用脉冲激光沉积技术制备了钛酸锶钡(Ba0.5Sr0.5TiO3)薄膜。用X射线光电子能谱和原子力显微镜分别分析了薄膜的化学组分和表面形貌。在交流信号为50 mV和100 kHz时测量了薄膜的介电系数和介电损耗随外加电场的变化关系,得出最高的介电可调率达到45%。利用单光束纵向Z扫描的方法研究了薄膜的非线性光学性质,得到非线性折射率为5.04×10-6 cm2/kW, 非线性吸收系数为3.59×10-6 m/W,测量所用光源的波长为532 nm,脉宽为55 ps,表明Ba0.5Sr0.5TiO3薄膜有较快的非线性光学响应。

Thin films of barium strontium titanate (Ba0.5Sr0.5TiO3) were fabricated by pulsed-laser deposition technique. X-ray photoelectron spectroscopy and atomic-force microscopy were used to characterize the chemical composition and surfacial profile of the films. The permittivity and dielectric loss as a function of applied electric field were conducted with an alternating current (AC) signal of 50 mV at 100 kHz. The obtained value of dielectric tunability is about 45%. The nonlinear optical properties of the films were determined by a single beam z-scan method at a wavelength of 532 nm with laser pulse duration of 55 ps. The results show that Ba0.5Sr0.5TiO3 thin films exhibit a fast third-order nonlinear optical response with the nonlinear refractive index and nonlinear absorption coefficient of 5.04×10-6 cm2/kW and 3.59×10-6 m/W, respectively.