Techniques for Observing Weak Raman Signals in the Diamond Pressure Cell

We wish to report a technique of using the 752.5 nm line of the Kr+ laser to excite the Raman effect in weakly scattering samples in a gasketed diamond anvil pressure cell. The use of this near-infrared excitation substantially reduces the fluorescence of the diamond windows which otherwise tends to distort and overwhelm weak Raman signals. This excitation also reduces interference from the fluorescence of the ruby fragment placed in the cell for pressure measurement. These are, we believe, the first spectra obtained from weak Raman scatterers in a diamond/ruby pressure cell.