WAVEGUIDE STRUCTURES FOR GENERATION OF TERAHERTZ RADIATION BY ELECTRO-OPTICAL PROCESS IN GaAs AND ZuGeP₂ USING 1.55μm FIBER LASER PULSES

Abstract

Abstract-By discussing the basic schemes of the terahertz generation methods based on the 1550-nm ultrafast lasers briefly, GaAs and ZnGeP 2 are likely to be promising nonlinear optical crystals for terahertz waves generation by using optical rectification process. However, the mismatches of velocities between the terahertz waves and optical pulses are so large that the phase-matching coherent lengths are quite short, for example, the coherent length of 0.7 mm for GaAs and 0.5 mm for ZnGeP 2 at 2 THz around, respectively. That limited extremely the applications of these bulk excellent nonlinear optical crystals in terahertz regime. In this paper, we demonstrated theoretically that the dielectric planar waveguide could be used to enhance the coherent length of optical rectification process in THz regime. And for the first time, a dielectric planar THz waveguide that has potential applicable value in THz generation by optical rectification method was proposed. We predicted that the effective coherent length could be extended to 4 mm at 2 THz in a GaAs/ZnGeP 2 dielectric planar waveguide during optical rectification process pumped by ultrafast optical pulses at wavelength of 1550 nm.

Effects of Antenna Design Parameters on the Characteristics of a Terahertz Coplanar Stripline Dipole Antenna

“…There are several methods for generating and detecting THz electromagnetic waves, such as photoconductive switching, optical rectification, photomixing, quantum cascade lasers, free electron lasers, and backward wave oscillator [6][7][8][9][10].…”

GROWTH AND CHARACTERIZATION OF SiO₂ FILMS DEPOSITED BY FLAME HYDROLYSIS DEPOSITION SYSTEM FOR PHOTONIC DEVICE APPLICATION

“…To achieve this, we must continue improving the waveguide fabrication process by carrying out computational analyses [1][2][3][4][5][6][7][8][9][10][11]. A PLC fabricated using a technique for fabrication of optical fiber can provide a high quality lightwave circuits on a substrate.…”

The Analytical Design of a Folded Waveguide Traveling Wave Tube and Small Signal Gain Analysis Using Madey's Theorem

“…Dohler et al also did some work on an FWTWT at 45 GHz in the early 1990s [1,2]. The FWTWT is an excellent candidate for many applications such as in communications, radar, military and medical fields, especially at millimeter-wave or terahertz frequencies [3][4][5][6][7][8]. The characteristics of the folded waveguide traveling wave tube fall under the umbrella of the general traveling wave tube (TWT) [9].…”