Knorr Matthias, Steinleitner Philipp, Raab Jürgen, Gronwald Imke, Merkl Philipp, Lange Christoph, Huber Rupert
Opt Express. 2018 Jul 23;26(15):19059-19066. doi: 10.1364/OE.26.019059.
We demonstrate ultrabroadband electro-optic detection of multi-THz transients using mechanically exfoliated flakes of gallium selenide of a thickness of less than 10 µm, contacted to a diamond substrate by van-der-Waals bonding. While the low crystal thickness allows for extremely broadband phase matching, the excellent optical contact with the index-matched substrate suppresses multiple optical reflections. The high quality of our structure makes our scheme suitable for the undistorted and artifact-free observation of electromagnetic waveforms covering the entire THz spectral range up to the near-infrared regime without the need for correction for the electro-optic response function. With the current revolution of chemically inert quasi-two-dimensional layered materials, we anticipate that exfoliated van-der-Waals materials on index-matched substrates will open new flexible ways of ultrabroadband electro-optic detection at unprecedented frequencies.
我们展示了使用厚度小于10μm的机械剥离硒化镓薄片与金刚石衬底通过范德华键合接触来对多太赫兹瞬态进行超宽带电光检测。虽然低晶体厚度允许实现极宽带相位匹配，但与折射率匹配衬底的良好光学接触抑制了多次光学反射。我们结构的高质量使得我们的方案适用于在无需对电光响应函数进行校正的情况下，对覆盖直至近红外波段的整个太赫兹光谱范围的电磁波形进行无失真且无伪像的观测。随着当前化学惰性准二维层状材料的变革，我们预计在折射率匹配衬底上的剥离范德华材料将以前所未有的频率开启超宽带电光检测的新灵活方式。
