TR201700931A2 - Fiber Coupler Isolator Application for Measurement and Protection of Back Reflected Beam in Fiber Laser Systems - Google Patents

Abstract

In fiber laser systems, the invention provides fiber-laser insulators (11) which enable the red laser connection when the system is active, and which provide protection of the system components by guiding the reflected laser beam (17) on a separate line during cutting, and measuring the reflection intensity. the modules 100.

Description

TECHNICAL FIELD The invention is particularly useful in laser cutting benches where fiber laser systems are used. fiber optic connection forming fiber laser during cutting of materials and externally measuring the amount of back reflections occurring at the points of To prevent possible damages that may occur due to reflections. with fiber laser modules coupled with a fiber multiplier insulator to provide PRIOR ART In the literature, the intensity of back reflection is “Cladding Mode Stripper / Cladding Power Stripper”. Fiber output laser diode known as "CPS" and its main purpose is fiber laser systems. with rare earth elements excited by laser beam produced by modules along the doped active fiber optic cable, in the core structure of the fiber optic cable laser at the output of the system, which remains unabsorbed by the active atoms present Both the poor quality of the work and the connection within the fiber laser system. as the pumping work that causes extra heating at the points and components using the optical component, which is to remove the so-called light from the fiber being measured.

CPS is also used to protect the fiber laser system from the aforementioned back reflections. structures are used. These structures are fiber optic structures that make up the fiber laser system. Considering that the material occurring during the cutting and the cutting head from the end-cap at the end of the inserted transmission fiber to the laser diode modules that the advancing beam is only guided into the sheath structure of the fiber optic cable and It removes the rays moving in its region from the system and this It determines the amount of back reflection by measuring the intensity of the rays. In this context, it is clearly It is seen that the current applications are the feedback transmitted to the core structure of the fiber optic cable. removing the reflected laser beams from the system and It is insufficient to measure the intensity of the reflected laser beams.

In fiber laser systems, what is meant by protection from back reflection is the protection of back reflected rays. Although it covers the components that pass through the entire fiber optic structure, rather, the reflected light is transmitted to the laser diode modules, which is the starting step of the system. as much as possible and to prevent these structures from being damaged. is to pass. However, considering the current applications, the fiber optic in the fiber laser system In the structure, only the rays transmitted to the sheath area are removed from the system and their Measuring the intensity is not an adequate control and also the heat in the core region. must be taken into account.

Except for those mentioned above, laser diode module with fiber output in existing systems input fibers that have identical inputs to the output fibers and are welded to these output fibers. collecting the laser beams coming from each of them by combining them in a hexagonal structure and then into a single fiber optic cable to pump the active fiber optic cable. It provides transmission and is known as “tapered fiber bundle / fiber combiner” in the literature. In this method, the central input of the passive component is left idle and the reflection from this input is left blank. Tests can be made by measuring the strength of the heat. During these tests, only the most Maximum back reflections during cutting glossy material can be measured. Limiting to only the tests that have been carried out, “the system is the brightest” It is resistant to back reflection even when cutting materials”.

Since a laser diode module is not connected to this input, an indirect protection is provided. However, during material cutting in fiber laser systems, the laser beam is used to determine its position before the laser beam is activated and The red laser (red laser) placed in the system by connecting to the central entrance of the TFB structure Using red light emitting laser diode modules known as (laser point / laser point) not possible.

BRIEF DESCRIPTION OF THE INVENTION The embodiment of the present invention and the best use of its advantages with additional elements To be understood, it should be evaluated together with the figures explained below. The main object of the invention is to use both the red laser and the red laser when the fiber laser system is active. It separates the laser beam that is reflected back during cutting, which makes the connection of Preventing the laser diode from reaching the modules by guiding it on the line and protecting it. It is related to a fiber laser module that provides the power and measures the intensity of the back reflection.

In the scope of the invention, unlike examining laser beams thrown out by CPS structures, directly within the fiber laser system, through the core structure of fiber optic cables, on a different line of laser beams advancing to the laser diode modules. separated from the main line by directing and a photo diode placed at the output of this line or photo diodes (thermal sensors can also be included in this package structure, so The temperature of the package structure, which also acts as a blocker for the reflected light, can also be controlled.) It is possible to measure the intensity of back reflection with high precision. Like this real-time display of the intensity of the reflected heat compared to the applications in the current art. laser measurement and directing the reflected rays to a separate line. The diode modules are prevented from being damaged by the reflected rays.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows the fiber laser module of the invention in connection with the laser cutting machine. is the view.

Figure 2 is a schematic view of the fiber laser module of the invention.

Figure 3 shows the fiber multiplying insulator and shows fiber connections.

Figure 4 shows the fiber multiplier isolator inlet and the direction of movement of the beams.

Figure 5 shows the splicer input and the splicer in the fiber laser module of the invention. indicates the direction of motion of the rays.

Figure 6 is a section view of the 7-input coupler.

Figure 7 is a section view of the 19-input coupler.

REFERENCE NUMBERS 100 Fiber Laser Modules 11 Fiber multiplier insulator 12 Input fiber of fiber multiplier insulator 121 Kiif region 122 Core region 13 Red laser diode 131 Red laser beam 14 fiber cables measurement module 16 Fiber multiplier insulator empty zone 17 Reflected heat 18 Laser diode modules 19 Laser diode module output fiber 191 Kilif districts 192 Core regions combiner 21 Splicer input fiber 22 Splicer output fiber 221 Kilif region 222 Core region 23 High reflective FBG 24 FBG fiber active fiber 26 CPS 27 CPS input-output fibers 28 Low reflectance FBG 29 FBG fiber junction point 200 transmission cable 300 End pieces 400 Fiber laser cutting machine body 31 Cutter head chamber 32 Cutter head 33 Sheet material 34 Cut grid fiber laser unit DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the innovation subject of the invention is only intended for a better understanding of the subject. It is explained with examples that will not have any limiting effect on the subject. invention, fiber in laser cutting machines (400) where laser systems are used, especially with glossy surfaces fiber optic junction forming the fiber laser externally and during the cutting of materials (33) the amount of back reflections occurring at the points (30) (boiling points) to be measured in a healthy way and the possible consequences that may arise from these back reflections. will be used to prevent damage.

Figure 1 shows the inventive fiber laser module (100), a fiber laser cutting machine (400) shows in conjunction with. Fiber laser cutting machine (400), sheet materials (33) performs the cutting with the laser beam. Fiber laser module (100), cooling It is positioned in a fiber laser unit (35) together with its connections.

The output of the fiber laser module (100) is connected to a transmission cable (200). Said transmission cable (200), laser beams, connected fiber laser cutting machine (400) It carries the laser cutter head (32) in it. Another alternative In the configuration, more than one fiber laser module (100) is used as a so-called "work combiner". It is brought together with the elements and connected to the transmission cable (200) of the output of this combiner. laser beams can be transmitted to the laser cutter head (32). laser cutter head (32) reflects the laser beam coming from the transmission cable (200) with the optical mirror and from a nozzle outlet by directing it with lenses, to the sheet material to be cut (33) focusing optomechanical unit. Laser cutter head (32), laser cutting machine (400) It is placed in a laser cutter head chamber (31) provided in it.

In the fiber laser cutting machine (400), especially stainless steel etc. glossy surface While the sheet materials (33) are being cut, the light (17) reflected back from the surface of the material (33) the tip connected to the laser cutter head (32) in the cutter head chamber (31) fiber laser along the transmission cable (200) by entering the end-cap (300) It moves towards the module (100). Reflected radiation (17) (200) enters both the core and the sheath structure and progresses in these regions.

Figure 2 is a schematic view of the inventive fiber laser module (100). fiber laser in module (100); Laser diode modules that radiate in the near infrared (NIR-near infrared) range (18), Laser diode module output connected to the output of the mentioned laser diode modules (18) fibers (19), Positioned between the laser diode modules (18), the red laser beam (131) emitting a red laser diode (13), The red laser beam (131) is connected to the mentioned red laser diode (13) output. a fiber multiplier insulator input fiber (12), carrying From the laser diode modules (18) and the red laser diode connected to the center input. (13) collecting incoming rays and transmitting them to the main line and reflecting back from the main line The beam (17) is substantially transferred to the sheath (121) of the fiber multiplying insulator input fiber (12). a guiding combiner (20), The fiber multiplier insulator input fiber (12) is connected, and it transmits both the red laser beam. (131) is another fiber optic cable that transmits to the main line and is connected to it. a fiber that separates the reflected light (17) from the main line through multiplier isolator (11), Realizing the function of separating the aforementioned reflected light (17) from the main line, a fiber cable (14) connected to the fiber multiplier isolator (11), The power of the reflected light (17) leaving the main line through the fiber cable (14). photo diode(s) inside and applied to the end of the fiber cable (14) a measurement module (15) that allows measuring with methods (15), On the main line, which provides cavity formation in fiber laser systems formed high reflective FBG (23) and low reflective FBG (28), The rays remaining within the sheath area of the transmission cable (200) CPS (26) providing removal, From the output of the combiner (20), to be combined with the transmission cable (200) forming the main line carrying the laser beams within the fiber laser module (100), o Combiner output fiber (22) connected to the output of the combiner (20), 0 High reflective FBG (23) grids are embroidered and FBG structure Active fiber doped with 0 Yitterbium element (25), o Input and output fibers (27) of the CPS (26) structure, 0 Low reflective FBG (28) grids are embedded into it and the FBG structure is The back-reflected light (17) is the one that is guided by the sheath of the transmission cable (200) and is the part that moves along the laser line in the same sheath area, again in the sheath region The generated CPS (26) structures are thrown out and removed from the system.

By the CPSs (26) located in certain regions on the main line in the current art. The amount of back reflection is determined by measuring the thrown laser beams. of this app that is, in the fiber laser module (100) of the invention, the transmission of the reflected light (17) the portion of the cable (200) that guides the core structure, the fiber multiplier insulator (11) It is separated from the main line by being transmitted to the fiber cable (14) by the The mentioned fiber cable (14) is preferably coreless fiber because it is more optically favorable. However Core fiber can also be used. performed at the end of the fiber cable (14) After the applied miscellaneous, it is returned with the measurement module (15) containing photo diodes. The amount of reflection is measured efficiently.

The measurement module 15 may include the following structures and features; The end of the fiber cable (14) is cut at an ideal angle and the measurement module (15) is positioned in the package structure so that its tip is in the air. Pain Depending on the given direction, the orientation of the rays is provided and these rays are Photodiodes positioned to detect the amount of reflected light is measuring. Depending on this application, the fiber cable is angled due to the surface. The transition of the back-reflected heat (17) carried in (14) from the fiber to the air medium Due to the density difference during the process, it is prevented to reflect back again and the reflected beam (17) can be reduced to the photo diodes at the maximum level.

Unlike the above-mentioned embodiment, the measuring module (15) is The fiber cable (14) is placed in a semi-section metal cylinder of certain length and placed on it. After applying a polymer or polymer mixture with high temperature resistance, this Photograph positioned to detect the heat that will occur on the structure may contain diodes.

Another method is optical fiber called ball-lens to the end of the fiber cable (14). The structures are formed by heat treatments and the end part of the fiber is sphericalized. Thus, the fiber The back-reflected light (17) moving in it is scattered from the flat surface to the air environment. (expanding) photo diodes coming out linearly thanks to the spherical structure can be dropped on it. In this way, the amount of reflected light can be measured.

The spherical structure formed at the end, as on the fiber surface cut with an angle, By preventing possible back reflections caused by the density difference, the rays are maximized. It ensures that the rate is taken out.

Within the scope of the invention, the reflected rays (17) go to the laser diode modules (18). The fiber laser module (100) and thus the entire system are likely protected from damage. On the other hand, the reflected light (17) leaves the main line. transmit the red laser beam (131) to the fiber laser cutting machine (400) over the main line. can be sent.

During the cutting of the sheet material (33) the reflected heat (17) is transferred to the transmission line (200). while the guides to the sheath area are thrown over the CPSs (26), The guided back-reflected beam (17) is the same diameter and toward the laser diode modules (18) It proceeds through fiber components and active fiber (25).

The back-reflected light (17) traveling towards the laser diode modules (18) is from the main line. combiner to allow it to be separated and transported on a separate line. The back-reflected light (17) traveling through the core structure (222) of the output fiber (22) The difference in diameter at the junction (30) of the output fiber (22) and the splicer input fiber (21) The fiber multiplying insulator is attached to the sheath of the input fiber (12) rather than its core (122). (121) is guided. Here, the fiber carrying the red laser beam (131) in the center core/sheath diameter, initially 10/125, for the multiplier insulator input fiber (12) (122/121), thermal effect with other fibers around this structure at a certain distance It is combined under and thinned to a smaller diameter. On the other hand, do this Considering that, heating and splicing thinning of the splicer input fiber (21) is taken into account. a 20 µm core (222) for the reflected ray (17) even when we do not receive it. there is a transition from a diameter of 10 µm to a core (122) diameter. fiber from here back-reflected guiding the core region (122) of the multiplier insulator input fiber (12). negligible in comparison to the back-reflected heat (17) guided by the sheath region (121). appears to be at an acceptable level. Input fiber (12) of fiber multiplier insulator The back-reflected light (17) advancing within the sheath region (121) is also a testament to the structure allowed. standard practice in the present art, since it is directed mainly at the fiber cable (14). On the contrary, it provides a high level of protection. Due to the differences in the refractive index of the core and sheath structures, the laser propagating inside It shows different resistances to the heat. Therefore, the fiber multiplier isolator input the reflected light (17) guided by the sheath region (121) of the fiber (12) from the main line. the crack index difference between the core (122) and the sheath (121) to separate It is preferred as seedless in order to prevent possible loss and internal reflections. The fiber cable (14), which is the fiber multiplier, is heated to the insulator input fiber (12) at a certain distance. fiber multiplying insulator (11) is formed by boiling.

Laser beam (17), which is reflected back and moves in the core region of the transmission line (200), the highly reflective FBG (23) located on the main line as it moves on the main line, and In low reflectance FBG (28) regions, the reflectivity of these elements it is directed towards the exit direction again. Thus, the total back reflection is large. part of it is directed to the exit direction again. However, laser diode modules (18) filtered straight (not reflected by high reflective FBG(23)) The strength of the rays is in the bright material (33) parts of the power of the reflected light (17). It can be up to 100% of the total power, especially in piercing (piercing) processes. It is a size that must be taken into account when considering it. Meet Within the scope of the scope, transfer of the reflected light (17) to a different line by leaving the main line. Thanks to this, the possibility of damaging the laser diode modules (18) is eliminated.

The fiber multiplying insulator (11) mentioned within the scope of the invention is used in fiber laser modules (100). It can also be used instead of used CPS (18) components. In this structure, from left to right A system that comes with a single cable and is divided into two lines with a fiber cable (14) over the main line. As the laser beam travels through the core structure of the mainline fiber, the sheath laser beams remaining in the region of the fiber cable (14) are divided by the fiber cable (14) It will be possible to block from the end part. It will even be placed in the blocking area. While the fiber laser system is working with the sensors, the laser diode in real time pumping from the modules (18) that remains unabsorbed by the active fiber (25) power and the rays that filter into the sheath originating from the junction points (30) The total power can also be measured.

Claims (1)

REQUESTS 1. It is a fiber laser module (100) that is connected to a laser cutting machine (400), which performs the cutting of sheet materials (33) with laser beam, via a fiber transmission cable (200) and enables the laser beams to be carried to the laser cutting machine (400), and its feature is as follows: in order to ensure that the heat (17) reflected back on the cut sheet material (33) surface can be measured and possible damages that may occur due to these back reflections are prevented; Laser diode modules (18) that radiate in the near infrared (NIR) range, Laser diode module output fibers (19) connected to the outputs of the said laser diode modules (18), The laser diode module output fibers (19), which are combined with the said laser diode module output fibers (19) and consist of laser diode modules ( 18) Combining input fibers (21 ) that allow the emitted rays to be carried to the next component, Red laser diode (13) emitting the red laser beam (131), A fiber connected to the said red laser diode (13) output and carrying the red laser beam (131) The multiplier insulator input fiber (12) collects the rays coming from the laser diode (131), which is connected to the laser diode modules (18) and the center input, and transmits the rays to the main line and reflects back from the main line (17). a combiner (20) that guides the fiber (12) to the sheath (121), a fiber multiplier insulator input fiber (12) is connected, transmits the red laser beam (131) to the main line and is connected. a fiber multiplier insulator (11) that ensures the separation of the reflected light (17) from the main line through the other fiber optic cable, A fiber cable (14) connected to the fiber multiplier isolate (11), which performs the function of separating the said back-reflected beam (17) from the main line. ) contains a 'measurement module (15) that enables to measure the amount of the reflected light (17) that is reflected back from the main line through the fiber cable (14) with the photo diode(s) inside and the methods applied to the end of the fiber cable (14). . It is a fiber laser module (100) in accordance with claim 1, and its feature is that it contains CPS (26), which enables to remove the rays remaining within the sheath area on the main line. . It is a fiber laser module (100) according to claim 1, and its feature is to prevent cavity formation in fiber laser systems and reflectivity ratios of the part of the reflected beam (17) carried on the core line in the same diameter as the core region (222) of the combiner output fiber (22) on the main line. It contains high-reflective FBG (23) and low-reflective FBG (28), which ensures that it is directed towards the exit direction again. . It is a fiber laser module (100) in accordance with claim 1. Its feature is to be combined with the transmission cable (200), it is connected to the combiner (20) output, forming the main line carrying the laser beams within the fiber laser module (100) from the combiner (20) output. splicer output fiber (22), 0 Fiber in which highly reflective FBG (23) grids are processed and FBG structure is formed, (24) 0 Input and output fibers of CPS (26) structure, which differs from other fibers in that it is doped with Yitterbium element (27) , 0 It contains fiber (29) into which low reflective FBG (28) grids are processed and FBG structure is formed. . It is a fiber laser module (100) according to claim 1, characterized in that said fiber cable (14) is a coreless fiber. . A fiber laser module (100) according to claim 1, characterized in that the back-reflected light (17) is guided to the sheath (121) rather than the core (122) of the fiber multiplier insulator input fiber (12) with the combiner output fiber (22). fiber (21) has a diameter difference at the junction points (30). . It is a fiber laser module (100) according to claim 5, characterized in that (12) the back reflected light (17) guided to the sheath region (121) of the fiber multiplier insulator input fiber (12) can be separated from the main line and transmitted to the fiber cable (14). The coreless fiber cable (14) is heat welded at a certain distance to the fiber multiplier insulator input fiber (12) in order to prevent possible losses caused by the refractive index difference between (122) and sheath (122).