A method and apparatus for measuring polarization crosstalk in optically birefringent media

Abstract

The invention relates to a method and device for measuring polarization crosstalk in an optical double-refraction medium. The method comprises the following steps: coupling a linear polarization light into the optical double-refraction medium and generating an optical signal in the optical double-refraction medium; transferring the optical signal into an interferometer, thereby obtaining a light interference signal between two cross-polarization modes; processing the obtained light interference signal, thereby obtaining a spectrum envelope function for a polarization crosstalk point between the two cross-polarization modes in the optical double-refraction medium containing a double-refraction dispersion influence; measuring the spectrum envelope function, thereby obtaining a double-refraction dispersion parameter in an optical medium; using a solved envelope width broadening compensation function for correcting the broadening of the spectrum envelope function, thereby obtaining a corrected spectrum envelope function; and obtaining the polarization crosstalk in the optical double-refraction medium by utilizing the corrected spectrum envelope function. According to the method provided by the invention, the adverse effect on the measuring precision caused by the spectrum envelope broadening resulted from the double-refraction dispersion is eliminated.

Description

technical field [0001] The invention belongs to the technical field of optical polarization characteristic measurement, and particularly relates to realizing the measurement of polarization crosstalk points in birefringent optical materials and instruments by compensating and correcting the linear widening of the envelope width of crosstalk points caused by birefringence dispersion. Background technique [0002] For various optical devices, systems and applications, optical polarization characteristics are a very important physical parameter of optical signals. Since optical signals are transmitted in different polarization states in media with different refractive indices, optical media with different birefringence will change or affect the polarization states of optical signals. For example, optical fibers are inherently birefringent, so that the polarization state of light propagating through them changes. The birefringence in optical fibers typically varies with time an...

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Problems solved by technology

[0029] Although this patent solves the measurement of polarization crosstalk in polarization maintaining fibers and optical birefringent materials, and eliminates the influence of ghost interference signal peaks on the measurement accuracy of polarization crosstalk, however, when measuring polarization crosstalk in long-distance polarization maintaining fibers, Due to the existence of birefringence dispersion in the polarization maintaining fiber, there will be broadening of the crosstalk peak, which will affect the measurement accuracy of determining the crosstalk point

In the prior art, the influence of the birefringence dispersion existing in polarization-maintaining optical fiber and optical birefringent materials on the measurement accuracy of polarization crosstalk points is not considered, thus resulting in the measurement accuracy of polarization crosstalk points using the method adopted in the above-mentioned patents varies. Measure the attenuation due to the increase of the length of the polarization maintaining fiber and the optical birefringence material, which affects the actual polarization crosstalk measurement accuracy

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