Sapphire fiber evanescent wave absorption in turbid media.
The influence of particulates on sapphire fiber evanescent wave absorption by water has been studied. Suspensions containing micro-sized graphite flakes and glassy carbon powder were used. Conventional free-space transmittance measurements of these samples showed strong absorption and scattering, which severely screened the absorption by water. However, the absorption on the water band determined from the evanescent wave interaction was unaffected by the presence of the graphite flakes. These results indicate that fiber-optic evanescent wave chemical sensors may be suitable for process control applications involving turbid reactor streams.
Zhang
Jian
J
MicroMaterials, Inc., Tampa, Florida 33637, USA.
Xiong
Feibing
F
Djeu
Nicholas
N