POF sensor for measurement of the clock and anti-clockwise rotation based on cascading of TMBC

The developed angle sensors are usually used for either clockwise or an anti-clockwise direction. Here, we present a relatively new setup of two angle sensors for independent and simultaneous clock and anti-clockwise rotational measurement. The proposed sensor is based on the twisted macro-bend coupling method (TMBC), in which two fibers are twisted and bent. The angle measurement relies on the coupling of macro-bend loss in which transmitting fiber generates bend loss, and receiving fiber couples the loss. The two-angle sensors are presented in which sensor-1 consists of a single twisted bend and sensor-2 contain two twisted bends on a single transmitting fiber. The stepper motor is used to drag the twisted fiber, resulting in a change in the bending radius that increases or decreases the macro-bend loss. A cascading method is introduced in the TMBC method for the sensor-2 and, two stepper motors are used in the second experiment. Several test scenarios are conducted for both sensor configurations. The experimental results show that sensor-1 can measure angle ± 180º, whereas the full clock and anti-clockwise cycle are achieved through sensor-2, having a measurement range is ± 360º. Therefore, the proposed sensor can be a potential means for accurate angle measurement in industrial applications.