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1

Transverse electric guided modes in metal-LHM-ferrite slab waveguide structures

Elwasife Khitam Y., Al Massri Mustafa R., Taya Sofyan A.

Optica Applicata

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2024

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Vol. 54, nr 1

31--40

EN

TE guided modes at microwave frequencies in metal-left-handed material-ferrite waveguide structures are studied numerically. The effect of ferrite layer parameters on the dispersion properties of the waveguide structure is investigated in details. It is found that the modal index of the guided mode is negative as if the overall structure was left-handed material. A considerable effect of the gyromagnetic ferrite layer on the dispersion properties of the structure is observed. The power propagating in each layer is also evaluated.

2

Phase and group velocities of surface waves in left-handed material waveguide structures

Taya S. A., Elwasife K. Y., Qadoura I. M.

Optica Applicata

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2017

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Vol. 47, nr 2

307--318

EN

We assume a three-layer waveguide structure consisting of a dielectric core layer embedded between two left-handed material claddings. The phase and group velocities of surface waves supported by the waveguide structure are investigated. Many interesting features were observed such as normal dispersion behavior in which the effective index increases with the increase in the propagating wave frequency. The phase velocity shows a strong dependence on the wave frequency and decreases with increasing the frequency. It can be enhanced with the increase in the guiding layer thickness. The group velocity peaks at some value of the normalized frequency and then decays.

3

Guided modes in slab waveguides with both double-negative and single-negative materials

Dong P., Yang H. W.

Optica Applicata

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2010

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Vol. 40, nr 4

873--882

EN

A new dielectric slab waveguide with double-negative (DNG) film layer and single-negative (SNG) cover layer is proposed. The dispersion relations of an asymmetric left-handed materials (LHM) slab waveguide are investigated by using normalized parameters. An analytical method is then proposed to calculate the dispersion curves. TE-polarized guided modes differ dramatically from TM-polarized guided modes. For TE-polarized oscillating guided modes, fundamental modes exist all the time, but in a narrow range of low frequency values only. First order mode behaves as other higher order modes and exists up to infinite high frequency. Higher order modes have double degeneracy. For TE-polarized surface guided modes, the existence and the type of the mode solutions with respect to different parameters are classified systematically and discussed in detail. TE0 surface mode exists only in one case. The dispersion curve of TE1 surface mode continues with that of oscillating TE0 mode. It seems that the two different kinds of modes compensate each other to form one whole mode. For TM-polarized wave, both oscillating and surface guided modes act as the waveguide with DNG (LHM) film sandwiched in between two normal dielectrics.

4

Thermodynamic and optical parameters of the RF pulse excited slab-waveguide CO2 laser

Wojaczek D. A., Pliński E. F., Witkowski J. S.

Optica Applicata

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2005

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Vol. 35, nr 2

215-224

EN

In the paper, changes of the optical and thermodynamic parameters, such as a refractive index, pressure, and temperature are investigated on an RF pulsed C02 slab-waveguide laser. Changes of the refractive index, and pressure are measured with a Mach-Zehnder interferometer, and microphone, respectively. A Gladstone-Dale formula is applied to calculate the changes of the temperature. It is shown how an acoustic wave in the laser cavity modifies the pressure of the laser medium in the course of the pulse duration. The results of measurements allow explaining a line hopping effect observed during the laser plasma pulse evolution.