Photonics Research, 2019, 7 (12): 12001493, Published Online: Nov. 22, 2019
Third-order nonlinear optical properties of WTe2 films synthesized by pulsed laser deposition Download: 594次
Abstract
The prominent third-order nonlinear optical properties of films are studied through the Z-scan technique using a femtosecond pulsed laser at 1030 nm. Open-aperture (OA) and closed-aperture (CA) Z-scan measurements are performed at different intensities to investigate the nonlinear absorption and refraction properties of films. OA Z-scan results show that films always hold a saturable absorption characteristic without transition to reverse saturable absorption. Further, a large nonlinear absorption coefficient is determined to be by fitting the OA Z-scan curve at the peak intensity of . In addition, through the slow saturation absorption model, the ground state absorption cross section, excited state absorption cross section, and absorber’s density were found to be , , and , respectively. CA Z-scan results exhibit a classic peak–valley shape of the CA Z-scan signal, which reveals a self-defocusing optical effect of films under the measured environment. Furthermore, a considerable nonlinear refractive index value can be obtained at . Ultimately, the values of the real and imaginary parts of the third-order nonlinear s
Mi He, Yequan Chen, Lipeng Zhu, Huan Wang, Xuefeng Wang, Xinlong Xu, Zhanyu Ren. Third-order nonlinear optical properties of WTe2 films synthesized by pulsed laser deposition[J]. Photonics Research, 2019, 7(12): 12001493.