Beam Polarization Research Articles

Optimal determination of new physics couplings: a comparative study

We study the determination of new physics (NP) parameters using the optimal observable technique (OOT) in situations where the standard model (SM) dominates over the NP effects, and when the NP dominates over the SM contribution, using the 2-Higgs doublet model as an illustrative example; for the case of SM domination we extend our results using an effective theory parameterization of NP effects. For the case of SM dominance we concentrate on tt¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t} $$\\end{document} production in an e+e− collider, while for the case of NP dominance we consider both tt¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t} $$\\end{document} production and pair production of charged scalars, also in an e+e− collider. We discuss the effects of the efficiency of background reduction, luminosity and beam polarization, and provide a comparison of the optimal uncertainties with those obtained using a standard χ2 analysis of (Monte Carlo generated) collider data.

Ultracompact Single-Photon Sources of Linearly Polarized Vortex Beams.

Ultracompact chip-integrated single-photon sources of collimated beams with polarization-encoded states are crucial for integrated quantum technologies. However, most of currently available single-photon sources rely on external bulky optical components to shape the polarization and phase front of emitted photon beams. Efficient integration of quantum emitters with beam shaping and polarization encoding functionalities remains so far elusive. Here, ultracompact single-photon sources of linearly polarized vortex beams based on chip-integrated quantum emitter-coupled metasurfaces are presented, which are meticulously designed by fully exploiting the potential of nanobrick-arrayed metasurfaces. The authors first demonstrate on-chip single-photon generation of high-purity linearly polarized vortex beams with prescribed topological charges of 0, - 1, and +1. The multiplexing of single-photon emission channels with orthogonal linear polarizations carrying different topological charges are further realized and their entanglement is demonstarated. The work illustrates the potential and feasibility of ultracompact quantum emitter-coupled metasurfaces as a new quantum optics platform for realizing chip-integrated high-dimensional single-photon sources.

Detecting the coupling of axion-like particles with fermions at the ILC

New pseudoscalars, axion-like particles (ALPs), provide the exciting target for present and future collider-based experiments. Search for ALPs is performed in this paper via the W+W− fusion process e−e+→νeνe‾a→νeνe‾ff‾ at the 1 TeV ILC corresponding to an integrated luminosity of 1 ab−1 and the beam polarization P(e−, e+)=(−80%, +20%). Owing to the good capability of the ILC in performing b-tagging and the sufficiently large branching ratio of the ALP decaying into a pair of b quarks, the decay channel a→bb‾ is mainly concerned. The prospective sensitivities provided by the ILC on the ALP-fermion coupling as low as 1 TeV−1 and 1.75 TeV−1 are derived at 95% confidence level in the ALP mass intervals 37−50 GeV and 52−300 GeV, respectively. Our results will help to probe significant parameter space in an unexplored region beyond the existing constraints.

Exploring the Zeeman effect in spectroscopy for laser frequency manipulation in optical systems

In optical systems, acousto-optic modulators (AOMs) and electro-optic modulators (EOMs) are commonly utilized for laser frequency manipulation. However, these devices come with drawbacks such as high cost and the requirement of optical adjustments to change the frequency shift direction. In this study, we propose an alternative method that harnesses the Zeeman effect in the saturated-absorption spectroscopy to shift the energy levels in atom. With this technique, the laser frequency can be shifted without the need for AOMs or EOMs. The stability of laser locking was investigated for any case of polarization of probe and pump beam. We found when the polarization of the probe and pump beams is linear and perpendicular, it results in the highest level of stability in laser locking compared to other polarization configurations.

Backward stimulated Brillouin scattering spatial gain with polarization, spatial, and temporal beam smoothing techniques

A recent study [Ruyer et al., Phys. Rev. E 107, 035208 (2023)] modeling the influence of a random phase plate on the backward stimulated Brillouin scattering growth is here supplemented with the effect of temporal and polarization smoothing. Our analytical predictions are validated by a large number of three dimensional Hera paraxial simulations for various beam smoothing techniques and relevant to most high energy laser facilities. Neglecting all non-linear effects apart from the pump depletion, we then reconstruct the system of differential equations that the backward stimulated Brillouin scattering convective amplification of a smoothed beam propagating in a non-homogeneous plasma satisfies. Its resolution is successfully confronted with our simulation data and prepares the accurate modeling, in a ray tracing scheme, of the effect of laser smoothing techniques on laser plasma instabilities.

Spintronic terahertz polarization programmable system for information encoding

Terahertz (THz) wave as an important electromagnetic wave has been increasingly applied in wireless communication and imaging sensing technology. It has been an increasingly practical application. Ultra-high data rates in communication technology push toward a broadband, controllable polarization, and multiple transmission channels signal sources. Here, we propose a programmable polarization spintronics terahertz source (PP-STS), in which contains a controllable polarization spintronic THz emitter and a microcontroller unit. The PP-STS not only can generate THz waves with wide frequency bandwidth, but also has the function of switching the orthogonal linear polarization state of the generated THz waves flexibly. By coding the microcontroller unit, the designed PP-SPS can directly program the orthogonal linear polarization states as a series of information to transmit. To achieve the interconversions between digital codes and the THz polarization information, an optimum matching THz polarization beam splitter (THz-PBS) is also designed via simulations and experiments. The THz-PBS, as a decoder, can accurately split the transverse electric (TE) and transverse magnetic (TM) modes into two THz detectors. At last, a coding and decoding prototype system of spintronic THz polarization is built by integrating the PP-STS, the THz-PBS and two THz detectors. The send and receive information with high speed and accuracy are verified in this prototype system as well. We believe that our work takes THz applications for multiplexing communications one step further and sheds light on commercializing the PP-STS with exciting manufacturing lines for efficient and economical THz polarization technology.

Compact Mobile Terminal Antenna With Endfire Circularly Polarized Beam for Satellite Communications

Compact Mobile Terminal Antenna With Endfire Circularly Polarized Beam for Satellite Communications

Adaptive micro-projection system based on liquid lens

Projectors play an important role in the fields of education, entertainment, etc. The conventional projectors are generally bulky, lack of portability and adaptability. In this paper, an adaptive micro-projection system based on liquid lens is proposed. The main part of the system consists of a sequential three-color light source module, a light-homogenized module, a piece of liquid–crystal-on-silicon (LCoS) with high refresh rate, a polarization beam splitter (PBS), a zoom projection lens based on liquid lenses, a liquid lens controller and a display driver board. By adjusting the driving voltages on the liquid lenses, the adaptive micro-projection system can work with the distance at least from 150 mm to 310 mm continuously. Moreover, by synchronously controlling the refresh of the LCoS and the sequential lighting of the three-color light source through the display driver board, a 60 Hz color video display can be realized with only one piece of LCoS. We introduce the design method of the liquid lens based zoom projection lens in detail and provide an optical structure of the liquid lens based zoom projection lens with excellent performance. The control software and hardware of the system are carefully developed. Simulations and experiments demonstrate the feasibility of the system. The proposed system has the characteristics of fast response, portability, integration and high adaptability and is expected to be used in virtual reality (VR), augmented reality (AR), on-board display, head-mounted display and so on.

High-Performance Silicon Polarization Beam Splitter Assisted by the Sub-Wavelength Structures

High-Performance Silicon Polarization Beam Splitter Assisted by the Sub-Wavelength Structures

Designing Bypass Channels in NICA Accelerator Complex for Polarized Beam Experiments for EDM Search

Designing Bypass Channels in NICA Accelerator Complex for Polarized Beam Experiments for EDM Search

X-ray single photon detection with XPOL-III

XPOL-III is a newly developed CMOS ASIC simultaneously working for collecting charge and processing signals inside Gas Pixel Detectors (GPD). Starting from the architecture of the XPOL ASIC and its successful operation in the IXPE space mission, we implemented specific design changes aiming at increasing the rate capability and the uniformity of response.XPOL-III includes more than 100k pixels at 50 μm pitch in a total active area of about 15 × 15 mm2. Each pixel acts as a charge-collecting anode and is connected to its charge-sensitive amplifier, followed by a shaping circuit and a sample-and-hold system. The chip, like its predecessor, provides self-triggering capability, with automatic localization of the region of interest (ROI) to be readout for each single photon. A new programmable definition of the margin pixels around the ROI was implemented to reduce readout time. Other improvements include the sensitivity of the trigger electronics and an increase in the maximum speed for the serial event readout.In this work we describe the design of this new ASIC and the results of its preliminary tests, in particular in the context of the gas detector application, in which imaging the photoelectron track emitted by single X-ray absorption allows us to measure beam polarization together with timing, imaging, and spectroscopy.

Associated production of neutrino and dark fermion at future lepton colliders

Fermionic dark matter can be pairly produced and hence searched with missing energy at colliders. We extend such probe to the associated production of a neutrino and a dark sector fermion at the future e+e− colliders such as CEPC, FCC-ee, ILC, and CLIC. Two typical processes, the mono-photon and electron-positron pair productions associated with missing energy, can serve the purpose. While the mono-photon search prevails at CEPC, FCC-ee, and ILC, the channel has more significant contributions at CLIC with much higher collision energy s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{s} $$\\end{document}. The beam polarizations can help further suppressing the SM backgrounds to enhance the signal significance while differential cross sections can distinguish the Lorentz structure of various effective operators. The combined sensitivity can reach well above 1 TeV at CEPC/FCC-ee and ILC while it further touches 30 TeV at CLIC. Comparing with the updated results from the direct detection experiments (XENON1T, PandaX-II, PandaX-4T, LZ, and XENONnT), astrophysical X/γ-ray observations, and cosmological constraints for the sub-MeV absorption dark matter, the collider searches are actually more sensitive and hence can provide a complementary approach to addressing the dark fermions.

Double nested dual-core negative curvature fiber polarization beam splitter

In this paper, a polarization beam splitter（PBS） based on double nested dual-core negative-curvature fiber (DNHC-NCF) is designed. Two hollow cores are constructed by eight double nested cladding tubes arranged at certain angles. The influences of structural parameters on the performances of the DNHC-NCF PBS have been studied by using the finite element method (FEM). According to the simulation results, the structure of the proposed DNHC-NCF PBS is optimized. The final results indicate that the length of the proposed DNHC-NCF PBS is 1.38 cm and the extinction ratio (ER) is less than −20 dB in the wavelength range of 1.48–1.80 µm (320 nm, covers S + C + L + U bands). Besides, the higher order mode extinction ratio (HOMER) in the wavelength range of 1.3–1.71 µm is greater than 100, showing good single-mode characteristic as well. It is believed that the proposed double nested dual-core negative curvature fiber polarization beam splitter will have important applications in the fields of optical communication system.

A wide band polarizing beam splitter based on complementary mode modulation in the hyperbolic metamaterial structures

An optimal beam splitter using the polarization mode modulation technique in different alignments of layered hyperbolic metamaterials is presented. The transmission and reflection modes in different arrangements of layered HMMs are studied in the presence of TM and TE waves by analyzing dispersion relations. Results show a duality in the mode modulations between structures aligned in the Y and Z axes. The response of one structure to a beam with zero polarization in terms of transmission and reflection is the same as the response of another to a beam with 90-degree polarization. We utilize this approach to propose a polarizing beam splitter (PBS) based on layered Ag-SiO2 unit cell HMM. FDTD simulations show that in a structure with two complementary outputs, when one of the outputs is in transmission mode, the other output is in reflection mode, and when the incident wave mode is changed from TM to TE, the operating modes of the outputs are reversed. Our structure can be used from 340 nm to Mid-IR with a high extinction ratio, and considering that the outputs work independently, the proposed PBS can prevent the destructive effect of waveguides on each other, which limits conventional beam splitters based on HMMs.

Broadband Polarization Beam Splitter Based on Silicon Dual-Core Photonic Crystal Fiber with Gold Layers Operating in Mid-Infrared Band

Broadband Polarization Beam Splitter Based on Silicon Dual-Core Photonic Crystal Fiber with Gold Layers Operating in Mid-Infrared Band

Grain Orientation, Angle of Incidence, and Beam Polarization Effects on Ultraviolet 300 ps‐Laser‐Induced Nanostructures on 316L Stainless Steel

AbstractLaser‐induced periodic surface structures (LIPSS) represent a unique route for functionalizing materials through the fabrication of surface nanostructures. Commercial AISI 316L stainless steel (SS316L) surfaces are laser treated by ultraviolet 300 ps laser pulses in a laser line scanning (LLS) approach. Processing parameters are optimized (pulse energy of 2.08 µJ, pulse repetition frequency of 300 kHz, and suitable laser scan and sample displacement rates) for the generation of low spatial frequency LIPSS over a large 25 × 25 mm2 area. Different angles of incidence of the laser radiation (0°, 30°, and 45°) and different linear laser beam polarizations (s and p) produce a plethora of rippled surface morphologies at distinct grains. Scanning electron microscopy and 2D Fourier transforms, together with calculations of the optical energy deposited at the treated surfaces using Sipe's first‐principles electromagnetic scattering theory, are used to study and analyze in detail these surface morphologies. Combined with electron backscattering diffraction, analyses allow associating site‐selectively various laser‐induced‐surface morphologies with the underlying crystalline grain orientation. Resulting grain orientation maps reveal a strong impact of the grain crystallographic orientation on LIPSS formation and point toward possible strategies, like multi‐step processes, for improving the manufacturing of LIPSS and their areal coverage of polycrystalline technical materials.

Multi-wavelength sub-100 Hz linewidth Brillouin fiber laser with cascaded SBS polarization parity-time symmetry

A multi-wavelength sub-100 Hz linewidth Brillouin fiber laser (BFL) with cascaded stimulated Brillouin scattering (SBS) polarization parity-time (PT) symmetry is proposed and experimentally investigated. Multi-order Stokes wave generation using a structure consisting of a main fiber ring (MFR) and a sub fiber loop (SFL). The MFR is used to excite the Stokes laser and to guarantee single longitudinal mode (SLM) operation of the generated stokes laser of each order and the SFL cascades each Stokes lasing emission to act as a Brillouin pump for the next order of Stokes generation. A Sagnac loop in the MFR consisting of optical coupler (OC), polarization beam splitter (PBS) and two polarization controllers (PCs), is used to achieve cascaded SBS polarization PT symmetry. By tuning the PC to control the polarization state of each order linearly polarized light injected into PBS at each order, thus controlling the gain and loss of the loop corresponding to the two backpropagating light waves. When the gain and loss of the coupling loops are the same in magnitude and greater than the coupling coefficient, the cascaded SBS polarization PT symmetry is broken, resulting in SLM operation for each order of Stokes waves. Experimental results reveal that thirteen Stokes waves were obtained from two different output ports at an erbium-doped fiber amplifier (EDFA) output power of 28 dBm. The measured linewidths at — 20 dB power were 0.34, 0.39, 0.33, 0.4, 0.39 and 0.43 kHz for the 1st-6th order Stokes emission, corresponding to linewidths of 17.1, 19.6, 16.6, 20.1 19.6 and 21.6 Hz, respectively, while the maximum side mode suppression ratios (SMSRs) were measured to be 47, 45, 49, 44, 41 and 41 dB for the 1st-6th order Stokes emission. Within 60 min of the stability experiment, the wavelength and power stability were ±2 pm and ±0.6 dB, respectively. Compared with previous studies, the present design guarantees the operation of SLM for each order of Stokes waves with sub-100 Hz laser linewidth.

Polarization beam combining by fused silica subwavelength grating

The fused silica subwavelength grating is applied to the combination of orthogonally polarized beams, of which wavelength tunability and robustness of geometric deviation is numerically investigated by combining efficiency based on the modal method. The experimental beam combining efficiencies of fabricated fused silica subwavelength gratings applied at 532 nm, 832 nm, and 1064 nm, respectively, are 82.9%, 80.3% and 86.6% for continuous-wave lasers without anti-reflection coatings. The experimental output combined from two 6J, 10ns, 1064 nm pulse lasers is 9.67J by fabricated 4-inch-wafer fused silica subwavelength grating with laser-induced damage threshold measured up to 26.4J/cm2. The polarization beam combining method by the subwavelength grating is applicable not only in the combination of diode laser arrays as pumping source but also in the power enhancement of bulky laser systems in fields such as laser cleaning, laser cutting and laser shock peening.

Silicon Multimode Anti-Symmetric Apodized Bragg Gratings for Ultra-Broadband High-Extinction-Ratio Polarization Beam Splitter

Silicon Multimode Anti-Symmetric Apodized Bragg Gratings for Ultra-Broadband High-Extinction-Ratio Polarization Beam Splitter

The Design and Performance Evaluation of a 1550 nm All-Fiber Dual-Polarization Coherent Doppler Lidar for Atmospheric Aerosol Measurements

A 1550 nm all-fiber dual-polarization coherent Doppler lidar (DPCDL) was constructed to measure the depolarization ratio of atmospheric aerosols. In lidar systems, the polarization state of the laser source is typically required to be that of linearly parallel polarization. However, due to the influence of the fiber-optical transmission and the large-mode field output of the telescope, the laser polarization state changes. Hence, a polarizer was mounted to the emitting channel of the telescope to eliminate the depolarization effect. A fiber-optical polarization beam splitter divided the backscattered light into components with parallel and perpendicular polarization. The DPCDL used two coherent channels to receive each of these two polarization components. A calibration procedure was designed for the depolarization ratio to determine the differences in gain and non-responsiveness in the two polarization channels. The calibration factor was found to be 1.13. Additionally, the systematic error and the measured random error of the DPCDL were estimated to evaluate the performance of the system. The DPCDL’s systematic error was found to be about 0.0024, and the standard deviation was lower than 0.0048. The Allan deviations of a 1-min averaging window with a low SNR of 19 dB and a high SNR of 27 dB were 0.0104 and 0.0031, respectively. The random errors at different measured heights were mainly distributed below 0.015. To confirm the authenticity of the atmospheric depolarization ratio measured with the DPCDL, two field observations were conducted with the use of a co-located DPCDL and micro-pulse polarization lidar to perform a comparison. The results showed that the correlation coefficients of the aerosol depolarization ratios were 0.73 and 0.77, respectively. Moreover, the two continuous observations demonstrated the robustness and stability of the DPCDL. The depolarization ratios were detected in different weather conditions.