Spontaneous Raman Spectroscopy in Flames Containing High Concentrations of Silica Particles

Abstract

Spontaneous Raman spectra of nitrogen have been measured in hydrogen/methane/oxygen/nitrogen flames containing high concentrations (up to 109/cm3) of small (<0.2 p,m diameter) silica particles. In contrast with carbon soot particles, which emit large quantities of broadband visible radiation at high temperatures, the addition of silica particles at these concentrations has little or no effect on the SRS measurement at temperatures up to 2100 K. The spatially-resolved, time-averaged SRS measurements reported here are thus the first obtained in the submicron, high number density regime, similar to that found in flame synthesis processes. They indicate that spontaneous Raman spectroscopy should be an effective technique for the measurement of temperatures and species concentrations in flames produced by burners used in the manufacturing of optical fiber.Index EntriesRaman spectroscopyflame synthesissilica particlesoptical fiberlight scattering