Terahertz-wave generation and detection via surface phonons and plasmons in Reststrahlen bands

为了探索太赫兹声子频率下的Reststrahlen波段，研究了基于表面声子模式的新型太赫兹波产生和探测。通过数值分析，我们发现了非线性光学晶体中表面声子的新型色散关系以及辐射太赫兹场模式。在分析结构的基础上，采用反应离子刻蚀法在铌酸锂晶体上成功制备了高质量的表面光栅。利用太赫兹与光波的非线性混频，实现了常温下超宽、灵敏的太赫兹波探测。

Novel terahertz-wave generation and detection via surface phonon modes were studied, in order to explore Reststrahlen bands at terahertz-phonon frequencies. Using numerical analysis, we found novel dispersion relations of surface phonons in a nonlinear optical crystal as well as radiative terahertz field patterns. Based on the analyzed structures, high-quality surface gratings were successfully fabricated on lithium niobate crystals, using reactive ion etching. Ultra-broad, sensitive terahertz-wave detection was also realized under ambient temperature, using nonlinear frequency mixing of terahertz and optical waves.