利用飞秒激光脉冲,在50μm厚的铌酸锂晶体薄片中产生了太赫兹声子极化激元波。使用飞秒加工技术在铌酸锂晶体薄片上刻制了针对太赫兹声子极化激元波的衍射和干涉微结构。利用已经构建的偏振门探测成像系统实时动态地记录了太赫兹声子极化激元波的时间和空间传播过程。对不同频率的声子极化激元波在不同尺寸狭缝的动态衍射和干涉的过程进行了时间分辨的二维成像探测和分析,直观地展示了其衍射和干涉的时空特性。
THz phonon polariton was generated in 50 μm LiNbO3 slab waveguide using femtosecond laser pulse.Diffractive and interferential micro structures,which were designed for the THz phonon polariton wave,were fabricated by the femtosecond laser machining system.The spatiotemporal electric field profiles for THz wave were recorded using the time resolved polarization gating imaging system.The dynamic processes of diffraction and interference in different size structures were observed and analyzed,which intuitively showed the spatiotemporal characteristics of the diffraction and interference for the phonon polariton wave.