Microbend Sensor Research Articles

Backscatter readout from serial microbending sensors

Backscattering measurements performed on test fibers perturbed by several serially placed microbending sensors reveal the surprising result that the loss induced in a given sensor is nearly independent of the losses induced in the other sensors. A simple theoretical model is constructed to predict the conditions under which this desirable phenomenon can occur.

Stabilisation of single and multimode fibre-optical microbend sensors

Stability and reproducibility problems in single and multimode fibre-optic microbend strain sensors are found to be due to interference between the core mode and cladding modes in the bend region. Microbend strain sensors are stabilised by preventing the interference effect.

Microbend Fiber-Optic Sensor As Extended Hydrophore

A novel microbend fiber-optic acoustic sensor has been studied, both analytically and experimentally. The sensor is simple mechanically, insensitive to acceleration, and achieves shape flexibility by utilizing fairly long fiber lengths for the sensing element. The acoustic sensitivity and minimum detectable pressure of the sensor were found to be significantly improved over previously reported microbend sensors. Further optimization of the sensor appears possible.

Microbend fiber-optic sensor as extended hydrophone

A novel microbend fiber-optic acoustic sensor has been studied, both analytically and experimentally. The sensor is simple mechanically, insensitive to acceleration, and achieves shape flexibility by utilizing fairly long fiber lengths for the sensing element. The acoustic sensitivity and minimum detectable pressure of the sensor were found to be significantly improved over previously reported microbend sensors. Further optimization of the sensor appears possible.

The development of fibre optic microbend sensors

Investigations concerning the development of a fibre optic pressure sensor are reported. The phenomenon of light power attenuation in a periodically deformed graded index fibre has been studied theoretically. It appears that available theories are not suited to describe this attenuation process in the case of strong fibre deformations. We therefore suggest an approach which takes account of a correlation length in such strong attenuation processes. Experimental results, obtained with a newly developed test device, are given and are compared with this theory and with former results. It is concluded that the attenuation process is understood qualitatively, but that further research is needed to obtain a more detailed description of the observed behaviour.