TWI490570B - U-type optical fibermanufacturing apparatus and manufacturing method thereof - Google Patents

Description

U-shaped optical fiber manufacturing device and manufacturing method thereof

The present invention relates to a U-shaped optical fiber manufacturing apparatus and a method of manufacturing the same, and more particularly to a manufacturing apparatus capable of fabricating a U-shaped optical fiber structure having a large bending curvature and a method of manufacturing the same.

In recent years, thanks to the booming optoelectronic industry, optical fibers have been used in large quantities to make fiber gratings, probes, biomedical wafers or other sensing components in addition to traditional signal transmission applications. Therefore, the processing and detection methods of optical fibers have become the technical direction for the development of the academic community and the industry.

When an optical fiber is used for communication or sensing purposes, it is often necessary to bend the fiber. However, limited by the material properties of the fiber itself, once the fiber is bent beyond an upper limit, permanent damage is likely to occur (for example, breakage). Or broken). Therefore, the curvature of the fiber can usually be bent, which limits the application range and the utility is greatly reduced.

For example, a curved interferometric fiber optic sensor can be fabricated using the principle of Whispering Gallery Mode (WGM) as a highly sensitive sensor for temperature, tensile and strain measurement. A typical method of manufacturing the curved interferometric fiber optic sensor requires bending the fiber into a ring or a semi-ring U-shape, but is limited to the case where it is susceptible to damage when bending the fiber, and the curved interferometric fiber optic sensor Production technology can never be broken. It can only rely on high-precision melting device or buffer oxide etch (BOE) technology to make a small amount. It is difficult to enter the mass production stage and develop related commercial products.

It is conventional to fabricate a U-shaped fiber structure by bending a fiber in advance and then shaping the fiber to form a U-shaped fiber structure. Since the amplitude of bending of the optical fiber at room temperature is limited, the U-shaped optical fiber structure produced by the prior art has a small bending curvature, and if the bending force of the optical fiber is excessively applied, the optical fiber may be broken or broken. In fact, the conventional technique can only produce a U-shaped fiber structure having an inner diameter of 4 mm or more. Moreover, as the force applied when bending the optical fiber is different, although a U-shaped optical fiber structure having different inner diameters can be formed, please refer to FIG. 1 to bend the optical fibers to form an inner diameter of 9.9 mm by a conventional technique. U-shaped fiber structures with different inner diameters such as 8mm, 7mm, 6.1mm and 4mm, and the fiber gratings produced according to them, are limited by the inner diameter of the U-shaped fiber structure, and the waveform of the penetration spectrum It is quite confusing and irregular between them, resulting in poor industrial utilization and poor production yield.

In view of the above, there is a need to provide a U-shaped optical fiber manufacturing apparatus and a manufacturing method thereof for fabricating a U-shaped optical fiber structure having a larger bending curvature, thereby effectively improving the utility of the U-shaped optical fiber structure and its application range.

The object of the present invention is to provide a U-shaped optical fiber manufacturing device, wherein an optical fiber is commonly held by a fixing portion and a through hole of a limiting member, and the position of the limiting member is adjusted through a tension adjusting portion to The tensile force is adjusted to a predetermined value, and then the bending portion is heated by a heating device, so that the bending portion is stretched and deformed along the direction of the pulling force to generate a U-shaped optical fiber structure, and the U-shaped optical fiber structure is improved. The effect of sex.

Another object of the present invention is to provide a U-shaped optical fiber manufacturing method, wherein the optical fiber is formed into a bent portion of the through hole by inserting the two ends of the optical fiber into the through hole of the limiting member, respectively, and Adjusting the position of the limiting member by the tension adjusting portion, the limiting member applies a pulling force to the optical fiber, and heating the bending portion by the heating device, thereby changing the bending curvature of the bending portion, and having an enlarged U shape The efficacy of the application range of fiber optic structures.

In order to achieve the foregoing object, the technical means used in the present invention include: A U-shaped optical fiber manufacturing device includes: a fixing base, comprising a joint portion for coupling an optical fiber, the fixing base further comprising a tension sensor, the tension sensor connecting the joint portion to sense the optical fiber a fiber-restricted seat; a fiber-optic limiting seat includes a limiting member, the limiting member is spaced apart from the fixing seat, and the limiting member defines a constant hole for limiting the fixing of the optical fiber, the through hole The optical fiber limiting seat is further provided with a tension adjusting portion for adjusting the position of the limiting member to make the limiting member approach or away from the joint portion along the direction; and a position opposite to the joint portion of the fixing base; The heating device is disposed on a side of the limiting member away from the joint portion, and the heating device has a heating portion, and the heating portion is opposite to the through hole.

The U-shaped optical fiber manufacturing apparatus of the present invention, wherein the limiting member defines a plurality of through holes, the plurality of through holes have different apertures, and the limiting member is provided with a movable member to switch opposite to the joint portion of the fixed seat The through hole of the bit.

The U-shaped optical fiber manufacturing apparatus of the present invention, wherein the plurality of through holes are arranged in a row on the limiting member, and the movable member is a telescopic structure for telescopically adjusting the length of the limiting member to switch between A through hole opposite to the joint of the fixing seat.

The U-shaped optical fiber manufacturing apparatus of the present invention, wherein the heating means is an electrode, a laser generator or a flame spray gun.

In the U-shaped optical fiber manufacturing apparatus of the present invention, the joint portion is connected to a buffer member, and the joint portion is coupled to the optical fiber via the buffer member.

In the U-shaped optical fiber manufacturing apparatus of the present invention, the bonding portion is coupled to fix both ends of the optical fiber.

In the U-shaped optical fiber manufacturing apparatus of the present invention, the two ends of the optical fiber are respectively inserted into the through hole from the side of the binding member away from the coupling portion, and are respectively fixedly coupled to the joint portion, and the optical fiber is The limiting member forms a curved portion away from one side of the joint portion, and the curved portion forms a click with the through hole.

The U-shaped optical fiber manufacturing apparatus of the present invention, wherein the tension adjusting portion includes a push The block and an adjusting member are combined with the limiting member, and the adjusting member is a screw structure, and the pressing member is forced to move to adjust the position of the limiting member by rotating the adjusting member.

A U-shaped optical fiber manufacturing method includes: extending two ends of an optical fiber into a consistent hole of a limiting member, and fixing two ends of the optical fiber to one side of the through hole, so that the optical fiber is in the The other side of the through hole forms a bent portion, and the bent portion forms a latch with the through hole, and the pulling member is used to apply a pulling force to the optical fiber; and the position of the limiting member is adjusted through a tension adjusting portion to The tensile force of the optical fiber is adjusted to a predetermined value; the bending portion is heated by a heating device, the bending portion is stretch-deformed along the direction of the tensile force, thereby changing the bending curvature of the bending portion; and the heating The device stops heating to fix the shape of the curved portion.

In the U-shaped optical fiber manufacturing method of the present invention, the tension adjusting portion is used to adjust the position of the limiting member, forcing the limiting member to approach or away from the joint portion to adjust the tensile force of the optical fiber.

The U-shaped optical fiber manufacturing method of the present invention, wherein the two ends of the optical fiber are combined and fixed to a joint portion, and the joint portion is opposite to the through hole, so that the optical fiber is respectively stretched and fixed by the joint portion and the limit member. .

The U-shaped optical fiber manufacturing method of the present invention, wherein the fixing base is provided with a tensile sensor, the tensile sensor is connected to the joint to sense the tensile force of the optical fiber, and the tension sensor is used to read the optical fiber. The pulling force of the optical fiber is adjusted to a predetermined value by the tension adjusting portion.

1‧‧‧ fixed seat

11‧‧‧Combination Department

111‧‧‧ cushioning parts

12‧‧‧Laser sensor

2‧‧‧Fiber Limiting Block

21‧‧‧Limited parts

211‧‧‧through holes

22‧‧‧Right Adjustment Department

221‧‧‧ push block

222‧‧‧Adjustment

3‧‧‧ heating device

31‧‧‧ heating department

32‧‧‧Slide

F‧‧‧Fiber

F1‧‧‧Bend

R‧‧‧Initial diameter

R’‧‧‧Predetermined inner diameter

X‧‧‧ direction

P‧‧‧ platform

Figure 1 is a perspective view of a fiber grating produced by a U-shaped fiber structure produced by a conventional technique.

Fig. 2 is a schematic view showing the structure of a U-shaped optical fiber manufacturing apparatus according to a preferred embodiment of the present invention.

Fig. 3 is a view showing the use of the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention (1).

Fig. 4 is a view showing the use of the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention (2).

Fig. 5 is a view showing the use of the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention (3).

Figure 6 is a diagram showing the use of the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention (4).

Fig. 7 is a perspective view showing the penetration spectrum of a fiber grating manufactured by the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention.

Figure 8 is a diagram showing the penetration spectrum of a curved interferometric fiber optic sensor fabricated using the preferred embodiment of the U-shaped optical fiber manufacturing apparatus of the present invention.

Figure 9 is a flow chart showing a preferred embodiment of the U-shaped optical fiber manufacturing method of the present invention.

The above and other objects, features and advantages of the present invention will become more <RTIgt; The U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention comprises a fixing base 1, a fiber limiting seat 2 and a heating device 3. The fixing base 1, the optical fiber limiting seat 2 and the heating device 3 can be used together. Combined on a platform P.

The fixing base 1 includes a joint portion 11 which can be combined with an optical fiber F. The joint portion 11 is preferably connected to a buffer member 111 and coupled to the optical fiber F via the buffer member 111, whereby the buffer member 111 can absorb the vibration generated between the joint portion 11 and the optical fiber F to prevent the optical fiber F from being improperly pulled. In more detail, the bonding portion 11 is used for bonding and fixing the two ends of the optical fiber F, and the fixing base 1 is further provided with a tension sensor 12, which can be a conventional force gauge and a tension meter. Or a strain gauge connecting the joint portion 11 to sense the tensile force that the optical fiber F is subjected to.

The optical fiber limiting seat 2 includes a limiting member 21, and the limiting member 21 is disposed at a distance from the fixing base 1 along a direction X, and the limiting member 21 defines a constant hole 211, and the through hole 211 is The joint portion 11 of the fixing base 1 is opposite to fix the optical fiber F. The through hole 211 may be a circular hole or a long hole, and the invention is not limited thereto. The fiber limit seat 2 A tension adjusting portion 22 is provided for adjusting the position of the limiting member 21 such that the limiting member 21 approaches or moves away from the joint portion 11 along the direction X. In the embodiment, the tension adjusting portion 22 includes a pushing block 221 and an adjusting member 222. The pushing block 221 is combined with the limiting member 21, and the adjusting member 222 is a conventional screw structure. The member 222 can force the push block 221 to move along the direction X to adjust the position of the limit member 21. However, in addition to the screw structure, the adjusting member 222 may be another conventional resisting structure capable of forcing the limiting member 21 to approach or away from the joint portion 11 along the direction X, which is not limited by the present invention.

In detail, the two ends of the optical fiber F can be respectively inserted into the through hole 211 from the side of the limiting member 21 away from the connecting portion 11 to be respectively fixedly coupled to the connecting portion 11 due to the optical fiber F. The amplitude of the bend is limited, so the fiber F will form a curved portion F1. The diameter of the through hole 211 is appropriately designed to be smaller than the inner diameter of the curved portion F1. Therefore, the curved portion F1 is located on a side of the limiting member 21 away from the joint portion 11 and forms a latch with the through hole 211. The optical fiber F is stretched and fixed by the joint portion 11 and the limiting member 21, respectively. Wherein, the optical fiber F will bear a pulling force parallel to the direction X, and the pulling force will be affected by the distance between the joint portion 11 and the through hole 211. Accordingly, the tension adjusting portion 22 adjusts the position of the limiting member 21 so that the limiting member 21 approaches or moves away from the joint portion 11 along the direction X, thereby adjusting the tensile force of the optical fiber F, and the tension is received. The tension sensor 1 is provided with the tension sensor 12, so that the user can read the tensile force of the optical fiber F through the tension sensor 12, and then adjust the tension to the predetermined value by the tension adjusting portion 22.

The heating device 3 is disposed on a side of the limiting member 21 away from the connecting portion 11, and the heating device 3 has a heating portion 31 opposite to the through hole 211 for heating the optical fiber F. The bending device F1, the heating device 3 can be an electrode, a laser generator or a flame spray gun, etc., and the invention is not limited thereto. In the embodiment, the heating device 3 is exemplified by a flame spray gun. After the heating device 3 is activated, a flame can be emitted toward the through hole 211 via the heating portion 31, and the optical fiber F is fired according to the bending portion F1. It is heated and melted. In addition, the heating device Preferably, the slider 3 is provided with a sliding seat 32 for driving the heating device 3 to slide along the direction X to change the distance between the heating portion 31 and the limiting member 21. Since the heating device 3 is a flame spray gun, The temperature of the flame emitted by the heating unit 31 is not easily adjusted, and the efficiency of heating the heating portion 31 by the bending portion F1 can be effectively adjusted by changing the distance between the heating portion 31 and the stopper 21.

As shown in FIG. 3, a schematic diagram of the use of the U-shaped optical fiber manufacturing apparatus according to the preferred embodiment of the present invention, the two ends of the optical fiber F are respectively inserted into the through hole 211 and fixed to the joint. After the optical fiber F, the curved portion F1 is formed. The curved portion F1 has an initial inner diameter R, and the initial inner diameter R is preferably a minimum inner diameter of the optical fiber F which can be bent at room temperature. The initial inner diameter R is larger than the aperture of the through hole 211 to form a click with the through hole 211. In other words, the optical fiber F is stretched and fixed by the joint portion 11 and the limiting member 21, respectively, and the tensile force of the optical fiber F can be adjusted by the tension adjusting portion 22, and the optical fiber is received via the tensile sensor 12. The tension applied by F is adjusted to a predetermined value.

Next, as shown in FIGS. 4 and 5, the heating portion 31 of the heating device 3 emits a flame toward the through hole 211, and then fires the curved portion F1 of the fiber to be processed F, because the optical fiber F is subjected to a tensile force parallel to the direction X. Therefore, when the curved portion F1 is gradually heated by the heating portion 31, the curved portion F1 is affected by the tensile force of the optical fiber F, and is continuously stretched along the direction X. Deformation. Therefore, during the deformation of the curved portion F1, the inner diameter of the curved portion F1 will gradually decrease, so that the partial curved portion F1 can pass through the through hole 211. When the inner diameter of the curved portion F1 continues to decrease, so that the portion of the curved portion F1 passing through the through hole 211 continues to increase, the tensile force of the optical fiber F is also reduced.

Finally, referring to FIG. 6 again, when the inner diameter of the curved portion F1 continues to be reduced to a predetermined inner diameter R′ close to the aperture of the through hole 211, most of the curved portion F1 will pass through the The through hole 211 causes the tensile force of the optical fiber F to continue to be reduced, and the bending portion F1 cannot be continuously deformed. At this time, the heating portion 31 can stop heating, and the bent portion F1 is cooled and fixed in shape to form a U-shaped optical fiber structure having the predetermined inner diameter R'.

With the above structure, the optical fiber F is commonly applied to the optical fiber F through the joint portion 11 of the fixing base 1 and the through hole 211 of the limiting member 21, and the heating portion 31 of the heating device 3 bends the optical fiber F. The portion F1 is heated to cause the curved portion F1 to be tensilely deformed along the direction of the tensile force, and the inner diameter of the curved portion F1 is gradually reduced to a predetermined inner diameter R', which is smaller than the optical fiber F in the chamber. The minimum inner diameter that can be bent under temperature creates the desired U-shaped fiber structure.

Referring to FIG. 7, a perspective view of a fiber grating of a U-shaped optical fiber manufacturing apparatus according to a preferred embodiment of the present invention is used. In detail, according to the foregoing structure, the curved portion F1 of an optical fiber F is heated. It is formed into a U-shaped fiber structure with an inner diameter of 0.6 mm, and the fiber grating produced therefrom can be measured to obtain a breakthrough spectrum as shown in the figure. It can be found that the light intensity is attenuated to a position at a wavelength of 1549.7 nm. 50.76db, forming a waveform with good sensing characteristics, the waveform of the transmission spectrum of the U-shaped fiber structure made by the prior art is quite confusing and irregular between each other (as shown in Fig. 1), The U-shaped fiber structure produced by the U-shaped optical fiber manufacturing apparatus of the preferred embodiment is more suitable for fabricating a fiber grating sensor.

Referring to FIG. 8, a penetration spectrum diagram of a carbon dioxide bending interference optical fiber sensor manufactured by using a U-shaped optical fiber structure produced by the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention, more specifically, The U-shaped fiber structure having the predetermined inner diameter R' is coated with a carbon dioxide adsorbent, which can be used as a carbon dioxide sensor, and the carbon dioxide adsorbent can be Tetraethylenepentamine (TEPA). The carbon dioxide bending interference optical fiber sensor is placed in an environment containing a mixed gas of 15% carbon dioxide and 85% nitrogen gas of 0.2 ml/m, and is projected into the U-shaped fiber structure by a broadband source, with the time of placement. The difference can be measured as shown in Figure 8. Wherein, the carbon dioxide bending interferometric optical fiber sensor has excellent sensitivity at a wavelength of about 1550 nm, because the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention can make the U-shaped optical fiber structure have more Large curved curvature, so the curved interferometric fiber optic sensor produced has better sensitivity, so that The utility of the U-shaped fiber structure has been greatly improved.

It should be noted that the aperture of the through hole 211 will affect the predetermined inner diameter R' of the U-shaped fiber structure finally formed by the curved portion F1 of the optical fiber F. Therefore, the plurality of through holes 211 may be defined in the limiting member 21, The plurality of through holes 211 may have different apertures, and the limiting member 21 is provided with a movable member 212 for switching the through hole 211 opposite to the joint portion 11 of the fixing base 1 so that the preferred embodiment of the present invention is U. The type of fiber manufacturing apparatus is capable of fabricating U-shaped fiber structures having different predetermined inner diameters R'. In detail, in the embodiment, the plurality of through holes 211 are arranged in a row on the limiting member 21, and the movable member 212 is a telescopic structure, and the movable member 212 is telescopically adjusted to adjust the limiting member. With the length of 21, the through hole 211 which is opposite to the joint portion 11 of the fixing base 1 can be switched. However, the movable member 212 can also be a pivotal structure or other conventional activity adjustment mechanism, which is not limited by the present invention.

Wherein, if the aperture of the through hole 211 is smaller, the predetermined inner diameter R′ of the U-shaped optical fiber structure formed by the through hole 211 is smaller, and the aperture of the through hole 211 is smaller, and the limit is small. The tensile force applied to the optical fiber F by the member 21 should be increased to ensure that the curved portion F1 of the optical fiber F can be smoothly stretched and deformed after being heated, and the predetermined inner diameter R' formed by the curved portion F1 and the optical fiber F The contrast between the tensile forces it receives is as follows:

Therefore, the U-shaped optical fiber manufacturing apparatus of the preferred embodiment of the present invention has a fixing portion 11 of the fixing base 1 and a through hole 211 of a limiting member 21 for holding an optical fiber F together, and is transmitted through a tension adjusting portion 22 Adjusting the position of the limiting member 21 to adjust the tensile force of the optical fiber F to a predetermined value, and heating the curved portion F1 by a heating device 3, so that the curved portion F1 is stretched along the direction of the pulling force. The deformation is such that the inside of the curved portion F1 is gradually reduced to a predetermined inner diameter R' to produce a U-shaped fiber structure. Accordingly, the U-shaped optical fiber manufacturing apparatus of the present invention can make the U-shaped optical fiber structure have a larger bending curvature, which can be used by bending a fiber and bending it to form a U-shaped fiber structure. To make high-sensitivity fiber optic sensors, it has the effect of improving the usability of U-shaped fiber structures.

Please refer to FIG. 9 , which is a schematic flowchart of a U-shaped optical fiber manufacturing method according to a preferred embodiment of the present invention. The U-shaped optical fiber manufacturing method of the preferred embodiment can be implemented by using the U-shaped optical fiber manufacturing apparatus as described above. Not limited to this.

First, the two ends of an optical fiber F are respectively inserted into the consistent holes 211 of a limiting member 21, and the two ends of the optical fiber F are fixed to one side of the through hole 211, so that the optical fiber F is in the through hole. A bending portion F1 is formed on the other side of the 211, and the bending portion F1 forms a latch with the through hole 211, and the limiting member 21 applies a pulling force to the optical fiber F. The limiting member is adjusted through a tension adjusting portion 22. The position of 21 is adjusted to a predetermined value by the tensile force to which the optical fiber F is subjected.

The two ends of the optical fiber F can be coupled to the joint portion 11 of the fixing base 1 , and the joint portion 11 is opposite to the through hole 211 , so that the optical fiber F is the joint portion 11 and the limiting member 21 respectively. The tensile force is fixed, and the tension of the optical fiber F is affected by the distance between the joint portion 11 and the through hole 211. Therefore, the position of the limiting member 21 is adjusted by the tension adjusting portion 22, and the limiting member is forced. The tension of the optical fiber F can be adjusted by approaching or moving away from the joint portion 11. In addition, the fixing base 1 is provided with a tension sensor 12, and the tension sensor 12 is connected to the joint portion 11 to sense the tensile force of the optical fiber F, so the optical fiber can be read through the tension sensor 12 The tension applied by F is further adjusted by the tension adjusting portion 22 Whole to a predetermined value.

Then, the curved portion F1 is heated by a heating device 3, and the curved portion F1 is stretched and deformed along the direction of the tensile force, thereby changing the bending curvature of the curved portion F1. During the deformation of the curved portion F1, The inner diameter of the curved portion F1 will be gradually reduced, so that the partial curved portion F1 can pass through the through hole 211, and the tensile force of the optical fiber F will be reduced; when the inner diameter of the curved portion F1 continues to shrink to the same When the aperture of the hole 211 approaches a predetermined inner diameter R', the heating device 3 stops heating to fix the shape of the curved portion F1.

By the above method, the two ends of the optical fiber F are respectively inserted into the through holes 211 of the limiting member 21, so that the optical fiber F forms a curved portion F1 that is engaged with the through hole 211, and is adjusted by the pulling force. The portion 22 adjusts the position of the limiting member 21 such that the limiting member 21 applies a pulling force to the optical fiber F, and then heats the curved portion F1 by a heating device 3, thereby changing the bending curvature of the curved portion F1. The inner diameter of the curved portion F1 will gradually shrink to a predetermined inner diameter R' which is smaller than the minimum inner diameter of the optical fiber F which can be bent at room temperature to form a desired U-shaped fiber structure. . Accordingly, compared with the conventional technology, only a fiber is bent and then shaped by heat to form a U-shaped fiber structure. The U-shaped fiber manufacturing method of the present invention can make the U-shaped fiber structure have a larger curvature and can be applied. For a variety of communication or sensing applications, it does have the effect of expanding the application range of U-shaped fiber structures.

In summary, the U-shaped optical fiber manufacturing apparatus and the manufacturing method thereof according to the preferred embodiment of the present invention can achieve many functions such as improving the practicability of the U-shaped optical fiber structure and expanding the application range thereof.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1‧‧‧ fixed seat

11‧‧‧Combination Department

111‧‧‧ cushioning parts

12‧‧‧Laser sensor

2‧‧‧Fiber Limiting Block

21‧‧‧Limited parts

211‧‧‧through holes

22‧‧‧Right Adjustment Department

221‧‧‧ push block

222‧‧‧Adjustment

3‧‧‧ heating device

31‧‧‧ heating department

32‧‧‧Slide

F‧‧‧Fiber

F1‧‧‧Bend

X‧‧‧ direction

P‧‧‧ platform

Claims (12)

A U-shaped optical fiber manufacturing device includes: a fixing base, comprising a joint portion for coupling an optical fiber, the fixing base further comprising a tension sensor, the tension sensor connecting the joint portion to sense the optical fiber a fiber-restricted seat; a fiber-optic limiting seat includes a limiting member, the limiting member is spaced apart from the fixing seat, and the limiting member defines a constant hole for limiting the fixing of the optical fiber, the through hole The optical fiber limiting seat is further provided with a tension adjusting portion for adjusting the position of the limiting member to make the limiting member approach or away from the joint portion along the direction; and a position opposite to the joint portion of the fixing base; The heating device is disposed on a side of the limiting member away from the joint portion, and the heating device has a heating portion, and the heating portion is opposite to the through hole. The U-shaped optical fiber manufacturing apparatus according to claim 1, wherein the limiting member defines a plurality of through holes, the plurality of through holes have different apertures, and the limiting member is provided with a movable member to switch between The joint of the fixing seat is opposite to the through hole. The U-shaped optical fiber manufacturing apparatus according to claim 2, wherein the plurality of through holes are arranged in a row on the limiting member, and the movable member is a telescopic structure for telescopically adjusting the limiting member. The length is to switch the through hole opposite to the joint of the fixing seat. The U-shaped optical fiber manufacturing apparatus according to claim 1, wherein the heating device is an electrode, a laser generator or a flame spray gun. The U-shaped optical fiber manufacturing apparatus according to claim 1, wherein the joint portion is connected to a buffer member, and the joint portion is coupled to the optical fiber via the buffer member. The U-shaped optical fiber manufacturing apparatus according to claim 1, 2, 3, 4 or 5, wherein the bonding portion is coupled to fix both ends of the optical fiber. The U-shaped optical fiber manufacturing apparatus according to claim 6, wherein the two ends of the optical fiber are respectively inserted into the through hole from a side of the limiting member away from the connecting portion, and are respectively fixed and fixed to the limiting hole. The connecting portion forms a bent portion on a side of the limiting member away from the joint portion, and the bent portion forms a click with the through hole. The U-shaped optical fiber manufacturing apparatus according to the first, second, third, fourth or fifth aspect of the invention, wherein the tension adjusting portion comprises a push block and an adjusting member, and the push block is combined with the limiting member. The adjusting member is a screw structure, and the pushing block can be forced to move to adjust the position of the limiting member by rotating the adjusting member. A U-shaped optical fiber manufacturing method includes: extending two ends of an optical fiber into a consistent hole of a limiting member, and fixing two ends of the optical fiber to one side of the through hole, so that the optical fiber is in the The other side of the through hole forms a bent portion, and the bent portion forms a latch with the through hole, and the pulling member is used to apply a pulling force to the optical fiber; and the position of the limiting member is adjusted through a tension adjusting portion to The tensile force of the optical fiber is adjusted to a predetermined value; the bending portion is heated by a heating device, the bending portion is stretch-deformed along the direction of the tensile force, thereby changing the bending curvature of the bending portion; and the heating The device stops heating to fix the shape of the curved portion. The U-shaped optical fiber manufacturing method according to claim 9, wherein the tension adjusting portion adjusts a position of the limiting member, forcing the limiting member to approach or away from the joint portion to adjust the optical fiber to be subjected to pull. The U-shaped optical fiber manufacturing method of claim 9, wherein the two ends of the optical fiber are fixedly coupled to a joint portion, and the joint portion is opposite to the through hole, so that the optical fiber is the joint portion and the The limit member is stretched and fixed. The U-shaped optical fiber manufacturing method according to claim 11, wherein the fixing The pedestal is provided with a tension sensor, the tension sensor is connected to the joint portion to sense the tensile force of the optical fiber, and the tension force received by the optical fiber is read through the tension sensor to pass through the tension adjusting portion. The tensile force of the optical fiber is adjusted to a predetermined value.