Nonradiating anapole modes of dielectric particles in terahertz range

Transformation of a Bessel beam by a lens results in the formation of a “perfect” vortex beam (PVB) in the focal plane of the lens. The PVB has a single-ring cross-section and carries an orbital angular momentum (OAM) equal to the OAM of the “parent” beam. PVBs have numerous applications based on the assumption of their ideal ring-type structure. For instance, we proposed using terahertz PVBs to excite vortex surface plasmon polaritons propagating along cylindrical conductors and the creation of plasmon multiplex communication lines in the future (Comput. Opt. 2019, 43, 992). Recently, we demonstrated the formation of PVBs in the terahertz range using a Bessel beam produced using a spiral binary silicon axicon (Phys. Rev. A 2017, 96, 023846). It was shown that, in that case, the PVB was not annular, but was split into nested spiral segments, which was obviously a consequence of the method of Bessel beam generation. The search for methods of producing perfect beams with characteristics approaching theoretically possible ones is a topical task. Since for the terahertz range, there are no devices like spatial modulators of light in the visible range, the main method for controlling the mode composition of beams is the use of diffractive optical elements. In this work, we investigated the characteristics of perfect beams, the parent beams being quasi-Bessel beams created by three types of diffractive phase axicons made of high-resistivity silicon: binary, kinoform, and “holographic”. The amplitude-phase distributions of the field in real perfect beams were calculated numerically in the approximation of the scalar diffraction theory. An analytical expression was obtained for the case of the binary axicon. It was shown that a distribution closest to an ideal vortex was obtained using a holographic axicon. The resulting distributions were compared with experimental and theoretical distributions of the evanescent field of a plasmon near the gold–zinc sulfide–air surface at different thicknesses of the dielectric layer, and recommendations for experiments were given.

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Paraffin diffractive lens for sub-terahertz range simple and cost efficient solution

IEEE Transactions on Terahertz Science and Technology ◽

10.1109/tthz.2021.3063809 ◽

2021 ◽

pp. 1-1

Author(s):

Agnieszka Siemion ◽

Mateusz Surma ◽

Pawe Komorowski ◽

Przemyslaw Zagrajek ◽

Micha Walczakowski ◽

...

Keyword(s):

Efficient Solution ◽

Terahertz Range ◽

Diffractive Lens ◽

Cost Efficient

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A statistical field theory of salt solutions of ‘hairy’ dielectric particles

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ab4d38 ◽

2019 ◽

Vol 32 (5) ◽

pp. 055101 ◽

Cited By ~ 2

Author(s):

Yury A Budkov

Keyword(s):

Field Theory ◽

Salt Solutions ◽

Dielectric Particles ◽

Statistical Field ◽

Statistical Field Theory

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Optical and conductive properties of Antimony-Bismuth co-doped titanium dioxide in terahertz range

Infrared Physics & Technology ◽

10.1016/j.infrared.2020.103570 ◽

2021 ◽

Vol 112 ◽

pp. 103570

Author(s):

Muhammad Mumtaz ◽

M. Ahsan Mahmood ◽

Sabih D. Khan ◽

M. Aslam Zia ◽

Amjid Iqbal ◽

...

Keyword(s):

Titanium Dioxide ◽

Terahertz Range ◽

Doped Titanium Dioxide ◽

Conductive Properties ◽

Co Doped

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Terahertz-wave generation using graphene

MRS Proceedings ◽

10.1557/opl.2012.1186 ◽

2012 ◽

Vol 1437 ◽

Author(s):

Taiichi Otsuji ◽

Stephane Boubanga Tombet ◽

Akira Satou ◽

Maxim Ryzhii ◽

Victor Ryzhii

Keyword(s):

Terahertz Wave ◽

Wave Generation ◽

Nonequilibrium Carrier ◽

Terahertz Range ◽

Two Dimensional ◽

Carrier Relaxation ◽

Dynamic Conductivity ◽

Electrically Pumped ◽

Terahertz Lasers ◽

Recombination Dynamics

ABSTRACTIn this paper recent advances in terahertz-wave generation in graphene are reviewed. First, fundamental basis of the optoelectronic properties of graphene is introduced. Second, nonequilibrium carrier relaxation and recombination dynamics in optically or electrically pumped graphene is described to introduce a possibility of negative dynamic conductivity in a wide terahertz range. Third, recent theoretical advances toward the creation of current-injection graphene terahertz lasers are described. Fourth, unique terahertz dynamics of the two-dimensional plasmons in graphene are described. Finally, the advantages of graphene materials and devices for terahertz-wave generation are summarized.

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