Optical fiber temperature sensor for detection based on wavelength corresponding to extreme value and temperature sensing method

Abstract

The invention discloses an optical fiber temperature sensor for detection based on wavelength corresponding to an extreme value. The optical fiber temperature sensor determines length of a polarization maintaining fiber sensing head by calculation so that a transmitted spectrum at a transmission port of a hybrid fiber Sagnac interferometer which consists of the polarization maintaining fiber sensing head, a fiber coupler and a broadband light source has single extremum property. The wavelength corresponding to an extreme value of the transmitted spectrum also changes with ambient temperature variation, and the wavelength and the temperature acting on the fiber sensing head form a linear proportional relation T=(m/aL) Lambada m-b/a. The optical fiber temperature sensor realizes temperaturemeasurement by detecting the wavelength change corresponding to the extreme value of the transmitted spectrum. The optical fiber temperature sensor can realize temperature measurement by detecting thewavelength change corresponding to the extreme value of the transmitted spectrum, can eliminate the influence such as light source floating, light path loss and the like, and can improve the sensingsensitivity. The optical fiber temperature sensor is an all-fiber structure, and has the advantages of a small quantity of devices, easy realization, low cost, strong adaptability and strong anti-interference capability.

Description

technical field [0001] The invention relates to an optical fiber temperature sensor, more particularly, to an optical fiber temperature sensor based on wavelength detection corresponding to an extreme value. Background technique [0002] Optical fiber temperature sensor uses optical fiber as the sensing and transmission medium, which has the advantages of not being interfered by electromagnetic field, electrical insulation, intrinsic safety, explosion-proof, radiation resistance, easy to reuse and easy to form a network. Optical fiber temperature sensor has a wide range of applications and development prospects . [0003] In the patent application number 200310113311.0, an optical fiber temperature sensing method based on a SAGNAC interferometer and its sensor are disclosed. The structure of the sensor is shown in the attached image 3 As shown, the polarization-maintaining optical fiber sensor head 33 is added into the closed optical path of the full polarization-maintaini...

AI Technical Summary

Problems solved by technology

The optical fiber temperature sensor is detected based on light intensity, and the measured object is directly affected by the optical power signal, so the stability of the light source and the optical path loss of the system will affect the stability and accuracy of the optical fiber temperature sensor.

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