Ultra-high modulation depth exceeding 2,400% in optically controlled topological surface plasmons
- Title
- Ultra-high modulation depth exceeding 2,400% in optically controlled topological surface plasmons
- Author
- 심상완
- Issue Date
- 2015-10
- Publisher
- NATURE PUBLISHING GROUP
- Citation
- NATURE COMMUNICATIONS, v. 6, Article no. 8814
- Abstract
- Modulating light via coherent charge oscillations in solids is the subject of intense research topics in opto-plasmonics. Although a variety of methods are proposed to increase such modulation efficiency, one central challenge is to achieve a high modulation depth ( defined by a ratio of extinction with/without light) under small photon-flux injection, which becomes a fundamental trade-off issue both in metals and semiconductors. Here, by fabricating simple micro-ribbon arrays of topological insulator Bi2Se3, we report an unprecedentedly large modulation depth of 2,400% at 1.5 THz with very low optical fluence of 45 mu J cm(-2). This was possible, first because the extinction spectrum is nearly zero due to the Fano-like plasmon-phonon-destructive interference, thereby contributing an extremely small denominator to the extinction ratio. Second, the numerator of the extinction ratio is markedly increased due to the photoinduced formation of massive two-dimensional electron gas below the topological surface states, which is another contributor to the ultra-high modulation depth.
- URI
- https://www.nature.com/articles/ncomms9814https://repository.hanyang.ac.kr/handle/20.500.11754/100591
- ISSN
- 2041-1723
- DOI
- 10.1038/ncomms9814
- Appears in Collections:
- COLLEGE OF ENGINEERING SCIENCES[E](공학대학) > ELECTRICAL ENGINEERING(전자공학부) > Articles
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