[2Bp01-10] Surface Analysis/Applied Surface Science/Evaluation Technique (ASS)

[2Bp07] Gapless detection of broadband terahertz pulses using second-harmonic generation from a metal surface in air

*Shunsuke Tanaka¹, Yuta Murotani¹, Shunsuke A. Sato^2,3, Tomohiro Fujimoto¹, Takuya Matsuda¹, Natsuki Kanda¹, Ryusuke Matsunaga¹, Jun Yoshinobu¹ (1. The Institute for Solid State Physics, The University of Tokyo, 2. The University of Tsukuba, 3. Max Planck Institute for the Structure and Dynamics of Matter)

We developed a novel method for detecting broadband THz pulses in the time domain by simply using a polished metal surface and air molecules. We named it air-metal coherent detection (AMCD), which is based on the interference between the THz electric field-induced second harmonic light from air molecules and the second harmonic generation light from the metal surface. The present AMCD method does not suffer from phonons or phase matching in solid-state optics and does not require any power supply, bias voltage, or fabrication process, but offers a simple and gapless sampling method for broadband THz pulses in the region of 0.2 - 20 THz.