Efficient terahertz wave generation of diabolo-shaped Fe/Pt spintronic antennas driven by a 780-nm pump beam

We report on efficient terahertz (THz) wave generation of Fe/Pt diabolo-shaped spintronic antennas with different Pt thicknesses fabricated on MgO substrates. Compared with the antenna-free spintronic bilayer, similar to 45% and similar to 98% emission amplitude improvements were obtained when using the antennas with thin and thick Pt, respectively, as THz radiation sources. The improvement can be attributed to the enhanced outcoupling of THz radiation to free space and to the enhanced THz emission with the deposition of thicker Pt layer at the displacement current direction. Our results suggest that efficient spintronic radiation sources can be obtained with proper design of these THz emitters.