Multi-point Measurement Of Liquid Refractive Index Using Optical Fiber Sensor Based On An AWG

In biomedical, environmental protection, food processing, pharmaceuticalchemicals industry areas, there will need a high precision measurement of therefractive index of liquid. In many refractive index measurement techniques, thefiber refractive index sensor has many advantages for example, compact structure,high precision measurement, anti-electromagnetic interference and easy to makenetwork, etc., and has attracted great research interest. This paper has summarizedthat the multi-point refractive index measurement of the liquid is needed urgently,basing on the refractive index optical fiber sensor research. So, we designed theeconomical and practical multi-point refractive index （RI） measurement fibersensor basing an AWG to meet application, in the practical. Following are the maincontents：1. Describing the development process and the standard classification of theoptical fiber in domestic and international; Introducing the optical fiber sensingtechnology and the development of the multi-point fiber optic sensors; I have aresearch and summarize on the development and status of domestic and internationalstandards for optical fiber sensor,then fiber optic sensor can be designed more in linewith the relevant industry standards and the foundation.2. The Fresnel formula is simplified processing according to the characteristicsof transmission light in the optical fiber; studying on the optical fiber RI sensor basedon the Fresnel formula; the structure and multiplexing/demultiplexing workingprinciple of the AWG are analyzed.3. In this paper, we demonstrate a simple Fresnel reflection based optical fiberrefractometer for multipoint measurement only using an AWG. The AWG is not onlyused as distributed sensor heads, but also as a demultiplexing unit. Through theexperimental studies of the sensor, it demonstrates that the proposed sensor isfeasibility. Experiment results show that the sensor works very well and has a high RIsensitivity: the highest sensitivity148.1dB/RIU, the average sensitivity101.9dB/RIU, in the RI range of1.33~1.42. The average resolution of RI is9.9e-5inthe range of1.33to1.42. And the average resolution of RI is9.9e-5in the range of1.33to1.42.