A kind of device and method based on supercontinuum light source otdr

Abstract

The invention is an OTDR device and method based on a supercontinuum light source. The invention is mainly used to solve the problem that the traditional OTDR spatial resolution and dynamic range cannot be improved simultaneously. The invention adopts a supercontinuum light source with a spectral range as wide as hundreds of nm, which is wider than traditional lasers; a wavelength-tunable laser signal is generated through an adjustable optical filter, so that its spatial resolution reaches the order of millimeters. The output of the supercontinuum light source is stable, the output power is large, the dynamic range is large, and it does not affect the spatial resolution of the system. Its energy can be continuously output, and it has a high signal-to-noise ratio. The device includes a mode-locked laser, two polarization controllers, a high-speed electro-optical modulator, a microwave signal source, a pulsed optical amplifier, a highly nonlinear optical fiber, two tunable optical filters, an optical isolator, and a 1×2 optical fiber coupling device, optical circulator, optical fiber to be tested, variable optical delay line, two photodetectors, optical amplifier, oscilloscope, computer.

Description

technical field [0001] The invention is applied to the field of distributed optical fiber sensing and detection, and is specifically a device and method based on a supercontinuum light source OTDR, which can realize long-distance and high-resolution real-time measurement of optical fiber faults. Background technique [0002] In the distributed optical fiber sensing system based on Rayleigh scattering system of OTDR, the OTDR test is generally analyzed by sending light pulses into the optical fiber, and then receiving the returned information at the OTDR port. As a pulse of light travels within an optical fiber, it can scatter and reflect due to the nature of the fiber itself, connectors, splices, bends, or other similar events. Part of the scattering and reflection will return to the OTDR, and the device can judge the state of the fiber by measuring and processing the scattering and reflection signals. [0003] OTDR is currently the main instrument used for optical cable li...

AI Technical Summary

Problems solved by technology

However, the chaotic laser in chaotic OTDR technology is composed of semiconductor lasers using optical feedback. The laser relaxation oscillation is obvious and the bandwidth is limited. At present, the spatial resolution of chaotic laser is 2cm (Journal of Lightwave Technology, 2012, 30(21) :3420-3426.)

[0010] Ordinary OTDR is limited in dynamic range and spatial resolution, especially there is an insurmountable bottleneck problem in the receiving blind area of ​​large dynamic photoelectric signals; coherent OTDR adopts coherent reception of optical pulses, which can improve the receiver's performance without increasing the pulse power. Sensitivity, thereby improving the dynamic range and signal-to-noise ratio of OTDR, but coherent detection requires high stability of light source frequency, and the distance resolution is low

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