Modulating phase by metasurfaces with gated ultra-thin TiN films. Issue 23 (31st May 2019)

• Record Type: Journal Article
• Authors: Jiang, Huan; Reddy, Harsha; Shah, Deesha; Kudyshev, Zhaxylyk A.; Choudhury, Sajid; Wang, Di; Jiang, Yongyuan; Kildishev, Alexander V.
• Is Part Of: Nanoscale. Volume 11:Issue 23(2019)
• Page Start: 11167
• Page End: 11172
• Publication Date: 2019-05-31
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr00205g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Deep control over the phase of light is critical to information processing, telecommunication, and spectroscopic imaging. We design an electrically tunable gold strip/TiN film hybrid metasurface with a deep phase modulation of 337°, employing the tunability of carrier density in a 1-nm titanium nitride film. Abstract : Active control over the flow of light is highly desirable because of its applicability to information processing, telecommunication, and spectroscopic imaging. In this paper, by employing the tunability of carrier density in a 1 nm titanium nitride (TiN) film, we numerically demonstrate deep phase modulation (PM) in an electrically tunable gold strip/TiN film hybrid metasurface. A 337° PM is achieved at 1.550 μm with a 3% carrier density change in the TiN film. We also demonstrate that a continuous 180° PM can be realized at 1.537 μm by applying a realistic experiment-based gate voltage bias and continuously changing the carrier density in the TiN film. The proposed design of active metasurfaces capable of deep PM near the wavelength of 1.550 μm has considerable potential in active beam steering, dynamic hologram generation, and flat photonic devices with reconfigurable functionalities.