Effect of water absorption on the stability of a polymer based Young´s interferometric sensor

In this work the refractive index change of a polymer (Ormocer) based waveguide interferometer under the influence of water absorption was analyzed. The water absorption caused refractive index change was up to 10^-4. After half an hour contacting with deionized water a pseudo-equilibrium state was reached and the response of the sensor tended to be stabilized. We performed refractive index measurement with glucose water dilutions. The measured refractive index change showed a linear relationship with the glucose concentration.