TY - JOUR
T1 - Bi-directional terahertz emission from gold-coated nanogratings by excitation via femtosecond laser pulses
AU - Garwe, F.
AU - Schmidt, A.
AU - Zieger, G.
AU - May, T.
AU - Wynne, K.
AU - Huebner, U.
AU - Zeisberger, M.
AU - Paa, W.
AU - Stafast, H.
AU - Meyer, H. -G.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - We report on the investigation of terahertz (THz) emission from gold-coated nanogratings (500 nm grating constant) upon femtosecond laser irradiation (785 nm, 150 fs, 1 kHz, a parts per thousand currency sign1 mJ/pulse). Unlike common assumptions, THz emission is not only observed in case of rear side irradiation (through substrate (Welsh et al. in Phys. Rev. Lett. 98:026803, 2007; Welsh and Wynne in Opt. Express 17:2470-2480, 2009)) of the nanograting, but also in case of front side excitation (through air). Furthermore in both cases, THz emission propagates in the direction of laser beam propagation and reverse. Based on these findings, we suggest a new approach to describe the newly observed phenomena. Using a highly sensitive and fast superconducting transition edge sensor (TES) as calorimeter, it was possible to directly measure the absolute energy of the emitted THz pulses in a defined spectral and spatial range, enabling for the first time a quantitative analysis of the THz emission process.
AB - We report on the investigation of terahertz (THz) emission from gold-coated nanogratings (500 nm grating constant) upon femtosecond laser irradiation (785 nm, 150 fs, 1 kHz, a parts per thousand currency sign1 mJ/pulse). Unlike common assumptions, THz emission is not only observed in case of rear side irradiation (through substrate (Welsh et al. in Phys. Rev. Lett. 98:026803, 2007; Welsh and Wynne in Opt. Express 17:2470-2480, 2009)) of the nanograting, but also in case of front side excitation (through air). Furthermore in both cases, THz emission propagates in the direction of laser beam propagation and reverse. Based on these findings, we suggest a new approach to describe the newly observed phenomena. Using a highly sensitive and fast superconducting transition edge sensor (TES) as calorimeter, it was possible to directly measure the absolute energy of the emitted THz pulses in a defined spectral and spatial range, enabling for the first time a quantitative analysis of the THz emission process.
KW - terahertz emission
KW - gold-coated nanogratings
KW - femtosecond laser irradiation
KW - transition edge sensor
UR - http://www.scopus.com/inward/record.url?scp=79955914440&partnerID=8YFLogxK
U2 - 10.1007/s00340-011-4377-7
DO - 10.1007/s00340-011-4377-7
M3 - Article
SN - 0946-2171
VL - 102
SP - 551
EP - 554
JO - Applied Physics B: Lasers and Optics
JF - Applied Physics B: Lasers and Optics
IS - 3
ER -