Grating detection system for low reflection energy transmission fiber grating and method

Abstract

The invention provides a grating detection method for low reflection energy transmission fiber grating. The method is suitable for a fiber grating detection and measurement system. The system consistsof a broadband light source, a first high-speed optical switch, a first attenuator, a circulator, an optical cable, a fiber grating, a second attenuator, a second high-speed optical switch, a tracking filter, a demodulator, and a logic controller. By using two high-speed optical switches to perform high-precision time domain control on the emitted and reflected light, using the tracking filter tofilter the reflected light of the fiber grating in a specific band, and using the background noise suppression technology, stable identification of the wavelength of the low reflection energy transmission fiber grating and accurate distance measurement can be realized. The technology has the characteristics of simple structure, low cost and high detection accuracy.

Description

technical field [0001] The invention relates to a detection method of a low-energy reflective fiber grating, which belongs to the field of optical fiber communication and fiber grating sensors, and can realize the detection and identification of the low-energy reflective fiber grating. Background technique [0002] With the continuous development of fiber optic sensing technology, fiber gratings are widely used in the sensing field of various physical quantity measurement and communication links. At present, the fiber grating detection system is mainly limited by the dynamic response performance of the demodulator, signal demodulation and noise processing technology, which limits the use of fiber gratings. The reflection energy value of the grating is low, which makes it difficult to detect and identify the lowest energy reflection fiber grating. [0003] In the prior art, two fiber grating sensors, a wavelength demodulator, a dense wave decomposition multiplexer and a phot...

AI Technical Summary

Problems solved by technology

When the above devices and detection methods detect the optical fiber that contains a large number of fiber grating sensors, crosstalk often occurs between multiple gratings, and its detection distance is limited, so it cannot be well applied to complex long-distance fiber grating networks

[0004] Other existing technical solutions include: in order to realize the detection of the fiber grating in the optical fiber with a large fiber grating sensor, by setting two pairs of SOA high-speed photoelectric switches and signal generators, using time division multiplexing and wavelength division multiplexing phase The combination method realizes the detection of a large number of optical grating sensors. However, the system structure of this setting method is complex, and it is easily affected by factors such as the environment and the bending and breakage of the optical fiber itself, resulting in serious superimposition of the detected curves. , thus affecting the detection accuracy of the sensor and easily causing misreading

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