A plastic optical fiber microbend sensor used as a low-cost anti-squeeze detector

This paper presents a low-cost fiber optic anti-squeeze sensor, suitable for use in high-volume cost driven applications. The sensor, used as a car window anti-squeeze detector, complies with EC 2000/4/EC and U.S. Federal Motor Vehicle Safety Standard No. 118. The proposed design relies on microbend, loss induced in plastic optical fiber (POF). The sensor assembly employs only low-cost optoelectronic components readily in use by automotive and consumer markets. The lifetime tests have been performed on prototype sensors. The results show that the proposed design can easily reach and exceed 100 000 operational cycles even though it relies on flexible and all-polymer design. The proposed sensor design can be easily extended to other nonautomotive applications, such as protection devices in automatic door openers.