Polarization state control system in high-speed optical fiber communication based on polarization detection module

Abstract

The invention discloses a polarization state control system in high-speed optical fiber communication based on a polarization detection module, which comprises a four-wave-plate electro-optic crystal polarization controller, a power supply module, a polarization detection module, a signal acquisition module, a DSP (Digital Signal Processing) control module, a PC (Personal Computer) module and a DAC (Digital Analogue Converter) module. An electric signal carrying polarization information is detected by adopting the polarization detection module, and is converted into a digital signal capable of being processed by the DSP through analog-to-digital conversion and used for realizing polarization-state algorithm control and displaying a current polarization state on the PC machine in real timeby using a USB interface technology. The output of the DSP control algorithm is loaded to the electro-optic crystal polarization controller after being converted by the DAC module, and finally the polarization-state closed loop control function is realized. The invention realizes the repair compensation of unpredictable changes of the polarization state in the actual optical fiber communication, and can be used for converting any polarization state into a target polarization state. The whole system has the advantages of good stability, high cost performance, wide application range and important significance in the application in the high-speed optical fiber communication.

Description

technical field [0001] The invention relates to the field of high-speed optical fiber communication, in particular to a polarization state control system in high-speed optical fiber communication based on a polarization detection module. Background technique [0002] In an idealized fiber, the state of polarization (SOP) of the transmitted light does not change, while in standard communication fibers used in practice, the SOP of the transmitted light changes continuously along the fiber. Generally speaking, the output light of ordinary optical fiber is elliptically polarized light, the ellipticity is constantly changing, and the main axis is at an arbitrary angle with respect to the reference direction. The reason for this change is the irregular birefringence in the fiber caused by factors such as thermal stress, mechanical stress, and irregularity of the fiber core. In addition, the birefringence effect in the optical fiber is constantly changing with temperature, pressur...

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