[18p-221B-1~15] 4.6 Terahertz Photonics

▲ [18p-221B-5] Polarization-tunable THz emitters composed of ferromagnetic heterostructures and liquid crystals

〇(DC)Hongsong Qiu¹, Lei Wang², Zhixiong Shen³, Kosaku Kato¹, Nobuhiko Sarukura¹, Masashi Yoshimura¹, Wei Hu³, Yanqing Lu³, Makoto Nakajima¹ (1.Osaka Univ., 2.Nanjing Univ. of Post and Telecommunications, 3.Nanjing Univ.)

Keywords:terahertz emission, polarization tuning, liquid crystals

We demonstrate a magnetically and electrically polarization-tunable terahertz emitter that integrates a ferromagnetic heterostructure and large birefringence liquid crystals. The ferromagnetic heterostructure acts as the THz source as well as the electrode on the optical pumping side. The liquid crystal cell acts as the phase retarder. The state of the polarization can be switched between liner and circular polarization by changing the direction of the external magnetic field in a non-contact way. The phase retardation between e and o wave can be electrically tuned with a high efficiency. This compact and economical THz emitter can be widely used for polarization sensitive researches and engineering applications.