The wafer-scale La:YIG single crystal thick films were fabricated on a three-inch gadolinium gallium garnet (GGG) substrate by liquid phase epitaxy method. The terahertz (THz) optical and magneto-optical properties of La:YIG film were demonstrated by THz time domain spectroscopy (THz-TDS). The results show that a high refractive index of approximately 4.09 and a low absorption coefficient of 10–50 cm⁻¹ from 0.1 to 1.6 THz for this La:YIG film. Moreover, the THz Faraday rotation effect of La:YIG film was measured by the orthogonal polarization detection method in THz-TDS system, which can be actively manipulated by a weak longitudinal magnetic field of up to 0.155 T. With 5 samples stacked together, the Faraday rotation angle varies linearly from −15° to 15°, and the Verdet constant of La:YIG is about 100 °/mm/T within the saturation magnetization. This magneto-optical single crystal thick film with large area shows low loss, high permittivity and strong magneto-optical effect in the THz regime, which will be widely used in magneto-optical polarization conversion, nonreciprocal phase shifter and isolator for THz waves.

中文翻译：

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晶片级La：太低损耗和高介电常数的La：钇铁石榴石单晶膜的太赫兹磁光效应。

通过液相外延法在三英寸g镓石榴石（GGG）衬底上制备了晶圆级La：YIG单晶厚膜。La：YIG薄膜的太赫兹（THz）光学和磁光特性通过THz时域光谱（THz-TDS）进行了证明。结果表明，高折射率约为4.09，低吸收系数为10–50 cm ^-1此La：YIG薄膜在0.1至1.6 THz范围内。此外，通过THz-TDS系统中的正交极化检测方法测量了La：YIG薄膜的THz法拉第旋转效应，可以通过高达0.155 T的弱纵向磁场对其进行主动控制。将5个样品堆叠在一起，法拉第旋转角度从-15°到15°线性变化，并且La：YIG的Verdet常数在饱和磁化强度内约为100°/ mm / T。这种大面积的磁光单晶厚膜在太赫兹波段具有低损耗，高介电常数和强磁光效应，将广泛用于太赫兹波的磁光偏振转换，不可逆移相器和隔离器。