the crust‐mantle boundary along the path. Combined gravimetric modeling suggests that the observed average crustal thickness favors the absence of large‐scale density differences across the topographic dichotomy. Plain Language Summary The first detection and analysis of surface waves on Mars (Kim et al., 2022, https://doi.org/10.1126/science.abq7157) revealed that the crustal structure away from the InSight lander is fairly uniform between 5 and 30 km depth in the northern lowlands. This is strikingly different from the crustal structure inferred beneath the lander. The largest marsquake recorded during the InSight mission to Mars, S1222a, provides the first clear signals of both types of surface waves—called Rayleigh and Love waves—as well as their first overtones. We analyze the speed at which these waves travel changes with their frequency to see deeper into Mars than possible with previous data. We find that the crustal structure along the path to S1222a, which covers a different part of the northern lowlands, is similar to that found previously, suggesting that uniform velocities in the depth range of 5–30 km may be characteristic for this region. By combining our seismic data with variations in the strength of gravity, we determine that the density of the crust in the northern lowlands and the southern highlands is similar. Finally, by analyzing both types of surface waves, we find that the speed of horizontally polarized waves is up to 12% faster than that of vertically polarized waves. Key Points By jointly analyzing Rayleigh and Love waves, and their overtones in the S1222a record, we obtain the seismic velocity structure of Mars down to 90 km depth Radial anisotropy up to 12% (VSH > VSV) is required in the crustal structure along the path to S1222a Absence of large‐scale density differences across the martian dichotomy better explains the average crustal thickness along the propagation path

The application of electromagnetic materials to mobile systems and other platforms requiring complex utilization of radio waves necessitates compatibility with various polarizations. For nonreciprocal metasurfaces that support unidirectional propagation, achieving dual polarization (vertical and horizontal) presents significant design challenges. This study proposes a simple structure for dual‐polarization nonreciprocal metasurfaces and presents theoretical and experimental analyses of its performance. As a result, a dual‐polarization nonreciprocal metasurface exhibiting high‐pass filter characteristics at C‐band is realised by incorporating ferrite into a strip line lattice structure, achieving an isolation of 7 dB. We present a design method that enables the straightforward integration of functionality into nonreciprocal electromagnetic metasurfaces. This approach uniquely supports the simultaneous handling of both vertical and horizontal polarizations, addressing a critical need in complex electromagnetic environments.

This article proposes a dual mode dual-polarized antenna configuration for IRNSS and fifth generation (5G) applications, operating at a frequency of 3.5 GHz based on characteristic mode analysis (CMA), and aims to provide broadband dual-polarized functionality. The original design of the antenna is a traditional patch antenna, and its dual-polarized features are determined using characteristic mode analysis. The full-wave method is used to stimulate both orthogonal modes using a 50 Ω coaxial input line at 3.5 GHz. In this design, the circular patch has been extended into an elliptical patch through a process of mode separation. The circular patch exhibits resonance at a frequency of 2.5 GHz, whereas the extended elliptical radiator demonstrates two resonance modes at 2.5 GHz and 3.5 GHz. The operational mechanism is elucidated by modal analysis and characteristic angle. This antenna operates on two different frequencies at the 2.5 GHz IRNSS band with horizontal polarization and the 3.5 GHz 5G service with vertical polarization. The maximum gain achieved with these frequency ranges is 5.31 dBi and 4.72 dBi, respectively. A ring resonator is chosen to improve the axial ratio and impedance bandwidth of the suggested prototype. The antenna's ground plane is shaped like a rectangle and features a V-shaped slot in the radiating patch. The antenna's physical footprint is 50 mm × 50 mm × 1.6 mm and an FR4 dielectric substrate serves as its foundation. Through its interaction with a PIN diode, the diode modifies the polarization of the antenna. The antenna functions as a right-handed circular polarization (RHCP), when the diode is operational. The bandwidth from 4.3 to 7.5 GHz is covered. On the other hand, it generates linear polarization (LP) between 4.2 and 5.3 GHz. The experimental antenna is evaluated and examined for its performance characteristics. The simulations are carried out utilizing the CST simulator. A prototype antenna has been manufactured and its performance has been validated against simulated findings.