Planar broadband dual-linearly polarized MEMS steerable antenna

We study the behaviour of a charge bound on a graphene annulus under the assumption that the particle can be treated as a massless Dirac electron. The eigenstates and relative energy are found in closed analytical form. Subsequently, we consider a large annulus with radius ρ∈[5000,10,000]a0 in the presence of a static magnetic field orthogonal to its plane and again the eigenstates and eigenenergies of the Dirac electron are found in both analytical and numerical form. The possibility of designing filiform currents by controlling the orbital angular momentum and the magnetic field is shown. The currents can be of interest in optoelectronic devices that are controlled by electromagnetic radiation. Moreover, a small radial force acts upon the annulus with a stretching effect. A linearly polarized electromagnetic field propagating in the orthogonal direction is added; the time evolution of the operators show that the acceleration of the electron is proportional to the rate of change of the spin of the particle.

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Cylindrically and non-cylindrically symmetric expansion dynamics of tin microdroplets after ultrashort laser pulse impact

Applied Physics A ◽

10.1007/s00339-020-04207-9 ◽

2021 ◽

Vol 127 (2) ◽

Author(s):

Tiago de Faria Pinto ◽

Jan Mathijssen ◽

Randy Meijer ◽

Hao Zhang ◽

Alex Bayerle ◽

...

Keyword(s):

Laser Pulse ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Droplet Deformation ◽

Cylindrically Symmetric ◽

Linearly Polarized ◽

Particle Hydrodynamics ◽

Deformation Dynamics ◽

Smoothed Particle ◽

Asymmetric Shock

AbstractIn this work, the expansion dynamics of liquid tin micro-droplets irradiated by femtosecond laser pulses were investigated. The effects of laser pulse duration, energy, and polarization on ablation, cavitation, and spallation dynamics were studied using laser pulse durations ranging from 220 fs to 10 ps, with energies ranging from 1 to 5 mJ, for micro-droplets with an initial radius of 15 and 23 $$\upmu$$ μ m. Using linearly polarized laser pulses, cylindrically asymmetric shock waves were produced, leading to novel non-symmetric target shapes, the asymmetry of which was studied as a function of laser pulse parameters and droplet size. A good qualitative agreement was obtained between smoothed-particle hydrodynamics simulations and high-resolution stroboscopic experimental data of the droplet deformation dynamics.

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