Noise suppression device and noise suppression method for distributed polarization crosstalk measurement of optical polarizer

Abstract

The present invention relates to the technical field of optical fiber measurement and specifically relates to a noise suppression device and a noise suppression method for the distributed polarization crosstalk measurement of an optical polarizer. The noise suppression device for the distributed polarization crosstalk measurement of the optical polarizer comprises a broadband optical source, a polarizer, a first fiber-optic rotary connector, a second fiber-optic rotary connector, a to-be-detected optical fiber device, an optical path correlator, and a polarization crosstalk detecting and signal recording device. According to the technical scheme of the invention, the transmission light and the coupled light are thoroughly separated by means of a polarization beam splitter, so that the noise influence on the interference beat length can be avoided. On the basis of the thermal noise of a control circuit, the transmission light is attenuated by an attenuator, and the coupled light is enabled to be main detecting light. In this way, the shot noise becomes the main noise for limiting the signal noise ratio of the system. Based on the above method, the parameters of the device are adjusted to be appropriate. In this way, on the premise that the dynamic range of the system is kept unchanged, the signal noise ratio of the system is improved by 20 to 40 dB. Therefore, the measurement sensitivity is effectively increased.

Description

technical field [0001] The invention belongs to the technical field of optical fiber measurement, and in particular relates to a noise suppression device and suppression method for distributed polarization crosstalk measurement of an optical polarization device. Background technique [0002] Polarization optical devices are an important part of high-precision optical measurement and sensing systems. At present, the performance testing and evaluation methods and devices of optical devices are backward, which seriously hinders the development of high-precision optical measurement and sensing systems. For example, the chip extinction ratio of lithium niobate integrated waveguide modulator (commonly known as Y waveguide), the core device of high-precision fiber optic gyroscope, has reached more than 80dB; The rate is around 50dB (according to the definition of energy, it is 10 5 ), the highest resolution is the Model 4810 polarization extinction ratio developed by the US dBmOpt...

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Problems solved by technology

However, none of the above devices have significantly improved the signal-to-noise ratio of the test system, and most of them are polarization-maintaining fibers, which will cause an increase in polarization crosstalk noise

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