Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity

Anna C. Tasolamprou, Anastasios D. Koulouklidis, Christina Daskalaki, Charalampos P. Mavidis, George Kenanakis, George Deligeorgis, Zacharias Viskadourakis, Polina Kuzhir, Stylianos Tzortzakis, Maria Kafesaki, Eleftherios N. Economou, Costas M. Soukoulis

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We present an experimental demonstration and interpretation of an ultrafast optically tunable, graphene-based thin film absorption modulator for operation in the THz regime. The graphene-based component consists of a uniform CVD-grown graphene sheet stacked on an SU-8 dielectric substrate that is grounded by a metallic ground plate. The structure shows enhanced absorption originating from constructive interference of the impinging and reflected waves at the absorbing graphene sheet. The modulation of this absorption, which is demonstrated via a THz time-domain spectroscopy setup, is achieved by applying an optical pump signal, which modifies the conductivity of the graphene sheet. We report an ultrafast (on the order of few ps) absorption modulation on the order of 40% upon photoexcitation. Our results provide evidence that the optical pump excitation results in the degradation of the graphene THz conductivity, which is connected with the generation of hot carriers, the increase of the electronic temperature, and the dominant increase of the scattering rate over the carrier concentration as found in highly doped samples.

Original languageEnglish
JournalACS Photonics
DOIs
Publication statusPublished - 1 Jan 2019

Fingerprint

Graphite
Graphene
absorbers
graphene
Demonstrations
Modulation
modulation
Thin films
conductivity
thin films
Pumps
pumps
Hot carriers
Photoexcitation
reflected waves
photoexcitation
Modulators
Carrier concentration
modulators
Chemical vapor deposition

Keywords

  • experimental grapheme absorber
  • flat optics modulation
  • grapheme photoexcitation
  • hot carrier generation
  • THz graphene
  • ultrafast THz tunable grapheme metasurface

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

Cite this

Tasolamprou, A. C., Koulouklidis, A. D., Daskalaki, C., Mavidis, C. P., Kenanakis, G., Deligeorgis, G., ... Soukoulis, C. M. (2019). Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity. ACS Photonics. https://doi.org/10.1021/acsphotonics.8b01595

Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity. / Tasolamprou, Anna C.; Koulouklidis, Anastasios D.; Daskalaki, Christina; Mavidis, Charalampos P.; Kenanakis, George; Deligeorgis, George; Viskadourakis, Zacharias; Kuzhir, Polina; Tzortzakis, Stylianos; Kafesaki, Maria; Economou, Eleftherios N.; Soukoulis, Costas M.

In: ACS Photonics, 01.01.2019.

Research output: Contribution to journalArticle

Tasolamprou, AC, Koulouklidis, AD, Daskalaki, C, Mavidis, CP, Kenanakis, G, Deligeorgis, G, Viskadourakis, Z, Kuzhir, P, Tzortzakis, S, Kafesaki, M, Economou, EN & Soukoulis, CM 2019, 'Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity', ACS Photonics. https://doi.org/10.1021/acsphotonics.8b01595
Tasolamprou, Anna C. ; Koulouklidis, Anastasios D. ; Daskalaki, Christina ; Mavidis, Charalampos P. ; Kenanakis, George ; Deligeorgis, George ; Viskadourakis, Zacharias ; Kuzhir, Polina ; Tzortzakis, Stylianos ; Kafesaki, Maria ; Economou, Eleftherios N. ; Soukoulis, Costas M. / Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity. In: ACS Photonics. 2019.
@article{8bae6725657440bc826ee4ab12db8ed4,
title = "Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity",
abstract = "We present an experimental demonstration and interpretation of an ultrafast optically tunable, graphene-based thin film absorption modulator for operation in the THz regime. The graphene-based component consists of a uniform CVD-grown graphene sheet stacked on an SU-8 dielectric substrate that is grounded by a metallic ground plate. The structure shows enhanced absorption originating from constructive interference of the impinging and reflected waves at the absorbing graphene sheet. The modulation of this absorption, which is demonstrated via a THz time-domain spectroscopy setup, is achieved by applying an optical pump signal, which modifies the conductivity of the graphene sheet. We report an ultrafast (on the order of few ps) absorption modulation on the order of 40{\%} upon photoexcitation. Our results provide evidence that the optical pump excitation results in the degradation of the graphene THz conductivity, which is connected with the generation of hot carriers, the increase of the electronic temperature, and the dominant increase of the scattering rate over the carrier concentration as found in highly doped samples.",
keywords = "experimental grapheme absorber, flat optics modulation, grapheme photoexcitation, hot carrier generation, THz graphene, ultrafast THz tunable grapheme metasurface",
author = "Tasolamprou, {Anna C.} and Koulouklidis, {Anastasios D.} and Christina Daskalaki and Mavidis, {Charalampos P.} and George Kenanakis and George Deligeorgis and Zacharias Viskadourakis and Polina Kuzhir and Stylianos Tzortzakis and Maria Kafesaki and Economou, {Eleftherios N.} and Soukoulis, {Costas M.}",
year = "2019",
month = "1",
day = "1",
doi = "10.1021/acsphotonics.8b01595",
language = "English",
journal = "ACS Photonics",
issn = "2330-4022",
publisher = "American Chemical Society",

}

TY - JOUR

T1 - Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity

AU - Tasolamprou, Anna C.

AU - Koulouklidis, Anastasios D.

AU - Daskalaki, Christina

AU - Mavidis, Charalampos P.

AU - Kenanakis, George

AU - Deligeorgis, George

AU - Viskadourakis, Zacharias

AU - Kuzhir, Polina

AU - Tzortzakis, Stylianos

AU - Kafesaki, Maria

AU - Economou, Eleftherios N.

AU - Soukoulis, Costas M.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - We present an experimental demonstration and interpretation of an ultrafast optically tunable, graphene-based thin film absorption modulator for operation in the THz regime. The graphene-based component consists of a uniform CVD-grown graphene sheet stacked on an SU-8 dielectric substrate that is grounded by a metallic ground plate. The structure shows enhanced absorption originating from constructive interference of the impinging and reflected waves at the absorbing graphene sheet. The modulation of this absorption, which is demonstrated via a THz time-domain spectroscopy setup, is achieved by applying an optical pump signal, which modifies the conductivity of the graphene sheet. We report an ultrafast (on the order of few ps) absorption modulation on the order of 40% upon photoexcitation. Our results provide evidence that the optical pump excitation results in the degradation of the graphene THz conductivity, which is connected with the generation of hot carriers, the increase of the electronic temperature, and the dominant increase of the scattering rate over the carrier concentration as found in highly doped samples.

AB - We present an experimental demonstration and interpretation of an ultrafast optically tunable, graphene-based thin film absorption modulator for operation in the THz regime. The graphene-based component consists of a uniform CVD-grown graphene sheet stacked on an SU-8 dielectric substrate that is grounded by a metallic ground plate. The structure shows enhanced absorption originating from constructive interference of the impinging and reflected waves at the absorbing graphene sheet. The modulation of this absorption, which is demonstrated via a THz time-domain spectroscopy setup, is achieved by applying an optical pump signal, which modifies the conductivity of the graphene sheet. We report an ultrafast (on the order of few ps) absorption modulation on the order of 40% upon photoexcitation. Our results provide evidence that the optical pump excitation results in the degradation of the graphene THz conductivity, which is connected with the generation of hot carriers, the increase of the electronic temperature, and the dominant increase of the scattering rate over the carrier concentration as found in highly doped samples.

KW - experimental grapheme absorber

KW - flat optics modulation

KW - grapheme photoexcitation

KW - hot carrier generation

KW - THz graphene

KW - ultrafast THz tunable grapheme metasurface

UR - http://www.scopus.com/inward/record.url?scp=85062489892&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062489892&partnerID=8YFLogxK

U2 - 10.1021/acsphotonics.8b01595

DO - 10.1021/acsphotonics.8b01595

M3 - Article

AN - SCOPUS:85062489892

JO - ACS Photonics

JF - ACS Photonics

SN - 2330-4022

ER -