Jutas, R., Grumm, J., Staechelin, Y. U., Pugžlys, A., Baltuška, A., Knorr, A., & Lange, H. (2025). Nonlinear Transmission of Strong THz-Electric Fields Through Thin Gold Films. Advanced Optical Materials, 13(35), Article e01831. https://doi.org/10.1002/adom.202501831
Au films; microscopic theory; nonlinear physics; THz spectroscopy
en
Abstract:
This study reports on a nonlinear response in thin gold films in the terahertz (THz) frequency region. In an experimental study, the THz-electric peak field strength is increased and the transmission through the gold film is found to increase nonlinearly with the field strength when it exceeds a few hundred kV cm⁻¹. Numerical calculations of the electron dynamics based on the momentum-resolved Boltzmann equation show that the fast ((sub-) picosecond) electron depolarization activates a THz field-induced Pauli blocking nonlinearity of the electron–phonon interaction, resulting in an increased transmission.