摘要 :
In this work, first the necessary conditions for a versatile cross-polarization conversion meta-atom that operates both for linear and circular cross polarizations are discussed. Based on these, a versatile chiral metasurface cros...
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In this work, first the necessary conditions for a versatile cross-polarization conversion meta-atom that operates both for linear and circular cross polarizations are discussed. Based on these, a versatile chiral metasurface cross-polarization converter is proposed. The correspondence between its physical geometry and polarization domain characteristics is studied. To verify the design concept, a prototype is fabricated and measured. An effective vertical and horizontal linear cross-polarization conversion is achieved from 29.3 to 38.8 GHz (27.90%) and from 34.0 to 36.6 GHz (7.36%), respectively. Furthermore, the proposed converter also achieves circular polarization handedness rotation from 34.5 to 36.6 GHz (5.91%).
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A dual broadband cross-polarization-conversion (CPC) metasurface is designed, simulated, fabricated and results are experimentally verified. The designed patch of metasurface unit cell is composed of a triangular loop connected wi...
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A dual broadband cross-polarization-conversion (CPC) metasurface is designed, simulated, fabricated and results are experimentally verified. The designed patch of metasurface unit cell is composed of a triangular loop connected with two arcs at both ends. The metasurface is made of 44 x 44 unit cells arranged periodically on 1.6-mm-thick FR4 dielectric substrate, backed by a metallic copper sheet as a reflector surface on the back side of the dielectric substrate. The surface achieves CPC in two bands (7-8.5 GHz) and (13-19 GHz), in the microwave regime. The simulation results show that the polarization conversion ratio (PCR) is almost 90% for both x polarized (TM) and y polarized (TE) electromagnetic (EM) waves. The proposed metasurface is fabricated on 308 x 308 mm(2) FR4 substrate plane. The simulated results are validated and are found in close covenant with the measured results.
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We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dumm...
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We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dummy channel into the fiber.
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摘要 :
We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dumm...
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We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dummy channel into the fiber.
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摘要 :
We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dumm...
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We experimentally demonstrate all-optical wavelength conversion at lOGbit/s using polarization rotation in 2m long Bismuth fiber. -2.5dB power penalty and 23dB extinction ratio is achieved co-injecting 25dBm pump and -3dBm CW dummy channel into the fiber.
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In this paper, the synthesis of two wideband metamaterial cross-polarizers (MCPs) is proposed. The synthesis of the proposed MCPs is done using the binary wind-driven optimization (BWDO) technique, which is an advanced version of ...
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In this paper, the synthesis of two wideband metamaterial cross-polarizers (MCPs) is proposed. The synthesis of the proposed MCPs is done using the binary wind-driven optimization (BWDO) technique, which is an advanced version of the wind-driven optimization (WDO) technique. The maximum number of iterations is determined to achieve the desired wideband responses. Model-I is obtained after 10 iterations, which achieves a -10 dB conversion bandwidth of 5.09 GHz, ranging from 6.59 to 13.70 GHz, with three polarization conversion ratio (PCR) peaks at 7.6, 9.8 and 11.9 GHz and PCR percentage of 99.89, 99.90 and 99.02%, respectively. Similarly, Model-II is obtained after 18 iterations, which achieves a -10 dB conversion bandwidth of 5.67 GHz, with a range of 5.96 to 12.80 GHz and three PCR peaks at 6.8, 8.5 and 11.9 GHz with PCR percentage of 99.85, 99.88 and 99.29%, respectively. The wideband cross-polarization mechanism is investigated by the analysis of wideband MCPs with two different techniques: first, with the help of effective electromagnetic (EM) parameters epsilon(eff) and mu(eff), and secondly with the help of current distribution techniques. The proposed MCPs are fabricated on flame-retardant (FR-4) substrate and tested inside an anaerobic chamber. The tested and simulated results obtained are very close to each other, with only a small variance with respect to fabrication tolerance. Finally, the proposed MCPs are compared with previously reported MCPs.
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In this work, a broadband tunable reflective polarization convertor using a single layer complementary-cross-shaped (CCS) graphene metasurface was proposed and investigated numerically in terahertz (THz) region. The electric prope...
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In this work, a broadband tunable reflective polarization convertor using a single layer complementary-cross-shaped (CCS) graphene metasurface was proposed and investigated numerically in terahertz (THz) region. The electric property of CCS graphene could be flexibly tuned through the Fermi energy level (Ef). When Ef = 0.9 eV, the proposed graphene metasurface can realize a relative high polarization conversion ratio (PCR) of over 80% from 2.15 THz to 4 THz with a relative bandwidth of 60.16%. Furthermore, the PCR peak can reach up to as high as 99%, 99.5% and 91.5% at 2.4 THz, 3.4 THz and 3.96 THz, respectively. The physical origins of this polarization conversion properties are turned out to be supported by field distributions and Fabry-Perot interference theory. Furthermore, the broadband polarization conversion properties will be regulated by varying the Fermi energy level.
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We have presented two polarization convertors based on amorphous silicon metasurfaces. Results show that the cross-polarized transmission of the first polarization convertor is over 90% with over 95% polarization conversion effici...
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We have presented two polarization convertors based on amorphous silicon metasurfaces. Results show that the cross-polarized transmission of the first polarization convertor is over 90% with over 95% polarization conversion efficiency across the 300-nm bandwidth and maintains high-efficiency performance with big incident angles in this bandwidth. To steer cross-polarized light with an angle according to the generalized Snell's law, we have created another polarization convertor by choosing several resonators with different geometries in one supercell, achieving full 2 pi phase control, guiding the co-polarized and cross-polarized transmitted light spatially separated efficiently with broadband operation.
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In this paper, a broadband polarization conversion metasurface in microwave regime based on cross-shaped resonators was proposed. The simulated results show that the converter can convert linear polarization wave into its cross-po...
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In this paper, a broadband polarization conversion metasurface in microwave regime based on cross-shaped resonators was proposed. The simulated results show that the converter can convert linear polarization wave into its cross-polarization wave, 2 dB bandwidth is 11.5-21.8 GHz, and the Polarization Conversion Ratio is greater than 96% in this range. The simulated surface current distributions show that there are three plasmon resonances generated by magnetic resonances and electric resonance, resulting in broadband cross-polarized reflections, and electromagnetic composite resonances in the same direction will inhibit cross-polarization reflection. The proposed converter presents polarization selectivity, which can only convert the y- and x-polarized waves completely. When the incident angles reach 40°, the converter also shows high-efficiency polarization conversion. The experimental results are highly consistent with the simulation ones. This work may have some potential application in polarization-controlled devices, stealth surfaces, antennas and etc.
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A cross polarization conversion (CPC) structure using metasurface over wide bandwidth has been presented for practical applications in this article. The unit cell of the proposed metasurface is made of metallic patch of single cir...
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A cross polarization conversion (CPC) structure using metasurface over wide bandwidth has been presented for practical applications in this article. The unit cell of the proposed metasurface is made of metallic patch of single circular split-ring imprinted on top surface of a metal-backed single-layer dielectric substrate. Full width at half maxima bandwidth of polarization conversion ratio (PCR) of 11.12GHz is realized along with wide bandwidth of 9.92GHz extending from 6.06GHz to 15.98GHz with more than 0.8 PCR magnitude is realized using suitable optimization of the geometrical dimensions. Four distinct PCR peaks are observed at 6.56GHz, 10.38GHz, 15.12GHz, and 16.68GHz. The polarization conversion phenomena at these four frequencies have been analyzed in the light of electromagnetic resonances. The roles of several geometrical parameters of the design are simultaneously investigated. The proposed structure has been studied under oblique incidence, both for transverse electric and transverse magnetic polarizations. Wideband polarization conversion characteristics up to 45 degrees incident angles have been observed for both cases. A prototype of the proposed metasurface is fabricated, and experimental results are in good agreement with the simulated responses. The proposed structure is ultrathin; similar to/11.8 with respect to the center frequency of the CPC bandwidth.
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