Sensitivity enhancement of singlemode-multimode-singlemode fiber optic sensor based on macrobending effect for food composition monitoring

Abstract

The paper analyzes the sensitivity enhancement of the Fiber Optic Sensor (FOS) based on the Singlemode-Multimode-Singlemode (SMS) structure for food composition monitoring. The enhancement method utilized in this refractive index sensor is the macrobending effect with bending diameter of 2.8, 3.3 and 4 cm. The sensitivity of the sensor were analyzed in different food liquids such as water, oil and 1.0 mol sugar, with the refractive index of 1.333, 1.384 and 1.464 respectively. The device was developed using the fusion arc splicing technique and etching process of the sensor's area. The selected core diameter of the sensor's area according to the etching process analysis was 55 μm at etching time of 15 minutes. The results of the sensor with and without the macrobending effect were observed. Meanwhile, the smallest bending diameter experienced the highest sensitivity. Overall, the experiment demonstrated an improved sensitivity of the macrobending sensor by 38.14%. This study broadens the potential of the simple sensor configuration for application in food composition monitoring.