Terahertz wave emission from plasmonic chiral metasurfaces
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Plasmonic chiral metasurfaces with pinwheel-like structures are fabricated on silver films using a focused ion-beam milling technique. In time-domain spectroscopy, we observe terahertz (THz) wave emission from metasurfaces irradiated by a near-infrared Ti:sapphire ultrashort pulsed laser. The origin of the THz wave generation is likely to be tunnelling ionization accompanied with photoelectron acceleration by ponderomotive force. Numerical simulation is carried out toward improvement of the chiral metasurfaces for better emission of circularly polarized THz waves.
KeywordsElectric Field Distribution Ponderomotive Force Asymmetric Mode Optical Parametric Amplifier Show Reflection Spectrum
The authors acknowledge valuable contribution by K. Miyake in the FIB milling and fruitful discussion with K. Iwami and S. Ohno. English proofreading by L. McDowell is also acknowledged. This work was supported by MEXT/JSPS KAKENHI (Grants Nos. 22109003, 22109005 and 26287065).