Resonant terahertz generation from laser filaments in the presence of static electric field in a magnetized collisional plasma

Kumar, Sandeep; Vij, Shivani; Kant, Niti; Mehta, Alka; Thakur, Vishal

doi:10.1140/epjp/s13360-021-01089-5

Cited by 40 publications

(8 citation statements)

References 17 publications

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“…The SWCNTs are preferred by Titova et al [12] for THz generation by using a filamented laser beam. The filamentation under the influence of various fields also provides efficient THz generation [13][14][15][16]. The cross-focusing of laser beams in collisional plasma under the influence of various fields made a deep impact on the THz radiation [17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

THz Field Enhancement under the Influence of Cross-focused Laser Beams in the m-CNTs

Thakur

Kant²,

Kumar³

2023

Trends Sci

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In the present analysis, we have studied the effect of cross-focused Gaussian laser beams propagating through the array of magnetized carbon nanotubes (m-CNTs) to enhance the terahertz (THz) field amplitude of emitted radiation. The plasma present in the form of CNTs rearranges itself due to the ponderomotive nonlinearity, which gives rise to the nonlinear optical phenomenon known as the cross-focusing of laser beams. The ponderomotive nonlinearity, cross-focusing of lasers, and anharmonic behavior of m-CNTs are responsible for the very strong nonlinear current density in the system. The cross-focusing effect of the propagating Gaussian laser beams increases with the increase in the externally applied static magnetic field, which is applied along the longitudinal axis of the CNTs. As a result, the normalized THz field amplitude shows a significant enhancement, and the THz radiations emitted in this way can be utilized in biological diagnosis (of the living beings) instead of X-rays. The internal and external diameters of the CNTs also make a notable impact on the THz field amplitude. HIGHLIGHTS We have studied the effect of cross-focused laser beams propagating through the magnetized carbon nanotubes to enhance the terahertz field of emitted radiation The ponderomotive nonlinearity, cross-focusing of lasers, and anharmonic behavior are responsible for the strong nonlinear current density in the system The internal and external diameters of the m- CNTs also make a notable impact on the THz field amplitude The frequency of emitted radiation shows that these can be utilized in the biological diagnosis of living beings instead of X-rays GRAPHICAL ABSTRACT

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Section: Introductionmentioning

confidence: 99%

THz Field Enhancement under the Influence of Cross-focused Laser Beams in the m-CNTs

Thakur

Kant²,

Kumar³

2023

Trends Sci

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“…Thus, it is urgent to find ways to improve the energy conversion efficiency of THz waves. Researchers in this field have made many fruitful attempts to enhance the efficiency of THz generation by using two-color fields, [1,2] changing the focal length of the focusing lens, [3] changing the wavelength of the laser [4] and the working medium, [5] and adding electric field bias, [6] etc.…”

Section: Introductionmentioning

confidence: 99%

Terahertz shaping technology based on coherent beam combining

Zheng

Jiang³

et al. 2023

Chinese Phys. B

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The generation of terahertz (THz) waves by focusing a femtosecond pulsed laser beam at a distance is able to overcome the strong absorption properties of air and has rapidly attracted the attention of the industry. However, the poor directionality of the THz wave radiation generated by this method is not conducive to THz wave applications. By controlling the morphology of the ultrafast laser-excited plasma filament and its electron density distribution through coherent beam combining (CBC) technology, we achieve direct THz beam shaping and are able to obtain THz wave radiation of Gaussian or arbitrary transverse distribution. The novel experimental approach proposed in this paper opens up the research field of direct THz wave shaping using plasma. Moreover, it innovates multi-parameter convergence algorithms and, by doing so, has the potential to find beam patterns with higher energy conversion efficiency and break the energy limit of THz waves emitted by lasers at high power.

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“…Due to the high penetration and non-ionization properties, THz radiation found to have multitudinous applications in the field of medical diagnostics [1][2][3], spectroscopy, remote sensing, material characterization [4][5][6], security-safety, non-destructive testing, explosive detection [7,8], communication [9] and many more. For the development of innovative, proper, efficient, powerful, and compact THz sources various schemes have been suggested by the researchers, for example, THz waves by using filamentation of laser beams [10], by cross-focusing of laser beams in carbon nanoparticles and carbon nanotubes [11,12], nonlinear interaction of laser beams in the CNTs and, semiconductors [13][14][15][16]. From these schemes, it is observed that CNTs because of nano dimensions, excellent thermal transport, and electrical conductivity provide better conversion efficiency to obtain strong THz emissions.…”

Section: Introductionmentioning

confidence: 99%

Magnetically enhanced THz generation by self-focusing laser in VA-MCNTs

2023

Self Cite

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Magnetically enhanced terahertz (THz) radiations are generated on account of the self-focusing of the laser beam in the bunch of anharmonic Vertically Aligned Metallic Carbon Nanotubes (VA-MCNTs) embedded on the non-conductive sapphire or silicon on sapphire (SOS) substrate. The high-power Gaussian laser beam gets self-focused in the bunch of VA-MCNTs as the initial power of the propagating beam is greater than its critical power. The resulting laser beam interacts with the bunch of VA-MCNTs and as a result, the electrons of MCNTs experience a nonlinear ponderomotive force to show oscillatory behavior with resonant nonlinear transverse velocity. It produces the nonlinear current which drives the THz radiation generation. Enhanced THz generation is noticed in the regions where self-focusing becomes stronger. We have also observed that an applied magnetic field, anharmonic behavior of MCNTs, and dimensions of MCNTs also pave the way for the enhancement of the normalized THz amplitude The results shown (by the beautiful graphs and well supported by the numerical simulation) in the present scheme indicate that the bunch of VA-MCNTs can play a diverse and significant role in the important applications of THz medical photonics by varying the values of various parameters. The emitted THz radiation has the ability to detect changes in the DNA of human beings because the frequency of the emitted radiation is observed to lie in the frequency region of molecular spectra of DNA and the corresponding energy of THz radiation is not high enough to damage the DNA by ionization.

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Resonant terahertz generation from laser filaments in the presence of static electric field in a magnetized collisional plasma

Cited by 40 publications

References 17 publications

THz Field Enhancement under the Influence of Cross-focused Laser Beams in the m-CNTs

THz Field Enhancement under the Influence of Cross-focused Laser Beams in the m-CNTs

Terahertz shaping technology based on coherent beam combining

Magnetically enhanced THz generation by self-focusing laser in VA-MCNTs

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