Measurement of Sugar Concentration by Multimodal Fiber Optics Sensor

Abstract

In this work, we report on the fabrication and testing of a fiber optics sensor based on multimodal interference (MMI) that is capable of measuring sugar concentration in aqueous solutions. The sensor has a simple structure, built by splicing a segment of multimode fiber (MMF) between two single-mode fibers (SMS architecture). The sensor’s operating mechanism is based on the spectral shift due to changes in the effective refractive index (RI) of the media surrounding the MMF. The optical sensor was tested with fructose and sucrose, which were diluted in distilled water in a concentration range from 0% to 18.5%. The proposed device exhibits a linear response with a sensitivity of around 0.17524 nm/% and 0.16321 nm/% for sucrose and fructose, respectively. In addition, this optical sensor shows the advantage of simple construction, low cost, and linear response, it does not require additional processes or coatings on the optical fiber.

Keywords

• fiber optics sensor
• multimode interference
• sugar concentration
• sucrose
• fructose