Design and modeling of third-harmonic plasmonic metasurfaces coupled to multi-quantum well structures

Abstract

In this paper, we analyze plasmonic nonlinear metasurfaces based on multi-quantum well (MQW) substrates designed for the third-harmonic generation (THG) nonlinear process. MQW plasmonic metasurfaces have become one of the most noticeable structures in the implementation of nonlinear processes due to the high conversion efficiency for low pump intensities. We propose a semi-analytical algorithm to model TH metasurfaces using the Lorentz reciprocity theorem. Also, in order to predict the electromagnetic behavior of these structures accurately, the THG saturation effects are taken into account. In the next step, two MQW heterostructures and an efficient plasmonic resonator are designed for THG at 30 THz fundamental frequency. In our best design, power conversion efficiency up to 2.1×10−3% is achieved by applying pump intensity below the optical damage threshold (about 200 kW/cm2). The proposed TH metasurfaces can find application used in spectroscopy and as mid-infrared optical sources.