Analysis of terahertz generation via nanostructure enhanced plasmonic excitations

Abstract

In this paper, we conduct a quantitative study on the physical mechanism of electrons dynamics near the nanostructured metal film surfaces, as well as the efficiency of generated terahertz radiation associated with different types of nanostructures. The simulation results show that although the oscillating motion of emitted electrons outside the metal surface may affect the terahertz generation efficiency to some extent, this efficiency is predominantly determined by the electric field magnitude inside the metal film associated with nanostructure enhanced plasmonic excitations. Due to the field enhancement effect of the nanostructure, an appropriately designed nanostructured surface could greatly enhance the strength of generated terahertz signal via the increased nonlinear interactions between the light and the nanostructures.

Surface plasmon-enhanced terahertz emission from a hemicyanine self-assembled monolayer

“…Recently, the emission of coherent THz pulses, resulting from ultrafast laser illumination of plain and nano-structured gold (Au) surfaces, was reported by several groups [5][6][7][8][9][10][11][12][13]. Kadlec et al, who used an amplified Ti:sapphire laser to illuminate plain Au films of a few hundred nanometer thickness, observe that the emitted THz fluence depends on the square of the incident pump fluence [5].…”

Enhanced Terahertz Radiation Generation of Photoconductive Antennas Based on Manganese Ferrite Nanoparticles

“…4d. The electric field of THz radiation as generated from a PC antenna142529 is expressed as . Here, is the vector in the direction of the observation and is the time-dependent photocurrent density.…”

“…However, most of these PC antennas have complex structures, which rely on sophisticated fabrication techniques. Therefore, one key scientific challenge is to improve the performance of PC antennas by cost-effective simple methods2629303132. In this work, the effect of coating a silicon substrate with MnFe 2 O 4 NPs on its PC properties was investigated.…”

Substrate Effect on Plasmon Resonance of a Gold Nanoparticle Embedded Amorphous BaTiO<sub>3</sub> Film

“…The SPR (Surface Plasmon Resonance) concept is widely used for different kind of sensors like explosive detection and bio sensor [2,3]. Gold NPs have been proved to be very useful in sensor applications [4]. The periodic patterns of Au NPs are very useful in THz generation which has application in explosive detection [4].…”

“…Gold NPs have been proved to be very useful in sensor applications [4]. The periodic patterns of Au NPs are very useful in THz generation which has application in explosive detection [4]. Also metal NP embedded dielectrics are of current interest in studying metal induced crystallization.…”