The effect of optical pump on the absorption coefficient of 0.65CaTiO3-0.35NdAlO3 ceramics in terahertz range

The absorption coefficient of 0.65CaTiO3-0.35NdAlO3 ceramics under external optical fields was investigated by terahertz time-domain spectroscopy in a frequency range of 0.2 THz to 1 THz at room temperature. It could be found that the variation of the absorption coefficient is approximately from 8.95 cm−1 to 26.02 cm−1 in the frequency range of 0.2 THz to 1 THz, and the tuning range is about 3.32 cm−1 at 0.6 THz which almost reaches up to nearly 23.32%. The micromechanism of these results was attributed to the excited free carriers by the external optical pump intensity.