Influence of water sorption on acrylic polymer waveguide loss

The influence of water sorption on acrylic polymer waveguides was studied by measuring the loss changes in the atmosphere at 13 to 98% RH. The absorption peak at 1.41 μm increased from 0.5 to 2 dB/cm due to water sorption. This peak resulted in a small loss change of 0.03 dB/cm at 1.3 μm, which was successfully measured using a 57 cm waveguide with a loss of around 0.1 dB/cm. Relationships between loss change and water sorption were also revealed by measuring the water content of the polymers.