阅读说明：本技术 一种快速光纤锥区形貌测量方法 (Rapid optical fiber taper region shape measurement method ) 是由 王少华 卫炀 陈琳 黄钊 王琳楠 谢良平 于 2021-07-30 设计创作，主要内容包括：本发明属于图像处理技术,具体涉及一种对熔融拉锥后光纤锥区形貌的快速测量方法,本发明基于拉锥光纤形貌的整体空间对称性,提出一种快速测量方法,只需对待测区域光纤两端各聚焦一次,获得2个聚焦点的三维空间坐标,以此建立最佳聚焦位置的空间直线方程,测量显微镜沿此直线进行连续运动,运动的同时进行测量,可大幅降低测量时间,以扫描点数300为例,普通测量方法,单次聚焦时间3秒,测量总时间约为15分钟,采用本发明方法,大约仅需要2分钟。(The invention belongs to the image processing technology, and particularly relates to a method for rapidly measuring the appearance of a tapered area of an optical fiber after fused tapering, which is based on the integral space symmetry of the appearance of the tapered optical fiber, and provides a rapid measuring method, wherein two ends of the optical fiber in a region to be measured are respectively focused once to obtain three-dimensional space coordinates of 2 focusing points, so that a space linear equation of an optimal focusing position is established, a measuring microscope continuously moves along the line, and the measurement is carried out while moving, so that the measuring time can be greatly reduced, for example, the number of scanning points is 300, in a common measuring method, the single focusing time is 3 seconds, and the total measuring time is about 15 minutes, and only about 2 minutes is needed by adopting the method.)

1. A method for rapidly measuring the shape of an optical fiber taper region is characterized by comprising the following steps:

step 1, applying tension on two sides of a tapered optical fiber to enable an initial end, a tapered area finest part and a termination end of tapered optical fiber measurement to be positioned on a spatial straight line;

step 2, respectively carrying out micro-focusing on the initial end and the terminal end of the tapered optical fiber to be measured, recording the corresponding space coordinate sum of the optimal focusing position, and obtaining the space linear equation of the optimal focusing position of the tapered optical fiber to be measured through the two points;

and 3, setting the measuring microscope to move linearly along the space determined in the step 2, synchronously measuring the diameter of the optical fiber, and recording the space position coordinate of the microscope and the diameter of the tapered optical fiber measured at the same time in real time.

2. The method for rapid optical fiber taper profile measurement according to claim 1, wherein the determination of the applied tension in step 1 comprises: the applied tension is less than 10% of the breaking force of the tapered optical fiber to be detected, so that the tapered optical fiber is prevented from being damaged.

3. The method for rapid measurement of optical fiber taper profile as claimed in claim 1, wherein the starting end and the terminating end in step 1 and step 2 are: the starting end and the terminating end are respectively positioned at two sides of the optical fiber tapering region, and the specific position determination follows to shorten the distance between the starting position and the terminating position of the optical fiber tapering region as much as possible so as to reduce unnecessary measurement time.

4. The method for rapid optical fiber taper profile measurement according to claim 1, wherein the spatial straight line equation in step 2 is.

5. The method for rapid optical fiber taper profile measurement according to claim 1, wherein the microscope moving method in step 3 is a continuous movement, and the diameter measurement of the microscope is performed in synchronization with the movement.

6. The method according to claim 5, wherein the continuous movement is that, in order to accurately describe the shape of the tapered region of the optical fiber, the total number of points for measuring the diameter of the optical fiber should be greater than 100, the continuous movement speed of the microscope is set according to the actual length of the tapered optical fiber to be measured, and the continuous movement speed of the microscope cannot be greater than 500um/s to ensure the accuracy of the measurement of the tapered region of the optical fiber.

7. The method for rapid measurement of optical fiber taper profile as claimed in claim 1, wherein the measuring microscope in step 3 is such that the maximum magnification of the measuring microscope satisfies the following conditions: the maximum fiber diameter of the untapered area can be measured, namely the view field of the microscope can cover the untapered fiber diameter; the minimum magnification should satisfy: the fiber diameter measurement resolution is less than or equal to 1/10 of the diameter of the narrowest part of the fiber taper region.

8. The method according to claim 1, wherein the moving mechanism for controlling the microscope in step 3 is a stepping motor stage, and the position resolution is less than or equal to 100 nm.

Technical Field

The invention belongs to an image processing technology, and particularly relates to a method for rapidly measuring the shape of a tapered area of an optical fiber after fused tapering.

Background

The taper zone appearance of the tapered optical fiber is an important factor influencing the performance and reliability of an optical fiber fused taper device, and is one of important evaluation indexes for evaluating the controllability and repeatability of an optical fiber fused taper process, how to quickly acquire the appearance of the taper zone of the optical fiber has important significance for the development and production of the fused taper device, the quick measurement of the appearance of the taper zone is more important for the production of the fused taper device, on one hand, the increase of the measurement time can greatly increase the process time and the labor cost, on the other hand, the time of exposing in the external environment before the tapered optical fiber is packaged can be increased, the probability of attaching impurities such as dust to the taper zone of the optical fiber is increased, and the improvement of the reliability of the device is not facilitated.

The conventional cone area morphology measuring method is point-to-point displacement, point-to-point focusing and point-to-point measurement, and researches are mainly focused on reduction of the calculation amount of a focusing algorithm and improvement of calculation efficiency.

Disclosure of Invention

The purpose of the invention is: and the measurement time of the shape of the tapered area of the optical fiber after fusion tapering is reduced.

The technical scheme of the invention is as follows:

a rapid optical fiber taper region shape measuring method comprises the following steps:

step 1, applying tension on two sides of a tapered optical fiber to enable an initial end, a tapered area finest part and a termination end of tapered optical fiber measurement to be positioned on a spatial straight line;

step 2, respectively carrying out micro-focusing on the initial end and the terminal end of the tapered optical fiber to be measured, and recording the corresponding space coordinate (x) of the optimal focusing position_start,y_start,z_start) And (x)_stop,y_stop,z_stop) Obtaining the space linear equation of the optimal focusing position of the tapered optical fiber to be measured through the two points;

and 3, setting the measuring microscope to move linearly along the space determined in the step 2, synchronously measuring the diameter of the optical fiber, and recording the space position coordinates (x, y and z) of the microscope and the diameter d of the tapered optical fiber measured at the same time in real time.

The tension determination method in the step 1 comprises the following steps: the applied tension is less than 10% of the breaking force of the tapered optical fiber to be detected, so that the tapered optical fiber is prevented from being damaged.

The starting end and the terminating end in the step 1 and the step 2 are as follows: the starting end and the terminating end are respectively positioned at two sides of the optical fiber tapering region, and the specific position determination follows to shorten the distance between the starting position and the terminating position of the optical fiber tapering region as much as possible so as to reduce unnecessary measurement time.

The equation of the space straight line in the step 2 is

The movement method of the microscope in the step 3 is continuous movement, and the diameter measurement and the movement of the microscope are carried out synchronously.

The continuous motion is as follows: in order to accurately describe the appearance of the optical fiber cone area, the total number of optical fiber diameter measurement points is more than 100, the continuous movement speed of the microscope is required to be set according to the actual length of the tapered optical fiber to be measured, and meanwhile, in order to ensure the accuracy of the optical fiber cone area measurement, the continuous movement speed of the microscope cannot be more than 500 um/s.

The measuring microscope in the step 3 is that the maximum magnification of the measuring microscope should meet the following requirements: the maximum fiber diameter of the untapered area can be measured, namely the view field of the microscope can cover the untapered fiber diameter; the minimum magnification should satisfy: the fiber diameter measurement resolution is less than or equal to 1/10 of the diameter of the narrowest part of the fiber taper region.

And 3, controlling a movement mechanism of the microscope to be a stepping motor sliding table, wherein the position resolution is less than or equal to 100 nm.

The invention has the beneficial effects that:

the invention provides a rapid measurement method based on the integral space symmetry of the tapered optical fiber morphology, which only needs to focus two ends of an optical fiber in a region to be measured once to obtain three-dimensional space coordinates of 2 focus points, so as to establish a space linear equation of an optimal focus position, a measurement microscope continuously moves along the line, measurement is carried out while moving, the measurement time is greatly reduced, the number of scanning points is 300 as an example, the common measurement method has 3 seconds of single focusing time and total measurement time of about 15 minutes, and the method only needs about 2 minutes.

Drawings

FIG. 1 is a schematic view of a cone profile measuring apparatus

Wherein: 1-measuring microscope, 2-three-dimensional motion sliding table, 3-tapered optical fiber and 4-optical fiber clamp

FIG. 2 is a plot of the measured tapered fiber taper diameter.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

the measuring device is shown in figure 1, and figure 2 is a measured curve.

A rapid optical fiber taper region shape measuring method comprises the following steps:

step 1, as shown in fig. 1, applying tension to two sides of a tapered optical fiber to enable a starting end, a tapered area finest part and a terminating end of the tapered optical fiber to be positioned on a spatial straight line; the tension determination method comprises the following steps: the applied tension is less than 10% of the breaking force of the tapered optical fiber to be detected, so that the tapered optical fiber is prevented from being damaged.

Step 2, respectively carrying out micro-focusing on the initial end and the terminal end of the tapered optical fiber to be measured, and recording the position (x) of a space coordinate_start,y_start,z_start) And (x)_stop,y_stop,z_stop) Obtaining the space linear equation of the optimal focusing position of the tapered optical fiber to be measured through the two points; the equation of a space line is

The starting end and the terminating end are as follows: the starting end and the terminating end are respectively positioned at two sides of the optical fiber tapering region, and the specific position determination follows to shorten the distance between the starting position and the terminating position of the optical fiber tapering region as much as possible so as to reduce unnecessary measurement time.

And 3, setting the measuring microscope to move linearly along the space determined in the step 2, synchronously measuring the diameter of the optical fiber, and recording the space position coordinates (x, y and z) of the microscope and the diameter d of the tapered optical fiber measured at the same time in real time.

The microscope movement method is continuous movement, and diameter measurement and movement of the microscope are carried out synchronously.

The measuring microscope is that the maximum magnification of the measuring microscope is satisfied: the maximum fiber diameter of the untapered area can be measured, namely the view field of the microscope can cover the untapered fiber diameter; the minimum magnification should satisfy: the fiber diameter measurement resolution is less than or equal to 1/10 of the diameter of the narrowest part of the fiber taper region.

The moving mechanism of the control microscope is a stepping motor sliding table, and the position resolution is less than or equal to 100 nm.

The continuous motion is that, for accurately describing the appearance of the optical fiber cone area, the total number of optical fiber diameter measurement points is more than 100, the continuous motion speed of the microscope is required to be set according to the actual length of the tapered optical fiber to be measured, and meanwhile, the continuous motion speed of the microscope cannot be more than 500um/s for ensuring the accuracy of the optical fiber cone area measurement.

When the optical fiber is measured, the applied tension firstly satisfies that the tension cannot be larger than 10% of the breaking force of the tapered optical fiber, and the smaller the tension is, the better the tension is under the condition of satisfying the requirement, so long as the tapered optical fiber is tightened on a spatial straight line under the tension.

In example 1, when the diameter of the untapered area of the optical fiber is 40um, the diameter of the thinnest part of the untapered area of the optical fiber is 5um, the breaking force is about 15g, 1g of tension is applied to both sides, the total magnification of the microscope is 2400 times, the position resolution of the moving sliding table of the stepping motor for controlling the movement of the microscope is 50nm, the movement speed along the optical fiber is 100um/s, and fig. 2 shows an actually measured diameter curve.

In example 2, when the diameter of the unstretched region of the optical fiber is 80 μm, the diameter of the thinnest portion of the stretched region of the optical fiber is 10 μm, the breaking force is about 60g, tension is applied to both sides of the unstretched region of the optical fiber, the total magnification of the microscope is 1000 times, the position resolution of the moving sliding table of the stepping motor for controlling the movement of the microscope is 50nm, the movement speed along the optical fiber is 100 μm/s, and the measurement method is also applicable.

The method is a general measurement method, and can be used for measuring optical fibers with different tapered shapes by setting corresponding measurement parameters.