PtSe_(2)薄膜的时间分辨太赫兹光谱特性研究(特邀)

Exploration of PtSe_(2) Thin Film Based on Time-resolved Terahertz Spectroscopy(Invited)

基于时间分辨太赫兹光谱技术,研究了不同厚度的二硒化铂(PtSe2)薄膜在太赫兹波段的光学特性。实验结果表明,当泵浦光功率从0增强至2540μJ/cm2时,11 nm-PtSe2薄膜的电导率逐渐增大,透射太赫兹信号强度减小;而197 nm-PtSe2薄膜的电导率逐渐减小,透射太赫兹信号强度增大。由此构造的光控太赫兹调制器件的调制速度约为14 ps,工作带宽为0.2-1.8 THz,调制深度为15%-35%。研究证明PtSe2薄膜材料在高速光控太赫兹器件领域具有应用潜力。

Utilizing the time-resolved terahertz spectroscopy,the optical property of platinum selenide(PtSe2)thin films with different thicknesses in terahertz band are investigated experimentally.As the applied pump fluences increase from 0 to 2540μJ/cm2,the conductivity of 11 nm-PtSe2 film increases and further leading to the attenuation of the transmitted terahertz wave.Conversely,the conductivity of 197 nm-PtSe2 film decreases with the enhanced pump fluences that induces the increase of the transmitted terahertz wave.These characters enable PtSe2 thin film to be a photoactive terahertz modulator,which shows an ultrafast(-14 ps)and broadband(0.2-1.8 THz)modulation(15%-35%)of terahertz waves.The research provides a potential PtSe2-based platform to the active and ultrafast photonic devices at terahertz frequencies.