Terahertz Photoconductive Antennas based on Arrays of Metal Nanoparticle Structures

2021 ◽  
Author(s):  
Saeid Gholami ◽  
Ali Bahari
Keyword(s):  
Electric Current ◽  
Fdtd Method ◽  
Laser Pulses ◽  
Metal Nanoparticle ◽  
Thz Radiation ◽  
Photoconductive Antennas ◽  
Fem Method ◽  
Frequency Peak ◽  
Field Radiation ◽  
Antenna Surface

Abstract In this study, in order to amplify the radiation at Terahertz (THz) photoconductive antennas, metal nanoparticles are used in semiconductor layers based on plasmonic principles. The use of nanoparticles between antenna electrodes and semiconductor layers not only enhances the THz radiation intensity but also changes the radiation frequency peak. The changes of electric charge carriers versus the strike of laser pulses and the production of an electric current on the antenna surface are simulated with the COMSOL Multiphysics software through the FEM method. The changes of the electric current at the semiconductive surface generate electric field radiation. This has been simulated using the CST STUDIO software through the FDTD method.

Polarization Of THz radiation generated during two-color filamentation of arbitrarily polarized laser pulses

2016 ◽  
Author(s):  
V. A. Andreeva ◽  
M. N. Esaulkov ◽  
N. A. Panov ◽  
P. M. Solyankin ◽  
V. A. Makarov ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Thz Radiation

Fast quantum state transfer in hybrid quantum dot-metal nanoparticle systems by shaping ultrafast laser pulses

2019 ◽  
Vol 52 (42) ◽  
pp. 425101 ◽  
Author(s):  
Yihong Qi ◽  
Chuan-Cun Shu ◽  
Daoyi Dong ◽  
Ian R Petersen ◽  
Kurt Jacobs ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum State ◽  
Laser Pulses ◽  
Ultrafast Laser ◽  
Metal Nanoparticle ◽  
Quantum State Transfer ◽  
Ultrafast Laser Pulses ◽  
State Transfer

Terahertz radiation from multiferroic BiFeO3 thin films as a new approach for ferroelectric memory readout and ferroelectric domain imaging microscopy

2005 ◽  
Vol 902 ◽  
Author(s):  
Kouhei Takahashi ◽  
Noriaki Kida ◽  
Masayoshi Tonouchi
Keyword(s):  
Thin Films ◽  
Nonvolatile Memory ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ferroelectric Domain ◽  
Thz Radiation ◽  
New Approach ◽  
Multiferroic Bifeo ◽  
Multiferroic Bifeo3 ◽  
Nonvolatile Memory Devices

AbstractWe have observed novel terahertz (THz) radiation characteristics of multiferroic BiFeO3 thin films upon illumination of femtosecond laser pulses. The radiated THz pulses from BiFeO3 thin films were shown to originate from an ultrafast modulation of spontaneous polarization, which was introduced by the photoexcited charge carriers. Based on our findings, we briefly present new approaches to nondestructive readout for nonvolatile memory devices and ferroelectric domain imaging microscopy using THz radiation as a sensitive probe.

FDTD Method for Retrieving the Nonlinear-Index Coefficient Based on Self-Phase Modulation

2013 ◽  
Vol 798-799 ◽  
pp. 245-248
Author(s):  
Qing Wei Liu ◽  
Dong Mo Song
Keyword(s):  
Phase Modulation ◽  
Nonlinear Optical ◽  
Fdtd Method ◽  
Laser Pulses ◽  
Optical Pulses ◽  
Power Laser ◽  
Third Order ◽  
Self Phase Modulation ◽  
Nonlinear Index ◽  
Difference Time

In this paper we have retrieved the nonlinear-index coefficient based on the self-phase modulation which is resulted from a high-power laser pulses propagating in a third-order nonlinear optical material. Using the finite-difference time-domain method, the spectrum analyses have been performed with the optical pulses with different peak-powers propagating through the nonlinear optical materials with different lengths. The nonlinear-index coefficients were obtained by using the numbers of the spectrum peaks, and how to improve the accuracy has been discussed.

scholarly journals Organic crystal-based THz source for complex refractive index measurements of window materials using single-shot THz spectroscopy

2021 ◽  
Vol 127 (11) ◽  
Author(s):  
Lufan Du ◽  
Franz Roeder ◽  
Yun Li ◽  
Mostafa Shalaby ◽  
Burgard Beleites ◽  
...  
Keyword(s):  
Refractive Index ◽  
Complex Refractive Index ◽  
Accurate Determination ◽  
Laser Pulses ◽  
Thz Spectroscopy ◽  
Thz Radiation ◽  
Single Shot ◽  
Detection Scheme ◽  
Electro Optic

AbstractWe employed N-benzyl-2-methyl-4-nitroaniline (BNA) crystals bonded on substrates of different thermal conductivity to generate THz radiation by pumping with 800 nm laser pulses. Crystals bonded on sapphire substrate provided four times more THz yield than glass substrate. A pyrodetector and a single-shot electro-optic (EO) diagnostic were employed for measuring the energy and temporal characterisation of the THz pulse. Systematic studies were carried out for the selection of a suitable EO crystal, which allowed accurate determination of the emitted THz spectrum from both substrates. Subsequently, the THz source and single-shot electro-optic detection scheme were employed to measure the complex refractive index of window materials in the THz range.

scholarly journals Broadband THz Sources from Gases to Liquids

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yiwen E ◽  
Liangliang Zhang ◽  
Anton Tcypkin ◽  
Sergey Kozlov ◽  
Cunlin Zhang ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Laser Pulses ◽  
High Energy ◽  
Wave Generation ◽  
High Energy Density ◽  
Intense Laser ◽  
Thz Radiation ◽  
Flowing Liquid ◽  
Thz Wave ◽  
Thz Sources

Matters are generally classified within four states: solid, liquid, gas, and plasma. Three of the four states of matter (solid, gas, and plasma) have been used for THz wave generation with short laser pulse excitation for decades, including the recent vigorous development of THz photonics in gases (air plasma). However, the demonstration of THz generation from liquids was conspicuously absent. It is well known that water, the most common liquid, is a strong absorber in the far infrared range. Therefore, liquid water has historically been sworn off as a source for THz radiation. Recently, broadband THz wave generation from a flowing liquid target has been experimentally demonstrated through laser-induced microplasma. The liquid target as the THz source presents unique properties. Specifically, liquids have the comparable material density to that of solids, meaning that laser pulses over a certain area will interact with three orders more molecules than an equivalent cross-section of gases. In contrast with solid targets, the fluidity of liquid allows every laser pulse to interact with a fresh area on the target, meaning that material damage or degradation is not an issue with the high-repetition rate intense laser pulses. These make liquids very promising candidates for the investigation of high-energy-density plasma, as well as the possibility of being the next generation of THz sources.

Negative conductivity of graphene with direct electric current

2021 ◽  
Author(s):  
I.M. Moiseenko ◽  
V.V. Popov ◽  
D.V. Fateev
Keyword(s):  
Reflection Coefficient ◽  
Electric Current ◽  
Terahertz Radiation ◽  
Room Temperature ◽  
Negative Real Part ◽  
Wave Incident ◽  
Thz Radiation ◽  
Direct Electric Current ◽  
Radiation Sources ◽  
Dc Current

Problem formulating. Currently, there are no compact, efficient terahertz radiation sources operating at room temperature. To create such sources and amplifiers, structures based on graphene with DC-current can be used. Goal. Finding conditions for achieving the negative real part of graphene conductivity and amplification of THz radiation in graphene with a direct electric current. Result. It is shown that for a certain value of direct electric current in graphene, the reflection coefficient of the THz wave incident on the structure based on graphene with DC-current exceeds unity, which indicates the amplification of THz radiation in the structure. The amplification of the THz radiation in graphene is achieved due to negative values of the real part of the graphene conductivity. Practical meaning. Results can be used to create sources and amplifiers of terahertz radiation.

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