Ultrabroadband etalon-free detection of infrared transients by van-der-Waals contacted sub-10-mu m GaSe detectors

作者：Knorr Matthias; Steinleitner Philipp; Raab Juergen; Gronwald Imke; Merkl Philipp; Lange Christoph; Huber Rupert^*

来源：Optics Express, 2018, 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 mu m, 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 vander-Waals materials on index-matched substrates will open new flexible ways of ultrabroadband electro-optic detection at unprecedented frequencies.

• 出版日期2018-7-23