Techniques for far-ultraviolet resonance Raman spectroscopy

Resonance Raman spectroscopy performed in the 150-300-nm spectral region provides several unique opportunities in molecular spectroscopy and biophysics.1,2 The performance of such experiments in the far-UV region requires optimization of laser technology, nonlinear optical devices, collection efficiency, spectral dispersion, and detection. The construction of a UV resonance Raman spectrometer designed to operate to 150 nm is described. This spectrometer is based on a Q-switched Nd:YAG laser, harmonic generating crystals, and stimulated Raman scattering in hydrogen gas. Reflective optics with backscattering collection are used to focus the Raman scattered light onto the slits of a nitrogen or helium filled vacuum monochromator. The detector is a solar blind photomultiplier with a MgF2 window. The performance of this spectrometer is described.