Sensing range assessment of optical fibre physiological bending sensor

This paper presents the investigation of sensing range limit for intensity modulated optical fibre bending sensor using single input and dual input fibres. Plastic optical fibre is used to measure the bending angle by measuring the changes of light intensity using tilt angle loss measurement approach. To define the bending range of the sensor configurations under investigation, the fibre was bended at several bending angle for a 30 second period purposely to reduce the effect of light source fluctuation and drift in measurement. It was found that, with the use of dual input source fibres, the bending angle range can be extended at almost twice angle range than the single input fibre but with a lower output resolution.