This Small Business Innovative Research (SBIR) Phase I research project seeks to develop a real-time, non-invasive sensor for fine particle process control and measurement. This involves two patented innovations, dual detector dynamic light scattering and optical homodyne gain, which will be integrated into a single instrument, or probe, aimed at overcoming critical obstacles to efficient and cost-effective manufacturing. This will advance in-situ monitoring and characterization of fine particles. The goal of this research is to confirm and quantify the joint and/or separate advantages of these two innovative technologies, seeking theoretical insight and empirical closure. <br/><br/>The emphasis is focused on especially problematic industrial needs: characterization of high concentration particle suspensions and suspensions with weak scattering signals. Specimens from several industrial and academic collaborators, representing several application areas at the nanoscale (semiconductor polishing, paints, adhesives, fuel cell catalysts, and advanced ceramics) will be studied. The success of this project will enhance the scientific and technological understanding of fine particle behavior, down to the nano length-scale, and will assist in bringing the promise of nanotechnology closer to commercial reality.