Particle size effect on porous Sol-Gel doped cladding U-shaped optical fiber critical micelle concentration (CMC) sensor

In this paper, a sol--gel derived coating U-shaped optical fiber sensors for measurement of critical micelle concentration of surfactants has been studied. The doped sol--gel cladding fiber was used to construct an active cladding U-shaped optical fiber CMC measurement sensor. The porous sol--gel film was deposited a 1000 {/content/G0B5NJ8A10D8F7DR/xxlarge956.gif}m core plastic clad silica fiber after removing the cladding of the fiber at the middle portion nearly 6 cm and bending in U-shaped design. CMC detection is based on an adsorption effect in sample solution of sodium dodecylbenzenesulfonate. Three different types of particles size of sol--gel porous cladding were tested in our lab. Test results show that the sensitivity of the small particle size porous sol--gel cladding U-shaped optical fiber in sensing region is higher than that of large particle size sol--gel cladding based U-shaped.