Congratulations to Daiki Okazaki! Together with his colleagues from the FRIS-team, he has pushed the spectroscopic coverage for molecular fingerprinting deep into the far-infrared and low THz regime. The results were recently published in the paper “1-THz-to-mid-infrared field-resolved spectrometer driven by a Cr:ZnS oscillator” in the journal “Optics Express”.
Until now, molecular fingerprinting was limited to the mid-infrared regime. By employing organic nonlinear crystals, Daiki and his colleagues were able to overcome this limitation. The researchers demonstrated the generation and detection of broadband THz pulses spanning from one to 39 THz (7.7 to 300 micrometers). The full mid-infrared to THz fingerprint region can now be accessed simultaneously using compact Cr:ZnS laser oscillators, which enables the characterization of molecular dynamics across an unprecedentedly broad spectral window. Daiki demonstrated the capabilities of the new system by measuring both organic and inorganic samples.
The THz spectral range is particularly valuable because longer-wavelength light couples to collective molecular motions, such as backbone vibrations, large-scale structural fluctuations, and intermolecular interactions in solution, that are invisible to conventional infrared spectroscopy. Accessing these modes opens up a whole new array of possibilities for studying whole-molecule arrangements and structural flexibility, with potential implications for early disease detection.
Max Koch is continuing Daiki’s work in the team. In his PhD, he is pushing time-domain THz spectroscopy to apply it for the analysis of patient’s blood samples and explore its potential for early disease detection.
Original publication:
1-THz-to-mid-infrared field-resolved spectrometer driven by a Cr:ZnS oscillator
D. Okazaki, M. Koch, M. Aghakasiri, P. Steinleitner, W. Schweinberger, D. Potamianos, Y. Gui, A. Sebesta, B. Jahedi, V. Bhaliya, S. Tokita, F. Krausz, A. Weigel
Optics Express 34, 28928 (2026)
Picture: Yang Gui
