Nonlinear optical properties of neodymium-doped bismuth titanate thin films using Z-scan technique

Abstract

Bi 3.75 Nd 0.25 Ti 3 O 12 (BNT0.25) thin film with good surface morphology and layered perovskite structure was fabricated by a metalorganic solution deposition process. Their fundamental optical constants (the band gap, linear refractive index, and absorption coefficient) were obtained through optical transmittance measurements. The nonlinear optical properties of the film were investigated by using a top-hat Z-scan method. Large positive nonlinear refractive index n2 and two-photon absorption coefficient β were determined to be 4.52×10−7 esu and 5.24×10−7 m/W, respectively. All of the results show that the BNT0.25 thin film is promising for applications in nonlinear optical devices.