High-spatial-resolution OTDR device and method based on high-speed complementary Gray code

Abstract

The invention belongs to the field of optical fiber time domain reflection measurement, in particular to a high-spatial-resolution OTDR device and method based on a high-speed complementary Gray code, the high-speed complementary Gray code is used as a modulation signal, and a distributed feedback laser is directly modulated through a driving circuit to output broadband, stable and non-obvious-periodicity chaotic laser to serve as detection light, so that high-precision diagnosis of optical fiber faults is realized; a low-speed analog-to-digital converter is used for reducing the ADC rate and achieving a good detection effect, and a rapid Hadamard conversion module is used for rapidly calculating cross correlation; the designed chaotic OTDR is simple in structure, stable in performance and low in cost, integration and productization can be achieved easily, and the requirements in practical engineering application can be met.

Description

technical field [0001] The invention relates to the technical field of optical fiber time-domain reflection measurement, in particular to a high-speed complementary Gray code-based high-spatial-resolution OTDR device and method. Background technique [0002] Optical fiber fault detection is a basic requirement for optical fiber transmission systems. Typically, commercial fiber fault location systems are based on Optical Time Domain Reflectometers (OTDR). Optical time domain reflectometer (OTDR, optical time domain reflectometer) is an optical fiber fault detection method recommended by the International Telecommunication Union. The attenuation, breakpoint and other information of the optical fiber under test. OTDR can be used to measure fiber attenuation, connector loss, fiber fault point location and understand the loss distribution of fiber along the length, etc. It is an indispensable tool in fiber optic cable construction, maintenance and monitoring. However, this tec...

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Problems solved by technology

However, optical feedback chaotic laser generating devices are all composed of separate optical devices, which are large in size and the quality of the output chaotic light is not ideal

The reason: on the one hand, as a nonlinear optical device, the laser is very sensitive to the intensity and polarization state of the feedback light, resulting in chaotic light that is easily disturbed by external factors and difficult to maintain stable output; on the other hand, due to the existence of the delayed feedback cavity The chaotic laser generated by the above structure has weak periodicity, that is, there are periodic side lobes on its correlation curve, which will bring misjudgment to the measurement

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