College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Key Laboratory of Optoelectronics Information and Technology (Ministry of Education), Tianjin, 300072, China.
School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma, 74078, USA.
Sci Rep. 2017 Jul 20;7(1):6072. doi: 10.1038/s41598-017-05529-0.
The dielectric properties of an active KTaO hybrid metamaterial structure and its tunability under external electric fields are investigated at room temperature by means of terahertz time-domain spectroscopy. Application of the electric field leads to an appreciable tuning of the dielectric loss, which is up to 17%. Meanwhile, the refractive index also changes appreciably. These findings are attributed to the internal space charge field in the crystal caused by the excited free carriers.
利用太赫兹时域光谱技术，在室温下研究了有源 KTaO 混合超材料结构的介电性能及其在外电场下的可调谐性。施加电场会导致介电损耗显著调谐，最高可达 17%。同时，折射率也会发生明显变化。这些发现归因于晶体中由受激自由载流子引起的内部空间电荷场。
