Vibration sensing device based on photoelectric oscillator

Abstract

The invention discloses a vibration sensing device based on a photoelectric oscillator, and the device comprises a laser, a one-in-two optical coupler, an optical phase shifter, a sensing head, a polarization controller, a Mach-Zehnder modulator, a two-in-one optical coupler, an energy-storage optical fiber, a photoelectric detector, a band-pass filter, a radio frequency amplifier, a 3dB power divider, a reference oscillator, a frequency mixer, a low-pass filter, an analog-to-digital converter, and an upper computer. According to the invention, one arm of the Mach-Zehnder modulator serves as the sensing head, thereby improving the sensitivity of vibration signal detection, and improving the detection precision. Compared with other passive optical fiber sensors, the device enables vibration information to be coded on the frequency of the vibration signal not the intensity, so the device is not sensitive to the impact from the power fluctuation of a light source. Compared with an optical fiber based on an optical fiber laser, the device is higher in sensitivity, and the sensitivity of the device is not related with the oscillation frequency. The device can be implemented through a low-cost low-frequency device, and is high in practicality.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a vibration sensing device based on a photoelectric oscillator. Background technique [0002] Optical fiber sensors have the characteristics of high signal-to-noise ratio, high sensitivity, strong stability, and corrosion resistance. They are widely used in the measurement of parameters such as stress, temperature, vibration, and electric field, especially in fields where traditional sensors are no longer competent in harsh environments, such as nuclear power. , mines, oil wells, large generator sets and other strong radiation and electromagnetic interference environment measurement. [0003] Fiber optic sensors can be divided into two categories: passive and active. Typical passive sensors include sensors using optical fibers as sensing elements and fiber gratings as sensing elements. The principle of the former is: the change of the external physical...

AI Technical Summary

Problems solved by technology

Among them, the fiber laser-based sensor needs to work in a multi-mode state and beat frequency in order to achieve demodulation because the oscillation signal is an optical signal. However, the signal-to-noise ratio of the multi-mode beat frequency signal at high frequencies is not high, and its sensitivity is limited.

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