This presentation will focus on the development, optimization and use of a Raman spectroscopy immersion probe for the analysis of solid (powders, slurries, etc.) samples with emphasis on online process analysis applications. A novel high precision Raman probe for online process analysis will be described. The unique design of the Raman probe provides enhancements in measurement precision by increasing the reproducibility and accuracy of optical sampling of high solids content samples. The probe has been proven an effective sampling interface for the analysis of powders, suspensions, slurries, particles and solids. The ease of use of the Raman probe and the increased sampling precision has lead to its use in various proof of concept and online process analytical applications. These applications include dry powder-powder mixing efficiency, coating thickness measurements, solvent drying analysis, reaction monitoring and many other analytical processes. The physical and optical design of the Raman probe will be described and the applicability of the Raman probe as an online sampling tool will be demonstrated.