[9p-Z23-1~11] 4.6 Terahertz Photonics

▲ [9p-Z23-5] THz Emission Amplitude Enhancement of Fe/Pt Diabolo-shaped Spintronic Antennas Fabricated on MgO Substrates

〇(D)Miezel Legurpa Talara¹, Dmitry Bulgarevich², Valynn Katrine Mag-usara^1,3, Chiyaka Tachioka¹, Joselito Muldera¹, Hideaki Kitahara^1,3, Mary Clare Escano¹, Makoto Nakajima³, Makoto Watanabe², Masahiko Tani¹ (1.Res. Ctr. for Dev. of Far-Infrared Region, Univ. of Fukui, 2.Res. Ctr. for Structural Materials, Nat. Inst. for Mat. Sci., 3.Inst. of Laser Eng., Osaka Univ.)

Keywords:spintronic antennas, THz antennas, spintronics

In this paper, we report on THz emission amplitude performance of Fe/Pt diabolo-shaped spintronic antennas fabricated on MgO substrates. We performed THz-time domain spectroscopy (TDS) measurements of diabolo-shaped spintronic antenna with Fe and Pt thicknesses of 2 nm and 3 nm, respectively, and of diabolo-shaped spintronic antenna with Fe = 2 nm and Pt = 100 nm at both antenna flares. Results showed that the diabolo-shaped antenna with the same metal thicknesses with that of the spintronic bilayer showed ~51% improvement which may have been caused by the enhanced outcoupling of THz radiation brought by the diabolo-shaped structure. Moreover, the diabolo-shaped antenna with thicker Pt showed ~88% improvement. This improvement can be attributed to the enhanced coupling of THz wave to free space and improved radiation directivity. For THz detection, we used an LTG-GaAs dipole-type photoconductive antenna (PCA) with 2. 6 mW and 4.7 mW pump and probe power, respectively.