Title :
Terahertz-pulse emission by laser excitation of surface plasmons in a metal grating
Author :
Welsh, Gregor H. ; Hunt, Neil T. ; Wynne, Klaas
Author_Institution :
Dept. of Phys., Univ. of Strathclyde, Glasgow
Abstract :
Metallic nanostructures have been prepared by depositing thin layers of gold onto a fused-silica transmission grating. Excitation with 800-nm femtosecond laser pulses in air results in the emission of terahertz radiation with an angle-dependent efficiency and a third-order dependence on input power. Nanostructures consisting of metal nano-pyramids on glass as well as silver nano-pyramid arrays covered in gold also exhibit terahertz emission. We will show that the source of the terahertz radiation in all of these cases is surface-plasmon- assisted multiphoton ionisation and ponderomotive acceleration in the evanescent laser field.
Keywords :
glass; gold; nanoelectronics; plasmons; silver; submillimetre wave lasers; submillimetre waves; evanescent laser field; femtosecond laser pulses; fused-silica transmission grating; glass; gold thin layers; laser excitation; metal grating; metal nano-pyramids; metallic nanostructures; ponderomotive acceleration; silver nano-pyramid arrays; surface plasmons; surface-plasmon-assisted multiphoton ionisation; terahertz emission; terahertz radiation; terahertz-pulse emission; third-order dependence; Glass; Gold; Gratings; Laser excitation; Nanostructures; Optical pulses; Plasmons; Power lasers; Pulsed laser deposition; Surface emitting lasers; Electron Emission; Surface Waves; Terahertz pulse generation;
Conference_Titel :
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on
Conference_Location :
Cardiff
Print_ISBN :
978-1-4244-1438-3
DOI :
10.1109/ICIMW.2007.4516784
