Demonstration of nonperturbative and perturbative third-harmonic generation in MgO by altering the electronic structure

Mukhtar Hussain (1) , Fernando Lima (1) , Willem Boutu (2) , Hamed Merdji (2) , Marta Fajardo (1) , Gareth Williams (1)

1 GoLP/Instituto de Plasmas e Fusão Nuclear-Laboratório Associado
2 DICO - Dynamique et Interactions en phase Condensée

The surge of interest in nonperturbative high-harmonic generation in solids has been driven by the appeal of compact solid-state extreme ultraviolet sources and the prospect of untangling the material properties through high-harmonic generation response to strong fields. The traditional assumption is that the brighter, lower-order harmonics are purely perturbative in nature. However, the border between the perturbative and nonperturbativeregimes often remains unclear. Here, we show that third-harmonic generation (THG) using 800-nm, 40-fs pulses displays a nonperturbative response in a wide-band-gap insulator MgO. Furthermore, we show that with the introduction of dopants, the nonperturbative THG reverts to the perturbative behavior. We attribute this to the blockingof intraband oscillations and the increased linear absorption pathways introduced by the dopant energy levels

Domains: Theoretical and/or physical chemistry; Mechanics of materials [physics.class-ph]; Chemical Physics [physics.chem-ph]

Mukhtar Hussain, Fernando Lima, Willem Boutu, Hamed Merdji, Marta Fajardo, et al.. Demonstration of nonperturbative and perturbative third-harmonic generation in MgO by altering the electronic structure. Physical Review A, 2022, 105 (5), pp.053103. ⟨10.1103/PhysRevA.105.053103⟩. ⟨cea-03857499⟩