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ZnTe 결정을 이용한 테라헤르츠파의 발생 및 검출 특성

Pulsed Terahertz Emission and Detection Properties from ZnTe Crystal

  • 진윤식 (한국전기 연구원 전기물리 연구그룹) ;
  • 전석기 (한국전기 연구원 전기물리 연구그룹) ;
  • 김근주 (한국전기 연구원 전기물리 연구그룹) ;
  • 손채화 (한국전기 연구원 전기물리 연구그룹) ;
  • 정순신 (한국전기 연구원 전기물리 연구그룹)
  • Jin, Yun-Sik (Applied electro-physics research group, Korea Electrotechnology Research Institute) ;
  • Jeon, Seuk-Gy (Applied electro-physics research group, Korea Electrotechnology Research Institute) ;
  • Kim, Keun-Ju (Applied electro-physics research group, Korea Electrotechnology Research Institute) ;
  • Sohn, Chae-Hwa (Applied electro-physics research group, Korea Electrotechnology Research Institute) ;
  • Jung, Sun-Shin (Applied electro-physics research group, Korea Electrotechnology Research Institute)
  • 발행 : 2005.12.01

초록

(110) ZnTe 결정을 사용한 광정류(Optical Rectification)법에 의한 테라헤르츠파의 발생과 자유공간 전광 샘플링(Free-Space Electro-Optic Sampling; FS-EOS)법에 의한 테라헤르츠파의 검출특성에 대해서 보고한다. ZnTe 결정에 펌프용 레이저광에 대한 반사방지막 코팅을 실시함으로서 테라헤르츠파 신호크기가 $27\%$ 증가함을 알 수 있었다. ZnTe 결정의 두께가 얇을수록 테라헤르츠파의 신호의 크기는 작으나 광대역의 주파수를 가진 스펙트럼이 얻어졌다. 또한 레이저광의 편광방향과 ZnTe 결정의 (001)축사이의 각도에 따른 테라헤르츠파의 신호 변화, 펌프광 출력에 따른 테라헤르츠파의 신호크기 변화 등에 대한 특성이 조사되었다.

Pulsed terahertz (THz) radiation was generated by optical rectification and detected by a fee space electro-optic sampling (FS-EOS) method. We used ZnTe (110) crystals for both generation and detection. By coating dielectric anti-reflection film on the ZnTe crystal surface, we can reduce the reflectance of a pump laser beam from $30\%$ to $2\%$, and the terahertz pulse amplitude increased $27\%$ compared with an uncoated crystal. A wider bandwidth of THz radiation was obtained by using a thinner crystal but the signal intensity was decreased in this case. And variations of THz radiation by changing orientation of the ZnTe crystal with respect to the pump (or probe) laser polarization, and by changing the power of the pump laser have also been investigated and discussed.

키워드

참고문헌

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