Terahertz photoconductive antenna with metal nanoislands

Abstract

This work presents a nanoplasmonic photoconductive antenna (PCA) with metal nanoislands for enhancing terahertz (THz) pulse emission. The whole photoconductive area was fully covered with metal nanoislands by using thermal dewetting of thin metal film at relatively low temperature. The metal nanoislands serve as plasmonic nanoantennas to locally enhance the electric field of an ultrashort pulsed pump beam for higher photocarrier generation. The plasmon resonance of metal nanoislands was achieved at an excitation laser wavelength by changing the initial thickness of metal film. This nanoplasmonic PCA shows two times higher enhancement for THz pulse emission power than a conventional PCA. This work opens up a new opportunity for plasmon enhanced large-aperture THz photoconductive antennas.

Three-dimensional plasmonic contact electrodes for high-efficiency photoconductive terahertz sources

“…tilizing plasmonic contact electrodes has shown great promise for enhancing optical-to-terahertz conversion efficiency of photoconductive terahertz sources [1][2][3][4][5]. This is due to the unique capability of plasmonic contact electrodes in manipulating the distribution of photocarriers inside the device active area and increasing the concentration of the photocarriers in close proximity to the device contact electrodes [6][7][8][9].…”

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

“…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.…”

High power terahertz generation using 1550 nm plasmonic photomixers

“…9 This is because incorporating plasmonic contact electrodes enhances the concentration of photocarriers generated in close proximity to the photomixer contact electrodes. [10][11][12][13][14][15][16] By reducing the average transport path length of the photocarriers to the photomixer contact electrodes, a larger number of photocarriers are drifted to the terahertz radiating element in a sub-picosecond time scale and, thus, significantly higher radiation powers are achieved. [17][18][19] Additionally, in order to achieve high terahertz radiation power levels, the optical pump is modulated with a duty cycle below 10%.…”