A digital holographic system for online non-destructive measurement of special optical fiber refractive index

Abstract

The invention relates to a digital holography system for carrying out online non-destructive measurement on refractive index of a special optical fiber. The digital holography system is composed of a single-longitudinal mode laser light source, a light beam splitting device, an alignment device, a light transmission device and an image gathering module. The light beam splitting device is capable of dividing output light into multiple beams, and the light beams are transmitted through the light transmission device to realize the random multi-angle output of the light. The digital holography system is capable of realizing the random multi-angle simultaneous holography interference and gathering of the light in a limited space through the light transmission device. Compared with a traditional digital holography system for measuring the refractive index of the optical fiber, the digital holography system for carrying out the online non-destructive measurement on the refractive index of the special optical fiber is simple in structure, strong in anti-jamming capability, high in sensitivity, easy to manufacture, low in cost and suitable for the online real-time measurement for the special optical fiber, and a complex measured object rotating device is not needed.

Description

technical field [0001] The invention relates to a digital holographic system for on-line non-destructive measurement of the refractive index of a special optical fiber, which is used for the detection of the three-dimensional refractive index of the special optical fiber. Background technique [0002] With the development of science and technology, the development of new special optical fibers has become a research hotspot at home and abroad, and the requirements for the types and performance indicators of special optical fibers are also getting higher and higher. Refractive index distribution is an important index to measure the performance of optical fiber. It can not only reflect the characteristics of dispersion, loss, doping concentration, light transmission, etc., but also provide strong data support for the study of the internal causes of these characteristics. Therefore, it is of great significance to study the three-dimensional refractive index distribution of speci...

AI Technical Summary

Problems solved by technology

At present, this technology has been used at home and abroad to measure the three-dimensional refractive index distribution of conventional optical fibers and Panda polarization-maintaining optical fibers. However, the measurement system is mainly divided into two types based on the rotating and non-rotating types of the tested optical fiber. For the measurement system of the tested optical fiber rotating, it is necessary to Only when the test fiber is rotated can a multi-directional phase curve be obtained, so fast online real-time measurement of special fiber cannot be realized

Moreover, during the rotation process, due to the bending or inclination of the test sample, the sampling in each direction cannot be achieved at the same position, which will also lead to a decrease in measurement accuracy.

At present, the measurement system of the tested optical fiber at home and abroad can only achieve the acquisition of test data in three directions, and the entire optical system is relatively complicated, it is difficult to increase the signal beam, and cannot meet the number of data directions required for the reconstruction of the refractive index, resulting in Reconstruction accuracy is low

Images