阅读说明：本技术 一种基于侧面抛磨的端面腐蚀光纤应变结构及制备方法 (End face corrosion optical fiber strain structure based on side polishing and grinding and preparation method ) 是由 何巍 袁宏伟 祝连庆 张雯 董明利 李红 何彦霖 于 2020-12-07 设计创作，主要内容包括：本发明提供一种基于侧面抛磨的端面腐蚀光纤应变结构及制备方法,该制备方法使用氢氟酸腐蚀处理单模光纤,然后与另一个单模光纤熔接形成F-P结构,然后使用侧面抛磨技术,根据需要打磨出不同尺寸的抛磨区,该制备方法操作简单,成本低廉,可根据需要制备不同尺寸的F-P腔结构和抛磨区,所制备的光纤应变结构具有高度的灵敏性和稳定性。(The invention provides an end face corrosion optical fiber strain structure based on side polishing and a preparation method, wherein hydrofluoric acid is used for corrosion treatment of a single mode optical fiber, the single mode optical fiber is welded with another single mode optical fiber to form an F-P structure, and then a side polishing and grinding technology is used for polishing and grinding areas with different sizes according to requirements.)

1. A preparation method of an end face corrosion optical fiber strain structure based on side polishing is characterized by comprising the following specific steps:

(1) corroding the end face of the first single-mode optical fiber to obtain a corroded optical fiber;

(2) taking a second single-mode fiber, cutting the end face of the second single-mode fiber flat, and oppositely welding the corroded end of the corroded fiber in the step (1) and the cut end face of the second single-mode fiber to form an F-P cavity;

(3) after the fusion is finished, removing the coating layer at the F-P cavity as a polishing area, and fixing the optical fiber on a polishing machine for continuous polishing treatment;

(4) the polishing area was observed every one hour until the polishing thickness reached 50 μm.

2. The method for preparing a strained structure according to claim 1, wherein the etching process uses a 40% hydrofluoric acid solution for a treatment time of 20 min.

3. The method for preparing a strained structure according to claim 1, wherein the welding is arc discharge welding.

4. The method of claim 1, wherein the length of the polishing region is in the range of 20mm to 30mm, and the polishing depth is in the range of 30 μm to 50 μm.

5. The method of making a strained structure of claim 1, wherein the polishing machine is a wheel polishing machine.

6. A side-polished end-face corrosion-based optical fiber strain structure prepared by the preparation method of claims 1-5.

Technical Field

The invention relates to the field of optical fiber devices, in particular to an end face corrosion optical fiber strain structure based on side polishing and grinding and a preparation method thereof.

Background

The optical fiber Fabry-Perot (F-P for short) sensor is a sensor formed by an F-P cavity constructed by an optical fiber and a capillary tube, wherein an extrinsic F-P sensor forms a microcavity with the cavity length of L by utilizing an air gap formed between the end faces of two optical fibers, and the optical fiber sensor is the most widely applied optical fiber sensor at present because of the advantages of simple structure, small volume, high reliability, single optical fiber signal transmission, simple manufacture and the like. The working principle is that when a coherent light beam is transmitted into the F-P cavity through the incident optical fiber, the light is reflected for multiple times on two end faces of the F-P cavity of the optical fiber to form interference and returns along the original path, and an interference output signal is related to the cavity length of the F-P cavity. That is, when external environmental parameters (such as temperature, pressure, strain, etc.) act on the F-P cavity in a certain manner, the cavity length L changes, resulting in a corresponding change in the interference output signal. According to the principle, the change of the length of the F-P cavity can be derived from the change of the interference signal, so that the detection of various detected parameters is realized.

In a conventional method for manufacturing an extrinsic fiber F-P cavity sensor, two fibers are respectively inserted from two ends of a capillary tube to ensure that end faces of the two fibers are flat and keep a proper distance between the two end faces to form an F-P cavity, and then the capillary tube and the fibers are fixed by gluing or welding. The patent CN103335949A discloses an EFPI sensor formed by inserting an incident optical fiber and a reflective optical fiber into a capillary glass tube, and then welding the two by laser welding for fixing. However, the failure rate of the traditional method for manufacturing the optical fiber F-P cavity by inserting the optical fiber into the capillary glass tube is high, and the sensitivity of the manufactured sensor is not high and is easily influenced by factors in the environment.

Disclosure of Invention

The invention provides a preparation method of an end face corrosion optical fiber strain structure based on side polishing, aiming at solving the problems of high failure rate and poor sensitivity of the prepared structure in the preparation process of an optical fiber F-P cavity in the prior art, and the method comprises the following specific steps:

(1) corroding the end face of the first single-mode optical fiber to obtain a corroded optical fiber;

(2) taking a second single-mode fiber, cutting the end face of the second single-mode fiber flat, and oppositely welding the corroded end of the corroded fiber in the step (1) and the cut end face of the second single-mode fiber to form an F-P cavity;

(3) after the fusion is finished, removing the coating layer at the F-P cavity as a polishing area, and fixing the optical fiber on a polishing machine for continuous polishing treatment;

(4) the polishing area was observed every one hour until the polishing thickness reached 50 μm.

Furthermore, 40% hydrofluoric acid solution is used in the etching treatment, and the treatment time is 20 min.

Further, the welding mode is arc discharge welding.

Further, the length range of the polishing area is 20mm-30mm, and the polishing depth is 30 μm-50 μm.

Further, the polishing machine is a wheel polishing machine.

The invention also provides an end face corrosion optical fiber strain structure based on side polishing and grinding, which is prepared by the method.

Compared with the prior art, the invention has the advantages that:

the invention provides a preparation method of an end face corrosion optical fiber strain structure based on side surface polishing, which uses hydrofluoric acid to corrode a single mode optical fiber, then the single mode optical fiber is welded with another single mode optical fiber to form an F-P structure, and then a side surface polishing technology is used. . And polishing areas with different sizes are polished according to requirements, the preparation method is simple to operate and low in cost, F-P cavity structures and polishing areas with different sizes can be prepared according to requirements, and the prepared optical fiber strain structure has high sensitivity and stability.

Drawings

FIG. 1 is a schematic structural diagram of a first single-mode optical fiber after being subjected to etching treatment in the embodiment;

FIG. 2 is a schematic view of an F-P structure formed after completion of fusion bonding in the embodiment;

FIG. 3 is a schematic diagram of a side-polished optical fiber structure according to an embodiment;

FIG. 4 is a schematic diagram of a temperature measurement system in a test example;

FIG. 5 is an interference pattern formed at different temperatures in the experimental examples;

FIG. 6 is a graph showing the fitting results of the amount of wavelength shift with temperature in the test examples.

Description of reference numerals:

1-residual thickness of cladding, 2-core, 3-cladding.

Detailed Description

The objects and functions of the present invention and methods for accomplishing the same will be apparent by reference to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it may be embodied in different forms and the essence of the description is merely to assist those skilled in the relevant art in comprehensive understanding of the specific details of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar parts, or the same or similar steps. The following description of the method for preparing the end-face corrosion optical fiber strain structure based on side polishing according to the present invention is provided by specific examples:

examples

The embodiment provides a preparation method of an end face corrosion optical fiber strain structure based on side polishing, which comprises the following specific steps:

the end face of a single-mode optical fiber is corroded in hydrofluoric acid with the concentration of 40% for 20min to manufacture a groove with the depth of 20 micrometers as shown in figure 1, the corroded optical fiber and the single-mode optical fiber with the flattened end face are oppositely welded, and welding is carried out through arc discharge to form an F-P cavity structure as shown in figure 2. After the fusion is finished, a coating layer of the optical fiber is removed by 20mm by using a wire stripper, the distance is the length of a polishing area, then the optical fiber is fixed on a wheel type polishing machine, the polishing area is continuously polished by using a grinding wheel by starting the machine, the polishing thickness is observed every hour until the polishing thickness reaches 50 micrometers, and as shown in figure 3, the end face corrosion optical fiber strain structure based on the side surface polishing is prepared by the method.

Test examples

For the end face corrosion optical fiber strain structure of the side surface polishing and grinding prepared in the embodiment, a temperature sensing test is carried out by using a temperature measuring system shown in figure 4, firstly, the optical fiber prepared in the embodiment is fixed on a heating platform, one end of the optical fiber is connected with a broadband light source, the other end of the optical fiber is connected with an optical fiber sensing analyzer, the heating function is started, the temperature is adjusted to 50 ℃, 100 ℃ and 150 ℃, each temperature point is kept for 10min, an interference pattern in the temperature change process is collected, the obtained interference pattern is shown in figure 5, in the figure, 3 spectral lines are respectively interference spectra of the F-P sensor in the range of 1520nm to 1610nm at the temperature of 50 ℃, 100 ℃ and 150 ℃, it can be seen that the spectrum is uniformly shifted under the same temperature variation amplitude, which indicates that the optical fiber strain structure prepared in the embodiment has stronger sensitivity and high determination accuracy.

The optical fiber sensor prepared in the embodiment is further calibrated, the temperature is applied within the range of 50-400 ℃, the wavelength at the corresponding temperature is recorded every 50 ℃, then a wavelength-temperature relation curve is drawn, a fitting result graph of wavelength offset along with the temperature change shown in figure 6 is obtained, and the fitting curve in the graph shows that the end face corrosion optical fiber strain structure with polished side face prepared in the embodiment has good linearity.