JPS63118105A - Optical fiber splicing device - Google Patents

Abstract

PURPOSE:To accurately align the characteristic axes of polarization platen maintaining optical fibers (SPF) with each other by photodetecting light by a photodetecting element through a polarizing plate fitted to a polarizing plate rotating part, and rotating the polarizing plate and thus making an adjustment so that variation in the quantity of photodetection is maximum. CONSTITUTION:Light propagated in the 1st SPF 8 travels as linear polarized light because the polarizing direction of a linear polarized light source 7 is made coincident with the characteristic axis of the 1st SPF 8 previously, and the linear polarized light is outputted from the light projection end of the 1st SPF 8. While an electric signal from an output terminal 18 is monitored, the relative position between the rotary fixed part 12 of the SPFs and the light projection end fixation part 10 of the 1st SPF is so adjusted that the current light is maximum. Then a polarizer is rotated by a motor 21 and the rotary fixed part of the SPFs is rotated and adjusted so that the ratio of the maximum value Pmax and minimum value Pmin of the electric signal from the output terminal 18 is maximum. In this state, the polarizing direction of the linear polarized light from the 1st SPF 8 is aligned with the characteristic axis of the 2nd SPF 11.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an optical fiber connection device.

2. Description of the Related Art Conventionally, this type of optical fiber connection device has had a configuration as shown in FIG. In FIG. 2, 1 is a first optical fiber fixing part, 2 is a second optical fiber fixing part, 3 is a first polarization maintaining optical fiber (hereinafter abbreviated as SPF), and 4 is a second optical fiber fixing part.
SPF, 6 is a prism, and 6 is a microscope. When connecting SPFs using a conventional optical fiber connecting device, the connecting end surfaces of the first 5PF 3 and the second 5PF 4 are observed in the −Y-axis direction with the microscope 6 through the prism 6. Simultaneously observe both end faces of the SPF, and based on the features of the SPF, such as side bits and elliptical jacket, perform rotational adjustment around the Z-axis to align the unique axes that exist in a plane perpendicular to the longitudinal direction of the SPF. The relative positions of the first optical fiber fixing part 1 and the second optical fiber fixing part 2 are adjusted in each direction of the X-axis, Y-axis, and Z-axis, and the connection part between the first 5PF 3 and the second 5PF 4 is adjusted. Both SPFs were fixed to each other by fusion or physical means at the position where the loss of light amount was minimum.

Problems to be Solved by the Invention In such a conventional configuration, when aligning the intrinsic axes of two SPFs to be connected, the appearance of the SPF, such as the side bisso and elliptical jacket, is used as an index, so the intrinsic axis This is a virtual axis based on the optical properties (refractive index) of the SPF, and if there are variations in the appearance of the end face of the SPF, sufficient accuracy cannot be obtained, which is a problem. The purpose of the present invention is to solve these problems and to precisely align the intrinsic axis of the SPF.

Means for Solving the Problem In order to solve this problem, the present invention provides a light source that outputs linearly polarized light, a light input end rotation fixing part of the first SPF, and a light output end of the first SPF. a fixed part, a light input end rotation fixing part of the second SPF, a light output end fixing part of the second spv, a polarizing plate provided behind the light output end of the second SPF, and the polarizing plate. A configuration including a polarizing plate rotation unit that rotates the plate and a light receiving element provided behind the polarizing plate, and the first
It is possible to align the characteristic axes of the SPF and the second SPF.

Effect With this configuration, first, linearly polarized light from the light source is incident on the first SPF, and the light output from the light output end of the first SPF is sent to the light receiving element via the polarizing plate attached to the polarizing plate rotating section. receives light. Then rotate the polarizing plate,
The light incident end rotation fixing portion of the first SPF is rotated and adjusted so that the change in the amount of received light is maximized. This operation allows linearly polarized light to be incident parallel to the eigenaxis of the first sPF.

Next, the light input end of the second SPF is aligned with the light output end of the first SPF, and light is input to the second SPF. Then, the light from the light emitting end of the second SPF is received by the light receiving element via the polarizing plate attached to the polarizing plate rotating section. At this time, the polarizing plate is rotated by the polarizing plate rotating section, and the light incident end rotation fixing section of the second SPF is adjusted so that the change in the amount of received light is maximized. By the above operation, if the eigenaxis of the second SPF and the polarization plane of the linearly polarized light outputted from the first SPF become parallel, the linearly polarized light outputted from the first SPF will be reflected by the birefringence of the second spy. Since the extinction ratio is not felt, the rotation of the polarizing plate by the polarizing plate rotating section allows the observation of a large ratio between the maximum value and the minimum value of the amount of received light.
If the eigenaxis of F and the polarization plane of the linearly polarized light output from the first SPF are not parallel, the linearly polarized light output from the first SPF will feel the birefringence of the second SPF and the extinction ratio will become smaller. As the polarizing plate rotates, the ratio between the maximum value and the minimum value of the amount of light received due to the intra-abdominal pressure 1j becomes smaller. Using the above properties, the polarization plane of the linearly polarized light output from the first SPF and the second S
The characteristic axes of the PF can be aligned with high precision. It goes without saying that when a light source that outputs linearly polarized light and the first SPF are connected, the principle of alignment of the polarization plane of the linearly polarized light from the light source and the eigenaxis of the first SPF is the same.

Embodiment FIG. 1 is a schematic diagram of an optical fiber connection device according to an embodiment of the present invention. In FIG. 1, 7 is a linearly polarized light source; 8 is a linearly polarized light source;
is the first spy, and is set by the SPF rotation fixing part of the first 5PFa so that the polarization direction of the linearly polarized light source 7 matches the eigenaxis direction of the first 5pys at the light incidence end 9. .

1o is a light output end fixing part of the first 5 pys, 11 is a second SPF, and 12 is a spy rotation fixing part that supports the light input end of the second 5 PF 11, which is connected to the light output end fixing part 10. It is now possible to adjust the relative positional relationship.

13 is a second SPF fixing part; 14 is a polarizer fixed to the polarizer rotating part 16;
can be rotated. 16 is a light receiving element which is emitted from the light emitting end of the second 5PF 11 and is emitted from the polarizer 1.
The source metal transmitted through the signal line 4 is photoelectrically converted and connected to an output terminal 18 via a signal line 17.

19.20 is a discharge electrode for fusing the first 5pys and the second 5PF11. 21 is a motor that rotates the polarizer 14, and 22 is a belt that transmits its power.

Next, the operation of the optical fiber connection device according to an embodiment of the present invention will be explained with reference to FIG.

The light that has propagated through the first 5PFB is aligned in advance with the polarization direction of the linearly polarized light source A and the eigenaxis of the first 5PFs, so it propagates as linearly polarized light and exits from the light output end of the first 5PFs. Outputs linearly polarized light.

While monitoring the electrical signal from the output terminal 18, the relative position of the rotational fixing part 12 of the SPF and the light output end fixing part 1o of the first SPF is adjusted so that the output becomes maximum. Next, the polarizer is rotated by the motor 21, and the rotational fixed portion of the SPF is rotated and adjusted so that the ratio between the maximum value P max and the minimum value P winO of the electric signal from the output terminal 18 becomes maximum. This state is the first 5pys
The polarization direction of the linearly polarized light from the 5PF 11 coincides with the eigenaxis of the second 5PF 11. If from this state the second 5PF
11, the linearly polarized light incident on the second 5PF 11 will propagate through the second 5PF 11 separately as two linearly polarized lights vibrating in two orthogonal eigenaxis directions. Also, since the refractive index felt by each linearly polarized light is different,
At the light emitting end of the second 5PF 11, a phase difference occurs between the two linearly polarized lights, and the combined radiation is emitted into space, resulting in elliptical polarized light, and its extinction ratio decreases.

Based on the above principle, after setting the ratio of P max and P win to the maximum, a discharge is generated between the discharge electrodes 19° and 20°, and the first 5PFs and the second 5PFs are
All you have to do is fuse.

Note that the connection between the linearly polarized light source 7 and the first 5pys also includes the first
It goes without saying that by using the linearly polarized light source 7 instead of the first 8PFs shown in the figure and using the first 5pys instead of the second 5PF 110 shown in the figure, the polarization direction and the intrinsic axis of the SPF can be easily aligned.

Effects of the Invention As described above, according to the present invention, the unique axis alignment of the SPF can be performed with high accuracy and easily, so that an SPF connecting device of very high practical value can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical fiber connection device according to an embodiment of the present invention, and FIG. 2 is a partial perspective view of a conventional optical fiber connection device. 7... Linearly polarized light source, 8... First S
PF, 9... Light incidence end of the first SPF, 1o.
...Light emitting end fixing part of the first SPF, 11...
...Second SPF. 12... SPF rotation fixing part of second SPF, 1
3...Second SPF fixing part, 14...
Polarizer, 16...Polarizer rotating section, 16...
... Light receiving element, 17 ... Signal line, 18 ...
...Output terminal, 19.20...Discharge in, 21
...Motor, 22...Belt, 23.
...SPF rotation fixed part of the first SPF. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] a light source that outputs linearly polarized light, a light input end rotation fixing section of a first polarization maintaining optical fiber, a light output end fixing section of the first polarization maintaining optical fiber, and a second polarization maintaining optical fiber. a light input end rotation fixing part of the second polarization-maintaining optical fiber; a polarizing plate provided behind the light output end of the second polarization-maintaining optical fiber; A fiber connection device including a polarizing plate rotation unit that rotates a plate, and a light receiving element provided behind the polarizing plate.