Photonics (Sep 2024)

Tunable Polarization-Selective Absorption by Gating Ultrathin TiN Films in the Near-Infrared Region

  • Huan Jiang,
  • Junhao Huang,
  • Wenchang Zhu,
  • Yetian Wang,
  • Alexander V. Kildishev

DOI
https://doi.org/10.3390/photonics11100917
Journal volume & issue
Vol. 11, no. 10
p. 917

Abstract

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Ultrathin titanium nitride (TiN) is a novel material platform for constructing active metasurfaces in the near-infrared region (NIR). Here, we realized tunable polarization-selective absorption by gating ultrathin TiN in an Ultrathin TiN Grating Metasurface (UTGM) and a gold resonator/TiN film Hybrid Metasurface (GTHM), respectively. The TM wave absorption (0.96) was much larger than that of the TE wave in the UTGM. When the carrier density decreased by 12%, the near-perfect TM absorption peak blue-shifted by 0.3 μm. Similarly, the linear dichroism (0.96) peak in GTHM blue-shifted by 0.12 μm when gating ultrathin TiN film. Active metasurfaces with tunable polarization-selective absorption have huge potential in dynamic integrated electro-optic devices in NIR.

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