Low-cost optical fiber refractive-index sensor based on core diameter mismatch

A U-shaped double-side polished plastic optical fiber (POF) is demonstrated as a liquid refractive index (RI) sensor. The refractive index of glycerinum solutions is identified by the intensity detection on the bending and evanescent wave loss change. Heat treatment and mechanical polishing are adopted to form the symmetrical side-polished POF probe. The processing parameters are experimentally optimized on the power transmittance. The sensitivity of 1541%/RIU (Refractive Index Unit) can be obtained with a resolution of 5.35 × 10−4 in the scope of 1.33–1.39. The favorable temperature characteristic is proved to offer stable RI sensing from 20 to 50 °C. This simple POF sensor has potentials in low-cost visible light intensity RI detection.

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Sensing Characteristic of Optical Fiber Refractive Index Sensor Based on Core Diameter Mismatch

Acta Optica Sinica ◽

10.3788/aos20092905.1183 ◽

2009 ◽

Vol 29 (5) ◽

pp. 1183-1187 ◽

Cited By ~ 1

Author(s):

杨建春 Yang Jianchun ◽

徐龙君 Xu Longjun ◽

章鹏 Zhang Peng ◽

陈伟民 Chen Weimin

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Refractive Index Sensor ◽

Core Diameter

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Intensity-Modulated Polymer Optical Fiber-Based Refractive Index Sensor: A Review

Sensors ◽

10.3390/s22010081 ◽

2021 ◽

Vol 22 (1) ◽

pp. 81

Author(s):

Chuanxin Teng ◽

Rui Min ◽

Jie Zheng ◽

Shijie Deng ◽

Maosen Li ◽

...

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Low Cost ◽

Intensity Modulation ◽

Refractive Index Sensor ◽

Polymer Optical Fiber ◽

Optical Instruments ◽

Sensing Applications ◽

Recent Developments ◽

Sensing Performance

The simple and highly sensitive measurement of the refractive index (RI) of liquids is critical for designing the optical instruments and important in biochemical sensing applications. Intensity modulation-based polymer optical fiber (POF) RI sensors have a lot of advantages including low cost, easy fabrication and operation, good flexibility, and working in the visible wavelength. In this review, recent developments of the intensity modulation POF-based RI sensors are summarized. The materials of the POF and the working principle of intensity modulation are introduced briefly. Moreover, the RI sensing performance of POF sensors with different structures including tapered, bent, and side-polished structures, among others, are presented in detail. Finally, the sensing performance for different structures of POF-based RI sensors are compared and discussed.

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Refractive Index Sensor for Salty and Sugary Solution Based on Optical Fiber Technical

Journal of Physics Conference Series ◽

10.1088/1742-6596/1879/3/032077 ◽

2021 ◽

Vol 1879 (3) ◽

pp. 032077

Author(s):

Maher Khaleel Ibrahim ◽

Shehab A Kadhim ◽

Nabeil Ibrahim Fawaz

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Refractive Index Sensor

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Simultaneous Measurement of Temperature and Refractive Index Using High Temperature Resistant Pure Quartz Grating Based on Femtosecond Laser and HF Etching

Materials ◽

10.3390/ma14041028 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1028

Author(s):

Na Zhao ◽

Qijing Lin ◽

Kun Yao ◽

Fuzheng Zhang ◽

Bian Tian ◽

...

Keyword(s):

Refractive Index ◽

High Temperature ◽

Femtosecond Laser ◽

Optical Fiber ◽

Temperature Response ◽

High Sensitivity ◽

Xrd Analysis ◽

Refractive Index Sensor ◽

Compact Structure ◽

Fluid Analysis

The optical fiber temperature and refractive index sensor combined with the hollow needle structure for medical treatment can promote the standardization of traditional acupuncture techniques and improve the accuracy of body fluid analysis. A double-parameter sensor based on fiber Bragg grating (FBG) is developed in this paper. The sensor materials are selected through X-ray diffraction (XRD) analysis, and the sensor sensing principle is theoretically analyzed and simulated. Through femtosecond laser writing pure silica fiber, a high temperature resistant wavelength type FBG temperature sensor is obtained, and the FBG is corroded by hydrofluoric acid (HF) to realize a high-sensitivity intensity-type refractive index sensor. Because the light has dual characteristics of energy and wavelength, the sensor can realize simultaneous dual-parameter sensing. The light from the lead-in optical fiber is transmitted to the sensor and affected by temperature and refractive-index; then, the reflection peak is reflected back to the lead-out fiber by the FBG. The high temperature response and the refractive index response of the sensor were measured in the laboratory, and the high temperature characteristics of the sensor were verified in the accredited institute. It is demonstrated that the proposed sensor can achieve temperature sensing up to 1150 °C with the sensitivity of 0.0134 nm/°C, and refractive sensing over a refractive range of 1.333 to 1.4027 with the sensitivity of −49.044 dBm/RIU. The sensor features the advantages of two-parameter measurement, compact structure, and wide temperature range, and it exhibits great potential in acupuncture treatment.

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