講演情報
[7p-N106-14]Exploration of Two-Dimensional Electron Gas in AlGaN/AlN Waveguides for Electro-Optic Modulation
〇(PC)Hannaneh Hana Dortaj1,3, Sinan Gundogdu1,2, Domenica Romina Bermeo Alvaro1,2, Tommaso Pregnolato1,2, Tim Schroeder1,2 (1.Humboldt Univ, 2.Ferdinand-Braun Inst, 3.Tabriz Univ)
キーワード：
two-dimensional electron gas (2DEG)、heterostructures、semiconductors
The AlGaN/AlN material platform has emerged as a promising candidate for integrated photonics due to its relatively low optical losses, moderate electro-optic coefficients, and compatibility with heterointegration of diamond-based quantum photonic devices. The investigation of two-dimensional electron gas (2DEG) formation in AlGaN/AlN heterostructures has significant implications for electro-optic modulation and high-frequency device applications. This study explores the spontaneous polarization effects in n-polar heterostructures, where the 2DEG modifies the local refractive index and optical losses due to charge redistribution under an applied electric field. This 2DEG mode likely overlaps with the optical mode and could impact its effective refractive index. By employing computational simulations using Poisson equation and Drude-Lorentz model, we quantify the impact of 2DEG on waveguide performance. Our simulations confirm that the refractive index undergoes measurable changes when the electric field is applied, although the modulation effect remains weak in the current geometry. The shielding effect of 2DEG reduces the Pockels and Kerr electro-optic effects but introduces an alternative mechanism through free carrier modulation. Optimizing the waveguide design such as modifying electrode placement or repositioning the 2DEG within the waveguide can enhance modulation efficiency and reduce optical losses. Furthermore, this study explores potential applications in nonlinear optics, where 2DEG-based structures could be utilized for high-Q resonators and anomalous dispersion engineering.