Author(s): Meng, L (Meng, Lei); Chai, HY (Chai, Hongyu); Gao, JJ (Gao, Junjie); Lv, ZR (Lv, Zunren); Yang, XG (Yang, Xiaoguang); Liu, WK (Liu, Wenkai); Zhai, TR (Zhai, Tianrui); Yang, T (Yang, Tao)

Source: JOURNAL OF PHYSICS D-APPLIED PHYSICS Volume: 57  Issue: 27 Article Number: 275104  DOI: 10.1088/1361-6463/ad3b06  Published Date: 2024 JUL 12 

Abstract: The second-order nonlinear-polarization originated from the interaction between thin-film materials with second-order nonlinear susceptibility (chi((2))) and high-power laser is essential for integrated optics and photonics. In this work, strong second-order nonlinear-polarization was found in a-axis oriented Zn1-xMgxO (ZnMgO) epitaxial thin-films with Li incorporation, which were deposited by radio-frequency magnetron sputtering. Mg incorporation (x > 0.3) causes a sharp fall in the matrix element chi(33) of chi((2)) tensor, although it widens optical bandgap (E-opt). In contrast, moderate Li incorporation significantly improves chi(33) and resistance to high-power laser pulses with a little influence on E-opt. In particular, a Zn0.67Mg0.33O:Li [Li/(Zn + Mg + Li) = 0.07] thin-film shows a |chi(33)| of 36.1 pm V-1 under a peak power density (E-p) of 81.2 GW cm(-2), a resistance to laser pulses with E-p of up to 124.9 GW cm(-2), and an E-opt of 3.95 eV. Compared to that of ZnO, these parameters increase by 37.8%, 53.4%, and 18.6%, respectively. Specially, the Zn0.67Mg0.33O:Li shows higher radiation resistance than a Mg-doped LiNbO3 crystal with a comparable E-opt. First-principle calculations reveal the Li occupation at octahedral interstitial sites of wurtzite ZnO enhances radiation resistance by improving structural stability. X-ray photoelectron spectroscopy characterizations suggest moderate Li incorporation increases chi(33) via enhancing electronic polarization. These findings uncover the close relationship between the octahedra interstitial defects in wurtzite ZnMgO and its nonlinear-polarization behavior under the optical frequency electric field of high-power laser.

Accession Number: WOS:001206665900001

ISSN: 0022-3727

eISSN: 1361-6463