[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.)

キーワード：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.