Production method for sensitivity enhanced extrinsic F-P optical fiber temperature sensor

Abstract

The invention discloses a method for manufacturing a sensitized extrinsic F-P optical fiber temperature sensor, which belongs to the technical field of a sensor. The method is characterized by comprising the following steps that: deficiency is generated by carving, and a flat end surface of an optical fiber is formed by tensing carved deficiency and using the characteristic that stress on the carved deficiency is concentrated; and a metal capillary tube and a bare optical fiber of an extrinsic F-P interface cavity are bonded together by a bonding agent, and the sensitized extrinsic F-P optical fiber temperature sensor is formed by two optical flat end surfaces and the metal capillary tube which has thermal expansion coefficients more than those of a glass capillary tube. The method has the advantages that the sensitized extrinsic F-P optical fiber temperature sensor which has excellent optical end surface and has no impurities in the interference cavity can be obtained, has fast temperature response, high temperature sensitivity, small volume, simple structure, high reliability, flexible manufacture, and the like, and can be used for high accuracy temperature measurement in strong electromagnetic radiating, inflammable and explosive and other situations.

Description

technical field [0001] The invention belongs to the technical field of sensors, and relates to a manufacturing method of an optical fiber temperature sensor, in particular to a manufacturing method of a sensitive extrinsic F-P optical fiber temperature sensor. Background technique [0002] The non-electrical thermometer commonly used in temperature measurement is a mercury thermometer, and the measurement result is stable, but it cannot automatically record data by computer. Electronic temperature sensors can flexibly realize temperature measurement and control, and are widely used in various industrial control equipment and electronic instruments: thermocouples can achieve high temperature measurement, but the accuracy is not high, and the measurement is inaccurate when the cold junction compensation is not good; Platinum resistors have high measurement accuracy, but low measurement sensitivity, and the measurement results are inaccurate when the wire compensation is not go...

AI Technical Summary

Problems solved by technology

[0005] At present, the extrinsic F-P fiber optic temperature sensor is basically made of glass fiber and capillary glass tube, and the temperature sensitization effect is limited; the temperature sensitivity can be improved by sticking the extrinsic F-P fiber optic temperature sensor on a metal sheet or other materials with a large thermal expansion coefficient , but has the disadvantages of slow temperature response and large volume, and the influence of thermal stress on the measurement results needs to be considered

Because the glass capillary is thin, the extrinsic F-P fiber optic temperature sensor without any protection is easily damaged by extrusion and shearing of external force. The size is large and the temperature response speed is slow, so that the advantages of the original sensor cannot be fully displayed

[0006] When making extrinsic FP optical fiber sensors by traditional methods, it is necessary to cut out the flat end face of the optical fiber first, or obtain a flat end face of the optical fiber by grinding and polishing methods, and then operate the complete flat end face of the optical fiber under a microscope and insert it into the inner diameter of the optical fiber. In the capillary of about 130 microns, the flat end face of the optical fiber may rub against the capillary wall during insertion, resulting in incomplete end face of the optical fiber. In addition, fiber fragments enter the capillary with the insertion of the optical fiber. When the incident optical fiber and reflection of the interference cavity When the optical fibers are inserted from both sides of the capillary, the above problems are more prominent, which puts high demands on the operator, and it is difficult to obtain a sensor with good interference contrast; Various reasons will also cause the fiber end face to be stained, making the interference signal of the final extrinsic F-P fiber sensor poor, affecting the accurate demodulation of the cavity length; Care must be taken during the process of operation to prevent the dust retained on the nozzle and inner tube wall from entering the interference cavity with the insertion of the optical fiber, which will affect the contrast of the interference and the stable use of the sensor

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