Polarization maintaining fiber beat length measuring apparatus

Abstract

The invention discloses a polarization maintaining optical fiber beat length measuring apparatus, which comprises an optical path system, a force application device and a data acquisition and processing system. The optical path system containing a light source, a crystal polarizer, a focusing lens and a crystal polarization analyzer has the function of providing linearly polarized light for measurement; the force application device which adopts a travel mechanism with a high-precision bidirectional step motor, a clamp mechanism with protective measures, and a force application mechanism with a micrometer has the function of fixing a polarization maintaining optical fiber to be measured, applying a due radial pressure along the length direction of the polarization maintaining optical fiber to be measured in a mobile mode to enable the output optical power which has passed through the polarization maintaining optical fiber to be measured to have a periodical variation; the data acquisition and processing system picks up the optical power outputted by the measured optical fiber through an optical power meter and obtains the average beat length of the measured polarization maintaining optical fiber and the optical power variation curve with the acquisition time after a computer carries out corresponding processing and computation of the output of the optical power meter. The polarization maintaining optical fiber beat length measuring apparatus has the advantages of simple structure, convenient operation and high measurement precision.

Description

technical field [0001] The invention belongs to the technical field of inertial device measurement, and mainly relates to a polarization-maintaining optical fiber beat-length measuring instrument, in particular to a polarization-maintaining optical fiber beat-length measuring device with an extinction ratio test component as the core and the principle of a modulation pressure moving power method. technical background [0002] Polarization-maintaining fiber is a kind of single-mode fiber, which refers to the fiber whose core cross-section is deliberately elliptical, or which uses non-axisymmetric birefringence to transmit two orthogonal polarizations independently in an uncoupled manner. . Polarization-maintaining fiber is widely used in the field of fiber optic sensing, and its main applications include fiber optic gyroscopes, etc. Beat length is an important technical index of polarization maintaining fiber, which characterizes the birefringence performance of polarization...

AI Technical Summary

Problems solved by technology

However, the beat length tester still has the following problems: the force-applying mechanism is controlled by a magnet, and due to the existence of a close-range magnetic field, the influence of the magnetic field on the polarization state of the light in the polarization-maintaining fiber cannot be ignored; the force-applying mechanism is in direct contact with the optical fiber, The optical fiber is easy to be damaged; the polarization analyzer uses a fiber optic polarization device, and the polarization performance is not good enough; the optical system uses a collimator lens and an optical signal pre-processing module, and its structure is too complicated

The above problems all affect the measurement accuracy of the beat length measuring instrument, and bring inconvenience to the operation

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