Volumetric Raman spectral imaging with a confocal Raman microscope: image modalities and applications

The Fourier transform Confocal Raman Microscope (FT-CRM) enables non-invasive 3D Raman spectroscopic analysis and visualization of chemically heterogeneous preparations. The instrument combines a confocal optical microscope with a visible light Fourier transform Raman spectrometer to acquire and analyze the Raman spectrum of light scattered from a voxel in the sample defined by the confocal optics. Scanning the sample relative to the confocal voxel and recording the Raman spectrum at each scan position generates a multi- dimensional data set encoding the spatially-varying compositional properties of the sample. We report here on the spatial and spectral FT-CRM image properties that includes recent work on correlation-based Raman spectroscopic imaging and application of parametric spectral estimators for robust Raman spectrum estimation.