Bending Vector Sensor Based on a Pair of Opposite Tilted Long-Period Fiber Gratings

A novel optical fiber grating vector bending sensor head is demonstrated. The sensor head is composed by two cascaded 6° tilted long period fiber gratings, which are separated by a distance d. The asymmetric characteristics of the proposed sensor originate from two tilted long period gratings with angles placed oppositely and asymmetric exposure of the CO2 laser pulses. Two selected dips shift tow...