Optical harmonic generation on the exciton-polariton in ZnSe

Abstract

We study optical harmonic generation on the 1S exciton-polariton in the semiconductor ZnSe. Intense and spectrally narrow exciton resonances are found in optical second (SHG), third (THG), and fourth (FHG) harmonic generation spectra. The resonances are shifted to higher energy by 3.2 meV from the exciton energy in the linear reflectivity spectrum. Additional resonances are observed in the THG and FHG spectra and assigned to combinations of incident and backscattered photons in the crystal. Rotational anisotropy diagrams are measured and further information on the origin of the optical harmonic generation and the involved exciton states is obtained by a symmetry analysis using group theory in combination with a microscopic consideration.

Optical second and third harmonic generation on excitons in ZnSe/BeTe quantum wells

“…[ 0 1 0 ] Note that we observed similar shapes for the THG rotational diagrams for the 1S exciton in bulk ZnSe [23]. However, the theoretical description differs for bulk and MQW samples due to their different symmetries, as will be shown in Sec.…”