Quasi-Continuous Generation of 211-nm Excitation for Resonance Raman Spectroscopy

We demonstrate the generation of 211-nm radiation using sum frequency mixing of the second and third harmonics of a cw mode-locked Nd: YLF laser operating at 76 MHz as an excitation source for resonance Raman spectroscopy. Owing to the relatively low peak power (∼4 W) but high average power (∼8 mW), we obtain good-quality spectra with relatively short collection times. In order to demonstrate the utility of this source, we have obtained the Raman spectra of several biological molecules and an inorganic molecule, ruthenium trisbipyridine, using 211-nm excitation.