Optical fiber sensor based on high-purity quartz pressure sensitive element and preparation method thereof

Abstract

The invention discloses an optical fiber sensor based on a high-purity quartz pressure sensitive element and a preparation method thereof. The optical fiber sensor comprises an optical fiber, a quartz sleeve and the high-purity quartz pressure sensitive element, a through hole is formed in the quartz sleeve, and the optical fiber is inserted into the through hole; and the quartz pressure sensitive element is connected with the quartz sleeve. The optical fiber sensor can be suitable for severe environments such as corrosion resistance except hydrofluoric acid and hot phosphoric acid with the temperature of 150 DEG C or above, and is also suitable for intracranial pressure monitoring and the like due to the fact that biological tissue does not repel a quartz material; glue-free fixing is achieved in a laser hot melting mode, stability and reliability can be improved, and the application range can be widened; the thickness of the quartz pressure sensitive element is controlled by an optical cold machining process, chemical corrosion and other processes are not needed, and the stability, reliability and service life of the optical fiber sensing head are improved; the manufacturing process is simple and fast, the sensor is safe, reliable and good in stability, and quartz pressure sensitive element hot melting with the extremely small thickness can be achieved in combination with a traditional optical cold machining process.

Description

technical field [0001] The invention relates to the intersecting fields of optical fiber technology, Fabry-Perot interference and laser thermal melting of high-purity quartz, in particular to an optical fiber sensor based on high-purity quartz pressure sensitive elements and a preparation method thereof. Background technique [0002] Optical fiber sensors have electrical insulation, anti-electromagnetic interference, high sensitivity, high temperature resistance and corrosion resistance, and are intrinsically safe because they are passive at the sensor end. They can be transmitted over long distances without signal conversion and amplifiers, and are small in size and light in weight. , petrochemical, aerospace and other fields have a wide range of application prospects, Fabry-Perot fiber optic interference medium and low pressure sensors because the pressure sensitive element can sense very small pressure, so it has great potential in medium and low pressure applications. In...

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Problems solved by technology

[0003] Fabry-Perot optical fiber interference medium and low pressure sensors, the use of adhesives or the viscosity of certain chemical materials is a common method to construct and fix the pressure sensitive element of the sensor, and a silicon wafer or a certain chemical material is fixed on the tapered end of the capillary. The pressure sensitive element of the material, etc., but there are the following disadvantages: (1) After being fixed with an adhesive such as epoxy resin, the thermal expansion coefficient of the adhesive will affect the temperature performance of the optical fiber sensor, and it cannot be used at high temperatures, and cannot meet The requirements of using fiber optic sensors in harsh environments cannot give full play to the advantages of fiber optic sensors; (2) when the pressure sensitive element is fixed on the end face of the capillary by using the viscosity of a certain chemical material itself, the sensor will be under the action of ultrasonic waves or other strong vibration signals. The sensitive element is easy to fall off from the end face, so that the optical fiber sensor is completely invalid, and it cannot meet the harsh environment of high temperature; (3) If it is a quartz pressure sensitive element, the commonly used method is to glue the pressure sensitive element, but the adhesive It is easy to age and the thermal expansion coefficient of the adhesive is much larger than that of quartz, which leads to deterioration or failure of the sensor's operating point drift and other performance. At the same time, the adhesive cannot withstand the use in high temperature environments and is also susceptible to corrosion in harsh environments. The pressure sensitive element is loose or falls off, and because the biological tissue does not reject the quartz material, it is suitable for monitoring intracranial pressure and other applications

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