[15p-C301-1~12] 4.7 Terahertz Photonics

▼ [15p-C301-3] Enhancement of Terahertz Magnetic Near-field by Tapered Metallic Waveguide

〇(D)Hongsong Qiu¹, Hirofumi Harada¹, Kosaku Kato¹, Takayuki Kurihara¹, Keisuke Takano¹, Tohru Suemoto², Masahiko Tani³, Nobuhiko Sarukura¹, Masashi Yoshimura¹, Makoto Nakajima¹ (1.Osaka Univ., 2.Toyota Physical and Chemical Research Inst., 3.Univ. of Fukui)

Keywords:Terahertz magnetic near-field, metallic waveguide, split-ring resonator

The usage of magnetic field of terahertz (THz) wave provides novel means to control spin dynamics in ultrafast time scales. While previous studies revealed coherent spin dynamics in linear or small perturbation regime, much more drastic change of the permanent magnetic order is expected under stronger excitation fluence. For this purpose, tight focusing effect of THz waves in plasmonic waveguide is quite useful for enhancing the available magnetic fields. In this paper, we report on the direct enhancement of terahertz magnetic near-field amplitude in a tapered waveguide, observed by the magneto-optic sampling in a double split-ring resonator (D-SRR) coupled Tb₃Ga₅O₁₂ (TGG) crystal.