Bi-directional terahertz emission from gold-coated nanogratings by excitation via femtosecond laser pulses

F. Garwe, A. Schmidt, G. Zieger, T. May, K. Wynne, U. Huebner, M. Zeisberger, W. Paa, H. Stafast, H. -G. Meyer

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


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.
Original languageEnglish
Pages (from-to)551-554
Number of pages4
JournalApplied Physics B: Lasers and Optics
Issue number3
Publication statusPublished - 1 Mar 2011


  • terahertz emission
  • gold-coated nanogratings
  • femtosecond laser irradiation
  • transition edge sensor

Cite this