Paper: 2007 Absorption, luminescence, and Raman spectroscopic properties of thin films of benzo-annelated metal-free porphyrazines

Absorption, luminescence, and Raman spectroscopic properties of thin films of benzo-annelated metal-free porphyrazines

Reviews and Highlights Quantum Science Molecular and Soft-matter Ultrafast Nano-optics and Nanophotonics Mineralogy and Geochemistry

P. Gaal, M. B. Raschke, K. Reimann, and M. Woerner
Nat. Photonics 1, 577 (2007)
DOI PDF

Measurements using optical frequency combs are now important in high-precision spectroscopy. However, measurement techniques described so far are either restricted to narrow frequency ranges or are difficult to implement in the far-infrared regime. Here we present a time-domain method for the direct measurement of optical frequencies in the mid- and far-infrared spectral region. The method is analogous to a sampling scope, with the electric field of the source measured by electro-optic sampling using the light pulses from a femtosecond laser as a probe. The highest optical frequency that can be measured with our ‘sampling scope’ is determined by the pulse length of the femtosecond laser. When 12-fs probe pulses are used, a measurement of up to 40 THz, corresponding to a wavelength of 7.5 mm, is possible.