Abstract All optical THz wave modulation based on semiconductor is a convenient modulation method for real application, which is superior with wideband, large modulation depth and low insertion loss. In some scenario, it is required to use infrared light rather than visible light as the excitation signal where germanium is a better candidate than silicon. Here monolayer gold nanorods and graphene was used to modify the surface of germanium to enhance the THz wave modulation depth by the 1550 nm laser irradiation. Higher modulation depth was achieved by surface modification, which achieve the highest modulation depth of ~90% at 3.5 W/cm2. And the modulation rate is higher than 35 kHz.

中文翻译：

---

用于红外太赫兹调制的接口工程锗

摘要 基于半导体的全光太赫兹波调制是一种便于实际应用的调制方法，具有带宽宽、调制深度大、插入损耗低等优点。在某些情况下，需要使用红外光而不是可见光作为激发信号，其中锗是比硅更好的候选者。在这里，单层金纳米棒和石墨烯用于修饰锗表面，以通过 1550 nm 激光照射增强太赫兹波调制深度。通过表面改性实现了更高的调制深度，在 3.5 W/cm2 下实现了 ~90% 的最高调制深度。并且调制率高于35 kHz。