Fiber-Optic Remote Raman Probe Design for Use in Monitoring Processes in a High-Temperature Oven

The recent development of fiber-optic probes suitable for exciting and collecting Raman spectra remotely via optical fiber has given rise to the possibility of making in situ measurements for many different applications. Recently, the authors presented a remote Raman probe (RRP) design using special optics and custom filters to enable detection and identification of weak scattering inorganics through 100 meters of optical fiber. However, different applications may require special designs due to restrictions inherent to that application. In particular, the restricted viewing port and excessive temperatures of a high-temperature oven did not allow a dual fiber probe to be used, as in Ref. 24. A new fiber-optic probe design is, therefore, described here which, in conjunction with a charge coupled device (CCD) detector, is suitable for obtaining measurements of the Raman spectra of materials under high-temperature conditions remotely. As opposed to the earlier RRP design, the new design works at 180° scattering geometry, and so is referred to as RRP180. The probe has been successfully fabricated and tested to temperatures of 1223 K.