Open AccessLimitation of THz conversion efficiency in DSTMS pumped by intense femtosecond pulses
Author(s) -
Jiang Li,
Rakesh Rana,
Li-Guo Zhu,
Cangli Liu,
Harald Schneider,
Alexej Pashkin
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.423433
Subject(s) - terahertz radiation , femtosecond , optical rectification , materials science , optics , energy conversion efficiency , absorption (acoustics) , optoelectronics , infrared , dispersion (optics) , optical pumping , laser , nonlinear optics , physics
Terahertz (THz) generation via optical rectification (OR) of near-infrared femtosecond pulses in DSTMS is systematically studied using a quasi-3D theoretical model, which takes into account cascaded OR, three-photon absorption (3PA) of the near-infrared radiation, and material dispersion/absorption properties. The simulation results and the comparison with experimental data for pump pulses with the center wavelength of 1.4 µm indicate that the 3PA process is one of the main limiting factors for THz generation in DSTMS at high pump fluences. The THz conversion efficiency is reduced further by the enhanced group velocity dispersion effect caused by the spectral broadening due to the cascaded OR. We predict that for broadband pump pulses with a duration of 30 fs, the THz conversion efficiency can be enhanced by a factor of 1.5 by using a positive pre-chirping that partially suppresses the cascaded OR and the 3PA effects.