Surface Treatments to Enhance the Sensitivity of Plastic Optical Fiber Based Accelerometers

摘要

The paper presents an all-fiber accelerometer that uses plastic optical fibers and discusses the enhancement of its sensitivity through physical treatments on the polymer surface to modify the light propagation characteristics. Given the target of being low-cost and compact, the accelerometer exploits the variation of propagation loss induced by the deformations of a miniaturized cantilever on which the fiber is fixed. This simple setup, however, does not exhibit a sufficient sensitivity unless the fiber surface is properly treated in order to enhance the loss dependence with the cantilever bending. Two approaches are compared, namely plasma micro- and nano-texturing and laser localized ablations. Several prototypes of accelerometers have been fabricated using various types of plastic fibers and characterized using a vibration test facility. Preliminary results show that both techniques are effective and can produce similar results, although accelerometer made by laser localized ablation may be more suitable for industrial applications, like the monitoring of vibrations due to moving parts of machines.