Photoinduced variation of dielectric constant of silicon in the far infrared: applications to light-controllable photonic band-gap crystals in the terahertz frequency range

1999 ◽  
Author(s):  
Jean-Louis Coutaz ◽  
Lionel Duvillaret ◽  
Frederic Garet ◽  
A. Chelnokov ◽  
Sebastian Rowson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Far Infrared ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Photonic Band

Characteristics of 2D Cylindrical Photonic Crystals Band Gap with Square Lattice

2013 ◽  
Vol 712-715 ◽  
pp. 302-305
Author(s):  
Zhao Xia Wu ◽  
Wen Chao Li ◽  
Er Dan Gu ◽  
Li Fu Wang
Keyword(s):  
Dielectric Constant ◽  
Photonic Crystals ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Fdtd Method ◽  
Dielectric Constants ◽  
Square Lattice ◽  
The Difference ◽  
Difference Time ◽  
Photonic Band

The structure of two-dimensional (2D) photonic crystals (PCs) with square lattice is proposed in this paper, and researches on characteristics of photonic band gap (PBG) are conducted using finite difference time domain (FDTD) method, then the effects of the dielectric constant and the radius of dielectric rods on band gap are analysed, dielectric rods in air (rods/air). The research results indicate that in the case of TE and TM polarization mode, the difference value of dielectric constant of medium and dielectric rods affects forming PBG.The band gap broadens with the difference value increasing. Whats more, the complete band gap (CBG) appears in range of large rods radius structure when dielectric constants of rods are smaller than that of medium.

scholarly journals Оптические свойства халькогенидных сплавов на основе теллура в дальнем инфракрасном диапазоне (lambda>30 мкм)

2018 ◽  
Vol 52 (2) ◽  
pp. 221
Author(s):  
В.А. Рыжов ◽  
Б.Т. Мелех
Keyword(s):  
Heat Treatment ◽  
Far Infrared ◽  
Transmission Spectra ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Long Wavelength ◽  
Wide Wavelength Range ◽  
Transmission Window ◽  
Removal Of Impurities

AbstractTernary telluride alloys of Ge–Se(Sb)–Te and Si–Ge(Ga)–Te systems are synthesized in glassy and crystalline states for use in the terahertz frequency range. The transmission spectra of the obtained alloys are measured and studied in a wide wavelength range from 0.75 to 300 μm. The possible mechanisms of their formation are discussed. A comparative analysis of the results shows that the Ge_14Sb_28Te_56 alloy of the GST system is most promising. Its phonon spectrum is in the range of 40–280 cm^–1, limiting the long-wavelength transmission window of this alloy by 35 μm. Optimization of the Ge_14Sb_28Te_56 composition, the removal of impurities, and heat treatment will promote a further decrease in the absorbance in the far-infrared spectrum of this alloy.

scholarly journals Complex Refractive Index of Strontium Titanate in the Terahertz Frequency Range

2019 ◽  
Vol 7 (4) ◽  
pp. 71-80 ◽  
Author(s):  
V. R. Bilyk ◽  
K. A. Grishunin
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Strontium Titanate ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Complex Dielectric Constant ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Time Domain Spectroscopy ◽  
Terahertz Frequency Range

The recent progress in terahertz time-domain spectroscopy enables the accurate and reliable measurements of dielectric properties in comparison with the traditional far-infrared spectroscopy using an incoherent light source. The broadband THz-TDS is a powerful tool to determine the real and imaginary parts of a complex dielectric constant by the transmission which allows to detect the parameters of the soft modes in ferroelectrics. In this work, the terahertz time-domain spectroscopy was used to investigate the dependence of the complex refractive index of a single-crystal quantum paraelectric strontium titanate in the terahertz frequency range from 0.3 to 2 THz. It was shown that the low-frequency terahertz response of the material is determined by the soft phonon mode TO1. The measured experimental dependences showed a good agreement with the theoretical curves obtained from the analysis of the Lorentz oscillator model for the complex dielectric constant of strontium titanate. The obtained results are necessary for understanding the principle of possibility to manipulate the order parameter in ferroelectric materials and can be used to create energy-efficient memory devices with a speed of recording information close to the theoretical limit.

APPEARANCE OF A ZERO-n AND A ZERO-ϕeff GAP IN DIFFERENT FREQUENCY RANGES IN A SINGLE 1D PHOTONIC BAND GAP STRUCTURE

2011 ◽  
Vol 25 (22) ◽  
pp. 3027-3034 ◽  
Author(s):  
MUNAZZA ZULFIQAR ALI ◽  
TARIQ ABDULLAH
Keyword(s):  
Band Gap ◽  
Photonic Band Gap ◽  
Frequency Dispersion ◽  
Frequency Range ◽  
Double Positive ◽  
One Dimensional ◽  
Photonic Band Gap Structure ◽  
Band Gap Structure ◽  
Photonic Band ◽  
Gap Structure

We present a scheme to realize both the zero-n and the zero-ϕ eff gap in a one-dimensional photonic band gap structure containing metamaterials. The frequency dispersion of the effective electric permittivity and magnetic permeability of the metamaterials in the adjacent layers in one period are represented by the Drude model and the resonant model. The chosen structure is composed of alternate double-negative and double-positive layers which exhibit a zero-n gap in a certain frequency range whereas in a higher frequency range it behaves as alternate permittivity negative and permeability negative layers to exhibit a zero-ϕ eff gap. Some properties and benefits of having the zero-n and the zero-ϕ eff gap in the same physical system are discussed.

scholarly journals Терагерцовое излучение из наноструктур карбида кремния

2021 ◽  
Vol 55 (11) ◽  
pp. 1027
Author(s):  
Н.Т. Баграев ◽  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
Л.Е. Клячкин ◽  
А.М. Маляренко ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Faraday Effect ◽  
Far Infrared ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Edge Channel ◽  
Proposed Model ◽  
Source Current ◽  
First Time

For the first time, electroluminescence was discovered in the middle and far infrared ranges from silicon carbide nanostructures on silicon, obtained in the framework of the Hall geometry. Silicon carbide on silicon was grown by the method of substitution of atoms on silicon. The electroluminescence from the edge channels of nanostructures is induced due to the longitudinal drain- source current. The electroluminescence spectra obtained in the terahertz frequency range, 3.4, 0.12 THz, arise due to the quantum Faraday effect. Within the framework of the proposed model, the longitudinal current induces a change in the number of magnetic flux quanta in the edge channels, which leads to the appearance of a generation current in the edge channel and, accordingly, to terahertz radiation.

FORM BIREFRINGENT STRUCTURES MATCHING TO FREE SPACE IN THE TERAHERTZ FREQUENCY RANGE

2015 ◽  
Vol 74 (19) ◽  
pp. 1767-1776 ◽  
Author(s):  
V. I. Bezborodov ◽  
O.S. Kosiak ◽  
Ye. M. Kuleshov ◽  
V. V. Yachin
Keyword(s):  
Free Space ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range
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