Renishaw has expanded its range of Raman spectrographs with the its ultra-violet Raman microscope. This instrument uses ultra-violet laser excitation to produce Raman scattering, rather than the more usual visible laser excitation.
The spectrograph uses laser-blocking filters and a single diffraction grating (rather than an inefficient double- or triple-grating design) to give unprecedented throughput and signal-to-noise values. UV excitation has many benefits. For example, the resultant Raman scattering occurs at a shorter wavelength than most fluorescence, and therefore is not masked by it. Now highly fluorescent samples (eg biological systems) can be studied. In addition, most molecules have absorption bands in the UV and, with the appropriate selection of excitation wavelength, will give resonantly enhanced Raman scattering. The resonance can be used to boost sensitivity, and preferentially study just one component of multi-component samples. Application areas include biochemistry (distribution of material within cells), materials science (direct measurement of the hydrogen content of hard carbon films), and forensic science.
The instrument is a variant of the visible-excitation Renishaw Raman Microscope, with optics optimised for the UV, and a UV-enhanced CCD camera as a detector.
ENQUIRY No 71A
Renishaw plc, Spectroscopy Products Division, is based in Wotton-under-Edge, Gloucestershire, UK. www.renishaw.com
