Active control of the optical parameters in strontium titanate(SrTiO_(3),STO)thin films is highly desirable for tunable terahertz(THz)integrated devices such as filters,phase modulators,and electro-optical devices.In ...Active control of the optical parameters in strontium titanate(SrTiO_(3),STO)thin films is highly desirable for tunable terahertz(THz)integrated devices such as filters,phase modulators,and electro-optical devices.In this work,optically tuned dielectric parameters of a STO thin film epitaxially grown on a silicon wafer were characterized in the THz region with an 800 nm laser pump-THz detection system.The refractive index,extinction coefficient,and complex dielectric constant of the STO thin film were calculated using thin-film parameter extraction.Owing to carrier transportation and soft-mode oscillation,the above optical parameters changed notably with the pump power of the external laser.This study is of great significance for rapid and non-contact THz phase-modulation technology and may serve as a powerful tool to tune the dielectric properties of the STO thin films.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62075248)the National Key R&D Program of China(Grant Nos.2017YFB0405400 and 2020YFB2009300)the Program for the Innovation Team of Science and Technology in University of Henan,China(Grant No.20IRTSTHN014).
文摘Active control of the optical parameters in strontium titanate(SrTiO_(3),STO)thin films is highly desirable for tunable terahertz(THz)integrated devices such as filters,phase modulators,and electro-optical devices.In this work,optically tuned dielectric parameters of a STO thin film epitaxially grown on a silicon wafer were characterized in the THz region with an 800 nm laser pump-THz detection system.The refractive index,extinction coefficient,and complex dielectric constant of the STO thin film were calculated using thin-film parameter extraction.Owing to carrier transportation and soft-mode oscillation,the above optical parameters changed notably with the pump power of the external laser.This study is of great significance for rapid and non-contact THz phase-modulation technology and may serve as a powerful tool to tune the dielectric properties of the STO thin films.
