One trillionth of a second
Numerous biomedical and materials phenomena such as collective vibrations of proteins and electron transitions in semiconductor nanostructures take place in the terahertz (THz) frequency range. One THz is equivalent to one trillion times per second, reflecting the amazing speed of such activity. A dearth of high-power THz sources outside of expensive accelerator-based ones has contributed to a lack of investigation into non-linear THz spectroscopy. EU-funded scientists, building on laser-based THz technology they pioneered, initiated the project 'Nonlinear spectroscopy with high power THz waves' (HINTS) to study THz properties of new metamaterials. The team successfully established an optical system for generation of high-energy, single-cycle THz pulses with optimal energy and spectrum. The system has been already used to investigate molecular dissociation, non-linear nanoparticles and transport in semiconductor materials. In addition, researchers developed numerical simulations of THz generation mechanisms. These should enable an extension of the possible THz spectral range of titanium–sapphire lasers to address future research goals. HINTS outcomes in the field of THz spectroscopy have been published in peer-reviewed journals and presented at conferences. The project has strengthened ties between Switzerland and Russia. Continued collaboration stands to equally benefit the THz community and materials research as a whole.
