Spun fiber quarter-wave plate with optimized twist rate function and preparation method

Abstract

The invention relates to a rotatory optical fiber quarter wave plate possessing an optimized rotating speed variation factor and a manufacturing method thereof. The rotatory optical fiber quarter wave plate is a variable speed rotation birefringence optical fiber and a rotation speed change satisfies a function which is defined in the description, wherein z is greater than 0 and is less than L; and LB is a beat length of the birefringence optical fiber and a value range is from 2mm to 10mm. The rotatory optical fiber quarter wave plate can convert linearly polarized light into circularly polarized light. Polarization ellipticity of emergent circularly polarized light is defined in the description. By using a rotating speed change function provided in the invention, in the given value range, a birefringence optical fiber possessing an appropriate length and a maximum rotation speed are selected; and a technology method of combining translation heating (a translation speed v is generally 0.25mm / s) and speed changing rotation (the maximum rotation speed vtL generally satisfies the following condition that the vtL is greater than and equal to 0.5 pi / s and is less than and equal to 2 pi / s) is used to make the rotatory optical fiber quarter wave plate whose phase delay error satisfies a predetermined index (90 degree+ / -3.6 degree).

Description

technical field [0001] The invention relates to a fiber-spun quarter-wave plate and a preparation method thereof, in particular to a fiber-spun quarter-wave plate with an optimized rotational speed variation factor and a preparation method thereof. Background technique [0002] In fiber optic sensors, fiber lasers, and fiber amplifiers, the linearly polarized light transmitted in the fiber link often needs to be converted into circularly polarized light for better performance. The conversion from linearly polarized light to circularly polarized light requires a phase difference of π / 2 between two equal orthogonal components of polarized light, which is usually achieved by using a crystal wave plate or a birefringent fiber. [0003] The bulk crystal optical wave plate is made based on the birefringence characteristics of the material: when a beam of light is incident on the bulk crystal optical wave plate, the outgoing light will be divided into two beams of orthogonally pola...

AI Technical Summary

Problems solved by technology

The speed change curve used in the existing theoretical research and process production is a linear function or the raised cosine function Where L is the length of the optical fiber variable speed twist section, τ L is the maximum rotational speed, but under these two rotational speed function conditions, the cross-coupling coefficient of the polarization mode coupling equation will fluctuate greatly along the length of the fiber, and a strict analytical solution cannot be obtained, and the output Jones can only be obtained by an iterative method. The approximate solution of vector and polarization ellipticity cannot strictly design AFPT according to the actual required polarization ellipticity

Moreover, due to the large fluctuation of the coupling coefficient along each point of the fiber, it is difficult for the degree of elliptic polarization of the outgoing light and its stability to reach the predetermined target.

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