Articles de revues : « TM POLARIZATION »

1

Gao, Chenhao, Bo Wang, Hongtao Li, Kunhua Wen, Ziming Meng, Qu Wang, Xiangjun Xing, Li Chen, Liang Lei et Jinyun Zhou. « Modes simulation and numerical optimization of encapsulated connecting-layer grating for high efficiency ». Modern Physics Letters B 32, n^o 31 (10 novembre 2018) : 1850386. http://dx.doi.org/10.1142/s0217984918503864.

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We propose and investigate a polarization-independent high-efficiency encapsulated subwavelength grating with a connecting layer in this paper. Numerical simulated method of rigorous coupled-wave analysis is adopted for optimization. Based on the simulated precise results, a simplified modal method is used to give perspicuous physical propagating fundamentals and explain wideband performance in the grating, where the coupled efficiencies by means of the simplified modal method are to be in conformity with the calculated values of the rigorous coupled-wave analysis for TE and TM polarizations. Compared with the researched surface-relief polarization-independent single-port grating, efficiencies are improved with 98.1% for TE polarization and 98.2% for TM polarization. Hence, the novel gratings with some superiorities are suitable for promising photonic devices.

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Cammarata, Simone, Andrea Fontana, Ali Emre Kaplan, Samuele Cornia, Thu Ha Dao, Cosimo Lacava, Valeria Demontis et al. « Polarization Control in Integrated Graphene-Silicon Quantum Photonics Waveguides ». Materials 15, n^o 24 (7 décembre 2022) : 8739. http://dx.doi.org/10.3390/ma15248739.

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We numerically investigated the use of graphene nanoribbons placed on top of silicon-on-insulator (SOI) strip waveguides for light polarization control in silicon photonic-integrated waveguides. We found that two factors mainly affected the polarization control: the graphene chemical potential and the geometrical parameters of the waveguide, such as the waveguide and nanoribbon widths and distance. We show that the graphene chemical potential influences both TE and TM polarizations almost in the same way, while the waveguide width tapering enables both TE-pass and TM-pass polarizing functionalities. Overall, by increasing the oxide spacer thickness between the silicon waveguide and the top graphene layer, the device insertion losses can be reduced, while preserving a high polarization extinction ratio.

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Patsamanis, Georgios, Dimitra Ketzaki, Dimitrios Chatzitheocharis et Konstantinos Vyrsokinos. « Design and Optimization of a Compact Ultra-Broadband Polarization Beam Splitter for the SCL-Band Based on a Thick Silicon Nitride Platform ». Photonics 9, n^o 8 (6 août 2022) : 552. http://dx.doi.org/10.3390/photonics9080552.

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The polarization beam splitter is an essential photonic integrated circuit in applications where a high-performing on-chip polarization diversity scheme is required. The lower refractive index contrast of the silicon nitride material platform compared to silicon-on-insulator constitutes the separation of polarized light states a challenging task since for this purpose a large difference between the effective refractive indices of the fundamental TE and TM modes is highly desirable. In this paper, we present the design and optimization analysis of an ultra-broadband polarization beam splitter based on a thick silicon nitride platform through extensive 3D-FDTD simulations. The proposed device exploits two different Si3N4 thicknesses that enable the discrimination of the two polarizations at the proximity of an 800 nm thick slot and a 470 nm thick strip waveguide via directional coupling. The proposed two-stage PBS achieves higher than 30.6 dB polarization extinction ratio (PER) for both TE and TM polarizations across a 130 nm span at the SCL-band. The dimensions of the PBS are 94 × 14 μm2 and the insertion losses are calculated to be lower than 0.8 dB for both polarizations. The fabrication tolerance of the device is also discussed.

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Lee, Chee-Wei. « A Review of Polarization Dependence Applications for Asymmetric Waveguides Vertical Couplers in Compound Semiconductor Indium Phosphide ». International Journal of Optics 2011 (2011) : 1–11. http://dx.doi.org/10.1155/2011/164023.

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This paper reviews and presents a coherent approach to the design of compact vertical coupler (VC) in InP-based compound semiconductor with variable polarization dependence. As a polarization-independent (PI) coupler, the VC is shown to transfer light with more than 90% efficiency for both transverse-electric (TE) and transverse-magnetic (TM) polarizations. As a polarization-mode splitter (PMS), the VC is shown to preferentially couple TE or TM modes with a contrast ratio of up to 20 dB. We further demonstrate the single-mesa VC, which simplifies the fabrication process and potentially could improve the process yield, and its integration with a multimode interferometer (MMI). The versatility makes the VC a compact and useful input-stage device that not only maximizes input/output coupling efficiency to small active devices but also provides a degree of polarization control before the actual device.

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Dai, Zijie, Eryi Pan, Xuefeng Chen, Xiaoxian Song, Haiting Zhang et Ying Liang. « Compact Design for Bi-Polarization Quantum Routers on SOI Platform ». Photonics 10, n^o 8 (3 août 2023) : 897. http://dx.doi.org/10.3390/photonics10080897.

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An ultra-compact optical quantum router (QR) consisting of a Mach–Zehnder interferometer (MZI) and waveguide tapers is proposed and numerically simulated, using silicon-on-insulator (SOI). The interferometer is designed to work at the center wavelength of 1550 nm with visibilities of 99.65% and 98.80% for TE and TM polarizations, respectively. Using the principle of phase compensation and self-image, the length of the waveguide tapers is shortened by an order of magnitude with the transmission above 95% for both TE and TM polarizations. Furthermore, polarization beam splitters (PBS) with an ultra-compact footprint of 1.4 × 10.4 μm2 with transmissions of 98% for bi-polarizations are achieved by introducing anisotropic metamaterials. The simulated results indicate that the interferometer facilitates low loss, a broad operating spectral range, and a large tolerance to size variation in fabrications. The optical switch possesses the routing function while maintaining the polarization states, which promises to pave the point-to-point BB84 protocol into applications of network-based quantum communication.

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Lee, Chee-Wei. « Design of Polarization-Independent Coarse Wavelength Splitters Based on Ridge-Waveguide Directional Couplers ». International Journal of Optics 2011 (2011) : 1–9. http://dx.doi.org/10.1155/2011/263182.

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We present the first unique design of a polarization-independent dual-wavelength splitter for wavelengths around 1.3 μm and 1.55 μm that is potentially of great interest to passive optical network (PON) applications. The filter design is simple compared with the other architectures and is based on ridge-type lateral directional couplers that can be readily integrated with other planar waveguide devices. Two design examples, based on InP/InGaAsP and Si/SiGe waveguides, are given. This polarization-independent wavelength splitting is achieved by exploiting the polarization dependence of the waveguides to produce coupling lengths that are sensitive to polarization and wavelength. We show that, to split the wavelengths without splitting the polarizations, the coupling lengths must be sufficiently different for TE and TM and for the different wavelengths in order to give the correct required ratios between the TE and TM coupling lengths for the two wavelengths of interest. We also show that the same approach can be applied to the design of a polarization splitter. The crosstalk, optical bandwidth, and fabrication sensitivity for the wavelength filter are evaluated.

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Zhang, Jingjing, Zhaojian Zhang, Chao Ma, Xuefeng Chen, Liping Liu, Wei Zhao, Xiaoxian Song et al. « Ultra-Compact and Ultra-Broadband Polarization-Insensitive Mach–Zehnder Interferometer in Silicon-on-Insulator Platform for Quantum Internet Application ». Photonics 8, n^o 10 (19 octobre 2021) : 455. http://dx.doi.org/10.3390/photonics8100455.

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Polarization dependence in integrated silicon photonics has a detrimental effect on the manipulation of quantum state with different polarizations in the quantum technology. Those limits have profound implications for further technological developments, especially in quantum photonic internet. Here, we propose a polarization-independent Mach–Zehnder interferometer (MZI) structure based on a 340 nm-thick silicon-on-insulator (SOI) platform. The MZI facilitates low loss, broad operating bandwidth, and large tolerance of the fabrication imperfection. We achieve an excess loss of <10% and an extinction radio of >18 in the 100 nm bandwidth (1500∼1600 nm) for both transverse electric (TE) and transverse magnetic (TM) modes. We numerically demonstrate an interference visibility of 99% and a polarization-independent loss (PDL) of 0.03 for both polarizations at 1550 nm. Furthermore, by using the principle of phase compensation and self-image, we shorten the length of the waveguide taper by almost an order of magnitude with the transmission of >95% for both TE and TM polarizations. Up to now, the proposed structure could significantly improve the integration and promote the development of monolithic integrated quantum internet.

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Shu, Wenhao, Bo Wang, Hao Pei, Hongtao Li, Li Chen, Liang Lei et Jinyun Zhou. « Investigation on multilayer microstructure grating for three-port splitting ». Modern Physics Letters B 30, n^o 16 (20 juin 2016) : 1650195. http://dx.doi.org/10.1142/s0217984916501955.

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A new structure of microstructure reflection three-port beam splitter grating is described in this paper. The grating includes two dielectric layers and a metal slab on the substrate, where incident waves are reflected into the zeroth-order and the ± first-order with polarization-independent property. With the optimized grating profile, reflection efficiencies’ ratios between the first-order and the zeroth-order can reach 0.998 and 1.001 for TE and TM polarizations, respectively. Especially, the reflection grating can diffract efficiencies more than 30% into the ± first-order and the zeroth-order with the incident angular bandwidth of −1.9–1.9[Formula: see text] for TM polarization, which can have merits compared with single-layer transmission grating.

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Calò, Giovanna, Gaetano Bellanca, Franco Fuschini, Marina Barbiroli, Velio Tralli et Vincenzo Petruzzelli. « Polarization Effect on the Performance of On-Chip Wireless Optical Point-to-Point Links ». Applied Sciences 13, n^o 5 (27 février 2023) : 3062. http://dx.doi.org/10.3390/app13053062.

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Optical on-chip wireless interconnection is an emerging technology that aims to overcome the communication bottleneck in computing architectures and in which multiple processing units are exploited for data-intensive applications. In this work, we propose an integrated dielectric Vivaldi antenna, which exhibits the same gain performances for both TE and TM input polarizations. Point-to-point on-chip communication links between two Vivaldi antennas are analyzed. Moreover, the effect of wave polarization on the link performances is numerically studied in on-chip multilayer structures in connection with the multilayer characteristic parameters, i.e., cladding layer thickness and refractive index. The numerical results show that, with the same antenna gain, TM polarization is affected by lower propagation losses when suitable cladding layer thickness and refractive index are considered.

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Tang, Geyu, Huamao Huang, Yuqi Liu et Hong Wang. « Compact Photonic Crystal Polarization Beam Splitter Based on the Self-Collimation Effect ». Photonics 8, n^o 6 (4 juin 2021) : 198. http://dx.doi.org/10.3390/photonics8060198.

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We propose a new compact polarization beam splitter based on the self-collimation effect of two-dimensional photonic crystals and photonic bandgap characteristics. The device is composed of a rectangular air holes-based polarization beam splitting structure and circular air holes-based self-collimating structure. By inserting the polarization beam splitting structure into the self-collimating structure, the TE and TM polarized lights are orthogonally separated at their junction. When the number of rows in the hypotenuse of the inserted rectangular holes is 5, the transmittance of TE polarized light at 1550 nm is 95.4% and the corresponding polarization extinction ratio is 23 dB; on the other hand, the transmittance of TM polarized light is 88.5% and the corresponding polarization extinction ratio is 37 dB. For TE and TM polarized lights covering a 100 nm bandwidth, the TE and TM polarization extinction ratios are higher than 18 dB and 30 dB, respectively. Compared with the previous polarization beam splitters, our structure is simple, the size is small, and the extinction ratio is high, which meets the needs of modern optical communications, optical interconnection, and optical integrated systems.

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11

Lin, Zefan, Bo Wang et Chen Fu. « Stack-based grating for wideband polarization splitter in terahertz ». Physica Scripta 96, n^o 12 (1 décembre 2021) : 125540. http://dx.doi.org/10.1088/1402-4896/ac4549.

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Abstract A novel wideband terahertz polarization beam splitter with special diffraction orders working at terahertz band is described in this paper. The polarizer can achieve high diffraction efficiency and uniformity in the 2.50–2.56 THz band. Based on rigorous coupled-wave analysis (RCWA) and simulated annealing algorithm, we proposed an efficient algorithm to optimize the polarizer. After calculations, 98.45% single-port high-efficiency reflection for transverse electric (TE) polarization and 42.33%/42.57% highly uniform dual-port beam splitting for transverse magnetic (TM) polarization were finally obtained. In addition, through RCWA and simplified modal method, the electromagnetic field distributions of TE and TM polarizations are shown visually and described quantitatively. Moreover, the results displayed in section 3 prove that the grating possesses the characteristics of relatively large bandwidth and insensitivity to the incident angle. Therefore, the novel scheme in this paper has great reference value for the research of terahertz modulation devices and the integration of terahertz communication systems.

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Wang, Xiaofeng, Bo Wang et Liqun Liu. « High uniformity splitter with great inhibition of ±1st orders ». Laser Physics 33, n^o 10 (7 septembre 2023) : 106201. http://dx.doi.org/10.1088/1555-6611/acf4e6.

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Abstract A transmissive double-groove grating under vertical incidence is proposed in this paper. The grating has a total of five diffraction orders, and the effect of a three-channel beam splitter is achieved by inhibiting the diffraction efficiency of ±1st orders. This is a polarization-independent micro-nano structure that achieves triple beam splitting under both TE and TM polarization. The diffraction efficiency of the 0th order and ±2nd orders for TE polarization orders can reach 32.55% and 32.72%, respectively. And the diffraction efficiency of 0th order and ±2nd orders for TM polarization can reach 32.28% and 32.59%, respectively. Both TE and TM polarization can achieve 99% uniformity. The grating performs well in terms of manufacturing tolerances and immunity to interference.

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Wei, Huihui, Jiatian Guo, Xiaobo Yuan et Junfeng Ren. « Spin Polarization Properties of Two Dimensional GaP3 Induced by 3d Transition-Metal Doping ». Micromachines 12, n^o 7 (24 juin 2021) : 743. http://dx.doi.org/10.3390/mi12070743.

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The electronic structure and spin polarization properties of monolayer GaP3 induced by transition metal (TM) doping were investigated through a first-principles calculation based on density functional theory. The calculation results show that all the doped systems perform spin polarization properties, and the Fe–doped system shows the greatest spin polarization property with the biggest magnetic moment. Based on the analysis from the projected density of states, it was found that the new spin electronic states originated from the p–d orbital couplings between TM atoms and GaP3 lead to spin polarization. The spin polarization results were verified by calculating the spin density distributions and the charge transfer. It is effective to introduce the spin polarization in monolayer GaP3 by doping TM atoms, and our work provides theoretical calculation supports for the applications of triphosphide in spintronics.

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Janaszek, Bartosz, et Paweł Szczepański. « Spatial Dispersion in Hypercrystal Distributed Feedback Lasing ». Materials 15, n^o 10 (12 mai 2022) : 3482. http://dx.doi.org/10.3390/ma15103482.

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This work is a first approach to investigate the role of spatial dispersion in photonic hypercrystals (PHCs). The scope of the presented analysis is focused on exploiting nonlocality, which can be controlled by appropriate design of the structure, to obtain new light generation effects in a distributed feedback (DFB) laser based on PHC, which are not observable under weak spatial dispersion. Here, we use effective medium approximation and our original model of threshold laser generation based on anisotropic transfer matrix method. To unequivocally identify nonlocal generation phenomena, the scope of our analysis includes comparison between local and nonlocal threshold generation spectra, which may be obtained for different geometries of PHC structure. In particular, we have presented that, in the presence of strong spatial dispersion, it is possible to obtain spectrally shifted Bragg wavelengths of TE- and TM-polarization spectra, lowered generation threshold levels for both light polarizations, generation of light of selected light polarization (TE or TM), or simultaneous generation of TE- and TM-polarized waves at different frequencies with controllable spectral separation, instead of single mode operation anticipated with local approach.

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Teranishi, Takashi, Takuya Hoshina, Hiroaki Takeda et Takaaki Tsurumi. « Wide Range Dielectric Spectroscopy of Barium Strontium Titanate Ceramics ». Key Engineering Materials 421-422 (décembre 2009) : 273–76. http://dx.doi.org/10.4028/www.scientific.net/kem.421-422.273.

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Wide band dielectric spectroscopy was applied from kHz to THz region for the analysis of both the ionic and the dipole polarization in Ba0.6Sr0.4TiO3 ceramics. The dielectric permittivity above the dielectric maximum temperature (Tm) is mostly dominated by the ionic polarization, while that below Tm is governed by the dipole polarization. Dielectric permittivity given by the dipole polarization increased and the relaxation frequency decreased with decreasing temperature. These phenomena are related to a increase of the size of polar nanoregions (PNRs).

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Wu, Feng, Zijin Wang, Jiaqi He, Zhenzhe Li, Lijuan Meng et Xiuyun Zhang. « Effect of 3d Transition Metal Atom Intercalation Concentration on the Electronic and Magnetic Properties of Graphene/MoS2 Heterostructure : A First-Principles Study ». Molecules 28, n^o 2 (4 janvier 2023) : 509. http://dx.doi.org/10.3390/molecules28020509.

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The electronic and magnetic properties of graphene/MoS2 heterostructures intercalated with 3d transition metal (TM) atoms at different concentrations have been systematically investigated by first principles calculations. The results showed that all the studied systems are thermodynamically stable with large binding energies of about 3.72 eV–6.86 eV. Interestingly, all the TM-intercalated graphene/MoS2 heterostructures are ferromagnetic and their total magnetic moments increase with TM concentration. Furthermore, TM concentration-dependent spin polarization is obtained for the graphene layer and MoS2 layer due to the charge transfer between TM atoms and the layers. A significant band gap is opened for graphene in these TM-intercalated graphene/MoS2 heterostructures (around 0.094 eV–0.37 eV). With the TM concentration increasing, the band gap of graphene is reduced due to the enhanced spin polarization of graphene. Our study suggests a research direction for the manipulation of the properties of 2D materials through control of the intercalation concentration of TM atoms.

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Kuzubov, Alexander A., Evgenia A. Kovaleva, Paul Avramov, Artem V. Kuklin, Natalya S. Mikhaleva, Felix N. Tomilin, Seiji Sakai, Shiro Entani, Yoshihiro Matsumoto et Hiroshi Naramoto. « Contact-induced spin polarization in BNNT(CNT)/TM (TM=Co, Ni) nanocomposites ». Journal of Applied Physics 116, n^o 8 (28 août 2014) : 084309. http://dx.doi.org/10.1063/1.4894157.

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Li, Lei, Bin Zhang, Ke Yin et Jing Hou. « Multiwavelength Tm-doped fiber laser based on nonlinear polarization rotation ». Chinese Optics Letters 13, Suppl. (2015) : S20602. http://dx.doi.org/10.3788/col201513.s20602.

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Zlobinskiy, Arkadiy, et Vladimir Mogilatov. « MODERN CONDITION OF TM-POLARIZATION ELECTRICAL PROSPECTING ». Interexpo GEO-Siberia 2, n^o 2 (2019) : 154–57. http://dx.doi.org/10.33764/2618-981x-2019-2-2-154-157.

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Dong, Chengkun, Sijie Dai, Jun Xia, Guodong Tong, Zhihai Wu, Hao Zhang et Bintao Du. « Ultracompact Polarization Splitter–Rotator Based on Shallowly Etched Subwavelength Gratings and Anisotropic Metasurfaces ». Nanomaterials 12, n^o 19 (7 octobre 2022) : 3506. http://dx.doi.org/10.3390/nano12193506.

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Polarization splitter–rotators (PSRs) are an essential component in on-chip polarization-sensitive and polarization–division multiplexing systems. In this work, we propose an ultracompact and high-performance silicon-based polarization splitter–rotator utilizing anisotropic metasurfaces, which is the first to combine the two, to our knowledge. The tilted periodic metasurface structure has different modulation effects on different polarized light fields, such as the transverse–electric (TE) mode and the transverse–magnetic (TM) mode, which are beneficial for designing polarization management devices. According to the results, the entire length of the silicon PSR was ~13.5 μm. The TE-to-TM conversion loss and polarization conversion ratio ere −0.154 dB and 96.5% at 1.55 μm, respectively. In the meanwhile, the cross talk and reflection loss were −27.0 dB and −37.3 dB, when the fundamental TE mode was input. The insertion loss and cross talk were −0.19 dB and −25.01 dB at the central wavelength when the fundamental TM mode was input. In addition, the bandwidth reached up to ~112 nm with polarization conversion loss and insertion loss higher than −0.46 dB and −0.36 dB. The simulations also show that the designed devices had good fabrication tolerance.

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Bordag, M., et I. G. Pirozhenko. « Surface plasmon on graphene at finite T ». International Journal of Modern Physics B 30, n^o 19 (20 juillet 2016) : 1650120. http://dx.doi.org/10.1142/s0217979216501204.

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Using the recently developed polarization tensor in [Formula: see text] dimensions for the electronic excitations of graphene, we investigate the influence of temperature on the surface plasmons on graphene. We consider nonzero mass gap, but zero chemical potential. Plasmons may exist for both polarizations, transverse electric (TE) and transverse magnetic (TM), of the electromagnetic field. For TE, the momentum region, where the dispersion function is real, appears bounded from below, whereas for TM it is bounded from above. We discuss the similarities of these features with those found previously in the case with nonzero chemical potential, but zero temperature.

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Lin, Mi, Lixin Fu, Shakeel Ahmed, Qiong Wang, Yaoxian Zheng, Zixian Liang et Zhengbiao Ouyang. « Polarization-Independent Circulator Based on Composite Rod of Ferrite and Plasma in Photonic Crystal Structure ». Nanomaterials 11, n^o 2 (2 février 2021) : 381. http://dx.doi.org/10.3390/nano11020381.

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We propose a type of polarization-independent circulator based on a composite rod of ferrite and plasma materials in a two-dimensional photonic crystal (PhC) slab. Only one composite rod was set at the center of the structure to provide circulation for both TE- and TM-polarized waves. Additionally, to improve the performance of the circulator, three additional rods were inserted to improve the coupling condition between the center magneto-optical microcavity and the corresponding waveguides. Finite element method was used to calculate the characteristics of the structure and the Nelder–Mead optimization method was employed to obtain the optimum parameters. The results show that a low insertion loss (~0.22 dB) and high isolation (~14 dB) can be achieved in our structure for waves of both TE and TM polarizations. The idea presented here may be useful for designing compact polarization devices in large-scale integrated photonic circuits.

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Chuang, Kuei-Ya, Te-En Tzeng et Tsong-Sheng Lay. « Coupled InGaAs Quantum Dots for Electro-Optic Modulation ». Crystals 11, n^o 10 (23 septembre 2021) : 1159. http://dx.doi.org/10.3390/cryst11101159.

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We investigated the growth of vertically coupled In0.75Ga0.25As quantum dots (QDs) by varying the GaAs spacer thickness (d). Vertically-aligned triple-layer QDs of uniform size and highest accumulated strain are formed with d = 5 nm. The electroluminescence (EL) characteristics for In0.75Ga0.25As QDs show an emission spectrum at optical wavelength (λ) of 1100−1300 nm. The EL spectra exhibit the highest optical gain at λ ~ 1200 nm, and the narrowest FWHM = 151 nm of the sample with d = 5 nm at injection current = 20 mA. Fabry–Perot measurements at λ = 1515 nm of TE and TM polarizations were carried out to investigate the electro-optic modulation for a single-mode ridge waveguide consisting of vertically-coupled triple-layer In0.75Ga0.25As QDs (d = 5 nm). The linear (r) and quadratic (s) electro-optic coefficients are r = 2.99 × 10−11 m/V and s = 4.10 × 10−17 m2/V2 for TE polarization, and r = 1.37 × 10−11 m/V and s = 3.2 × 10−17 m2/V2 for TM polarization, respectively. The results highlight the potential of TE/TM lightwave modulation by InGaAs QDs at photon energy below energy band resonance.

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Jeong, Seok-Hwan, Heuk Park et Joon Ki Lee. « Silicon-Nanowire-Type Polarization-Diversified CWDM Demultiplexer for Low Polarization Crosstalk ». Nanomaterials 13, n^o 16 (21 août 2023) : 2382. http://dx.doi.org/10.3390/nano13162382.

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Coarse wavelength division multiplexing (CWDM)-targeted novel silicon (Si)-nanowire-type polarization-diversified optical demultiplexers were numerically analyzed and experimentally verified. The optical demultiplexer comprised a hybrid mode conversion-type polarization splitter rotator (PSR) and a delayed Mach–Zehnder interferometric demultiplexer. Si-nanowire-based devices were fabricated using a commercially available Si photonics foundry process, exhibiting nearly identical spectral responses regardless of the polarization states of the input signals under the PSR. The experiment demonstrated a low insertion loss of 1.0 dB and a polarization-dependent loss of 1.0 dB, effectively suppressing spectral crosstalk from other channels by less than −15 dB. Furthermore, a TM-mode rejection-filter-integrated optical demultiplexer was designed and experimentally validated to mitigate unwanted TM-mode-related polarization crosstalk that arose from the PSR. It exhibited an improved polarization crosstalk rejection efficiency of −25 dB to −50 dB within the whole CWDM spectral range.

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Gong, Bowen, et Huiying Wen. « Enhanced polarization-independent two-layer five-port grating with covering layer ». Modern Physics Letters B 35, n^o 25 (3 août 2021) : 2150348. http://dx.doi.org/10.1142/s0217984921503486.

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In this paper, an enhanced polarization-independent two-layer five-port grating with covering layer is proposed. The rigorous coupled-wave analysis (RCWA) is used to predict grating parameters. In addition, the total efficiency of the polarization-independent five-port grating with covering layer can exceed 80% with the good uniformity of 1.97% for TE and TM polarization. The inherent coupling mechanism and the electric field energy distribution of the gratings are explained well under TE and TM polarization by the simplified mode method (SMM) and the finite element method (FEM). According to the reported five-port gratings, the proposed transmission five-port grating with a covering layer has good uniformity for TE and TM polarization. Moreover, the grating can be protected and the groove of the grating can be kept clean by adding a covering layer during the actual fabrication. At the same time, the fabrication errors of the two-layer five-port diffraction grating are further considered. Therefore, the numerically simulated five-port grating with covering layer has a wide application prospect in precision displacement measurement and holographic projection imaging.

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Bhowmik, Tanmay, et Debabrata Sikdar. « Parallel directional coupler based dual-polarization electro-absorption modulator using epsilon near-zero material ». Journal of Physics D : Applied Physics 55, n^o 13 (31 décembre 2021) : 135107. http://dx.doi.org/10.1088/1361-6463/ac4455.

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Abstract Electro-optical modulation, where a radio frequency signal can be encoded in an optical field, is crucial to decide the overall performance of an integrated photonics system. Due to the growing internet penetration rate worldwide, polarization-division-multiplexing (PDM) technique has emerged to increase the link capacity, where polarization-independent modulators are desirable to reduce system complexity. In this study, we propose a novel parallel directional coupler based dual-polarization electro-absorption modulator based on epsilon-near-zero (ENZ) material. The proposed design is capable of independent and synchronized modulation of two fundamental modes viz. transverse magnetic (TM) and transverse electric (TE) mode of a standard silicon (Si) rib waveguide. Indium-tin-oxide (ITO)–Si based two parallel hybrid plasmonic waveguides (HPW1 and HPW2) are placed such that fundamental TM (TE) mode of the input bus waveguide can be coupled to HPW1 (HPW2). The ENZ-state of ITO, acquired upon two independent electrical gating, enables large modulation depth by utilizing enhancement of electric field at the absorptive carrier accumulation layer. With a 27 μm active length, the extinction ratio (ER) of the proposed design is 10.11 dB (9.66 dB) for TM (TE) modulation at 1550 nm wavelength. This results in a 0.45 dB ER-discrepancy and indicates the polarization-insensitive nature of the modulator. The insertion losses and modulation bandwidths of our design are less than 1 dB and more than 100 GHz, respectively, for both polarizations over the entire C-band of wavelength. The proposed design can find potential applications in the PDM-enabled integrated photonics systems and high speed optical interconnections at data center networks.

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Nia, B. Arghavani, R. Moradian et M. Shahrokhi. « Structural, electronic and magnetic properties of Fe, Co, Ni monatomic nanochains encapsulated in armchair LiF nanotubes ». Materials Science-Poland 35, n^o 2 (26 juillet 2017) : 283–90. http://dx.doi.org/10.1515/msp-2017-0045.

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Abstract Structural, electronic and magnetic properties of transition metal TM (TM = Fe, Co and Ni) atomic chains wrapped in single walled LiF armchair nanotubes have been investigated by the first-principles calculations in the framework of the density functional theory. The generalized gradient approximation (GGA) with Hubbard repulsion potential and without Hubbard repulsion was employed to describe the exchange-correlation potential. It is found that all these TM chains @LiFNTs systems have negative formation energy so they are stable and exothermic. Total density of states and partial densities of states analyses show that the spin polarization and the magnetic moment of TM chains @LiFNTs(n,n) systems come mostly from the TM atom chains. All these nanocomposites are ferromagnetic (FM) and spin splitting between spin up and down is observed. The high magnetic moment and spin polarization of the TM chains @LiFNT(n,n) systems show that they can be used as magnetic nanostructures possessing potential current and future applications in permanent magnetism, magnetic recording, and spintronics.

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Jafari, A., et A. Rahmat. « Band structure of one-dimensional photonic crystal with graphene layers using the Fresnel coefficients method ». International Journal of Modern Physics B 32, n^o 11 (16 avril 2018) : 1850132. http://dx.doi.org/10.1142/s0217979218501321.

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In this paper, we have calculated the band structure of an instance of one-dimensional photonic crystal (1DPC) composed of double-layered dielectrics via the Fresnel coefficients method. Then, we supposed the addition of a thin layer of graphene to each dielectric layer and the given photonic crystal (PC) composed of dielectric–graphene composites. The effects of graphene layers on the PC band structure were evaluated. We found out that according to the effective medium theory unlike the TE polarization, the electric permittivity of the dielectric layers changed at TM polarization. As such, the band structure of PC for TM polarization changed, too. Moreover, instead of bandgap related to “zero averaged refractive index” an approximately omnidirectional bandgap appeared and a related bandgap to “[Formula: see text] = 0” disappeared. In addition, a new angular gap branch appeared at a new frequency at TM polarization in which the width of gap increased as the angle increased.

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Fang, Yuxi, Changjing Bao, Zhonghan Wang, Yange Liu, Lin Zhang, Hao Huang, Yongxiong Ren, Zhongqi Pan et Yang Yue. « Polarization Beam Splitter Based on Si3N4/SiO2 Horizontal Slot Waveguides for On-Chip High-Power Applications ». Sensors 20, n^o 10 (18 mai 2020) : 2862. http://dx.doi.org/10.3390/s20102862.

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In this paper, we propose an Si3N4/SiO2 horizontal-slot-waveguide-based polarization beam splitter (PBS) with low nonlinearity for on-chip high-power systems. The coupling length ratio between the quasi-TE and quasi-TM modes (LTE/LTM) was optimized to 2 for an efficient polarization splitting. For the single-slot design, the coupling length of the PBS was 281.5 μm, while the extinction ratios (ER) of the quasi-TM and quasi-TE modes were 23.9 dB and 20.8 dB, respectively. Compared to PBS based on the Si3N4 strip waveguide, the coupling length became 22.6% shorter. The proposed PBSs also had a relatively good fabrication tolerance for an ER of >20 dB. For the multi-slot design, the coupling length of the PBS was 290.3 μm, while the corresponding ER of the two polarizations were 24.0 dB and 21.0 dB, respectively. Furthermore, we investigated the tradeoff between the ER and coupling length for the optimized PBSs with single slot or multiple slots.

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Ataei, Elahe, Mehdi Sharifian et Najmeh Zare Bidoki. « Magnetized plasma photonic crystals band gap ». Journal of Plasma Physics 80, n^o 4 (9 avril 2014) : 581–92. http://dx.doi.org/10.1017/s0022377814000105.

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In this paper, the effect of the magnetic field on one-dimensional plasma photonic crystal band gaps is studied. The one-dimensional fourfold plasma photonic crystal is applied that contains four periodic layers of different materials, namely plasma1–MgF2–plasma2–glass in one unit cell. Based on the principle of Kronig–Penney's model, dispersion relation for such a structure is obtained. The equations for effective dielectric functions of these two modes are theoretically deduced, and dispersion relations for transverse electric (TE) and transverse magnetic (TM) waves are calculated. At first, the main band gap width increases by applying the exterior magnetic field. Subsequently, the frequency region of this main band gap transfers completely toward higher frequencies. There is a particular upper limit for the magnitude of the magnetic field above which increasing the exterior magnetic field strength doesn't have any significant influence on the dispersion function behavior. (With an increase in incident angle up to θ1= 66°, the width of photonic band gap (PBG) changes for both TM/TE polarization.) With an increase in incident angle up to θ1= 66°, the width of PBG decreases for TM polarization and the width of PBG increases for TE polarization, but it increases with further increasing of the incident angle from θ1= 66° to 89° for both TE- and TM-polarizations. Also, it has been observed that the width of the photonic band gaps changes rapidly by relative difference of the two-plasma frequency. Results show the existence of several photonic band gaps that their frequency and dispersion magnitude can be controlled by the exterior magnetic field, incident angle, and two plasma frequencies. The result of this research would provide theoretical instructions for designing filters, microcavities, fibers, etc.

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Brand, Omer, Benjamin Wolftson et Dror Malka. « A Compact Polarization MMI Combiner Using Silicon Slot-Waveguide Structures ». Micromachines 14, n^o 6 (6 juin 2023) : 1203. http://dx.doi.org/10.3390/mi14061203.

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The study of designing a compact transverse electric (TE)/transverse magnetic (TM) polarization multimode interference (MMI) combiner based on silicon slot-waveguide technology is proposed for solving the high demands for high-speed ability alongside more energy power and minimizing the environmental impact of power consumption, achieving a balance between high-speed performance and energy efficiency has become an important consideration in an optical communication system. The MMI coupler has a significant difference in light coupling (beat-length) for TM and TE at 1550 nm wavelength. By controlling the light propagation mechanism inside the MMI coupler, a lower order of mode can be obtained which can lead to a shorter device. The polarization combiner was solved using the full-vectorial beam propagation method (FV-BPM), and the main geometrical parameters were analyzed using Matlab codes. Results show that after a short light propagation of 16.15 μm, the device can function as TM or TE combiner polarization with an excellent extinction ratio of 10.94 dB for TE mode and 13.08 dB for TM mode with low insertion losses of 0.76 dB (TE) and 0.56 dB (TM) and the combiner function well over the C-band spectrum. The polarization combiner also has a robust MMI coupler length tolerance of 400 nm. These attributes make it a good candidate for using this proposed device in photonic integrated circuits for improving power ability at the transmitter system.

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Liao, Yan-Lin, et Yan Zhao. « Near-infrared TM-polarization ultra-narrowband absorber with dielectric metamaterials ». Modern Physics Letters B 33, n^o 18 (26 juin 2019) : 1950201. http://dx.doi.org/10.1142/s0217984919502014.

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Ultra-narrowband light absorption is desired for many applications. A near-infrared TM-polarization (magnetic field is parallel to grating grooves) ultra-narrowband absorber with dielectric metamaterials has been reported theoretically in this paper. The simulation results show that we can achieve an ultra-narrowband absorption at the incident wavelength of [Formula: see text] with the absorption bandwidth less than 0.9 nm and the absorption rate more than 0.99 for TM polarization. At the same time, we find that the high absorption rate can only remain up to [Formula: see text], which means our absorber has high directivity. In addition, the field distribution at the resonance wavelength shows that the ultra-narrowband absorption in our absorber has originated from magnetic resonance effect. Our near-infrared TM-polarization ultra-narrowband absorber is a good candidate for laser stealth.

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Saad, Yasmeen, et Amin Habbeb AL-Khursan. « Deep Ultraviolet BGaN Quantum Dot structures ». University of Thi-Qar Journal of Science 8, n^o 2 (12 septembre 2022) : 104–15. http://dx.doi.org/10.32792/utq/utjsci.v8i2.871.

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This research studies boron-containing quantum dot (QD) structures that emit the ultraviolet. Ternary and quaternary lattice-matched structure:, , , , ,, , and and their TE and TM gain spectra, spontaneous emission, spontaneous polarization, and piezoelectric polarization have been examined in these structures. They have high TE and TM spectra under reducing boron content in the QD or barrier layer. The total polarization decreases for the Al-containing systems, which is preferred. Binary systems emit at 199nm, while the quaternary can have a peak wavelength near 235nm. Elongating of the wavelength to 290nm is possible with with high gain at a few boron contents.

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Lei, Danqi, Dae-Hyun Kim, Nasser Babazadeh, David T. D. Childs et Richard A. Hogg. « Polarization-pinning in substrate emission multi-mode vertical-cavity surface-emitting lasers using deep trenches ». Applied Physics Letters 120, n^o 21 (23 mai 2022) : 211102. http://dx.doi.org/10.1063/5.0087166.

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We investigated the stable polarization-pinning properties of substrate emission InGaAs-based 980 nm multi-mode vertical-cavity surface-emitting lasers (VCSELs). For the multi-mode 40 um diameter aperture VCSELs, we introduced 30 μm wide, 9 μm depth deep trenches that are 15 μm away from the cavity aperture. The VCSELs with trench structure produced higher transverse-electric (TE) polarized light output power, as compared with transverse-magnetic (TM) polarized light output power, namely, the effective TM polarization suppression was realized. These trench-etched VCSELs exhibited a 7.5 dB orthogonal polarization suppression ratio with 16.8 mW of light output power at 60 mA of current injection. The dominant TE polarization distribution was observed in polarization-resolved near-field images of spontaneous and stimulated emission due to the induced strain by the etched trenches.

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Zheng, Xinzhi, Yujie Ma, Chenxi Zhao, Bingxi Xiang, Mingyang Yu, Yanmeng Dai, Fang Xu et al. « Polarization Splitting at Visible Wavelengths with the Rutile TiO2 Ridge Waveguide ». Nanomaterials 13, n^o 12 (20 juin 2023) : 1891. http://dx.doi.org/10.3390/nano13121891.

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On-chip polarization control is in high demand for novel integrated photonic applications such as polarization division multiplexing and quantum communications. However, due to the sensitive scaling of the device dimension with wavelength and the visible-light absorption properties, traditional passive silicon photonic devices with asymmetric waveguide structures cannot achieve polarization control at visible wavelengths. In this paper, a new polarization-splitting mechanism based on energy distributions of the fundamental polarized modes in the r-TiO2 ridge waveguide is investigated. The bending loss for different bending radii and the optical coupling properties of the fundamental modes in different r-TiO2 ridge waveguide configurations are analyzed. In particular, a polarization splitter with a high extinction ratio operating at visible wavelengths based on directional couplers (DCs) in the r-TiO2 ridge waveguide is proposed. Polarization-selective filters based on micro-ring resonators (MRRs) with resonances of only TE or TM polarizations are designed and operated. Our results show that polarization-splitters for visible wavelengths with a high extinction ratio in DC or MRR configurations can be achieved with a simple r-TiO2 ridge waveguide structure.

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Chen, Ming, et Chen Chen. « TE/TM polarization splitters in LiNbO3 photonic wires ». Optik 126, n^o 2 (janvier 2015) : 184–86. http://dx.doi.org/10.1016/j.ijleo.2014.08.149.

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Massaro, A., A. F. Cavallari et T. Rozzi. « Polarization Switching by TM Passing of Laminated Cover ». Journal of Lightwave Technology 22, n^o 2 (février 2004) : 558–66. http://dx.doi.org/10.1109/jlt.2004.824395.

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Ho, Pui Lin, et Ya Yan Lu. « Improving the beam propagation method for TM polarization ». Optical and Quantum Electronics 35, n^o 4/5 (mars 2003) : 507–19. http://dx.doi.org/10.1023/a:1022925907084.

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Wang, Guan Jun, Zhi Bin Wang, You Hua Chen, Yuan Yuan Chen, Yong Quan An, Shi Wei Li, Min Juan Zhang et Jin Hua Li. « Polarization-Insensitive Holey Fiber with Ultra-Small Mode Areas Using a Cross-Slot-Structure Core ». Key Engineering Materials 609-610 (avril 2014) : 775–78. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.775.

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A high nonlinear, dispersion flattened hybrid nanofiber with a silicon/silica cross-slot-structure nanocore is firstly proposed and analyzed, which is insensitive to polarization for implementing quasi-TE and quasi-TM fundamental modes transmission due to cross slot effect. Simulation results show that fundamental mode of ultra-small mode effective areas and high nonlinearity at TE and TM polarizations, which are confined in the narrow cross slot by four silicon ribs, can be achieved via this cross sot structure core. Moreover, the cladding of four large-air-holes promotes tailoring the group velocity dispersion (GVD) and enhancing nonlinearity furthermore. Our results indicate that ultra-small Aeff of 0.098μm2 and flat anomalous GVD with less than 13.5 ps.km-1.nm-1 dispersion ripple at C-band are realizable.

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Kozlov, D., et V. Kotlyar. « Focusing of laser light using a dielectric cylinder carrying higher-order whispering gallery modes ». Computer Optics 39, n^o 3 (2015) : 324–31. http://dx.doi.org/10.18287/0134-2452-2015-39-3-324-331.

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We demonstrated that plane wave diffraction on a dielectric cylinder with resonant radius produces a broader focal spot in case of TM-polarization, and resonant radiuses of whispering gallery modes (WGM) for TM-polarized illumination are significantly greater than corresponding radiuses for TE-polarization. We also showed that high order WGM are exited in cylinders with radiuses close to extreme value conditions of Bessel functions, and that increasing WGM order not necessary leads to stronger light confinement in the focal spot.

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Abdullahi, M. B., et M. H. Ali. « DESIGN AND PERFORMANCE SIMULATION OF STRUCTURED MICROWAVE ABSORBER BASED ON CONDUCTIVE ABS 3D PRINTING FILAMENT ». FUDMA JOURNAL OF SCIENCES 4, n^o 4 (14 juin 2021) : 425–31. http://dx.doi.org/10.33003/fjs-2020-0404-499.

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Electromagnetic absorbing materials with broadband, lightweight, wide-angle, and polarization-insensitive characteristics attracts extensive research interest recently, due to rapid advancement in radar detection techniques and communication devices. Three-dimensional printing is being employed to realize cost-effective structured electromagnetic absorbers that has lately become a common practice of improving radar stealth performance and shielding effectiveness. Structured absorbers permit realization of desired absorption characteristics by careful design of their geometrical structures. In this study, a two-layer structured microwave absorber using conductive ABS polymer is simulated. COMSOL Multiphysics environment is used to investigate the absorption characteristics of the designed structure. Under normal incidence, simulation results revealed at least 90% of absorption from 7.2 GHz to 18.0 GHz for both Transverse Electric (TE) and Transverse Magnetic (TM) polarizations. Oblique incidence results for TE polarization indicate that the absorption rate is more than 90% in the whole range of 7.2–18 GHz frequency band up to 450 while the absorption rate is more than 80% for 600 incident waves. The absorption rate is more than 90% in the 7.2-18 GHz range for oblique incidences of up to 300 only for TM polarization, but greater than 70% at 450 incident angles. Additionally, the designed absorber is independent of the polarization of the incident wave. As a result of the exhibited favourable absorption characteristics, the studied absorber provides great potentials for its experimentation and practicability using the low-cost 3D printing manufacturing process

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Jiao, Xiao-Fei, Zi-Heng Zhang, Yun Xu et Guo-Feng Song. « Resonant cavity enhanced waveguide transmission for high-efficiency Terahertz polarization beam splitter ». Modern Physics Letters B 35, n^o 05 (18 janvier 2021) : 2150089. http://dx.doi.org/10.1142/s0217984921500895.

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In this study, a design for the high-efficiency transmissive terahertz polarization beam splitter is proposed. Based on the metal–insulator–metal waveguide array structure, it is found that the phase change between the transverse-electric (TE) and transverse-magnetic (TM) modes of terahertz wave transmission depends greatly on the medium width. According to this phenomenon, our designed devices can achieve polarization splitting of TE and TM modes in the frequency range 0.8–2.4 THz, and the transmittance can be maintained above 85%. In addition, through judicious design, polarization splittings with 93% transmittance at 1 THz and 95% transmittance at 1.5 THz are obtained, and polarization splitting at different angles is achieved according to variable periods. Compared with the traditional polarization beam splitter, this design has the advantages of adjustable frequency, high efficiency, and easy integration, thus having potential application in terahertz optical systems.

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Wang, Zhibin, Mengxiong Zhao, Shaojie Yin, Mengfei Jia et Xuwei Hou. « Silicon-based subwavelength grating polarization beam splitter with asymmetric directional coupler ». Laser Physics 33, n^o 8 (4 juillet 2023) : 086204. http://dx.doi.org/10.1088/1555-6611/acdbc4.

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Abstract In this paper, a novel polarization beam splitter (PBS) is proposed. The silicon-based subwavelength grating (SWG) is successfully applied to the asymmetric directional coupled PBS, and the research shows that its performance has improved in many aspects. By carefully optimizing structural parameters, the transverse electric (TE) polarization is in a reflected state in the SWG, which effectively weakens the coupling strength, while the transverse magnetic (TM) polarization is almost unaffected. Simulation results show that the bandwidths of TE polarization and TM polarization are 200 nm (1450–1650 nm) and 141 nm (1450–1650 nm) in the extinction ratio of >20 dB, respectively, while the insertion loss is <0.5 dB and <1.3 dB, respectively. The PBS is very robust to the process production. With the manufacturing error exceeding 20 nm, the performance is only reduced by 0.6 dB, effectively solving the problem of complex preparation process.

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Yu, Fan, Guo-Qiang He, Xue-Xia Yang, Jinxin Du et Steven Gao. « Polarization-Insensitive Metasurface for Harvesting Electromagnetic Energy with High Efficiency and Frequency Stability over Wide Range of Incidence Angles ». Applied Sciences 10, n^o 22 (13 novembre 2020) : 8047. http://dx.doi.org/10.3390/app10228047.

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In this paper, a polarization-insensitive metasurface, harvesting electromagnetic (EM) energy with high efficiency and frequency stability over a wide range of incidence angles, is proposed. The previously reported metasurfaces suffer from their maximum efficiencies shifting with the frequency when the incidence angle increases. By introducing a square-shaped metal via ring around the elements, the mutual coupling among adjacent cells is reduced so that the proposed metasurface can maintain maximum efficiency at the fixed operation frequency over a wide range of incidence angles. Furthermore, with one single harvesting via in the proper position for the connection of a harvesting load, the metasurface can collect EM energy effectively with both transverse electric (TE) and transverse magnetic (TM) polarizations in one single harvesting load. Compared with the reported metasurfaces, this proposed metasurface has a higher efficiency and fixed operation frequency within a wide incidence range. The energy distribution, harvesting efficiency, and surface current are simulated to investigate the operation mechanism of the proposed metasurface. The simulation results show that the maximum harvesting efficiency is 91% at 5.8 GHz for both TE and TM polarizations at the normal incidence. When the incident angle increases to 75°, the maximum efficiency is achieved at 5.79 GHz (0.19% shift), and the maximum efficiencies of TM and TE polarizations are 91% and 68%, respectively. A 5 × 5 array is fabricated and tested. The experimental results are in good agreement with the simulated ones.

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Li, Songquan, Laixu Gao, Changwei Zou, Wei Xie, Yong Wei, Canxin Tian, Zesong Wang, Feng Liang, Yanxiong Xiang et Qian Yang. « A Polarization-Independent Fiber-Optic SPR Sensor ». Sensors 18, n^o 10 (22 septembre 2018) : 3204. http://dx.doi.org/10.3390/s18103204.

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Fiber-optic surface plasmon resonance (SPR) sensors possess the advantages of small size, flexible, allowing for a smaller sample volume, easy to be integrated, and high sensitivity. They have been intensively developed in recent decades. However, the polarizing nature of the surface plasmon waves (SPWs) always hinders the acquisition of SPR spectrum with high signal-noise ratio in wavelength modulation unless a polarizer is employed. The addition of polarizer complicates the system and reduces the degree of compactness. In this work, we propose and demonstrate a novel, polarization-independent fiber-optic SPR sensor based on a BK7 bi-prism with two incident planes orthogonal to each other. In the bi-prism, TM-polarized components of non-polarized incident lights excite SPWs on the first sensing channel, meanwhile the TE components and the remaining TM components are reflected, then the reflected TE components serve as TM components of incident lights for the second sensing channel to excite SPWs. Simulations show the proposed SPR structure permit us to completely eliminate the polarization dependence of the plasmon excitation. Experimental results agree well with the simulations. This kind of devices can be considered an excellent option for development of simple and compact SPR chemical sensors.

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Jiang, Kai Wei, Yu Tian Pan, Guan Jun Wang et Jing Xiao. « Dispersion Management and Nonlinearity Enhancement in a Hybrid Nanofiber with a High Index, Cross-Slot-Structure Nanocore ». Applied Mechanics and Materials 668-669 (octobre 2014) : 17–21. http://dx.doi.org/10.4028/www.scientific.net/amm.668-669.17.

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A highly nonlinear, dispersion flattened hybrid nanofiber with a silicon/silica cross-slot-structure nanocore is proposed and analyzed, which is insensitive to polarization for implementing quasi-TE and quasi-TM fundamental modes transmission due to the cross slot effect. Simulation results show that fundamental mode with ultra-small mode effective areas and high nonlinearity at TE and TM polarizations, which are confined in the narrow cross slot by four silicon ribs, can be achieved via this cross-slot-structure core. Moreover, the cladding of four large-air-holes contributes to the tailoring of the group velocity dispersion (GVD) and further enhancment of the nonlinearity. Our results indicate that ultra-small Aeff of 0.098μm2 and flat anomalous GVD with less than 13.5 ps.km-1.nm-1 dispersion ripple at C-band are realizable.

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Kaewrawang, Arkom, et Naruemon Wannawong. « Design of Multilayer Polarization Beam Splitters Using Multiobjective Evolutionary and Genetic Algorithms ». Advanced Materials Research 931-932 (mai 2014) : 973–78. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.973.

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Multilayer polarization beam splitters (MPBSs) are important optical components in optical communication systems and optical devices. The components of transverse electric (TE) and transverse magnetic (TM) light plane wave in MPBSs are separated in different ways. In this paper, the Pareto optimization (multiobjective evolutionary and genetic algorithms) is used to design MPBSs on C-band frequency. The reflectances of TM light plane wave for Pareto optimization are the lowest and zero at the wavelength of 1.535 μm. The degree of polarization for Pareto optimization is the highest at wavelength from 1.528 - 1.54 μm and reaches 100% at wavelength of 1.535 μm.

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Li, Qian, Junjie Tu, Yang Tian et Yanli Zhao. « Polarization-Insensitive Waveguide Schottky Photodetectors Based on Mode Hybridization Effects in Asymmetric Plasmonic Waveguides ». Sensors 20, n^o 23 (2 décembre 2020) : 6885. http://dx.doi.org/10.3390/s20236885.

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Two types of configurations are theoretically proposed to achieve high responsivity polarization-insensitive waveguide Schottky photodetectors, i.e., a dual-layer structure for 1.55 µm and a single-layer structure for 2 µm wavelength band. Mode hybridization effects between quasi-TM modes and sab1 modes in plasmonic waveguides are first presented and further investigated under diverse metal types with different thicknesses in this work. By utilizing the mode hybridization effects between quasi-TE mode and aab0 mode, and also quasi-TM and sab1 mode in our proposed hybrid plasmonic waveguide, light absorption enhancement can be achieved under both TE and TM incidence within ultrathin and short metal stripes, thus resulting in a considerable responsivity for Si-based sub-bandgap photodetection. For 1.55 µm wavelength, the Au-6 nm-thick device can achieve absorptance of 99.6%/87.6% and responsivity of 138 mA·W−1/121.2 mA·W−1 under TE/TM incidence. Meanwhile, the Au-5 nm-thick device can achieve absorptance of 98.4%/90.2% and responsivity of 89 mA·W−1/81.7 mA·W−1 under TE/TM incidence in 2 µm wavelength band. The ultra-compact polarization-insensitive waveguide Schottky photodetectors may have promising applications in large scale all-Si photonic integrated circuits for high-speed optical communication.

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Zhou, Nan-Nan, Lei Kangxin, Guoqiang Xue et Wen Chen. « Induced polarization effect on grounded-wire transient electromagnetic data from transverse electric and magnetic fields ». GEOPHYSICS 85, n^o 4 (13 juin 2020) : E111—E120. http://dx.doi.org/10.1190/geo2019-0322.1.

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Transient electromagnetic (TEM) data can be seriously distorted by induced polarization (IP) phenomena when a polarizable body is present. The TEM field generated by a grounded-wire source contains transverse electric (TE) and transverse magnetic (TM) modes. The IP effect is most commonly studied with the TEM total field, rather than considering the difference between TE and TM fields. To investigate the effect of IP phenomena on the TE and TM fields, we have performed a detailed analysis on IP-distorted TEM data based on numerical and field examples. We first compare the IP effect on the TE and TM fields when polarizable bodies with different polarizable parameters are present. The TM field is more severely affected by the IP effect than the TE field. Compared to a single grounded-wire source, a double-line grounded-wire source can generate a larger TM field in the horizontal electric field. We compare the IP effect on TEM data from single- and double-line grounded-wire TEM configurations, and find that the data from the double-line configuration have a higher TM/TE ratio and are more severely affected by IP phenomena than in the single-line case. Thus, it would be easier to identify and extract the IP response from field data acquired with a double-line grounded-wire source configuration. These results have been verified by a field survey of the Kalatongke copper-nickel ore district, which has predominantly layered geology, in Xinjiang, China.

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Jafari, A., A. Rahmat et S. Bakkeshizadeh. « Band structure of one-dimensional doped photonic crystal with three level atoms using the Fresnel coefficients method ». International Journal of Modern Physics B 32, n^o 01 (8 janvier 2018) : 1750277. http://dx.doi.org/10.1142/s0217979217502770.

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We consider a one-dimensional photonic crystal (1DPC) composed of double-layered dielectrics. Electric permittivity and magnetic permeability of this crystal depends on the incident electromagnetic wave frequency. We suppose that three level atoms have been added to the second layer of each dielectric and this photonic crystal (PC) has been doped. These atoms can be added to the layer with different rates. In this paper, we have calculated and compared the band structure of the mentioned PC considering the effect of added atoms to the second layer with different rates through the Fresnel coefficients method. We find out that according to the effective medium theory, the electric permittivity of the second layer changes. Also the band structure of PC for both TE and TM polarizations changes, too. The width of bandgaps related to “zero averaged refractive index” and “Bragg” increases. Moreover, new gap branches appear in new frequencies at both TE and TM polarizations. In specific state, two branches of “zero permittivity” gap appear in the PC band structure related to TM polarization. With increasing the amount of the filling rate of total volume with three level atoms, we observe a lot of changes in the PC band structure.

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