Chirality Analysis on a Square Chiral Metamaterial

We have analyzed the chirality of terahertz (THz) wave emission from a square chiral metamaterial. The sample was manufactured with a periodic structure formed by a square pattern of chiral with different depth on a silver film. We have yield the specific polarization rotation in the THz region when the THz wave is emitted from a square chiral metamaterial. The THz emissions from these chiral metamaterials were elliptic polarization. A square chiral metamaterial was shown circular dichroism and optical activity properties at different frequencies. The ellipticity and rotation angle will reach a maximum value at a frequency of 1.2 THz and 0.6 THz, respectively. The results were indicated the possibility to controlled the polarization with chiral metamaterial structures.

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THz Wave emission from the intrinsic Josephson junctions of high Tcsuperconductors

Journal of Physics Conference Series ◽

10.1088/1742-6596/150/5/052156 ◽

2009 ◽

Vol 150 (5) ◽

pp. 052156

Author(s):

H Matsumoto ◽

T Koyama ◽

M Machida ◽

K Kadowaki

Keyword(s):

Josephson Junctions ◽

Intrinsic Josephson Junctions ◽

Thz Wave ◽

Wave Emission

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Circularly-polarized THz wave emission from a micro-thin water flow

10.21203/rs.3.rs-77877/v1 ◽

2020 ◽

Author(s):

Hsin-Hui Huang ◽

Saulius Juodkazis ◽

Eugene Gamaly ◽

Takeshi Nagashima ◽

Tetsu Yonezawa ◽

...

Keyword(s):

Water Flow ◽

Wavelength Region ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Intense Laser ◽

Practical Implementation ◽

Focal Volume ◽

Circularly Polarized ◽

Thz Wave ◽

Wave Emission

Abstract Intense THz wave sources are highly expected for further progresses in nonlinear THz science and practical implementation of non-ionizing radiation in sensing and communications. Solid-based sources have inherent limits of material breakdown, while intense laser irradiation of liquids is a promising emerging technique for THz wave and hard X-ray emission. Water-based THz emission shows intensity enhancements up to 103 times when laser-pulse pairs with nanosecond delay are used. Here we show circularly- polarized THz wave emission from thin water flow irradiated by two time-separated and linearly-polarized femtosecond laser pulses. THz time-domain spectroscopy reveals the circularly-polarized THz emission dominates 4.7 ns after the first pulse irradiation. THz wave detection delay in the spectroscopy and time-resolved micrography indicate that the THz wave emission originates from the rarefied volume in front of the flow. Radial relaxation of charges (currents) in the focal volume where ponderomotive charge depletion occurred is the origin for the circular polarization; tight focusing localized THz wave emission to the sub-wavelength region.

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Enhanced terahertz emission from mushroom-shaped InAs nanowire network induced by linear and nonlinear optical effects

Nanotechnology ◽

10.1088/1361-6528/ac3948 ◽

2021 ◽

Author(s):

Fugang Xi ◽

He Yang ◽

Vladislav Khayrudinov ◽

Yuhang He ◽

Tuomas Haggren ◽

...

Keyword(s):

Nonlinear Optical ◽

Optical Rectification ◽

Optical Effect ◽

Nonlinear Optical Effect ◽

Thz Wave ◽

Emission Component ◽

Optical Effects ◽

Nonlinear Optical Effects ◽

Linear And Nonlinear ◽

Wave Emission

Abstract The development of powerful terahertz (THz) emitters is the cornerstone for future THz applications, such as communication, medical biology, non-destructive inspection, and scientific research. Here, we report the THz emission properties and mechanisms of mushroom-shaped InAs nanowire (NW) network using linearly polarized laser excitation. By investigating the dependence of THz signal to the incidence pump light properties (e.g., incident angle, direction, fluence, and polarization angle), we conclude that the THz wave emission from the InAs NW network is induced by the combination of linear and nonlinear optical effects. The former is a transient photocurrent accelerated by the photo-Dember field, while the latter is related to the resonant optical rectification effect. Moreover, the p-polarized THz wave emission component is governed by the linear optical effect with a proportion of ~85% and the nonlinear optical effect of ~15%. In comparison, the s-polarized THz wave emission component is mainly decided by the nonlinear optical effect. The THz emission is speculated to be enhanced by the localized surface plasmon resonance absorption of the In droplets on top of the NWs. This work verifies the nonlinear optical mechanism in the THz generation of semiconductor NWs and provides an enlightening reference for the structural design of powerful and flexible THz surface and interface emitters in transmission geometry.

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THz wave emission from argon in two-color laser field

Chinese Physics B ◽

10.1088/1674-1056/24/4/043203 ◽

2015 ◽

Vol 24 (4) ◽

pp. 043203 ◽

Cited By ~ 2

Author(s):

Ling-Ling Du ◽

Song-Feng Zhao ◽

Xiao-Xin Zhou ◽

Zeng-Xiu Zhao

Keyword(s):

Laser Field ◽

Thz Wave ◽

Wave Emission

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Truncated pyramidal-shaped InAs/GaAs quantum dots in the presence of a vertical magnetic field: An investigation of THz wave emission and absorption

Physica E Low-dimensional Systems and Nanostructures ◽

10.1016/j.physe.2017.02.008 ◽

2017 ◽

Vol 89 ◽

pp. 105-114 ◽

Cited By ~ 8

Author(s):

Mohammad Sabaeian ◽

Maryam Riyahi

Keyword(s):

Magnetic Field ◽

Quantum Dots ◽

Vertical Magnetic Field ◽

Thz Wave ◽

Wave Emission

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THz wave emission of GaAs induced by He+ ion implantation

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/j.nimb.2013.01.085 ◽

2013 ◽

Vol 307 ◽

pp. 199-202

Author(s):

Kang Yang ◽

Jianqing Cao ◽

Can Huang ◽

Te Ji ◽

Zengyan Zhang ◽

...

Keyword(s):

Ion Implantation ◽

Thz Wave ◽

Wave Emission

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Intensity-dependent modulation of optically active signals in a chiral metamaterial

Nature Communications ◽

10.1038/ncomms14602 ◽

2017 ◽

Vol 8 (1) ◽

Cited By ~ 34

Author(s):

Sean P. Rodrigues ◽

Shoufeng Lan ◽

Lei Kang ◽

Yonghao Cui ◽

Patrick W. Panuski ◽

...

Keyword(s):

Optical Switching ◽

Optical Rotation ◽

Excitation Power ◽

Light Modulation ◽

Polarization Rotation ◽

Active Optics ◽

Chiral Metamaterials ◽

All Optical ◽

All Optical Switching ◽

Modest Level

Abstract Chiral media exhibit optical phenomena that provide distinctive responses from opposite circular polarizations. The disparity between these responses can be optimized by structurally engineering absorptive materials into chiral nanopatterns to form metamaterials that provide gigantic chiroptical resonances. To fully leverage the innate duality of chiral metamaterials for future optical technologies, it is essential to make such chiroptical responses tunable via external means. Here we report an optical metamaterial with tailored chiroptical effects in the nonlinear regime, which exhibits a pronounced shift in its circular dichroism spectrum under a modest level of excitation power. Strong nonlinear optical rotation is observed at key spectral locations, with an intensity-induced change of 14° in the polarization rotation from a metamaterial thickness of less than λ/7. The modulation of chiroptical responses by manipulation of input powers incident on chiral metamaterials offers potential for active optics such as all-optical switching and light modulation.

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