Design of Artificial Nonlinear Materials for Plasmonic Electro-Optic Modulators

We introduce artificial electro-optic materials with giant Pockels coefficients. Introducing them into plasmonic modulators addresses the long-standing issue of inherent losses. State-of-the-art plasmonic modulators offer small sizes, record-breaking bandwidths [1], and low electrical power consumption [2]. In order to combat losses, materials with high electro-optic (EO) activity can be employed to reduce the overall length of the plasmonic section. A currently unexplored option could be asymmetric quantum wells (QW), for which early demonstrations showed the possibility of reaching up to 1.6 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\cdot 10^{9}$</tex> pm V-<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> EO coefficients in the MIR [3], exploiting the significant dipole moments of intersubband (ISB) transitions. However, adaptation into NIR wavelengths is challenging, as the band offset necessary for the NIR proves difficult to reach with common III - V materials while staying in the ISB regime. Recently, it has been shown that ISB transitions are possible in TiN / Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> QWs with nonlinearities reaching up to 1.5 nm V-<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> at resonance [4]. This abstract highlights the potential ofnon-III-V artificial materials exploiting ISB transitions for Plasmonic EO applications in the NIR region.