Journal of Xidian University ›› 2020, Vol. 47 ›› Issue (3): 92-96.doi: 10.19665/j.issn1001-2400.2020.03.013

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Temperature and humidity sensor using the multimode fiber cascaded Bragg grating

LIU Xin,LI Jinze,SUN Hao()   

  1. School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
  • Received:2019-12-30 Online:2020-06-20 Published:2020-06-19
  • Contact: Hao SUN E-mail:hsun@xidian.edu.cn

Abstract:

In order to design an optical fiber sensor with a simple structure which can simultaneously measure temperature and relative humidity, we use the multimode fiber cascade Bragg grating to form the basic structure of the sensor. First, a 6mm multimode fiber is connected to a Bragg grating. Then the diameter of the multimode fiber is etched to 40μm by hydrofluoric acid. Finally, a layer of carboxymethyl cellulose hydrogel is coated on the multimode fiber. The temperature and humidity response of the fabricated optical fiber sensor is tested. Experimental results show that the designed sensor has a humidity sensitivity of 69.6pm/% RH and a temperature sensitivity of 15pm/℃. The designed sensor is very sensitive to temperature and humidity, and has a good application prospect.

Key words: optical fiber sensor, relative humidity, temperature, carboxymethyl cellulose, multimode fiber, Bragg grating

CLC Number: 

  • TN253