High-sensitivity stress sensing device of mach-zehnder interferometer (MZI) based on PCF

Abstract

The invention provides a high-sensitivity stress sensing device of a mach-zehnder interferometer (MZI) based on a photonic crystal fiber (PCF). The high-sensitivity stress sensing device comprises a broadband light source, a sensor and an optical spectrum analyzer, wherein the sensor is sequentially welded through a first single-mode optical fiber, a graded-index multimode fiber, the PCF and a second single-mode optical fiber; the high-sensitivity stress sensing device is characterized in that collapse parts with the certain length are arranged at welding portions between the PCF and other optical fibers; one end of the sensor is connected with the broadband light source, and the other end of the sensor is connected into a spectrograph; light enters the graded-index multimode fiber from the single-mode optical fiber, then is subjected to beam expanding through a collapse area to enter the PCF, and then is converged through a second collapse area to enter the single-mode optical fiber to form the mach-zehnder interferometer (MZI), and due to the self-focusing effect in the graded-index multimode fiber, the sensitivity of the sensor can be greatly improved. By measuring the wavelength shift amount of a transmission spectrum, numerical values of measured environmental parameters can be computed. The high-sensitivity stress sensing device has the advantages of being compact in structure, easy to manufacture, high in sensitivity, wind in measurement range, low in temperature cross sensitivity and the like, and is suitable for measuring multiple environmental parameters, particularly, is suitable for stress measurement.

Description

technical field [0001] The invention provides a high-sensitivity stress sensing device based on a photonic crystal fiber (PCF) Mach-Zehnder interferometer (MZI), which belongs to the technical field of optical fiber sensing. Background technique [0002] In today's world, most of the development, acquisition, transmission and processing of information are done by sensors, and people's requirements for sensors are getting higher and higher. They hope that sensors can be more sensitive, accurate, compact and intelligent. Any environment can maintain high performance. Among many fiber optic sensors, fiber optic sensors based on the characteristics of Mach-Zehnder interferometer (MZI) develop rapidly and become an important branch of fiber optic sensor research. The aspect of stress testing is in demand in many fields in the world today, such as production and control in aerospace, enterprise production, engineering manufacturing and other fields, and stress is one of their imp...

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Problems solved by technology

But the visibility of the response spectrum (the difference in spectral transmission between a peak and its adjacent troughs) is relatively low, and its 3-dB bandwidth is usually wide due to limited interference effects between core and cladding modes

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