Abstract-Broadband and narrowband laser-based terahertz source and its application for resonant and non-resonant excitation of antiferromagnetic modes in NiO

O. V. Chefonov, A. V. Ovchinnikov, C. P. Hauri, and M. B. Agranat

 Schematic diagram of a versatile THz source with tunable spectrum. (a) – the main elements of the laser system for generating optical pulses with different temporal shape. AODDL is an acousto-optic dispersion delay line, MZI is a Mach-Zehnder interferometer. (b), (c), (d) – examples of temporal shapes of laser pulses at the output of the temporal compressor. NC is a non-linear organic crystal for generating THz radiation (THz).

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-19-27273

A versatile table-top high-intense source of terahertz radiation, enabling to generate pulses of both broadband and narrowband spectra with a tunable frequency up to 3 THz is presented. The terahertz radiation pulses are generated by optical rectification of femtosecond pulses of Cr:forsterite laser setup in nonlinear organic crystal OH1. Electric field strengths of broadband and narrowband terahertz pulses were achieved close to 20 MV/cm and more than 2 MV/cm, correspondingly. Experiments on excitation of spin subsystem oscillations of an antiferromagnetic NiO were carried out. Selective excitation of 0.42 THz mode was observed for the first time at room temperature by a narrowband terahertz pulses tuned close to mode frequency.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement