Abstract

The fluorosensor discussed here is a fluorescent cladding optical fiber sensor. The sensitivity of such a sensor depends on the amount of light injected into the fiber core due to a fluorescent cladding. Conditions necessary for high injection, were experimentally determined for side excitation. Previous theoretical work has predicted that, for a side excited fiber, the refractive index difference between the core and cladding, n_core−n_clad, must be maximized to achieve high sensitivity. This prediction has used the exact field solution of an optical fiber and was qualitatively verified in the present work. This shows that standard optical fibers used for communication, which are weakly guiding, are not suitable for fluorosensor applications. Another result shows that the light injection increases with the fiber diameter.

© 1994 Optical Society of America