Quasi-distributed physical quantity measurement method, device and system based on distributed feedback laser array

Abstract

The invention discloses a quasi-distributed physical quantity measurement method based on a distributed feedback laser array, and the method enables a distributed feedback array laser to be applied toa quasi-distributed physical quantity measurement device based on direct intensity detection. Wavelength tuning of each waveband is realized by applying current modulation to each laser diode of thedistributed feedback array laser at different temperatures; and meanwhile, absolute wavelength information provided by the laser absolute wavelength monitoring unit is used as a basis to determine thelaser output splicing position of each section, so that large-range mode-hopping-free continuous laser output of the whole waveband is realized, and the spatial resolution and the measurement range of the quasi-distributed measurement method and device are improved. The invention further discloses a device and a system corresponding to the method.

Description

technical field

[0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a high-precision quasi-distributed physical quantity measurement method, device and system. Background technique

[0002] A fiber grating array is a fiber sensor that writes fiber gratings one by one on an optical fiber. Each fiber grating usually has a strong reflectivity, and the center wavelength is different. Since the fiber gratings on the sensor are distributed at discrete positions in space, the fiber grating array with this form is a quasi-distributed fiber sensor. The sensor is generally located at the measured object when in use, and can sense physical quantities such as temperature or strain at different positions of the measured object. The change of physical quantity will cause the central wavelength of the grating to shift. There are many demodulation methods for fiber grating arrays for sensing, including FP filter method, tunable light ...

Examples

Embodiment Construction

[0025] The distributed feedback array laser-based distributed physical quantity measurement method and device proposed in this patent will use the distributed feedback array laser as the system light source. In the present invention, the tuning of the output wavelength of each laser diode on the feedback array laser will be controlled by applying driving current tuning under each temperature gradient, and the output laser light of each laser will be multiplexed and spliced ​​on the wavelength, which is equivalent to expanding the distribution The frequency sweep or wavelength tuning range of the light source of the type physical quantity measuring device. At the same time, the size of the driving current also affects the optical power output by the laser, because in order to obtain a stable power laser output, a closed-loop power control unit with a semiconductor optical amplifier as the core is added behind the laser. In addition, the absolute wavelength information provided ...

technical field

[0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a high-precision quasi-distributed physical quantity measurement method, device and system. Background technique

[0002] A fiber grating array is a fiber sensor that writes fiber gratings one by one on an optical fiber. Each fiber grating usually has a strong reflectivity, and the center wavelength is different. Since the fiber gratings on the sensor are distributed at discrete positions in space, the fiber grating array with this form is a quasi-distributed fiber sensor. The sensor is generally located at the measured object when in use, and can sense physical quantities such as temperature or strain at different positions of the measured object. The change of physical quantity will cause the central wavelength of the grating to shift. There are many demodulation methods for fiber grating arrays for sensing, including FP filter method, tunable light ...

Examples

Embodiment Construction

[0025] The distributed feedback array laser-based distributed physical quantity measurement method and device proposed in this patent will use the distributed feedback array laser as the system light source. In the present invention, the tuning of the output wavelength of each laser diode on the feedback array laser will be controlled by applying driving current tuning under each temperature gradient, and the output laser light of each laser will be multiplexed and spliced ​​on the wavelength, which is equivalent to expanding the distribution The frequency sweep or wavelength tuning range of the light source of the type physical quantity measuring device. At the same time, the size of the driving current also affects the optical power output by the laser, because in order to obtain a stable power laser output, a closed-loop power control unit with a semiconductor optical amplifier as the core is added behind the laser. In addition, the absolute wavelength information provided ...

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