(Pb,La)TiO_3铁电薄膜的太赫兹时域光谱实验研究

Time Domain Terahertz Spectroscopy of(Pb,La)TiO_3 Ferroelectric Thin Films

利用THz时域光谱技术（THz-TDS）探测了制作在SiO2／Si衬底上的（Pb，La）TiO3铁电薄膜的频谱响应，获得了三种不同烧结温度的掺镧钛酸铅（PLT）薄膜的THz频谱。根据实验数据计算得到了PLT薄膜在0．2～3THz频段内的吸收系数、折射率和复介电常数，并对比了三种不同烧结温度的PLT薄膜的实验计算结果。实验结果表明，三种PLT薄膜在所测频段内均有较强吸收，且都在1．5THz处有一个明显的吸收峰，在2．25THz处有一个相对较弱的吸收峰。

Terahertz time-domain spectroscopic technique was applied to investigate the spectral properties of （Pb, La）TiO3 （PLT） ferroelectric thin films prepared on SiO2/Si substrates. The terahertz spectra of three kinds of PLT thin films with different sintering temperatures were observed. According to the experimental data, the absorption coefficients, refraction indexes and dielecric constants of the PLT thin films were computed, and the experimental results of the three kinds of PLT thin films with different sintering temperatures in the effective frequency range were compared. The results indicated that the PLT thin films had strong absorption in the frequency range of measurement, and had an obvious absorption peak at 1.5 THz and a weaker absorption peak at 2.25 THz.