Hardened quantitative Raman Spectrometer for Combusting Flows

We propose the development of a hardened raman spectrometer capable of shot-noise-limited detection sensitivity, that can simultaneously detect the quantify fuel, air, temperature, and other parameters in turbulent combusting flows. Raman scattering can quantitatively measure the concentration of species such as H2, O2, N2, etc. in combusting flows. Unfortunately, comparaed to elastic scattering processes, Raman signals are weak thus, as currently practiced, applications have been limited. We propose a Raman spectrometer design with ultra high throughput that will improve on the signal discrimination by up to 5 orders of magnitude over the best existing Raman methods. This radical improvement in signal/noise will lead to the quantitative measurement of fuel/air, temperature, etc., in heterogeneous flows. Furthermore, smaller and more rugged lasers can be employed in the implementation of the proposed technique. The proposed system will help the Air Force assess the performance of supersonic combustion systems and components. The system is highly attractive due to its inherently non-intrusive nature, rapid response, high sensitivity, and potentially small and rugged construction. These attributes will make it attractive to the air Force and to the combustion community in general.