Analysis of Fibre Cross-Coupling Mechanisms in Fibre-Optical Force Sensors

Abstract

The force-enhanced light coupling between two optical fibres is investigated for the application in a pressure or force sensor, which can be arranged into arrays and integrated into textile surfaces. The optical coupling mechanisms such as the influence of the applied force, the losses at the coupling point and the angular alignment of the two fibres are studied experimentally and numerically. The results reveal that most of the losses occur at the deformation of the pump fibre. Only a small percentage of the cross-coupled light from the pump fibre is actually captured by the probe fibre. Thus, the coupling and therefore the sensor signal can be strongly increased by a proper crossing angle between the fibres, which lead to a coupling efficiency of 3%, a sensitivity improvement of more than 20 dB compared to the orthogonal alignment of the two fibres.

A Self-Powered Sport Sensor Based on Triboelectric Nanogenerator for Fosbury Flop Training

“…Thus, we can more scientifically understand the physical condition of athletes in sports and formulate a reasonable training plan. Wearable sensors can be roughly divided into flexible pressure sensors, flexible biosensors, flexible optical fibre sensors, flexible temperature, and humidity sensors according to their sensing mechanisms [10][11][12][13]. However, traditional wearable sensors usually face the problem of continuous power supply; therefore, it is very meaningful to develop new self-powered wearable sport sensors.…”