Polarization Rotation Research Articles

Non-invasive Glucose Extraction by a Single Polarization Rotator System in Patients with Diabetes: erratum

Non-invasive Glucose Extraction by a Single Polarization Rotator System in Patients with Diabetes: erratum

Layered Babinet complementary patterns acting as asymmetric negative index metamaterial

Azimuthal orientation and handedness dependence of the optical responses, accompanied by asymmetric transmission and asymmetric dichroism, were demonstrated on multilayers constructed with subwavelength periodic arrays of Babinet complementary miniarrays, illuminated by linearly and circularly polarized light. In case of single-sided illumination asymmetric optical responses were observed at the spectral location of maximal cross-polarization that is accompanied by radiative electric dipoles and weak, slowly-rotating in-plane magnetic dipoles on the nano-objects; where the outgoing waves are elliptically (almost circularly) polarized. The negative index material phenomenon was demonstrated, where the electric and magnetic dipoles overlap both spatially and spectrally. The negative index material (NIM) phenomenon is accompanied by electric multipoles that add up non-radiatively and correlates with the strong, pronouncedly-tilted, rotating magnetic dipoles characteristic on the nano-entities, where the outgoing waves are linearly (slightly elliptically) polarized. By illuminating the multilayer with two counter-propagating circularly polarized beams it was proven that asymmetrical normal component displacement currents at the bounding interfaces, arising along flat and tilted bands, accompany the asymmetric copolarized and cross-polarized transmission. The latter correlates with the asymmetric dichroism in the cross-polarized signal observed in case of single-sided circularly polarized light illumination. The dispersion maps in the single-sided asymmetrical co-polarized reflectance and absorptance indicate flat bands of analogous and complementary extrema, proving the partially dichroic nature of the observed asymmetric phenomena. The Tellegen (chirality) coefficients exhibit a maximum in a spectral region coincident with the asymmetric transmission (maximal polarization rotation in the 90° azimuthal orientation). The multilayer is proposed as an ultrathin NIM and nonreciprocal nanophotonic element.

Assessing the Ubiquity of Bloch Domain Walls in Ferroelectric Lead Titanate Superlattices

The observation of unexpected polarization textures such as vortices, skyrmions, and merons in various oxide heterostructures has challenged the widely accepted picture of ferroelectric domain walls as being Ising-like. Bloch components in the 180° domain walls of PbTiO3 have recently been reported in PbTiO3/SrTiO3 superlattices and linked to domain wall chirality. While this opens exciting perspectives, the ubiquity of this Bloch component remains to be further explored. In this work, we present a comprehensive investigation of domain walls in PbTiO3/SrTiO3 superlattices, involving a combination of first- and second-principles calculations, phase-field simulations, diffuse scattering calculations, and synchrotron-based diffuse x-ray scattering. Our theoretical calculations highlight that the previously predicted Bloch polarization in the 180° domain walls in PbTiO3/SrTiO3 superlattices might be more sensitive to the boundary conditions than initially thought and is not always expected to appear. Employing diffuse scattering calculations for larger systems, we develop a method to probe the complex structure of domain walls in these superlattices via diffuse x-ray scattering measurements. Through this approach, we investigate depolarization-driven ferroelectric polarization rotation at the domain walls. Our experimental findings, consistent with our theoretical predictions for realistic domain periods, do not reveal any signatures of a Bloch component in the centers of the 180° domain walls of PbTiO3/SrTiO3 superlattices, suggesting that the precise nature of domain walls in the ultrathin PbTiO3 layers is more intricate than previously thought and deserves further attention. Published by the American Physical Society 2024

Robust Sodium Carboxymethyl Cellulose-Based Neuromorphic Device with High Biocompatibility Engineered through Molecular Polarization for the Emulation of Learning Behaviors in the Human Brain.

Sodium carboxymethyl cellulose (CMC-Na), derived from natural cellulose and frequently employed as a biocompatible coating, thus renders it an ideal component for the construction of highly biocompatible neuromorphic devices aimed at biomachine interfaces. Here, an array of Mo/CMC-Na/ITO neuromorphic devices is fabricated, with CMC-Na serving as the functional layer. The devices exhibit capabilities to emulate various synaptic learning rules and demonstrate high endurance performance among biomaterial-based electronics, achieving stability over 2 × 104 pulses. Then, simulations of human brain-inspired learning and forgetting paradigms are conducted, highlighting the versatility of the device array in mimicking learning processes. Applications in pattern recognition leverage "learning-forgetting" paradigms, showcasing the potential of the device in cognitive tasks. Electrical measurements elucidate the mechanism of molecular polarization rotation, which offers insights into the modulation of synaptic weights within biocompatible biomaterial-based devices. Furthermore, the biocompatible properties of the devices are evaluated using human embryonic kidney 293 cells, confirming their excellent biocompatibility. The biodegradability of the devices is assessed by using physical transient tests to evaluate their sustainability in biomedical applications. Such advances represent pivotal improvements in implantable bioinspired electronics and show potential in biomachine interface and cognitive computing applications.

A continuous plane of polarization rotator and detector based on the liquid crystal Θ-cell

Modulation of the polarization state of optical beams is crucial in advanced optical applications such as polarization microscopy, polarization rotation, and medical imaging. We demonstrate a continuous polarization rotator (PR) by utilizing the liquid crystals (LC) in Θ-cell configuration comprising of circular and parallel alignment of LC on two aligning glass substrates. A rotation of plane of polarization (PoP) up to ∼ 160˚ is observed using Stokes polarimetry. This is further substantiated by the mathematical analysis using Mueller matrix formalism. Further, the device is demonstrated as a PoP detector with high precision detection angle. The PoP is analyzed through single-shot imaging of the intensity distribution of transmitted light through the LC Θ-cell.

Photothermal Spectroscopy in Attenuated Total Internal Reflection Geometry by Polarization Rotation and Deflection

Photothermal Spectroscopy in Attenuated Total Internal Reflection Geometry by Polarization Rotation and Deflection

Optimized detection modality for radio-frequency sensing with a double-resonance alignment magnetometer

In this work, we present a comprehensive and comparative analysis of two detection modalities, i.e., polarization rotation and absorption measurement of light, for a double-resonance alignment magnetometer (DRAM). We derive algebraic expressions for magnetometry signals based on the description of multipole moments. Experiments are carried out using a room-temperature paraffin-coated cesium-vapor cell and measuring either the polarization rotation or absorption of the transmitted laser light. A detailed experimental analysis of the resonance spectra is performed to validate the theoretical findings for various input parameters. The results signify the use of a single isotropic relaxation rate, thus simplifying the data analysis for optimization of the DRAM. The sensitivity measurements are performed and reveal that the polarization-rotation detection mode yields larger signals and better sensitivity than absorption measurement of light. Published by the American Physical Society 2024

Temperature stability analysis of the all-fiber current sensor with a loop structure

Abstract All-fiber optical current sensor (AFOCS) is a perfect product formed by the combination of fiber-optic sensing technology and the Faraday effect. It boasts significant advantages such as resistance to electromagnetic interference, a high measurement dynamic range and precision, low power consumption, low cost, and insulation. Additionally, it enables long-distance transmission, making it one of the main devices for current monitoring in smart grids. However, the birefringence within the sensing fiber is highly susceptible to changes in temperature, causing the polarization state of light to be extremely sensitive to temperature variations. This sensitivity significantly impacts the accuracy of current measurements. A novel loop structure AFOCS with a coupled fiber polarization rotator (FPR) is introduced in this paper. The operating principle of this structure is theoretically analyzed, and the Jones matrix is used to analyze the output light intensity signal and derive the error formula. After comparing the measurement accuracy of the basic AFOCS and the loop structure AFOCS, it is demonstrated that this novel structure can improve current sensitivity by enhancing the temperature robustness of the system. Additionally, the error generated by the FPR is controlled below 1%, meeting the requirements for stable system operation. Therefore, this novel structure effectively improves the accuracy of current measurement and exhibits strong temperature stability.

Intelligent multi-parameter control of a rectangular pulse in a passively mode-locked fiber laser

Rectangular pulses with tunable width and intensity in fiber lasers are critical for the study of nonlinear pulse dynamics and applications of nanosecond laser sources. However, due to the complex nonlinear dynamics within the laser cavity, precisely controlling multiple parameters of the rectangular pulses in fiber lasers remains challenging. Here, we propose an approach for intelligently controlling the intensity and width of rectangular pulse using an improved particle swarm optimization (PSO) algorithm in a passively mode-locked fiber laser with a nonlinear polarization rotation (NPR) technique. By automatically adjusting the electronic polarization controller (EPC) and pump power, multiple parameters of the output rectangular pulse can be effectively tailored, and thus, to desirable ones. This enables the flexible setting of the intensity and width of the rectangular pulse within the permissible range in a passively mode-locked fiber laser. Our approach provides a promising way to meet the diverse demands of seed laser source in scientific and engineering fields.

Large Circular Dichroism and Polarization Rotation in Plasmonic Ψ-Like Structured Gold Metasurface

Large Circular Dichroism and Polarization Rotation in Plasmonic Ψ-Like Structured Gold Metasurface

L-band wavelength-switchable bound states in a hybrid mode-locked fiber laser

This paper presents a hybrid mode-locked fiber laser based on the nonlinear polarization rotation (NPR) and the nanomaterial saturable absorber. Due to the presence of the NPR filter, we obtain L-band wavelength-switchable conventional solitons (CSs) and bound states (BSs). The tightly BSs and loosely BS, as well as the "2 + 1" type BS, are also experimentally observed. We study the formation of CSs and BSs by numerical simulations, the results of which are consistent with the experimental results. Our work deepens the understanding of the formation of BSs in hybrid mode-locked fiber lasers and provides new solutions for L-band light sources.

Depolarization and Faraday effects in AGN Jets

ABSTRACT Radio interferometric observations of active galactic nuclei (AGN) jets reveal the significant linear polarization of their synchrotron radiation that changes with frequency due to the Faraday rotation. It is generally assumed that such depolarization could be a powerful tool for studying the magnetized plasma in the vicinity of the jet. However, depolarization could also occur within the jet if the emitting and rotating plasma are cospatial (i.e. the internal Faraday rotation). Burn obtained very simple dependence of the polarization on the wavelength squared for the discrete source and resolved slab that is widely used for interpreting the depolarization of AGN jets. However, it ignores the influence of the non-uniform large-scale magnetic field of the jet on the depolarization. Under the simple assumptions about the possible jet magnetic field structures, we obtain the corresponding generalizations of Burn’s relation widely used for galaxies analysis. We show that the frequency dependences of the Faraday rotation measure and polarization angle in some cases allow to estimate the structures of the jets magnetic fields.

Single- and dual-band high-order polarization rotating frequency selective surface

Abstract This work presents the design and development of dual- and single-band polarization rotating frequency selective surfaces (PR-FSSs) based on aperture-coupled patch multimode resonators. Initially, an open-loop slot is incorporated into the patch of a second-order resonator to design a dual-band second-order PR-FSS (DPR-FSS), which enables effective polarization rotation and frequency selection across two distinct passbands. Then, to develop a single-band fourth-order PR-FSS (SPR-FSS), we introduce a metallic via into the DPR-FSS. This modification results in a single-band fourth-order response. The SPR-FSS offers a bandwidth of 41% with minimal insertion loss and high roll-off characteristics. Finally, experiments are conducted to verify the performance of the proposed structures. Good agreement can be observed between simulation and measurement.

Electrically driven long-range solid-state amorphization in ferroic In2Se3.

Electrically induced amorphization is uncommon and has so far been realized by pulsed electrical current in only a few material systems, which are mostly based on the melt-quench process1. However, if the melting step can be avoided and solid-state amorphization can be realized electrically, it opens up the possibility for low-power device applications2-5. Here we report an energy-efficient, unconventional long-range solid-state amorphization in a new ferroic β″-phase of indium selenide nanowires through the application of a direct-current bias rather than a pulsed electrical stimulus. The complex interplay of the applied electric field perpendicular to the polarization, current flow parallel to the van der Waals layer and piezoelectric stress results in the formation of interlayer sliding defects and coupled disorder induced by in-plane polarization rotation in this layered material. On reaching a critical limit of the electrically induced disorder, the structure becomes frustrated and locally collapses into an amorphous phase6, and this phenomenon is replicated over a much larger microscopic-length scale through acoustic jerks7,8. Our work uncovers previously unknown multimodal coupling mechanisms of the ferroic order in materials to the externally applied electric field, current and internally generated stress, and can be useful to design new materials and devices for low-power electronic and photonic applications.

Multipulse bunches in the Yb-doped mode-locked fiber laser based on NLMMI-NPR hybrid mode locked mechanism

In this study, we propose a novel Ytterbium-doped ultrafast fiber laser based on nonlinear multimode interference-nonlinear polarization rotation (NLMMI-NPR) hybrid mode-locked mechanism. Stable single-pulse mode-locked state is achieved in the linear cavity, with a repetition rate of 12.8 MHz. By adjusting the polarization state and pump power inside the cavity, various characteristic modes are obtained, including multipulse bunches, second- and third-harmonic mode-locked states, second- and third-harmonic multipulse bunches states, and a chaotic multipulse state. This is the first exploration of multipulse bunches in Ytterbium-doped ultrafast fiber lasers based on the NLMMI-NPR hybrid mode-locked mechanism. And multipulse mode-locked fiber lasers have unique advantages in numerous fields owing to their higher energy and wider pulse width.

Optimization of the Raman spectroscopic method for crystal orientation and residual stress of aluminum oxide

A half-wavelength plate was set in the common light path to simultaneously alter the polarization directions of both incident laser and scattered Raman signals, and the distribution functions of the polarized Raman scattering intensity about the polarization rotation angle and the crystal orientation angle were deduced. The measurement accuracies of crystal orientations when using different correction methods of light intensity were compared, and on that basis, a measurement system and a measurement method for the crystal orientation of 95% aluminum oxide (Al2O3) were established, which improved the accuracy and handleability of crystal orientation detection. Then, the number of Raman peak shifts needed for solving equations was reduced to three by studying the simplification method of stress fields, exploring the Raman selection method, and introducing the differential evolution algorithm. In this way, the method that can calculate the residual stress in the absence of peaks in Raman spectroscopic tests was proposed. The established test system and method were also adopted to test single-crystal and polycrystal Al2O3 samples with known stress. Results show that the established stress measurement method is highly reliable and accurate. Finally, the residual stress distribution in the ceramic side of 95%Al2O3/4J33 brazed joints was also tested.

Nonlinear polarization rotation based 635 nm praseodymium doped mode-locked fiber laser

We demonstrated a mode-locked fiber laser oscillator using nonlinear polarization rotation as a saturable absorption system. The fiber laser generates mode-locked pulses by adjusting four waveplates. A single-clad Pr3+-doped single mode fluoride fiber with a 425 mW threshold pump power serves as the foundation for the ring cavity, which operates in the dissipative soliton resonance regime. The radio frequency signal-to-noise ratio of the pulses at 634.9 nm is 60 dB, maximum output power of 5.5 mW, and repetition rate of 34.5 MHz. These findings provide a foundation for the advancement of photonic applications in the visible spectrum.

Chiral sensing via dielectric waveguide-nanoparticle array interactions.

Identifying the handedness of chiral materials in small quantities remains a significant challenge in biochemistry. Nanophotonic structures offer a promising solution by enhancing weak chiroptical responses through increased optical chirality. Utilizing a silicon-based approach for chiral sensing on a photonic integrated platform is highly desirable. In this study, we explore the interaction between a dielectric waveguide and silicon nanoparticles for detecting the handedness of chiral analytes. A chiral core induces polarization rotation of wavefields traveling along a dielectric waveguide with a square cross-section. This polarization rotation affects waveguide coupling differently depending on the left- or right-handed arrangement of nanoparticles around the waveguide, enabling enantiomer detection through discernible transmission differences. From a basic design to more practical structures, we investigate configurations that maintain the same working principles. Theoretical results based on the transfer matrix method corroborate the numerical simulations.

Cylindrical Vector Beams with an MOPA Amplifier Based on Nonlinear Polarization Rotation Mode-Locking

CVBs (cylindrical vector beams) are widely used in optical imaging, optical trapping, material processing, etc. In this study, based on mode-selective couplers and passive mode-locking fiber technology, a cylindrical vector fiber amplifier with an MOPA (master oscillator power amplifier) structure was developed. In the experiment, the pre-amp stage reached 19.87 mW output power and a CVB output with a mode purity greater than 97%. The measured beam quality factor was M2 = 2.1. The CVB output power obtained by the first-amp stage was 152.4 mW, and the mode purity was greater than 92%. The measured beam quality factor was M2 = 1.99. The internal inhomogeneity and external effects of the isotropic LMA (large-mode-area) fiber led to a decrease in beam quality and mode purity. After amplification, the gain of the fundamental mode was higher and the power was greater, resulting in a greatly reduced mode purity. This CVB fiber amplifier yielded important research value in expanding the applications of high-power fiber lasers.

Achieving high piezoelectric performance in Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric single crystals through pulse poling technique

To maximize the piezoelectric performance of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) single crystals, a pulse poling (PP) method is proposed in this study. This study investigates the effects of pulse poling on the piezoelectric and dielectric properties of these PMN–PT single crystals and explores the polarization rotation mechanisms. Our findings indicate a significant improvement in the piezoelectric properties postpulse poling. The optimal PP conditions are identified as 30 pulse numbers at a pulsed electric field of 5 kV/cm. The dielectric constant ɛT33/ɛ0 and piezoelectric coefficient d33 of PMN–0.28PT post PP are 7000–7700 and 2200–2530 pC/N, respectively, representing increases of 49% and 66% compared with those of postdirect current poling (DCP). Additionally, the domain structures of the PMN–0.28PT single crystals after various DCP and PP treatments are examined and compared using piezoelectric force microscopy. The enhanced piezoelectric properties are attributed to the finer domain structures, as well as increased domain wall density achieved through PP. This research introduces a novel domain engineering approach to improve the electromechanical properties of relaxor ferroelectric single crystals.