Temperature-dependent terahertz dielectric modulation of a high-performance magneto-optic CeF3 crystal

We present experimental observations of the high-performance magneto-optic (MO) CeF3 crystal using terahertz time-domain spectroscopy (THz-TDS) in the temperature range 40-300 K for the first time. The complex refractive index strongly depends on temperature, which increases with increasing temperature. Intriguingly, the changes of complex refractive index values reach more than 0.1 between 40 K and 300 K, which is larger than terbium scandium aluminum garnet (TSAG) crystal. The weak loss tangent indicates that the crystal has a high potential as a high-dielectric-constant photovoltaic device in the terahertz domain.