CaCu₃Ti₄O₁₂ (CCTO) thin films of preference (220) orientation are deposited on MgO(111) substrates using pulsed laser deposition method. The third-order optical nonlinearity of CCTO films was investigated using Z-scan technique at a wavelength of 532 nm with 25 ps duration pulses. The self-focusing behavior in CCTO films was observed, which is different from the traditional CCTO films grown on LaAlO₃ (0001), MgO(100), and fused silica substrates of self-defocusing behavior. The third-order nonlinear refraction coefficient is determined of a value 0.76 cm²/GW, along with the fifth-order nonlinear refractive index -0.2 cm⁴/GW², the nonlinear absorption coefficient -1.87 × 10⁻⁷ m/W and saturable absorption intensity 1.72 GW/cm². The structure-changed nonlinear refraction and fast response at picosecond time-domain extend the potential applications of CaCu₃Ti₄O₁₂ thin films for nonlinear photonics devices.

使用脉冲激光沉积方法在MgO（111）衬底上沉积优先（220）取向的CaCu ₃ Ti ₄ O ₁₂（CCTO）薄膜。使用Z扫描技术在532 nm波长和25 ps持续时间脉冲下研究了CCTO膜的三阶光学非线性。观察到CCTO膜中的自聚焦行为，这与在LaAlO ₃（0001），MgO（100）和熔融石英衬底上生长的传统CCTO膜具有自聚焦特性不同。确定三阶非线性折射率的值为0.76 cm ² / GW以及五阶非线性折射率-0.2 cm ⁴ / GW ²，非线性吸收系数为-1.87×10 ^-7 m / W，饱和吸收强度为1.72 GW / cm ²。皮秒时域中结构改变的非线性折射和快速响应扩展了CaCu ₃ Ti ₄ O ₁₂薄膜在非线性光子器件中的潜在应用。