JPH11281821A - Optical fiber coil and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical fiber coil where physical and optical difference does not exist concerning the left and right of a whole optical fiber without requiring the preparation of a special winding wire equipment by dividing an optical fiber into plural groups in the axial direction of a winding axis from one end plate of a winding frame and laminating and winding it around the winding axis of the winding frame till the other end plate. SOLUTION: The optical fiber is divided into the plural groups 1-N in the axial direction of the winding axis 130 from one end plate 140 of the winding frame 120 and laminated and wound around the winding axis 130 of the winding frame 120 till the other end plate 140. In the group 1, the first layer of the fiber is contact-wound over 1/N of the whole length of the axis in the axial direction of the axis 130. Continuously, the second layer of the fiber is contact- wound around the front surface of the first layer reversely. Then, in the same way, the third layer to the n-th layer of the group 1 are successively laminated and wound by contact. Then, the fiber is returned to the part of 1/N of the whole length of the axis from the terminal end of the winding wire in the n-th layer of the group 1 and the first layer of the group 2 is wound by contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber coil and a method for manufacturing the same, and more particularly, to an optical fiber in which there is no physical optical difference between the right and left sides of the entire optical fiber without the necessity of preparing special winding equipment. The present invention relates to an optical fiber coil for manufacturing a fiber coil and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. FIG.
, The light emitted from the light source 1 is sent through the optical directional coupler 2, the polarizer 3, and the optical directional coupler 4 into the optical fiber 6 constituting the sensing coil as clockwise light and counterclockwise light. . This clockwise light is applied to the other end 1
7, the phase-modulated clockwise light is first phase-modulated in the phase modulator 5, and the phase-modulated clockwise light sequentially reaches the light receiver 7 via the optical directional coupler 4, the polarizer 3, and the optical directional coupler 2. . Similarly, the left-handed light is similarly phase-modulated from one end 16 in the phase modulator 5, and the phase-modulated left-handed light is sequentially transmitted to the light directional coupler 4, the polarizer 3, and the light directional coupler. The light arrives at the light receiver 7 through the second light receiving device 2. The phase-modulated light reaching the light receiver 7 is photoelectrically converted into an electric signal here. The electric signal photoelectrically converted in the light receiver 7 is input to the synchronous detector 8. In the synchronous detector 8, a fundamental wave component 13 which is an angular velocity output proportional to the rotational angular velocity about the central axis of the optical fiber 6 can be obtained using the signal supplied from the oscillator 9 as a reference signal. As described above, the optical fiber gyro makes light incident on the optical fiber 6 from both the one end 16 and the other end 17, and the other end 17 → the one end 16 and the one end 16 → The light is propagated in the direction of the other end portion 17 so that both lights having a phase difference interfere with each other, and the input angular velocity is measured from the change in the light intensity.

In FIG. 3, reference numeral 100 denotes the entire optical fiber coil. The optical fiber coil 100 is configured by winding the optical fiber 6 around a winding shaft 130 of a winding frame 120. 140 is an end plate of the winding frame 120. As described with reference to FIG. 2, the optical fiber gyro includes right-handed light incident through one end 16 of the optical fiber 6 of the optical fiber coil 100 and left-handed light incident through the other end 17 of the optical fiber coil 100. Is detected to detect the input angular velocity. Here, assuming that the optical fiber coil 100 has undergone a temperature change in the optical fiber 6 during use,
The optical fiber 6 undergoes thermal expansion and contraction, and the refractive index of the optical fiber changes. That is, generally, the optical fiber coil 100
Is significantly affected by changes in temperature. And
The optical fiber 6 is tightly wound around the winding frame 120,
Due to the thermal expansion and contraction of the optical fiber 6 itself and the application of pressure to the optical fiber, the optical fiber length changes and the refractive index also changes.

The above temperature change does not occur uniformly in the optical fiber 6, but shows an uneven temperature distribution.
That is, when the optical fiber 6 wound around the winding frame 120 of the optical fiber coil 100 constituting the optical fiber gyro is expanded into one coil, the total length becomes several hundreds.
For example, if the temperature changes particularly near one end of the optical fiber 6 where the right-handed light is incident, a physical change occurs between the right half and the left half. There is a difference in optical fiber length and refractive index, which are optical and optical differences. Due to this physical-optical difference, even when the angular velocity input of the optical fiber gyro is 0, the angular velocity output of the optical fiber gyro does not become 0, and the thermally induced bias as if the input angular velocity exists. An error occurs. Since the right-handed light and the left-handed light rotate in the same optical path of the optical fiber 6, even if there is a physical-optical difference in the optical fiber 6, the influence due to this physical-optical difference is canceled. hand,
At first glance, it is considered that the angular velocity output of the optical fiber gyro is irrelevant. However, it has been found that this physical-optical difference changes with time and causes a thermally-induced bias error.

[0005]

The occurrence of the thermally induced bias error caused by the thermal fluctuation of the optical fiber 6 causes the optical fiber 6 to be thermally disconnected from the outside or to be externally connected to the optical fiber 6. This can be prevented by adopting a configuration that allows heat to uniformly penetrate. However, neither thermally blocking the optical fiber 6 from the outside nor uniformly injecting heat into the optical fiber 6 can be performed satisfactorily.

The winding frame 1 generated in the optical fiber 6
The thermal gradient with respect to the surface of the 20 winding shafts 130 is mainly distributed in the radial direction of the coil. Focusing on this, a quadrupole winding method in which the optical fiber 6 is wound to configure the optical fiber coil 100 is adopted. Hereinafter, this will be described in detail with reference to FIG. In FIG. 4 (a), first, Equation 1
A preparatory step of winding a long optical fiber 6 ranging from 00 m to km around the right auxiliary coil R and the left auxiliary coil L with the middle point as a boundary is performed. Optical fiber 6 wound around right auxiliary coil R and left auxiliary coil L in the preparatory process
Is wound around the bobbin 120 with the middle point as a starting point as shown in FIG. Hereinafter, the winding step will be sequentially described.

At the beginning of the winding, the optical fiber 6 of the right auxiliary coil R is wound around the winding shaft 130 of the bobbin 120 with the first layer winding R1.
Wound as. The winding R1 corresponds to a region indicated by R1 in the entire optical fiber 6 in FIG. Next, the optical fiber 6 of the left auxiliary coil L is wound on the winding R1 as the winding L1 of the second layer. This winding L1 corresponds to a region indicated by L1 in the entire optical fiber 6 in FIG.

Here, subsequently, the optical fiber 6 of the left auxiliary coil L is used, and the winding L of the third layer is placed on the winding L1.
Wound as 2. This winding L2 corresponds to a region indicated by L2 in the entire optical fiber 6 in FIG. Finally, the optical fiber 6 of the right auxiliary coil R is used to form a fourth-layer winding R2. This winding R2 is shown in FIG.
(C) corresponds to a region indicated by R2 in the entire optical fiber 6.

[0009] The above four winding steps include one of the winding steps.
Make up the cycle. Hereinafter, similarly, the right spare coil R, the left spare coil L, the left spare coil L, the right spare coil R
Are sequentially wound as one cycle, and the optical fiber coil 1 is wound.
00. 4 (b) and 4 (c), windings R1, L1, L formed by one cycle.
2 and R2, the first layer winding R1
And the winding L1 of the second layer are symmetrical with respect to the midpoint of the optical fiber 6. The winding R1 of the first layer and the winding L1 of the second layer, which are symmetrical with each other, have a relationship of two layers adjacent to each other in a state of being wound around the winding shaft 13 of the winding frame 12. . That is, there is almost no difference between the dimensions of the two layers measured from the surface of the winding shaft 13, and the dimensions can be substantially equal. Therefore, the thermal inclination of the winding frame 120 with respect to the surface of the winding shaft 130 is the same, and there is no physical-optical difference between the two.

[0010] The winding L2 of the third layer and the winding R2 of the fourth layer are also:
The optical fiber 6 is symmetrical with respect to the center point. The winding L2 of the third layer and the winding R2 of the fourth layer are also formed by the winding frame 1.
Looking at the state of being wound around the 20 winding shafts 130, there is a relationship of two layers adjacent to each other. That is, there is almost no difference between the dimensions of the two layers measured from the surface of the winding shaft 130, and they can be substantially equal. Therefore, the reel 12
The thermal inclination with respect to the surface of the 0 winding shaft 130 is the same, and there is no physical optical difference between the two.

The above relationship between the windings of the first cycle is similarly established between the windings of the second and subsequent cycles. There will be no optical differences. However, in this quadrupole winding method, there is no physical optical difference between the right and left sides of the entire optical fiber 6, and the optical fiber coil 10 in which the generation of the thermally induced bias error is extremely small.
0 can be configured, but its implementation is not easy. That is, the preparation process of winding the optical fiber around the right auxiliary coil R and the left auxiliary coil L before winding the optical fiber 6 is an extremely complicated process, although detailed description is omitted. The step of alternately or successively using two different optical fiber supply coils, ie, the right auxiliary coil R and the left auxiliary coil L, to perform the winding is a special step different from a general winding step. Therefore, it becomes necessary to prepare special winding equipment.

The present invention provides an optical fiber coil for manufacturing an optical fiber coil in which there is no physical optical difference between the right and left sides of the entire optical fiber without having to prepare special winding equipment, and a method for manufacturing the same. Things.

[0013]

Means for Solving the Problems Claim 1: Optical fiber 6
To one end plate 1 of the bobbin 120 on the bobbin shaft 130 of the bobbin 120.
40 to a plurality of groups 1 to N in the axial direction of the winding shaft 130.
To form an optical fiber coil by laminating and winding up to the other end plate 140. Claim 2: In the optical fiber coil according to claim 1, the windings of groups 1 to N are wound around the first layer of the optical fiber 6 over 1 / N of the entire length of the winding shaft. The second layer of the optical fiber 6 is wound around the layer surface in the opposite direction, and thereafter, similarly,
An optical fiber coil was constructed by sequentially laminating and winding the third to n-th layers.

Claim 3: Claims 1 and 2
An optical fiber coil according to any of the above,
The number of groups constituted an even number of optical fiber coils.
Further, in the optical fiber coil according to any one of claims 1 to 3, the number of groups is large.

Here, the optical fiber is divided into a plurality of groups from one end plate of the bobbin on the bobbin of the bobbin in the axial direction of the bobbin and laminated and wound up to the other end plate. A coil manufacturing method was configured. In a sixth aspect of the present invention, the winding of the group is formed by winding the first layer of the optical fiber over 1 / N (N: the number of groups) of the entire length of the winding shaft. Then, the second layer of the optical fiber was wound around the surface of the first layer in the opposite direction, and thereafter, similarly, the third layer to the n-th layer were sequentially stacked and wound to form an optical fiber coil manufacturing method.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When an optical fiber of an optical fiber coil constituting an optical fiber gyro is wound around a bobbin, the optical fiber is wound around the bobbin bobbin from one end plate of the bobbin in the axial direction of the bobbin. And the other end plate is laminated and wound up to the other end plate. An embodiment of the present invention will be specifically described with reference to FIG.

Referring to FIG. 1A, regarding the group 1, one end plate 14 is provided on the surface of the winding shaft 130 of the bobbin 120.
The first layer of the optical fiber 6 is closely wound in the axial direction of the winding shaft 130 from 0 to 1 / N of the entire length of the winding shaft. Here, N represents the number of groups. Subsequently, the second layer of the optical fiber 6 is closely wound around the surface of the first layer in the opposite direction. Hereinafter, in the same manner, the third layer to the n-th layer of the group 1 are sequentially laminated in close contact to form a winding of the group 1.

After the windings of the group 1 have been formed, the windings of the group 2 are formed. For this, the optical fiber 6 is moved from the end of the winding of the n-th layer of group 1 to 1 / N of the total length of the winding shaft.
Then, the first layer of the group 2 is tightly wound therefrom in the axial direction of the winding shaft 130 over 1 / N of the entire length of the winding shaft. Subsequently, the optical fiber 6 is turned on the first layer surface in the opposite direction.
Is tightly wound. Hereinafter, similarly, the windings of the third layer to the n-th layer of the group 2 are successively closely adhered and laminated to form the windings of the group 2. Hereinafter, the windings of groups 3 to N are formed in the same manner.

Here, all the winding portions of the groups 1 to N have the same symmetrical structure with the axis of the winding shaft 130 as the axis of symmetry. Since the thermal inclination generated in the optical fiber 6 with respect to the surface of the winding shaft 130 of the winding frame 120 is mainly distributed in the radial direction of the coil, the winding shaft 130
The winding portions of groups 1 to N having the same symmetrical structure with the axis of symmetry as the axis of symmetry have the same structure thermally. By the way, FIG.
Group 1 of the optical fiber coil 100 shown in FIG.
The windings of group N correspond to the winding parts of groups 1 to N of the optical fiber 6 shown in FIG. FIG. 1 (b)
That the winding portions of group 1 to group N have the same structure thermally.
Since the thermal characteristics of the left half and the right half of the optical fiber coil 100 are symmetrical and identical to each other, there is no physical optical difference between the left and right of the entire optical fiber 6. Is configured.

In the above-described optical fiber coil, as the number of winding groups is increased, the symmetry of the thermal characteristics of the left half and the right half of the optical fiber coil is improved. By setting the number of winding groups to be an even number, the symmetry between the thermal characteristics of the left half and the right half of the optical fiber coil is further improved. When the number of winding groups is small, it is particularly preferable that the number of winding groups be an even number.

[0021]

As described above, according to the present invention, it is possible to physically and physically control the entire left and right optical fibers using a general simple winding device without having to prepare special winding equipment. An optical fiber coil having no optical difference can be easily configured. By increasing the number of winding groups, the symmetry between the thermal properties of the left half and the right half of the optical fiber coil can be greatly improved. Further, by making the number of winding groups even, the symmetry of the thermal characteristics of the left half and the right half of the optical fiber coil is further improved. When the number of winding groups is small, it is particularly preferable that the number of winding groups be an even number.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment.

FIG. 2 is a diagram illustrating a conventional example of an optical fiber gyro.

FIG. 3 is a diagram illustrating a conventional example of an optical fiber coil.

FIG. 4 is a diagram illustrating a conventional example of a method of winding an optical fiber coil.

[Explanation of symbols]

 6 Optical fiber 120 Reel 130 Reel 140 End plate

Claims (6)

[Claims] An optical fiber is constructed by dividing an optical fiber from a first end plate of a bobbin into a plurality of groups in an axial direction of the bobbin on a bobbin of a bobbin and laminating and winding up the other end plate. Optical fiber coil. 2. The optical fiber coil according to claim 1, wherein the winding of the group is 1 / N of the total length of the winding shaft (N: the number of groups).
The first layer of the optical fiber is wound over the first layer, the second layer of the optical fiber is wound on the surface of the first layer in the opposite direction, and likewise, the third to n-th layers are sequentially stacked and wound. An optical fiber coil characterized by comprising: 3. The optical fiber coil according to claim 1, wherein the number of groups is an even number. 4. The optical fiber coil according to claim 1, wherein the number of groups is large. 5. An optical fiber wherein an optical fiber is divided into a plurality of groups from one end plate of the bobbin on the bobbin of the bobbin in the axial direction of the bobbin and laminated and wound up to the other end plate. Coil manufacturing method. 6. The method for manufacturing an optical fiber coil according to claim 5, wherein the winding of the group is 1 / N of the total length of the winding shaft (N: the number of groups).
The first layer of the optical fiber is wound over the first layer, the second layer of the optical fiber is wound on the surface of the first layer in the opposite direction, and likewise, the third to n-th layers are sequentially stacked and wound. A method for manufacturing an optical fiber coil, comprising: