Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - A Terahertz Chiral Metamaterial modulator
AU - Kindness, Stephen
AU - Almond, Nikita
AU - Wei, Binbin
AU - Michailow, Wladislaw
AU - Delfanazari, Kaveh
AU - Braeuninger-Weimer, Philipp
AU - Hofmann, Stephan
AU - Beere, Harvey E.
AU - Ritchie, David
AU - Degl'Innocenti, Riccardo
PY - 2020/11/4
Y1 - 2020/11/4
N2 - Active control of chirality in artificial media such as metamaterials is fundamental in many scientific areas, ranging from research into fundamental optical phenomena to the investigation of novel materials, spectroscopy, and imaging. Precise control of the light polarization states has great importance for light‐matter interaction in chemistry and biology, as media with diverse chiral properties react differently to the incoming polarization of light. In this work an active double layer metamaterial device based on vertically stacked ring resonators is realized by integrating electrostatically tunable graphene as an active element. The device is characterized with a THz time domain spectroscopic system demonstrating an all‐electrical control of circular dichroism and optical activity at ≈2 THz, reporting a tunable ellipticity of 0.55–0.98 and >20° rotation of the plane polarization, respectively, by modifying the conductivity of graphene. Further integration with a narrow frequency quantum cascade laser emitting at ≈1.9 THz, in a crossed polarizer experimental arrangement, realizes an active amplitude modulator, hence highlighting the versatility of this approach. These results represent an important milestone for the investigation of novel concepts in optics and in several applications in the THz range, such as wireless communications and spectroscopy.
AB - Active control of chirality in artificial media such as metamaterials is fundamental in many scientific areas, ranging from research into fundamental optical phenomena to the investigation of novel materials, spectroscopy, and imaging. Precise control of the light polarization states has great importance for light‐matter interaction in chemistry and biology, as media with diverse chiral properties react differently to the incoming polarization of light. In this work an active double layer metamaterial device based on vertically stacked ring resonators is realized by integrating electrostatically tunable graphene as an active element. The device is characterized with a THz time domain spectroscopic system demonstrating an all‐electrical control of circular dichroism and optical activity at ≈2 THz, reporting a tunable ellipticity of 0.55–0.98 and >20° rotation of the plane polarization, respectively, by modifying the conductivity of graphene. Further integration with a narrow frequency quantum cascade laser emitting at ≈1.9 THz, in a crossed polarizer experimental arrangement, realizes an active amplitude modulator, hence highlighting the versatility of this approach. These results represent an important milestone for the investigation of novel concepts in optics and in several applications in the THz range, such as wireless communications and spectroscopy.
U2 - 10.1002/adom.202000581
DO - 10.1002/adom.202000581
M3 - Journal article
VL - 8
JO - Advanced Optical Materials
JF - Advanced Optical Materials
SN - 2195-1071
IS - 21
M1 - 2000581
ER -