Z-scan measurements of nonlinear refraction and absorption for aluminum-doped zinc oxide thin film.

In this paper, we investigate third-order nonlinearities in aluminum-doped zinc oxide (AZO) thin film by the Z-scan method at a wavelength of 1064 nm. We carried out experiments under different pulse widths (26 ns, 62 ns, and 101 ns) and energy densities (5.3  J/cm2, 10.6  J/cm2, and 15.9  J/cm2) and obtained the nonlinear absorption coefficient, nonlinear refractive index, and third-order nonlinear susceptibility of AZO thin film. The Z-scan results show that AZO thin film exhibits a larger nonlinear refractive index (-5.48×10-13  m2/W) and third-order nonlinear susceptibility (1.97×10-6  esu) than those of some other semiconductor materials at the wavelength of 1064 nm. This suggests that AZO thin film may be a very promising nonlinear medium for nonlinear photonics applications in the tens of nanoseconds regime.