Spin angular momentum controlled nonlinear harmonic generations from polaritonic metasurfaces

Abstract

In this work, we experimentally demonstrate second- and third-harmonic generation nonlinear gradient metasurfaces based on combining intersubband transitions in multiple quantum wells with plasmonic nanoantennas with C3 or C4 rotational symmetry to control the spin angular momentum (SAM) of light maintaining giant nonlinear response. Experimentally we achieved efficient control of SAM and 3.2 X 10-4 % and 3.7 X 10-4 % of SHG and THG power conversion efficiency, respectively.