Static pressure balanced fiber ultrasonic sensor array

Abstract

The invention provides a static pressure balanced fiber ultrasonic sensor array measuring system which comprises an extrinsic Fabry-Perot fiber ultrasonic sensor, a light source module, a wavelength division multiplexer, a tunable narrow-band optical filter, and a photoelectric detection and signal processing unit. The light source module is connected with a first port of the wavelength division multiplexer; a third port of the wavelength division multiplexer is connected with the fiber sensor by a transmission fiber; other output ports of the wavelength division multiplexer are respectively connected with different fiber sensors; therefore, light beams with different wavelength ranges respectively act on the different fiber sensors, simultaneously, a plurality of different interfered light beams reach a first port of the tunable narrow-band optical filter by a second port of the wavelength division multiplexer; and a second port of the tunable narrow-band optical filter outputs a narrow-band light to a photoelectric detection tube which converts optical signals into electric current signals and sends the electric signals into the signal processing unit. The static pressure balanced fiber ultrasonic sensor array has the beneficial effects of being capable of automatically eliminating the deviation of the working point of the sensor caused by static state pressure variation and temperature change and increasing the wavelength division multiplexing capability of the measuring system.

Description

technical field [0001] The invention relates to optical fiber sensing, which is a multiplexing measurement system for optical fiber sensors, specifically a wavelength division sensor composed of extrinsic Fabry-Perot optical fiber sensors that can eliminate the influence of static pressure and stabilize the working point. Multiplexing measurement system for underwater ultrasonic detection. Background technique [0002] Optical fiber sensors have many advantages such as high sensitivity, excellent electrical insulation performance, anti-electromagnetic interference, and corrosion resistance. The main application of optical fiber acoustic and ultrasonic sensors is optical fiber hydrophones. In terms of its implementation technology, the most successful optical fiber ultrasonic sensors are based on interfering technology. The sensitivity of the optical fiber water respirator based on interference technology is three orders of magnitude higher than that of the traditional piezo...

AI Technical Summary

Problems solved by technology

Wavelength division multiplexing technology has the advantages of simple multiplexing method and high light source power utilization rate, but a problem that needs to be solved is the offset of the working point of the sensor. The large offset of the working point will seriously affect the number of multiplexing

When environmental factors such as static pressure changes or temperature changes around the sensor, the pressure difference inside and outside the extrinsic Fabry-Perot interference cavity will change, causing the sensor to move away from the orthogonal working state, resulting in a single sensor occupying too much bandwidth , the multiplexing ability is reduced, and the output signal will be unstable or even blanked; in addition, the extrinsic Fabry-Perot interferometer sensor based on the thin film structure relies on the elastic film to sense the acoustic signal. When the sensor is used for underwater measurement, another outstanding problem is that it cannot withstand high static pressure.

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