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In this article, we have developed a new mathematical technique for synthesis of waveguide iris polarizers with optimal phase and matching characteristics. The technique applies theoretical single-mode expressions of the differential phase shift between the waves with orthogonal linear polarizations and of the voltage standing wave ratio to optimize the geometrical dimensions of the polarizer’s structure. These expressions were combined into a set of mathematical conditions to obtain the required values of characteristics. The proposed technique was implemented to synthesize a waveguide polarizer with two thin conducting irises. Such irises are equivalent to inductive or capacitive loads in a waveguide transmission line, depending on the polarization type of the fundamental electromagnetic mode. The mathematical model of the waveguide iris polarizer was developed based on the equivalent wave matrices. As a result, the main electromagnetic characteristics were determined through the elements of the polarizer’s scattering matrix. Suggested analytical synthesis technique allows to find all optimal geometrical dimensions of the iris polarizer including the transversal sizes of a square waveguide, the heights of the irises and the distances between them. Variation of these dimensions allows to obtain the required electromagnetic characteristics of microwave waveguide devices, namely the optimal matching and cross polarization level in the operating frequency band. The differential phase shift of 90° ± 0.5° was obtained for the square waveguide iris polarizer optimized for the operating satellite frequency band 8.0-8.5 GHz. The voltage standing wave ratio does not exceed 2 for the fundamental modes of vertical and horizontal linear polarizations. The crosspolarization level of the iris polarizer is less than − 34 dB. The axial radio does not exceed 0.4 dB. Therefore, the presented mathematical method for single-mode synthesis of waveguide polarizers with diaphragms can be used to initially optimize them before the application of specialized programs for simulation of microwave devices. In addition, the suggested technique of mathematical synthesis can be widely used for the development of new microwave polarizers, phase shifters and filters based on irises and posts in waveguides.

Today polarization-processing devices are widely used in satellite information systems. Waveguide polarizers are the key element of antenna systems used to convert signal polarization from linear to circular type and vice versa. The circularly polarized signals have many significant advantages over the signals with other types of polarization. Consequently, simultaneous application of polarizers with other radio signal processing devices highly increases the efficiency of new satellite information and telecommunication systems for various purposes, wireless data transmission systems, mobile communication systems, radar systems and medical diagnostic systems. In this article, we have developed a new matrix technique for the calculation of parameters and characteristics of a polarizer based on a square waveguide with three irises, which are inductive or capacitive loads depending on the wave’s polarization. Based on the theory of microwave circuits, the analytical expressions of the general wave scattering matrix were derived using the transmission and scattering wave matrices of elements of a polarizer structure. As a result, the main characteristics of the polarizer were obtained: differential phase shift, voltage standing wave ratio for vertical and horizontal polarizations, axial ratio and cross-polar discrimination. The presented method makes it possible to study the influence of the polarizer dimensions, such as the heights of the irises and the distances between them, on its main characteristics. Obtained analytical model makes it possible to find theoretically optimal sizes, which provide the required polarization characteristics of the device with the best matching in the operating frequency band. In addition, the developed wave matrix technique can be applied for further optimization using the specialized programs for microwave device simulation.

Metasurfaces are a topic of significant research and are used in various applications due to their unique ability to manipulate electromagnetic waves in microwave and optical frequencies. These artificial sheet materials, which are usually composed of metallic patches or dielectric etchings in planar or multi-layer configurations with subwavelength thickness, have the advantages of light weight, ease of fabrication, and ability to control wave propagation both on the surface and in the surrounding free space. Recent progress in the field has been classified by application and reviewed in this article. Starting with the development of frequency-selective surfaces and metamaterials, the unique capabilities of different kinds of metasurfaces have been highlighted. Surface impedance can be varied and manipulated by patterning the metasurface unit cells, which has broad applications in surface wave absorbers and surface waveguides. They also enable beam shaping in both transmission and reflection. Another important application is to radiate in a leaky wave mode as an antenna. Other applications of metasurfaces include cloaking, polarizers, and modulators. The controllable surface refractive index provided by metasurfaces can also be applied to lenses. When active and non-linear components are added to traditional metasurfaces, exceptional tunability and switching ability are enabled. Finally, metasurfaces allow applications in new forms of imaging.

In this article, we have proposed a new design for a waveguide polarizer with a metal plate. The plate has the shape of three steps. The septum polarizer has been designed to operate in the frequency band 7.7-8.1 GHz. Each step of the plate of such a device has its own height and thickness. It is necessary that the first step from the square port is the lowest and thinnest and the last one is the highest and thickest for better matching. The waveguide with a square cross section was chosen for simplicity of production. The basic electromagnetic characteristics of the developed waveguide polarization conversion device were optimized using commercial software. The well-known finite-domain electrodynamic method in the frequency domain was applied in the simulation program. The proposed development method also allows one to optimize the geometric dimensions of the entire waveguide polarizer based on a three-stepped metal plate. The obtained dimensions of the polarizer with the plates will provide the optimal phase characteristics, matching characteristics, polarization characteristics and isolation characteristics between the device ports. The method allows one to obtain the following dimensions: the height of the wall of a square waveguide, the height of three different steps of the plate, the distance between the steps of the plate. Accordingly, the waveguide septum polarizer is capable of cutting the following values of the electromagnetic characteristics in the operating frequency band 7.7-8.1 GHz. Differential phase shift can vary by 90º±0.86º. The maximum voltage standing wave ratio does is 1.044 for vertical and horizontal polarizations. The maximum value of the axial radio of the developed device is 0.13 dB. The maximum crosspolar discrimination of the polarization device is – 42 dB. The isolation between the first and second ports of a three-step polarizer with plates does not exceed – 39 dB. In this way the presented polarizer can be used in modern satellites and radar systems.

Emerging miniaturized atomic sensors such as optically pumped magnetometers (OPMs) have attracted widespread interest due to their application in high-spatial-resolution biomagnetism imaging. While optical probing systems in conventional OPMs require bulk optical devices including linear polarizers and lenses for polarization conversion and wavefront shaping, which are challenging for chip-scale integration. In this study, an integrated optical probing scheme based on localized-interference metasurface for chip-scale OPM is developed. Our monolithic metasurface allows tailorable linear polarization conversion and wavefront manipulation. Two silicon-based metasurfaces namely meta-polarizer and meta-polarizer-lens are fabricated and characterized, with maximum transmission efficiency and extinction ratio (ER) of 86.29 % and 14.2 dB for the meta-polarizer as well as focusing efficiency and ER of 72.79 % and 6.4 dB for the meta-polarizer-lens, respectively. A miniaturized vapor cell with 4 × 4 × 4 mm dimension containing Rb and N is combined with the meta-polarizer to construct a compact zero-field resonance OPM for proof of concept. The sensitivity of this sensor reaches approximately 9 fT/Hz with a dynamic range near zero magnetic field of about ±2.3 nT. This study provides a promising solution for chip-scale optical probing, which holds potential for the development of chip-integrated OPMs as well as other advanced atomic devices where the integration of optical probing system is expected.

Nowadays, one of the progressive and effective directions of modern wireless telecommunication technologies is the creation of antenna systems with adaptive processing of signal polarization. Such antenna systems provide the required characteristics of telecommunication systems for various purposes under the conditions of high noises for one of polarizations and influence of interferences caused by multipath propagation. The key elements of dual-polarization antenna systems are the devices of polarization transformation and separation. These devices are widely used in systems for electronic protection of aircrafts, radar systems for metrological purposes, systems for estimation of the state of crops and soil erosion, systems for the recognition and tracking of aircrafts, satellite information systems.This article presents the results of numerical analysis of polarization and matching characteristics of a polarizer based on a square waveguide with three irises. The mathematical model of a polarizer is based on the wave matrix technique. Using this technique, the characteristics of the developed polarizer were determined and optimized in the operating X-band 7.25-7.75 GHz, which is used in downlink satellite communication systems. The presented technique allows to study the evolution of the characteristics of polarizers with different dimensions, such as the heights of the irises and the distances between them. The results of this analysis were used to estimate the initial quasi-optimal dimensions of the polarizer to achieve simultaneously the specified matching and small deviations of the differential phase shift from 90° in the whole operating frequency band. The initial dimensions were used for further optimization of the polarizer design by the finite integration technique. Obtained numerically electromagnetic characteristics of the optimized waveguide iris polarizer showed satisfactory agreement with the same characteristics obtained using the developed analytical technique in the whole operating X-band 7.25-7.75 GHz.

Imaging the polarization of light scattered from an object provides an additional degree of freedom for gaining information from a scene. Conventional polarimeters can be bulky and usually consist of mechanically moving parts (with a polarizer and analyzer setup rotating to reveal the degree of polarization). Rubin et al. designed a metasurface-based full-Stokes compact polarization camera without conventional polarization optics and without moving parts. The results provide a simplified route for polarization imaging. Science , this issue p. eaax1839 A metasurface array is designed that can operate as a polarization camera Recent developments have enabled the practical realization of optical elements in which the polarization of light may vary spatially. We present an extension of Fourier optics—matrix Fourier optics—for understanding these devices and apply it to the design and realization of metasurface gratings implementing arbitrary, parallel polarization analysis. We show how these gratings enable a compact, full-Stokes polarization camera without standard polarization optics. Our single-shot polarization camera requires no moving parts, specially patterned pixels, or conventional polarization optics and may enable the widespread adoption of polarization imaging in machine vision, remote sensing, and other areas.

Polarization plays a key role in science; hence its versatile manipulation is crucial. Existing polarization optics, however, can only manipulate polarization in a single transverse plane. Here we demonstrate a new class of polarizers and wave plates—based on metasurfaces—that can impart an arbitrarily chosen polarization response along the propagation direction, regardless of the incident polarization. The underlying mechanism relies on transforming an incident waveform into an ensemble of pencil-like beams with different polarization states that beat along the optical axis thereby changing the resulting polarization at will, locally, as light propagates. Remarkably, using form-birefringent metasurfaces in combination with matrix-based holography enables the desired propagation-dependent polarization response to be enacted without a priori knowledge of the incident polarization—a behaviour that would require three polarization-sensitive holograms if implemented otherwise. Our work expands the use of polarization in the design of multifunctional metasurfaces and may find application in tunable structured light, optically switchable devices and versatile light–matter interactions.Using a metasurface that allows shaping of the polarization state of a light beam independently at each point of space along its propagation direction, longitudinally variable polarization optical components are demonstrated, inspiring new directions in structured light, polarization-switchable devices and light–matter interaction.