KR102124085B1 - Fiber array structure for high power fiber laser - Google Patents

Abstract

The present invention relates to an optical fiber array structure for a high-power optical fiber laser and a method for manufacturing the same, wherein an optical fiber receiving member in which a plurality of optical fiber mounting grooves in which an optical fiber is seated is located, each of which is seated in a plurality of optical fiber mounting grooves at an upper side of the optical fiber receiving member The optical fiber cover member covering the upper part of the optical fiber, the optical fiber support member, and the array block member adhered to the front surface of the optical fiber cover member are composed of a single module and are bonded at once by optical contact with the array block. By making it possible to obtain a high uniformity of the joint surface, it can improve the quality of the beam, reduce the heat generation problem, simplify the manufacturing process of manufacturing an optical fiber array structure including a plurality of optical fibers, increase productivity, and increase the defect rate. Can be reduced.

Description

Fiber array structure for high power fiber lasers{FIBER ARRAY STRUCTURE FOR HIGH POWER FIBER LASER}

The present invention relates to an optical fiber array structure for a high-power optical fiber laser, and more specifically, to configure a plurality of optical fibers as a single module and to attain a high uniformity of the bonding surface by bonding the array block at once with an optical contact method. The invention relates to an optical fiber array structure for a high power fiber laser.

In general, optical fiber laser beams using optical fiber arrays are widely used in optical switching, signal processing, optical tomography, sensing, and multi-wavelength beam combining.

Existing optical fiber arrays are usually manufactured in a form of fixing the optical fiber to the V groove using an adhesive such as epoxy.

However, if a high-power laser is applied to this type of array, damage occurs due to high power density at the end of the optical fiber.

In order to avoid this, a form of an optical fiber array with a lower power density by applying a glass block has been proposed.

In this case, the optical fiber array is made by fusing the optical fibers to the array blocks individually.

Heat is applied to bond the optical fiber with the array block. At this time, non-uniformity occurs due to the uneven stress distribution of the bonding surface, thereby causing beam quality degradation and thermal problems.

In addition, because the optical fibers are individually bonded, the process is complicated and heat can be conducted to the surrounding optical fibers, causing deformation.

Also, if any one problem occurred while splicing multiple optical fibers, there was a problem that the optical fiber array had to be rebuilt from the beginning.

That is, the conventional optical fiber array has a problem in that beam quality is deteriorated and heat is generated due to non-uniform bonding between the optical fiber and the array block.

In addition, the conventional optical fiber array has a problem that the defect rate increases as the number of optical fibers increases.

0001) Korea Patent Registration No. 1928406'Optical fiber laser generator' (2018.12.06.registration)

An object of the present invention is to construct a plurality of optical fibers into a single module, and to join the array block at a time in an optical contact (optical contact) method at a time, to obtain a high uniformity of the bonding surface, an optical fiber array structure for high power fiber lasers and a method of manufacturing the same To provide.

Another object of the present invention is to provide an optical fiber array structure for a high-power optical fiber laser, which simplifies the manufacturing process of manufacturing an optical fiber array structure including a plurality of optical fibers, and a method for manufacturing the same.

In order to achieve the above object of the present invention, an embodiment of an optical fiber array structure for a high-power optical fiber laser according to the present invention is an optical fiber support member in which a plurality of optical fiber mounting grooves in which an optical fiber is seated are located, at an upper side of the optical fiber support member It characterized in that it comprises an optical fiber cover member to form an optical fiber bundle module covering the upper portion of each optical fiber seated in a plurality of optical fiber mounting grooves, an optical fiber support member and an array block member bonded to the front surface of the optical fiber cover member.

In the present invention, the optical fiber seating groove may be formed in a V groove shape.

In the present invention, the optical fiber supporting member includes a base supporting portion having an upper surface formed in a flat surface; And a fiber-optic seating portion positioned to protrude on the base support portion and a plurality of optical fiber seating grooves spaced apart in the width direction.

In the present invention, the height at which the optical fiber seating portion protrudes on the base support portion may be formed equal to or greater than the depth of the optical fiber seating groove.

In the present invention, the exit surface of the optical fiber bundle module may be polished for optical bonding with the array block member.

In the present invention, the incidence surface of the array block member may be polished and fixed in an optical bonding manner with the exit surface of the polished optical fiber bundle module.

In the present invention, the incident surface of the array block member may have a surface in which the PV is polished to 633/4 (nm) or less to be optically bonded.

In the present invention, the optical fiber may be seated and fixed to the optical fiber mounting groove.

In the present invention, the optical fiber cover member may be fixed by being adhered to the upper side of the optical fiber.

In the present invention, the optical fiber cover member may be positioned to be spaced apart from the optical fiber support member.

In the present invention, the optical fiber cover member may be positioned parallel to the upper surface of the optical fiber support member having a flat bottom surface.

In the present invention, on the output surface of the array block member, a plurality of spaced micro lens members may be positioned to correspond to the optical fiber.

In the present invention, the array block member may apply a curvature in the y-axis direction to the output surface to adjust the divergence angle in the y-axis direction of the laser beam.

In the present invention, the array block member may apply a curvature in the x-axis direction to the output surface to adjust the divergence angle in the x-axis direction of the laser beam.

One embodiment of the optical fiber array structure for a high power fiber laser according to the present invention may further include a light source for a guide beam connected to the optical fiber seated in at least one of the plurality of optical fiber mounting grooves to emit a guide beam.

In the present invention, the light source for the guide beam may be a light source having a visible light wavelength of mW.

In addition, in order to achieve the above object of the present invention, a method of manufacturing an optical fiber array structure for a high-power optical fiber laser according to the present invention is an optical fiber placement step of placing an optical fiber in an optical fiber receiving groove of an optical fiber receiving member in which a plurality of optical fiber mounting grooves are located. , Optical fiber cover step of positioning the optical fiber cover member covering the upper side of the optical fiber disposed after the optical fiber placement step, optical fiber bundle module to form the optical fiber bundle module by fixing the optical fiber support member and the optical fiber and the optical fiber cover member with adhesive step; A surface treatment step of polishing the exit surface of the optical fiber bundle module and the incident surface of the array block member for optical bonding, and an optical bonding step of optically bonding the exit surface of the optical fiber bundle module and the incident surface of the array block member It is characterized by.

In the present invention, in the surface treatment step, PV may be polished to 633/4 (nm) or less so that the exit surface of the optical fiber bundle module can be optically bonded.

In the present invention, in the surface treatment step, PV can be polished to 633/4 (nm) or less so that the incident surface of the array block member can be optically bonded.

According to the present invention, a plurality of optical fibers are configured as a single module, and a high degree of uniformity of a bonding surface can be obtained by bonding the array block and an optical contact method at a time to improve beam quality and reduce heat generation problems. It has an effect.

The present invention has an effect of increasing productivity and reducing a defect rate by simplifying a manufacturing process for manufacturing an optical fiber array structure including a plurality of optical fibers.

1 is an exploded perspective view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention.
2 is a perspective view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention.
Figure 3 is a side view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention.
4 and 5 are perspective views showing a comparative example of an optical fiber array structure for a high power fiber laser according to the present invention.
6 is a graph showing different beam sizes, outputs, and densities in the propagation distance of the rail member in the optical fiber array structure for a high power fiber laser according to the present invention.
7 to 9 is a view showing another embodiment according to the type of optical fiber in the optical fiber array structure for a high power fiber laser according to the present invention.
10 to 12 is a side view showing another embodiment according to the type of optical fiber in the optical fiber array structure for a high power fiber laser according to the present invention.
13 to 15 are views showing another embodiment of an array block member in the optical fiber array structure for a high power fiber laser according to the present invention.
16 is a diagram showing an example in which a guide beam is applied in an optical fiber array structure for a high power fiber laser according to the present invention.
17 is a diagram illustrating an optical fiber laser multi-wavelength beam coupling device to which an optical fiber array structure for a high power fiber laser according to the present invention is applied.
18 is a process diagram showing an embodiment of a method of manufacturing an optical fiber array structure for a high power fiber laser according to the present invention.

The present invention will be described in more detail.

If described in detail by the accompanying drawings, preferred embodiments of the present invention. Prior to the detailed description of the present invention, terms or words used in the present specification and claims described below should not be interpreted as being limited to a conventional or dictionary meaning. Therefore, the configuration shown in the embodiments and drawings described in this specification are only the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, and thus can replace them at the time of application. It should be understood that there may be equivalents and variations.

1 is an exploded perspective view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention, and FIG. 2 is a perspective view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention, 3 is a side view showing an embodiment of an optical fiber array structure for a high power fiber laser according to the present invention.

An embodiment of an optical fiber array structure for a high power fiber laser according to the present invention will be described in detail below with reference to FIGS. 1 to 3.

One embodiment of an optical fiber array structure for a high-power optical fiber laser according to the present invention includes an optical fiber supporting member 100 in which a plurality of optical fiber mounting grooves 100a on which an optical fiber 10 is mounted are located.

As an example, the optical fiber receiving member 100 has a plurality of optical fiber mounting grooves 100a spaced apart from each other, and the optical fiber receiving grooves 100a have an open shape in the longitudinal direction of the optical fiber 10, respectively.

Optical fiber seating groove (100a) is formed so that both ends are open in the upper side and the longitudinal direction, that is, in the longitudinal direction of the optical fiber 10, respectively, can easily seat the optical fiber 10 on the upper side, The laser beam transmitted through the optical fiber 10 has a structure capable of being output to the end side of the optical fiber 10.

Each of the optical fiber mounting grooves 100a is formed in a V groove shape so that the optical fibers 10 having a circular cross section can be stably seated, and the optical fibers 10 having various sizes can be easily and stably seated.

In addition, the optical fiber support member 100 is positioned to protrude on the base support 110 and the base support 110, the upper surface of which is formed in a plane, and a plurality of optical fiber mounting grooves 100a are spaced apart in the width direction. It may include an optical fiber mounting portion 120.

The height of the optical fiber mounting portion 120 protruding from the base support portion 110 is formed to be equal to or greater than the depth of the optical fiber mounting groove 100a, so that the optical fiber 10 seated in the optical fiber mounting groove 100a has a base support portion 110. ) To be seated on the upper surface or spaced apart from the upper surface of the base support 110.

This is to ensure that the optical fiber 10 is seated on the upper surface of the base support 110 or is spaced apart from the upper surface of the base support 110 to be arranged in a straight line.

The optical fiber cover member 200 is positioned on the upper side of the optical fiber 10 seated in the optical fiber mounting groove 100a of the optical fiber supporting member 100.

The optical fiber cover member 200 is inserted into the optical fiber receiving member 100a on the optical fiber supporting member 100 to be positioned to cover the upper side of the optical fiber 10 seated to form an optical fiber bundle module.

The fiber optic bundle module may include several, tens or hundreds of optical fibers 10 depending on the application.

That is, the optical fiber mounting groove (100a) is formed of several, dozens, hundreds depending on the design suitable for the application can form a bundle of optical fibers including several, dozens, hundreds of optical fibers (10).

The exit surface of the optical fiber bundle module and the incident surface of the array block member are surface-treated through polishing for optical bonding with each other.

The array block member 300 is adhered and fixed in an optical optical manner to the front surface of the optical fiber cover member 200 of the surface-treated fiber bundle module, the front surface of the optical fiber 10, and the front surface of the optical fiber support member 100.

In the above, it is revealed that the front surface means a surface to which the array block member 300 is adhered, that is, a surface corresponding to the array block member 300 and does not indicate a specific direction.

The front surface of the optical fiber cover member 200 and the front surface of the optical fiber support member 100 are each formed in a plane and positioned to coincide with each other.

That is, the exit surface of the optical fiber bundle module and the incidence surface of the array block member 300 are each formed in a plane, that is, they have a plan view capable of optical bonding using Van der Waals force.

The exit surface of the optical fiber bundle module and the incident surface of the array block member 300 are polished so that they can be optically joined by having a surface roughness below a predetermined condition.

In more detail, the exit surface of the fiber bundle module and the incident surface of the array block member 300 are each polished to a PV (Peek and Valley; maximum bone depth) of λ/4 (nm) or less so as to be optically bonded to each other. Have

It is revealed that λ is a reference wavelength value and that the actual PV (Peek and Valley) is less than 633/4 (nm).

In addition, the optical fiber 10 may be seated in the optical fiber mounting groove 100a and fixed by being adhered with an optical adhesive such as epoxy, and the optical fiber cover member 200 may be seated on the upper side of the optical fiber 10 and thus the optical fiber 10 ) Can be fixed by bonding with an optical adhesive such as epoxy located between.

The optical fiber 10 is adhered and fixed with an optical adhesive on the optical fiber support member 100, and the optical fiber cover member 200 is fixed with an optical adhesive with an optical adhesive on the upper side, so that the optical fiber support member 100 and the optical fiber The position can be stably fixed between the cover members 200.

As an example, the optical fiber cover member 200 has a lower surface formed in a plane and positioned parallel to the upper surface of the flat optical fiber support member 100.

The optical fiber cover member 200 is positioned to be spaced apart from the optical fiber support member 100 and has a structure capable of dissipating heat generated from the optical fiber 10 to solve the heat generation problem.

In addition, it is revealed that the array block member 300 can transmit a laser beam, such as glass, and is made of a known material with less absorption for the wavelength of the laser beam, and a detailed description is omitted.

The optical fiber 10 is positioned in the optical fiber mounting groove 100a so that the end side is spaced apart from the incident surface of the array block member 300.

It is revealed that the distance between the array block member 300 and the optical fiber 10 can be carried out in various modifications depending on the type and design of the laser.

In addition, an anti-reflective coating layer is formed on the output surface of the array block member 300 to prevent loss of a laser beam and minimize problems due to reflection.

4 and 5 are perspective views showing a comparative example of an optical fiber array structure for a high power fiber laser according to the present invention.

In more detail, FIG. 4 shows a first comparative example including the optical fiber support member 100 and the optical fiber cover member 200 except for the array block member 300.

The first comparative example of FIG. 4 can be used for a low-power fiber laser, and in some cases, a polarization-maintaining optical fiber is used, in which case it is necessary to align the polarization axis in a desired direction.

In the case of the first comparative example, the laser beam comes directly from the end of the optical fiber. In the case of a high-power laser, the power density is high, so damage occurs.

To overcome this, a coreless optical fiber can be applied to the end side, but there is a limitation in applying high power of kW class.

5 is a comparative example for solving the high power density problem of the first comparative example as a second comparative example in which the optical fiber 10 is fused to the incident surface of the array block member 300.

That is, in the case of the second comparative example, when the optical fiber 10 is fused to the array block member 300 and the laser beam propagates a certain distance within the array block, the output density is lowered on the exit surface of the array block by laser divergence, and thus high power can be transmitted. There will be.

However, in the case of Comparative Example 2, the work process is complicated to fuse each optical fiber 10 to the array block, and in some cases, a polarization-maintaining optical fiber is used. In this case, the polarization axes must be aligned by aligning the polarization axes in a desired direction. There is a difficult problem to do.

6 is a graph showing the different beam sizes and power densities in the propagation distance in the array block member in the optical fiber array structure for a high power fiber laser according to the present invention.

The wavelength of the laser beam was 1.06um, the output was 1,000W, the beam quality was M2=1.1, and the optical fiber 10 assumed a core size of 30um and NA 0.06.

It can be seen that the size of the laser beam increases linearly with the propagation in the array block member 300 and the laser power density rapidly decreases.

7 to 9 are views showing another embodiment according to the type of the optical fiber 10 in the optical fiber array structure for a high power fiber laser according to the present invention.

10 to 12 are side views showing another embodiment according to the type of optical fiber in the optical fiber array structure for a high power fiber laser according to the present invention.

7 and 10 are examples in which the optical fiber 10 is a non-polarized transmission optical fiber, FIGS. 8 and 11 are examples in which the optical fiber 10 is a polarization-maintaining optical fiber, and in FIGS. 9 and 12, the optical fiber 10 is a coreless This is an example of an optical fiber.

As an example, the optical fiber mounting grooves 100a are formed at equal intervals, and it is revealed that it is possible to manufacture them at arbitrary intervals in some cases.

In addition, when applying the polarization-maintaining optical fiber as shown in FIGS. 8 and 11, it is revealed that the polarization axis needs to be aligned in a specific direction according to the application.

In addition, as shown in FIGS. 9 and 12, when the optical fiber 10 is a coreless optical fiber, there is an advantage of easy optical bonding with the array block member 300, and the coreless optical fiber length is of the NA or laser beam of the transmission optical fiber at the front end. As an example, it is determined by the beam quality, and the allowable length is within several mm in a high-power high-quality fiber laser using a large-diameter optical fiber.

13 to 15 are views showing another embodiment of the array block member 300 in the optical fiber array structure for a high power fiber laser according to the present invention.

Referring to FIG. 13, a plurality of spaced micro lens members 400 may be positioned on the output surface of the array block member 300.

The micro lens member 400 has a number corresponding to the number of optical fibers 10 and is positioned to correspond to each optical fiber 10.

The micro lens member 400 allows a collimated beam or a divergent angle to generate a relaxed beam.

Referring to FIG. 14, the array block member 300 may apply a curvature in the y-axis direction to the output surface to adjust the divergence angle in the y-axis direction of the laser beam.

In addition, referring to FIG. 15, the array block member 300 may apply a curvature in the x-axis direction to the output surface in order to adjust the divergence angle in the x-axis direction of the laser beam.

FIG. 16 is a view showing an example in which a guide beam is applied in an optical fiber array structure for a high power fiber laser according to the present invention. Referring to FIG. 16, an optical fiber array structure for a high power fiber laser according to the present invention includes a plurality of optical fiber mounting grooves (100a). ) May further include a light source 500 for a guide beam that is connected to at least one of the optical fibers 10 and emits a guide beam.

As an example, the guide beam light source 500 is an mW-class visible light wavelength light source, and may be connected to an optical fiber port at a specific position among the plurality of optical fibers 10 seated in the plurality of optical fiber mounting grooves 100a.

It is noted that the light source 500 for the guide beam may be applied as necessary for purposes such as alignment of the optical axis of the laser beam, and may be applied by emitting a plurality of guide beams connected to the plurality of optical fibers 10.

17 is a view illustrating an optical fiber laser multi-wavelength beam coupling device to which an optical fiber array structure for a high-power fiber laser according to the present invention is applied, and referring to FIG. 17, the multi-wavelength beam combining device is a typical application of applying an optical fiber array for a high-power laser It is used to secure laser power of kW, tens of kW, or hundreds of kW while maintaining excellent beam quality in the field.

The increase of the output of the individual laser modules is limited by nonlinear or thermal problems, so that the number of laser modules of appropriate output is increased to increase the output.

In this case, the number of optical fibers of the optical fiber array needs several, tens, or hundreds.

In the case of the optical fiber array structure for a high-power fiber laser according to the present invention proposed in the present invention, it can be confirmed that it is suitable for a beam combining device for a high-power laser because it is not significantly affected by the increase in the number of optical fibers in the manufacturing process.

On the other hand, Figure 18 is a process diagram showing an embodiment of a method for manufacturing an optical fiber array structure for a high power fiber laser according to the present invention, and referring to Figures 1 and 17 of the optical fiber array structure for a high power fiber laser according to the present invention The manufacturing method is arranged after the optical fiber placement step (S100) and the optical fiber placement step (S100) of placing the optical fiber 10 in the optical fiber receiving groove 100a of the optical fiber receiving member 100 in which a plurality of optical fiber mounting grooves 100a are located. Optical fiber cover step (S200) for positioning the optical fiber cover member 200 covering the upper side of the optical fiber 10, the optical fiber by fixing the optical fiber support member 100 and the optical fiber 10 and the optical fiber cover member 200 with adhesive Optical fiber bundle modularization step (S300) to form a bundle module, a surface treatment step (S400) of polishing the exit surface of the optical fiber bundle module and the incident surface of the array block member 300 for optical bonding, and the exit surface of the optical fiber bundle module An optical bonding step (S500) of optically bonding the incident surface of the array block member 300 may be included.

The optical fiber bundle modularization step (S300) is an example in which the optical fiber 10 is seated on the optical fiber receiving groove 100a of the optical fiber supporting member 100 to be adhered with an optical adhesive such as epoxy.

In addition, the optical fiber bundle modularization step (S300) is an example in which the optical fiber cover member 200 is mounted on the optical fiber 10 to be bonded with an optical adhesive such as epoxy.

In the surface treatment step, the PV can be polished to 633/4 (nm) or less so that the exit surface of the fiber bundle module can be optically bonded.

In the surface treatment step, PV can be polished to 633/4 (nm) or less so that the incident surface of the array block member 30 can be optically bonded.

According to the present invention, a plurality of optical fibers may be configured as one module and bonded to an array block at a time to obtain high uniformity of a bonding surface, thereby improving beam quality and reducing heat generation problems.

The present invention simplifies the manufacturing process of manufacturing the optical fiber array structure including the plurality of optical fibers 10, thereby increasing productivity and reducing a defect rate.

The present invention is not limited to the above-described embodiments, but can be carried out by variously changing within a range not departing from the gist of the present invention, and it is revealed that it is included in the configuration of the present invention.

10: optical fiber 100: optical fiber support member
100a: Optical fiber mounting groove 110: Base support
120: optical fiber mounting portion 200: optical fiber cover member
300: array block member 400: micro lens member
500: light source for the guide beam

Claims (19)

An optical fiber supporting member in which a plurality of optical fiber mounting grooves in which optical fibers are seated are located;
An optical fiber cover member covering an upper portion of each optical fiber seated in a plurality of optical fiber seating grooves at an upper side of the optical fiber supporting member to form a fiber bundle module;
An array block member adhered to the front surface of the optical fiber support member and the front surface of the optical fiber cover member; And
And a light source for a guide beam connected to the optical fiber seated in at least one of the plurality of optical fiber mounting grooves to emit a guide beam,
The light source for the guide beam is a light source of mW class visible light wavelength for use in alignment of the optical axis of the laser beam,
The optical fiber support member,
A base support portion having an upper surface formed in a plane; And
Includes an optical fiber seating portion which is located to protrude on the base support portion and a plurality of optical fiber seating grooves are spaced apart in the width direction,
The front surface of the optical fiber supporting member, the front surface of the optical fiber, and the front surface of the optical fiber cover member, which are the exit surface of the optical fiber bundle module, are respectively polished for optical bonding with the array block member,
The incidence surface of the array block member is polished and polished, and the front surface of the optical fiber supporting member, the front surface of the optical fiber, and the front surface of the optical fiber cover member, respectively, are van der Waals force. ) Is fixed by optical bonding method,
The front surface of the optical fiber support member, the front surface of the optical fiber, the front surface of the optical fiber cover member, and the incident surface of the array block member are PV 633/4 so that they can be optically bonded using Van der Waals force, respectively. (nm) or less with a polished surface,
On the output surface of the array block member, a plurality of spaced micro lens members corresponding to the optical fiber are positioned,
The array block member applies a curvature in the y-axis direction to the output surface to adjust the divergence angle in the y-axis direction of the laser beam, or in the x-axis direction to the output surface to adjust the divergence angle in the x-axis direction of the laser beam. A fiber array structure for a high power fiber laser, characterized by applying a curvature.
The method according to claim 1,
The optical fiber mounting groove is an optical fiber array structure for a high-power optical fiber laser, characterized in that formed in the form of a V groove.
delete The method according to claim 1,
The height of the optical fiber seating portion protruding on the base support portion is the same as or greater than the depth of the optical fiber seating groove.
delete delete delete The method according to claim 1,
The optical fiber is an optical fiber array structure for a high-power optical fiber laser, characterized in that the optical fiber is seated and fixed to the optical fiber mounting groove.
The method according to claim 8,
The optical fiber cover member is fixed to the upper side of the optical fiber is fixed, characterized in that the optical fiber array structure for high-power optical fiber laser.
The method according to claim 1,
The optical fiber cover member is an optical fiber array structure for a high power optical fiber laser, characterized in that it is spaced apart from the optical fiber support member.
The method according to claim 10,
The optical fiber cover member has an optical fiber array structure for a high-power optical fiber laser, characterized in that the lower surface is formed in a flat surface and positioned parallel to the upper surface of the flat optical fiber support member.
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