An Ultra-High Temperature Miniature Fiber Optic EFPI Strain Sensor

Abstract

The invention discloses an ultra-high temperature miniature optical fiber EFPI strain sensor. A sensitive chip is prepared by adopting a MEMS process and assembled with a special optical fiber to form an EFPI structure, which can effectively reduce the size of the sensor. At the same time, in view of the temperature and strain cross-sensitivity problems of traditional optical fiber EFPI strain sensors, the miniature optical fiber EFPI sensor is introduced into a solid EFPI cavity for temperature measurement, which has the ability of temperature self-compensation, and does not need additional temperature sensors during use, which greatly simplifies the application complexity. degree. The strain sensor of the present invention can be applied to contact strain measurement in an ultra-high temperature environment above 800°C and in a narrow area.

Description

technical field [0001] The invention belongs to the field of optical fiber sensing, in particular to an optical fiber external cavity Fabry-Perot interference type (EFPI) strain sensor for high temperature application. Background technique [0002] Optical fiber EFPI sensors are widely used in monitoring parameters such as pressure, strain, vibration, and temperature. They are typical representative products of optical fiber sensing technology and play an important role in aerospace, aviation, ocean, geology, medical and health fields. In the field of high-temperature strain measurement, the optical fiber EFPI strain sensor has gradually shown significant application prospects, and is regarded as a powerful tool for strain measurement in the 800°C or higher temperature range. [0003] For practical applications, the target structure of contact strain measurement, such as engine turbine blades, often has problems such as narrow area to be measured and limited installation spa...

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Problems solved by technology

[0003] For practical applications, the target structure of contact strain measurement, such as engine turbine blades, often has problems such as narrow area to be measured and limited installation space, which imposes strict requirements on the size of the strain sensor, and the existing optical fiber EFPI strain sensor cannot meet the requirements

On the other hand, the optical fiber EFPI strain sensor has the problem of temperature cross-sensitivity, and an additional temperature sensor is required to measure the sensor temperature synchronously, which increases the complexity of the system

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