Refraction characteristics of PbTiO3 film in THz range

Abstract
The refraction characteristics of 50 nm thickness of PbTiO3 (PTO) film pumped by various optical power in terahertz (THz) range is measured by THz time domain spectrum. Experiments indicated that the refraction index was 65–110 in the range of 0.2–1 THz and the tunability reached 36.95% when applied 400 mW optical field. The theoretical analysis revealed that the photorefractive and the photothermal effects is responsible for the refraction index monotonically varied with the optical pump power.
Funding Information
  • Science and Technology Research Program of Department of Education of Hubei Province, China (B2019186)