Kilowatt-peak Terahertz-wave Generation and Sub-femtojoule Terahertz-wave Pulse Detection Based on Nonlinear Optical Wavelength-conversion at Room Temperature Hiroaki Minamide & Shin’ichiro Hayashi & Koji Nawata & Takunori Taira & Jun-ichi Shikata & Kodo Kawase Received: 8 August 2013 /Accepted: 26 November 2013 / Published online: 19 December 2013 # Springer Science+Business Media New York 2013 Abstract Intense Terahertz (THz)-wave generation and highly sensitive THz-wave detection were obtained by wavelength conversion with nonlinear optical susceptibility χ (2) of LiNbO 3 crystals. Maximum peak output of about 50 kW (5 μJ/pulse) was demonstrated in an injection- seeded THz-wave parametric generator pumped by post-amplified emission from a microchip Nd:YAG laser. Using the sub-nanosecond pulse duration of the laser proposed herein provides effective mitigation of stimulated Brillouin scattering in LiNbO 3 , producing higher gain for wavelength conversion between near-infrared (near-IR) pump light and THz waves. Monochromatic THz radiation was obtained in the continuous tuning range of 0.7–2.9 THz. Additionally, highly sensitive THz-wave detection was demonstrated based on up-conversion from THz waves to near-IR light as well as efficient THz-wave generation. The signal generated with non-collinear phase-matching condition showed spectroscopic detection on the screen apart from the LiNbO 3 crystal. Highly sensitive detection with minimum energy of about 80 aJ/pulse (0.8 μW at peak) and a large dynamic range of more than 100 dB were achieved in this experiment. Keywords High peak-power . Tunable terahertz-wave parametric source . Highly sensitive detection . Room temperature operation J Infrared Milli Terahz Waves (2014) 35:25–37 DOI 10.1007/s10762-013-0041-0 H. Minamide (*) : S. Hayashi : K. Nawata : K. Kawase RIKEN, 519-1399 Aramaki-Aza Aoba, Aoba-ku, Sendai, Japan 980-0845 e-mail: minamide@riken.jp T. Taira Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki, Japan 444-8585 J.<i. Shikata Nihon University, 1 Nakagawara, Tokusada, Tamura, Koriyama, Japan 963-8642 K. Kawase Nagoya University, Furo-cho, Chikusa, Nagoya, Japan 464-8603