Abstract-Ultrahigh birefringence, ultralow material loss porous core single-mode fiber for terahertz wave guidance

Kawsar Ahmed, Sawrab Chowdhury, Bikash Kumar Paul, Md. Shadidul Islam, Shuvo Sen, Md. Ibadul Islam, and Sayed Asaduzzaman

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-56-12-3477&origin=search

In this paper, a novel polarization-maintaining single-mode photonic crystal fiber (PCF) has been suggested for terahertz (THz) transmission applications. The reported PCF has five layers of hexagonal cladding with two layers of porous core. The cladding and core territory of the PCF are constituted by circular and elliptical air cavities, accordingly acting as a dielectric medium. Different geometrical parameters of the proposed PCF including pitches and diameters of circular air holes with the major and minor axes of elliptical air cavities being varied with the optimized structure. Various effects on the proposed PCF such as eccentricity and porosity effects are also carefully investigated. The numerical process is investigated by one of the most popular methods, the finite element method (FEM). All numerical computational results have revealed the ultrahigh birefringence in the order of 1.19×10−02$1.19\times {10}^{-02}$ as well as the ultralow bulk absorption material loss of 0.0689  cm−1$0.0689{\mathrm{cm}}^{-1}$ at the 1 THz activation frequency. Besides, the V-parameter is also investigated for checking the proposed fiber modality. The proposed single-mode porous core hexagonal PCF is expected to be useful for convenient broadband transmission and numerous applications in the areas of THz technology.

© 2017 Optical Society of America

Abstract-The effect of beam pre-bunching on the excitation of terahertz plasmons in a parallel plane guiding system

Suresh C. Sharma¹ and Pratibha Malik¹
 http://scitation.aip.org/content/aip/journal/pop/22/4/10.1063/1.4916765?TRACK=RSS
1 Department of Applied Physics, Delhi Technological University (DTU), Shahbad Daulatpur, Bawana Road, Delhi-110042, India
Phys. Plasmas 22, 043301 (2015); http://dx.doi.org/10.1063/1.4916765

The excitation of terahertz (THz) plasmons by a pre-bunched relativistic electron beam propagating in a parallel plane semiconducting guiding system is studied. It is found that the n-InSb semiconductor strongly supports the confined surface plasmons in the terahertz frequency range. The growth rate and efficiency of the THz surface plasmons increase linearly with modulation index and show the largest value as modulation index approaches unity. Moreover, the growth rate of the instability scales as one-third power of the beam density and inverse one-third power of the THz radiation frequency.

Abstract-Terahertz Waveguiding in Silicon-Core Fibers

 

http://arxiv.org/abs/1305.0520

Derek A. Bas, Scott K. Cushing, John Ballato, Alan D. Bristow

(Submitted on 2 May 2013)

We propose the use of a silicon-core optical fiber for terahertz (THz) waveguide applications. Finite-difference time-domain simulations have been performed based on a cylindrical waveguide with a silicon core and silica cladding. High-resistivity silicon has a flat dispersion over a 0.1 - 3 THz range, making it viable for propagation of tunable narrowband CW THz and possibly broadband picosecond pules of THz radiation. Simulations show the propagation dynamics and the integrated intensity, from which transverse mode profiles and absorption lengths are extraced. It is found that for 140 - 250 micron core diameters the mode is primarily confined to the core, such that the overall absorbance is only slightly less than in bulk polycrystalline silicon.