Enhancing high harmonic generation in GaAs by elliptically polarized light excitation
Fumiya Sekiguchi, Minoru Sakamoto, Kotaro Nakagawa, Hirokazu Tahara, Shunsuke Sato, Hideki Hirori, Yoshihiko Kanemitsu
Abstract
High harmonic generation (HHG) in solids shows interesting behavior owing to their crystal structures. Here, the authors investigate a prominent example: HHG in GaAs can be enhanced by elliptically polarized light excitation. Remarkably, the enhancement is accompanied by emergent nonlinear optical activity, and it become salient only at particular ``intermediate'' excitation strengths. These results indicate that the key for HHG enhancement lies in the interference among nonlinear emission processes, revealing that not only material properties but optimal-strength excitations are important for controlling HHG properties via fine-tuning of the nonlinear dynamics.