Current Optics and Photonics

Optical Society of Korea (한국광학회)
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Terahertz Complex Refractive Index and Guiding of White Staghorn Coral

  • Kang, Chul (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Kim, Myunghwan (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Kim, Hyeongmun (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Park, Jin Young (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Kim, Bok Hyeon (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Maeng, Inhee (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Choi, SooBong (Department of Physics, Incheon National University) ;
  • Kim, Soeun (Advanced Photonics Research Institute, Gwangju Institute Science and Technology) ;
  • Kee, Chul-Sik (Advanced Photonics Research Institute, Gwangju Institute Science and Technology)
  • Received : 2021.05.18
  • Accepted : 2021.06.08
  • Published : 2021.08.25
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Abstract

Corals are the remains of animals that grow on warm beaches. They have been used as decorative jewels because of their variety of colors, and as medicinal materials for treating cancers, AIDS, and other therapeutic uses because of their chemical elements. Corals are mainly composed of calcium carbonate (CaCO3) and have many air pores, tens to hundreds of micrometers in size. The refractive indices and absorption coefficients of dried sliced staghorn corals are investigated using terahertz time-domain spectroscopy. The measured values are similar to those for CaCO3, as expected. It is observed that a sample with a microstructure formed by air pores can guide terahertz waves. The dispersion, effective index, and loss of the guiding modes of coral core surrounded by five triangular air pores are numerically calculated. The simulated spatial distribution of the electric field of the guide mode at 1.25 THz shows the mode to be tightly confined to the core.

Keywords

Acknowledgement

This work was supported by the Gwangju Institute of Science and Technology (GIST) Research Institute (GRI) grant, funded by the GIST in 2021, and the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT (NRF-2019R1F1A1063156).

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