JPH02304403A - Method for observing multi-core optical fiber - Google Patents

Abstract

PURPOSE:To easily observe an axis shift by slanting an image pickup surface at an image pickup angle to the optical axis of a microscope according to all focus positions of a real image and a virtual image which are picked up on the image pickup surface. CONSTITUTION:The image pickup surface 2 is slanted at the image pickup angle theta1 to the optical axis 3 of the microscope 1 according to all the focus position of the real image (a) and virtual image (b) picked upon on the image pickup surface 2. Therefore, optical fibers alpha0 and beta0 arranged on an operation surface L slanting at an optical axis angle theta1 to the optical axis 3 form images on alpha and beta on an image pickup surface P through an objective 4. Then the image pickup surface 2 of an image pickup device is arranged matching the position of the image pickup surface P (focus positions of all optical fibers to be picked up). Consequently, images can be picked up so that all the arrayed optical fibers alpha0 and beta0 are in focus at the same time, and the lens barrel of the microscope 1 is shortened to reduce the size of an observation position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) As shown in FIG. The present invention relates to a method of observing the axis misalignment of both multi-core optical fibers when the facing surfaces of both multi-core optical fibers B are fusion spliced so as to face each other.

(Prior art) When the opposing surfaces of multi-core optical fibers B are fused together as shown in FIG. Orthogonal two-wheel direction,
In other words, it must be ensured that there is no misalignment in either the y-axis (horizontal) direction or the two-axis (vertical) direction.Therefore, conventionally, the axial misalignment in the Z-axis direction of the tip fiber A is observed from the y-axis direction, and the Z The axial deviation of the optical fiber A in the y-axis direction was observed as well as in the axial direction.

However, this observation method requires observation from two axes, the y-axis direction and the Z-axis direction, which is cumbersome and time-consuming.In addition, an observation device such as a microscope is installed in the axial direction of husband i. Since the equipment has to be kept in place, the equipment becomes large-scale.

Therefore, conventionally, a method has been developed in which the axis deviation of the two axes 1ii is observed simultaneously from one direction. One of these observation methods is shown in FIG. This observation method uses optical fiber A.
An axis x perpendicular to the direction in which the fibers are arranged and to the same fiber:
A mirror C is installed in the F row, and a virtual image onto the optical fiber is projected onto the mirror C, and this virtual image (tab and real image a) is enlarged with a microscope from a direction shifted by an optical axis angle θ1 with respect to the parallel direction. Observe the magnified observation image on the imaging plane E of the CCD camera.
The images were captured and displayed on a TV monitor for monitoring.

Incidentally, in this case, the real image a observed by the microscope mD is the part e of the circumference of the optical fiber A, as shown in Figure 5, so by observing this real image a, the y-axis of the optical fiber A can be determined. The deviation in direction can be observed, and the virtual image observed with a microscope is the part r in the circumferential direction to the optical fiber as shown in the same figure, so by observing this virtual image b+:iu, the same fiber A The deviation in the Z-axis direction can be observed.

(Problems to be Solved by the Invention) The method for observing a multi-core optical fiber with a rear δ described above has the following problems.

■ Imaging surface EIJSillfi optical axis F
Since the real image a in FIG. 6 is replaced by the operating plane G3, G, which is parallel to the imaging plane E,
There is a distance H difference between the working surface G of optical fiber A and the working surface G6 of optical fiber A. This difference is mirror C
The same is true for the virtual image captured in . Therefore, when forming these real images a or virtual images on the imaging surface EL, for example, as shown in FIG. Now A,)
When the focal point of is aligned with the imaging plane E, it becomes 11! ! Since the focal points ht and h3 of the optical fibers are in front of the imaging plane E, the imaging becomes blurred, making it difficult to observe axis deviation.

■The length of the microscope tube J is limited by the magnification of the objective lens used, so it is not possible to shorten the GA tube J, so it is impossible to shorten the IQ. The entire device becomes larger.

(Objective of the Invention) The object of the present invention is to magnify the axis misalignment of multi-core optical fibers using a microscope, and when imaging and observing it, all the connected optical fibers are brought into focus at the same time. It is an object of the present invention to provide a method for observing a multi-core optical fiber, which allows imaging to be carried out in a similar manner, and which also allows the length of the microscope lens barrel to be shortened and the size of the observation apparatus to be reduced.

(Means for Solving the Problems) The method for observing multi-core optical fibers of the present invention is as shown in FIG. , facing in the axial direction, perpendicular to 9 of the same multi-core optical fiber B, and the axis X of the same fiber A.
In the direction! A virtual image of the multi-core optical fiber B is projected onto a PH mirror C, and a real image a and a virtual image of the same multi-core optical fiber B are projected at the same time or separately. Magnified observation is performed using a microscope tal from a direction shifted by an optical axis angle θ1 in the parallel direction of the optical fibers A, and the magnified observation image is captured on the imaging surface 2 of the imaging device to detect the parallel direction of the opposing portions of the optical fibers A and orthogonal thereto. In the method for observing a multi-core optical fiber in which the axis deviation in the direction of a! This mirror is characterized by being tilted by an imaging angle θ2 with respect to the optical axis 3 of the mirror s1.

(Function) As shown in FIG. 2, the optical fibers α are arranged on a working surface that is inclined at an optical axis angle θ with respect to the optical axis 3. , β.

is the FQI'll in the same figure by passing through the objective lens 4.
α of P, images are formed in a line on surface 1.

In the multi-core optical fiber observation method of the present invention, the imaging plane 2 of the image carrier as shown in FIG. The real image a or +j! All the optical fibers A of the rib are imaged on the same imaging surface 2 in a focused state.

In this case, the two points α on the operating plane in FIG. ,c.

The distance Mα from the optical axis 3. 1Mβ0 is uniaxially magnified only in the oblique direction as distances Mα and Mβ on the imaging surface 2L. According to the present invention, the image magnified by the microscope ml and captured on the imaging surface 2 is first magnified as shown in FIG. The axis X direction to the fiber is not expanded, and -1 to the optical fiber is expanded only in the installation direction Y.

(Example) FIG. 1 shows an example of an observation device used in the method for observing a multi-core optical fiber of the present invention.

B shown in the figure is a multi-core optical fiber, which has a tape-like configuration in which a plurality of optical fibers A are arranged side by side.

C in the same figure is a mirror installed in 4 of the optical fiber A perpendicularly to the installation direction and parallel to its axial direction. This mirror C reflects a virtual image of the optical fiber A.

In the N:tSifl microscope shown in the figure, 5 is a lens barrel. This microscope 1 is used for magnifying observation of a real image a and a virtual image 2 at the same time or separately, and its optical axis 3 is perpendicular to the axial direction to the optical fiber, and the optical axis 4 is at an optical axis angle θl with respect to the installation direction.
(for example, 45 degrees).

Reference numeral 2 shown in FIG. 1 is an imaging surface of an imaging device such as a CCD camera, and this is provided on the side opposite to the objective side of the microscope 1. This imaging surface 2 is inclined by an imaging angle θ2 with respect to the optical axis 3 of Si#i minute ml so that the focal positions of all the real images a and virtual images taken thereon are aligned. For this purpose, for example, point α on the operating plane in FIG. 3a. The fiber is imaged at the 0 point of the imaging surface 2, and this imaging Mα is enlarged compared to the image Mα in FIG. 6 (this imaging fg1M
α.

is an image taken when the imaging plane E in FIG. 6 is perpendicular to the optical axis F of the microscope), therefore, in the observation method of the present invention,
Conventional ll! In order to obtain an image of the same size as the image taken in the observation method, it is sufficient to use an objective lens with a smaller magnification than that used in the conventional observation method. In the observation method, as shown in Figure 3, the objective lens 4111 moves the imaging plane 2 by a distance
It can be brought close to 1. In this way, it becomes possible to shorten the mirror surface of the microscope. Incidentally, in this case, the image formed on the imaging surface 2 is focused by moving the object away from the objective lens 4 as shown in Figure 3 by moving the imaging surface 2 closer to the objective lens 41I11 by a distance d. .

In the present invention, the real image a and the virtual image A may be simultaneously imaged with one microscope, and both images may be simultaneously displayed on one monitor television to monitor the axis misalignment. As shown in Figure 1, the distance between the optical fibers at both ends of the real image a and the virtual image becomes large, making it easy to blur, so in reality, for example, only the real image a is captured first and then monitored on a monitor TV. First, move the microscope parallel to its axis to capture a virtual image, and monitor it on a TV monitor.In this way, the blurring is reduced to half that of capturing the real image A and the virtual image at the same time. (Effects of the Invention) The multicore optical fiber observation method of the present invention has the following effects.

■、Ji! Since the image plane 2 is tilted so as to match the focal position of all the optical fibers to be imaged, all of the several optical fibers to be imaged on the image plane 2 are all in focus at the same time. It becomes the state it was. Therefore, there is no need to focus on each optical fiber as in the past.
Observation of axis deviation becomes easier.

■Since the layer image direction of the microscope L matches the direction in which the optical fibers Δ are arranged in parallel, the image captured by the microscope L is magnified in the same direction, making it easier to observe axis deviation in the same direction. .

■ Since the image formed on the imaging plane 2 is enlarged more than in the conventional observation method, If! is the same size as in the conventional observation method. (To obtain tl, the imaging surface 2 is
In this way, m17+5 of the microscopic ml can be shortened, and the entire observation apparatus can be downsized.

■ The length of the lens barrel 5 of the FAT microscope used in the present invention is
If the length is the same as that of the microscope lens barrel used in the conventional observation method, the objective lens 4 can be of low magnification.
An inexpensive microscope can be used.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an observation device implementing the method for observing a multicore optical fiber of the present invention, FIG. 2 is an explanatory diagram of the principle of the present invention, and FIGS. 3 a and b are enlarged explanatory diagrams of imaging in the present invention. , FIG. 4 is an explanatory diagram of an image observed by the observation method of the present invention,
Figure 5a is an explanatory diagram of axis alignment of a multi-core optical fiber, the figure is an explanatory diagram showing the relationship between the real image of the optical fiber and the virtual image reflected on the mirror, and Figure 6a is an observation of a conventional multi-core optical fiber. FIG. 2 is an explanatory diagram of the observation device used in the method, and is an explanatory diagram of the imaging focal point position in section 7 of FIG. 1 is the optical axis angle θ2 is the imaging angle

Claims (1)

[Claims] Multicore optical fibers B, each of which is made up of a plurality of optical fibers A arranged in multiple rows, are arranged to face each other in the axial direction, and are perpendicular to the parallel plane of the multicore optical fibers B and in the axial x direction of the same fibers A. A virtual image of the multi-core optical fiber B is projected onto a parallel mirror C, and a real image a and a virtual image b of the multi-core optical fiber B are projected perpendicularly to the axis x direction and of the optical fiber A, simultaneously or separately. The microscope 1 is used for magnification observation from a direction shifted by an optical axis angle θ_1 in the parallel direction, and the magnified observation image is captured on the imaging surface 2 of the imaging device to observe the parallel direction of the opposing portions of the optical fibers A and the direction perpendicular thereto. In the method for observing a multi-core optical fiber, the axis shift of the imaging surface 2 is observed.
is set at an imaging angle θ_ with respect to the optical axis 3 of the microscope 1, with all focal positions of the real image a and virtual image b imaged thereon.
A method for observing a multicore optical fiber characterized by tilting it by 2.