상세정보
학술지
Subwavelength Localization and Toroidal Dipole Moment of Spoof Surface Plasmon Polaritons
- 저자
- 김성한, 오상순, 김갑중, 김재은, 박해용, Ortwin Hess, 기철식
- 발행일
- 201501
- 출처
- Physical Review B : Condensed Matter and Materials Physics, v.91, pp.1-9
- ISSN
- 1098-0121
- 출판사
- American Physical Society(APS)
- 협약과제
- 14PB5800, 실리콘 포토닉스 기반 SDN용 12채널 4x8 광스위치 모듈 개발, 이종무
- 초록
- We experimentally and theoretically demonstrate subwavelength scale localization of spoof surface plasmon polaritons at a point defect in a two-dimensional groove metal array. An analytical expression for dispersion relation of spoof surface plasmon polaritons substantiates the existence of a band gap where a defect mode can be introduced. A waveguide coupling method allows us to excite localized spoof surface plasmon polariton modes and measure their resonance frequencies. Numerical calculations confirm that localized modes can have a very small modal volume and a high Q factor both of which are essential in enhancing light-matter interactions. Interestingly, we find that the localized spoof surface plasmon polariton has a significant toroidal dipole moment, which is responsible for the high Q factor, as well as an electric quadrupole moment. In addition, the dispersion properties of spoof surface plasmon polaritons are analyzed using a modal expansion method and numerical calculations.
- KSP 제안 키워드
- Band gap, Coupling method, Defect mode, Dipole moment, Dispersion properties, Electric quadrupole moment, Numerical calculation, Quality-factor(Q-factor), Resonance frequency, Surface plasmon(SP), Waveguide coupling