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Electrically Controllable Asymmetric Split-Loop Terahertz Resonator with Outer Square Loop

전기적 제어 가능한 외곽 사각 고리 추가형 테라헤르츠 비대칭 분리고리공진기

  • Park, Dae-Jun (Department of Convergence Science, Sahmyook University) ;
  • Ryu, Han-Cheol (Department of Convergence Science, Sahmyook University)
  • Received : 2016.11.03
  • Accepted : 2017.02.28
  • Published : 2017.04.25

Abstract

This paper proposes an asymmetric split-loop resonator with an outer square loop (ASLR-OSL), which can actively control terahertz wave transmission properties while maintaining a high-Q-factor of the asymmetric split-loop resonator (ASLR). An added outer square loop is designed to play the roles of both a metamaterial and a micro-heater, which can control the temperature through a directly applied bias voltage. A vanadium dioxide ($VO_2$) thin film, which exhibits an insulator-metal phase transition with temperature change, is used to control the transmission properties. The proposed ASLR-OSL shows transmission properties similar to those of the ASLR, and they can be successfully controlled by directly applying bias voltage to the outer square loop. Based on these results, an electrically controllable terahertz high-Q metamaterial could be achieved simply by adding a square loop to the outside of a well-known high-Q metamaterial.

본 논문에서는 높은 품질 인자를 가지는 비대칭 분리고리공진기(ASLR: Asymmetric Split-Loop Resonator) 외곽에 사각 고리를 추가하여 ASLR의 높은 품질 인자 특성은 유지하면서 ASLR의 테라헤르츠파 투과 특성을 능동 제어 가능한 외곽 사각 고리 추가형 ASLR (ASLR-OSL: ASLR with Outer Square Loop)을 제시하였다. 추가된 외곽 사각 고리는 ASLR과 조합되어 메타물질 공진기 역할과 직접적인 전압 인가를 통하여 온도를 조절할 수 있는 마이크로 히터 역할을 동시에 수행하면서, ASLR-OSR이 ASLR의 품질 인자 특성과 유사한 품질 인자 특성을 유지할 수 있도록 설계하였다. ASLR-OSL의 테라헤르츠파 투과 특성을 능동 제어하기 위하여 온도 변화에 따라 절연체-금속 상전이 특성을 가지는 이산화바나듐 ($VO_2$) 박막을 사용하였고, 설계한 ASLR-OSL의 외곽 사각 고리에 직접적인 전압 인가를 통하여 $VO_2$의 특성을 조절하여 테라헤르츠파 투과 특성의 능동 제어가 가능하도록 하였다. 본 논문에서 제안한 높은 품질 인자를 가지는 메타물질에 간단한 외곽 사각 고리를 추가하여 구성한 능동형 고품질 메타물질 구조는 메타물질의 높은 품질 인자는 유지하면서 테라헤르츠파 투과 특성의 전기적 능동 제어를 가능하게 하여 다양한 형태의 테라헤르츠 능동형 메타물질 소자로 응용될 수 있을 것으로 기대한다.

Keywords

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