Bragg grating-based all-optical continuous two-dimensional force perceptron

In this paper, we propose a novel structure of a photonic two-dimensional force perceptron based on fiber Bragg gratings for the first time to demonstrate microforce detection and direction recognition in an all-optical transmission sensing platform. Silicone gel was used to encapsulate the Bragg gratings arranged in equilateral triangles with specific side lengths in a hollow cylindrical structure. The force stimulation is sensed by stress transfer ball located on top of the perceptron, and the force is transmitted to three Bragg gratings arranged in equilateral triangles through the encapsulation material. The perceptron can achieve force detection with a sensitivity of 0.06 mN and a force stimulation resolution of 0.1 mN . The reset operation mainly relies on the high elastic modulus of the material itself. The results demonstrate continuous optical sensing of microforce stimulation ranging from 0 mN to 2 mN , In addition, we presented the results of large-scale directional force stimulus recognition, successfully achieving directional recognition of force stimuli. Furthermore, we achieved angle recognition with an error rate of 1% , prove the practical potential of constructing a precise positioning continuous all-optical force sensing platform.