JP6210532B2 - Laser equipment - Google Patents

Description

  The present invention relates to a laser apparatus.

  In recent years, various high-power laser devices have been put into practical use. In particular, as a high-power laser device, an optical fiber laser using an optical fiber in which a rare earth element is added to a core portion as an amplification medium is attracting attention and is used for metal processing or the like. In such a high-power laser device, each component constituting the laser device is irradiated with light having a very strong light intensity, so that each component is likely to fail. If any component of the laser device fails, the role of the failed component causes a problem such that the laser device cannot be used or an output laser beam having an unintended light intensity is output. Therefore, there is a demand for a highly reliable laser device that does not output an output laser beam having an unintended light intensity even in a high output operation state.

  In recent years, lasers have been used for various purposes. For example, in the medical field, lasers are used for applications such as surgery. In such a medical laser device, there is a demand for a highly reliable laser device that does not output an output laser beam having an unintended light intensity. Furthermore, lasers are also used in fields such as aviation and space. In such a field, for example, when a laser device used for an artificial satellite or the like fails, it may be very difficult to repair. Therefore, there is a demand for a highly reliable laser device that can maintain a reliable output state for a long time without failure.

  In order to realize such a highly reliable laser device, the technology that monitors the laser beam output from the laser device and shuts off or weakens the output laser beam when an abnormality is found in the output state. Is disclosed (for example, see Patent Documents 1 and 2).

JP-A-6-302890 JP 2012-76106 A

  As described above, with higher output and more versatility of laser devices, more reliable laser devices are desired.

  The present invention has been made in view of the above, and an object thereof is to provide a highly reliable laser device.

  In order to solve the above-described problems and achieve the object, a laser apparatus according to the present invention includes a laser unit and one or more branching a part of laser light output from the laser unit into a plurality of branched lights The laser device includes a branching unit, a plurality of photodetectors for detecting the light intensity of each branched light, and one or more determination parameters obtained from the light intensity of each branched light detected by the plurality of light detectors. When the determination unit determines whether the output state of the laser device is a normal state or an abnormal state, and the determination unit determines that the output state of the laser device is the normal state, a laser beam is emitted from the laser device. And a control unit that controls not to output laser light from the laser device when the determination unit determines that the output state of the laser device is the abnormal state. To do.

  In the laser device according to the present invention, in the above invention, the determination unit determines whether the determination parameter is a value within a predetermined allowable range, and outputs a first determination result that is the determination result. A first determination unit that determines whether the output state of the laser device is the normal state or the abnormal state based on the first determination result, and outputs the determination result And.

  In the laser device according to the present invention as set forth in the invention described above, the second determination unit is configured to perform normal operation when all the determination parameters are values within the predetermined allowable range in the first determination result. It is determined that the state is abnormal, and when at least one of the determination parameters is a value outside the predetermined allowable range, it is determined that the state is abnormal.

  Further, in the laser device according to the present invention, in the above invention, when the second determination unit has a value within the predetermined allowable range when at least one of the determination parameters is a value in the first determination result, A normal state is determined, and when all of the determination parameters are values outside the predetermined allowable range, the abnormal state is determined.

  The laser device according to the present invention may further include three or more of the photodetectors and the first determination unit, and the first determination unit outputs three or more of the first determination results. The second determination unit determines the normal state when at least two of the determination parameters are values within the predetermined allowable range in the three or more first determination results, and determines the three or more When 0 or one of the determination parameters is a value within the predetermined allowable range, the abnormal state is determined.

  Further, in the laser device according to the present invention, in the above invention, when the first determination unit determines that one or more of the determination parameters are outside the predetermined allowable range, the control unit Using the light intensity detected by the photodetector other than the photodetector that has detected the light intensity for obtaining the determination parameter determined by the first determination unit as being out of an allowable range, the output of the laser device It is characterized by controlling the state.

  The laser apparatus according to the present invention is characterized in that, in the above invention, the first determination unit is provided separately for each of the plurality of photodetectors.

  In the laser device according to the present invention as set forth in the invention described above, one first determination unit out of the first determination units outputs the first determination result and the light intensity, and the one first determination unit. The first determination unit other than the unit outputs only the first determination result.

  In the laser device according to the present invention as set forth in the invention described above, the determination parameter is a light intensity of each branched light detected by the plurality of photodetectors.

  In the laser device according to the present invention, in the above invention, the determination parameter is a value obtained by calculating a laser light intensity output by the laser device from a light intensity of each branched light detected by the plurality of photodetectors. It is characterized by being.

  In the laser device according to the present invention as set forth in the invention described above, the determination parameter is a ratio of light intensities of the branched lights detected by the plurality of photodetectors.

  In the laser device according to the present invention as set forth in the invention described above, the determination parameter is a difference in light intensity of each branched light detected by the plurality of photodetectors.

  Further, in the laser device according to the present invention, in the above invention, a part of the laser beam branched by the branching unit is reflected light returning from the output side of the laser device to the laser unit side. .

  Further, in the laser device according to the present invention, in the above invention, the control unit causes the laser unit to output laser light when the determination unit determines that the output state of the laser device is the normal state. And when the determination unit determines that the output state of the laser device is the abnormal state, control is performed such that laser light is not output from the laser unit.

  In the laser device according to the present invention, in the above invention, the laser unit includes an excitation light source and an amplification optical fiber, and the control unit includes the determination unit. When it is determined that the output state of the apparatus is the normal state, control is performed so that a drive current is applied to the excitation light source, and when the determination unit determines that the output state of the laser apparatus is the abnormal state, the excitation light source It is characterized by controlling so that no drive current is applied.

  In the laser device according to the present invention, in the above invention, when the determination unit determines that the output state of the laser device is the normal state, the laser beam output from the laser unit is allowed to pass therethrough. When the output state is determined to be the abnormal state, a light blocking unit that blocks the laser beam output from the laser unit is provided.

  In the laser device according to the present invention, in the above invention, the determination result determined by the determination unit, the light intensity detected by the photodetector, the current value input from the photodetector to the determination unit, and the determination A display unit that displays at least one of a current value input from the unit to the control unit, the determination parameter, and an output state of the laser device.

  According to the present invention, a highly reliable laser device can be realized.

FIG. 1 is a schematic configuration diagram of a laser apparatus according to Embodiment 1 of the present invention. FIG. 2 is a schematic configuration diagram of a laser unit of the laser apparatus shown in FIG. FIG. 3 is a schematic configuration diagram of a laser unit of the laser device according to the first modification of the present invention. FIG. 4 is a schematic configuration diagram of a laser apparatus according to Embodiment 2 of the present invention. FIG. 5 is a schematic configuration diagram of a laser apparatus according to Embodiment 3 of the present invention. FIG. 6 is a schematic configuration diagram of a laser apparatus according to Embodiment 4 of the present invention.

  Embodiments of a laser apparatus according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same or corresponding elements are appropriately denoted by the same reference numerals. It should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, and the like may differ from the actual situation. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included.

(Embodiment 1)
First, the laser apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic configuration diagram of a laser apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the laser device 10 according to the first embodiment is the same as the laser unit 11, the branching unit 12, the photodetector 13, the determination unit 14, the branching unit 15, and the light. A detector 16 and a control unit 17 are provided.

The laser unit 11 may be any type of device having a function of emitting light when an electric current is applied. For example, the laser unit 11 may be an optical fiber laser including an excitation light source and an amplification optical fiber. FIG. 2 is a schematic configuration diagram of a laser unit of the laser apparatus shown in FIG. As shown in FIG. 2, the optical laser unit 11 is driven current E17 is input from the control unit 17, a plurality of excitation light sources 101 that oscillates excitation light, a plurality of pumping light outputted from the plurality of excitation light sources 101 TFB (Tapered Fiber Bundle) 102, FBG (Fiber Bragg Grating) 103a formed double clad optical fiber 103, and a rare earth element that is a double clad optical fiber with a rare earth element added to the core as an amplification optical fiber The optical fiber 104 includes a doped optical fiber 104, a double clad optical fiber 105 formed with an FBG 105a, and a single mode optical fiber 106. The FBGs 103a and 105a constitute an optical resonator. The double clad optical fiber 105 and the single mode optical fiber 106 are fusion-connected by a fusion-bonding portion 107. One end of the single mode optical fiber 106 is connected to the branching section 12 and outputs a laser beam L11.

  The optical laser unit 11 has a so-called double clad excitation structure. Then, for example, by supplying excitation light having a wavelength of 915 nm to the rare earth-doped optical fiber 104 in which ytterbium (Yb) is added to the core as a rare earth element, for example, a 1.1 μm wavelength having a light intensity of several W to several hundred W The band laser beam L11 can be output to the branching section 12.

  The branching unit 12 transmits the laser beam L11 output from the laser unit 11 as a laser beam L12a that is an output laser beam. At this time, a part of the laser beam L11 (for example, −60 dB to −20 dB) is branched as a laser beam L12b that is a branched beam for detecting the light intensity. The branching unit 12 is realized using an optical coupler, a beam splitter, a beam sampler, or the like. The branching unit 15 may have the same configuration as that of the branching unit 12 and transmits the input laser beam L12a as the laser beam L15a that is an output laser beam, and a part of the laser beam L12a is branched. The light is branched as laser light L15b which is a branched light for detecting light intensity.

  The photodetector 13 receives the laser light L12b, measures the light intensity of the laser light L12b, converts the light intensity into an electric signal E13, and outputs the electric signal E13. Such O / E conversion is realized, for example, by outputting an electric signal having a current proportional to the measured light intensity. The photodetector 13 is realized by using a Pin-PD (Photo Diode), an APD (Avalanche Photo Diode), or the like. The light detector 16 may have the same configuration as the light detector 13, receives the laser light L15b, measures the light intensity of the laser light L15b, converts the light intensity into an electric signal E16, and outputs the electric signal E16.

  Originally, in order to reduce the size of the laser device, it is preferable that the branch portion is composed only of a coupler. However, the maximum branching ratio of the coupler is about −20 dB. For example, if the light intensity of the laser beam output from the laser unit is 500 W and light of −20 dB (1%) is branched in the branching unit, the light intensity of the branched laser beam is 5 W. If a laser beam having such a strong light intensity is directly input to the photodetector, the photodetector will fail, and a mechanism for reducing the light intensity input to the photodetector is required. If the structure of the laser device is complicated by this, a failure is likely to occur, which causes a decrease in reliability, which is not preferable.

On the other hand, when a beam splitter or a beam sampler is used as the branching section, the branching ratio can be set to about −60 dB at the maximum. At this time, for example, if the light intensity of the laser beam output from the laser section is 500 W The light intensity input to the photodetector can be sufficiently reduced to 5 × 10 ⁻⁴ W (0.5 mW). Therefore, a mechanism for reducing the light intensity is not required, and the reliability is not lowered due to the complexity of the laser device. However, an apparatus using a lens such as a beam splitter or a beam sampler requires fine adjustment during installation, and further has a problem that it is vulnerable to vibration. Therefore, by providing a plurality of photodetectors, it is possible to achieve redundancy of the photodetectors and to reduce the light intensity input per photodetector, and to obtain a highly reliable laser device. It becomes possible.

  The determination unit 14 determines that the output state of the laser device is in a normal state based on a determination parameter obtained from the electric signal E13 proportional to the light intensity of the laser light L12b and the electric signal E16 proportional to the light intensity of the laser light L15b. It is determined whether there is an abnormal state. And the determination result is output as an electric signal E14. For example, the determination unit 14 applies an electric signal E14 having a predetermined current to the control unit 17 when it is determined to be in a normal state, and does not apply the electric signal E14 to the control unit 17 when it is determined as an abnormal state. It is realized by.

The determination unit determines whether the determination parameter is a value within a predetermined allowable range, and outputs a first determination result that is the determination result, and the first determination result, the output state of the laser device 10 is either a normal state or an abnormal state, it is determined, a second determination unit that to output the determination result may be separately provided in, but the determination unit 14 The first determination unit and the second determination unit are integrated.

  The control unit 17 performs control so that the laser signal is output from the laser device when the electrical signal E14 that is the determination result of the determination unit 14 is in a normal state, and does not output the laser beam from the laser device in an abnormal state. To control. For example, the control unit 17 controls the drive current E17 to be applied to the excitation light source 101 of the laser unit 11 in the normal state, and the drive current E17 to the excitation light source 101 of the laser unit 11 in the abnormal state. It is realized by controlling not to apply.

Next, the operation of the laser apparatus 10 according to the first embodiment will be described. First, as shown in FIG. 2, when the control unit 17 applies a drive current E17 to the excitation light source 101 of the laser unit 11, each excitation light source 101 oscillates excitation light. The excitation light is multiplexed by the TFB 102 and input to the double clad optical fiber 103. Further, the excitation light passes through the FBG 103a of the double clad optical fiber 103 and is input to an optical resonator formed by the FBG 103a, the rare earth-doped optical fiber 104, and the FBG 105a. In this resonator, for example, laser light having light intensity A _L11 is output by the excitation light. The laser light is input to the single mode optical fiber 106 through the fusion splicing portion 107. The laser unit 11 outputs a laser beam L11 that is a final output laser beam. In the following description, the light intensity of each laser beam LXX in each drawing will be expressed as light intensity _ALXX .

As shown in FIG. 1, the laser beam L11 output from the laser unit 11 is input to the branching unit 12 and branched into a laser beam L12a that passes through the branching unit 12 and a laser beam L12b that branches into the branching unit 12. The At this time, the light intensity _{A L12a} of the laser beam L12a when the branching ratio and _{B 1} represents _{a (1-B 1) A L11} , the light intensity _{A L12b} of the laser light L12b _is expressed as B _{1 A L11.} Similarly, the branching unit 15 branches the laser beam L12a into a laser beam L15a and a laser beam L15b. At this time, the light intensity _{A L15a} of the laser beam L15a when the branching ratio and _{B 2 includes} a _{(1-B 1) (1} -B 2) A L11, the light intensity _{A L15b} of the laser light L15b is (1-B ₁ ) It can be expressed as B ₂ A _L11 . Here, for simplification of explanation, it is assumed that absorption and scattering at each branch portion are so small that they can be ignored.

The laser beam L12b is input to the photodetector 13, and the laser beam L15b is input to the photodetector 16. The photodetector 13 and the photodetector 16 receive the laser beam L12b and the laser beam L15b, respectively, and output, for example, an electrical signal E13 and an electrical signal E16 that are currents proportional to the light intensity. The current of the electrical signal E13 is I ₁ , and the current of the electrical signal E16 is I ₂ . The determination unit 14 calculates a determination parameter from the current I ₁ and the current I _2, and determines whether the output state of the laser device 10 is a normal state or an abnormal state from the determination parameter. To do. Then, the determination result is output as an electric signal E14. Based on the determination result, the control unit 17 controls to apply the drive current E17 to the excitation light source 101 of the laser unit 11 and output the laser device 10 in the normal state, and to output the laser device 10 in the abnormal state. The output of the laser apparatus 10 is stopped without applying the drive current E17 to 101.

Next, the determination method of the determination unit 14 will be specifically described.
(Judgment example 1)
As a determination example 1, a case where the determination parameter is the light intensity of each branched light detected by a plurality of photodetectors will be described. First, since the current I ₁ applied to the determination unit 14 from the photodetector 13 should be proportional to the light intensity A _L12b of the laser beam L12a, if the proportionality constant is c, I ₁ = cA _L12b . . At this time, if the first determination parameter P ₁₁ is the light intensity A _L12b , then P ₁₁ = A _L12b = I ₁ / c. On the other hand, the light intensity A _L12b is A _L12b = B ₁ A _{L11 based} on the light intensity A _L11 and the branching rate B ₁ . Here, the light intensity A _L11 are known from the output characteristic and the driving current E17 Metropolitan laser unit 11, the branch ratio B ₁ represents a known constant determined during design of the laser device 10.

At this time, if the output state of the laser device 10 is normal, P ₁₁ = I ₁ / c = B ₁ A _{L 11} holds. However, for example, when the optical detector 13 fails, drop the current I _1, or increases, the relationship of this equation will not hold. Therefore, for example, regarding such a change in the determination parameter P ₁₁ , that is, the light intensity A _L12b , a decrease in a% and an increase in b% from the normal state are allowed, and when set as a predetermined allowable range, determining parameter P ₁₁ and the current I ₁ becomes to be allowed within a predetermined tolerance range below.

Similarly, if the second determination parameter P ₁₂ is the light intensity A _L15b , then P ₁₂ = A _L15b = I ₂ / c. Although the proportionality coefficient c may be different for each determination parameter, it is assumed here to be the same for simplification of description. On the other hand, the light intensity A _L15b is A _L15b = (1−B ₁ ) B ₂ A _{L11 based} on the light intensity A _L11 , the branching rate B _1, and the branching rate B ₂ .

At this time, if the output state of the laser device 10 is in a normal state, the relationship P ₁₂ = I ₂ / c = (1−B ₁ ) B ₂ A _L11 is established. However, for example, when the optical detector 16 fails, drop the current I _2, or increases, this relationship does not hold. Therefore, for example, _regarding the change in the determination parameter P ₁₂ , that is, the change in the light intensity A _L15b , a decrease in a% and an increase in b% from the normal state are allowed. P ₁₂ and the current I ₂ becomes to be allowed within a predetermined tolerance range below.

Accordingly, the determination unit, first using equation (1) and (2), determining whether each of the determination parameter P ₁₁ and determining parameter P ₁₂ is the value of the predetermined allowable range a predetermined To do. As a result, the determination parameter is outside the predetermined allowable range, that is, between the branch unit 12 and the determination unit 14, or between the branch unit 15 and the determination unit 14, such as a photodetector. Indicates that a component has failed.

The determination unit, when all the determination parameter P ₁₁ and determining parameter P ₁₂ is a value within a predetermined allowable range represented out with Formula (1) and (2), the normal state determined that, at least one determination parameter P ₁₁ or determination parameter P _12, when a predetermined acceptable range of values represented out with formula (1) and (2) is the abnormal state May be determined. At this time, the laser device 10 determines the output state of the laser device 10 with the two photodetectors until one of the photodetector 13 and the photodetector 16 breaks down. This is a highly reliable laser device that can maintain reliability even if the device breaks down. Further, since the laser device 10 stops the output in a state where either the photodetector 13 or the photodetector 16 is functioning normally, an output laser beam having an unintended light intensity may be output. There is no highly reliable laser device.

The determination unit, when at least one determination parameter P ₁₁ or determination parameter P _12, a value within a predetermined tolerance range expressed out with Formula (1) and (2), the normal state and judgment, all determination parameter P ₁₁ and determining parameter P ₁₂ is, in the case of a predetermined allowable range of values represented out with formula (1) and (2), if it is an abnormal state The structure which determines may be sufficient. At this time, the laser device 10 determines the output state of the laser device 10 with the two photodetectors until one of the photodetector 13 and the photodetector 16 breaks down. This is a highly reliable laser device that can maintain reliability even if the device breaks down. In addition, since the laser device 10 can be used until both the photodetector 13 and the photodetector 16 fail, the laser device 10 can maintain a reliable output state for a long time without failure. It is a highly reliable laser device that can be maintained.

  In this way, the characteristics of the laser device can be changed by changing the conditions for determining whether each determination parameter is in a normal state or an abnormal state with respect to each determination parameter. In other words, when using in a field such as aviation and space where a highly reliable laser device that can maintain a reliable output state for a long time without a failure is required, all the determination parameters are predetermined. If the value is outside the allowable range, it may be determined that the state is abnormal. At this time, the laser device can be used until all of the plurality of photodetectors fail. On the other hand, when used in fields such as metal processing and medicine where a reliable laser device that does not output an unintended output laser beam is required, any two or more determination parameters are predetermined. If it is a value within the permissible range, any configuration that determines that it is in a normal state may be used. At this time, since the output state of the laser device 10 is monitored by two or more normal photodetectors, there is very little possibility that output laser light having an unintended light intensity is output.

  As described above, in the laser apparatus according to the first embodiment, the monitoring mechanism that monitors the output state of the laser apparatus 10 by a plurality of photodetectors has a redundant configuration. This realizes a highly reliable laser device that can perform normal operation even if one of the photodetectors fails.

(Judgment example 2)
As a determination example 2, a case will be described in which the determination parameter is a value obtained by calculating the laser light intensity output from the laser device 10 from the light intensity of each branched light detected by a plurality of photodetectors. First, since the first determination parameter P ₂₁ and the second determination parameter P ₂₂ are the light intensity A _L15a of the laser beam L15a output from the laser device 10, P ₂₁ = P ₂₂ = A _L15a . is there. Similarly to the case of the determination example 1, when expressed by the light intensity A _L11 , the branching rate B ₁ and the branching rate B ₂ , P ₂₁ = P ₂₂ = A _L15a = (1-B ₁ ) (1-B ₂ ) A _L11 .

Here, if the output state of the laser apparatus 10 is normal, A _L11 can be expressed as A _L11 = I ₁ / cB ₁ by the current I ₁ . At this time, for example, _regarding the change of the determination parameter P ₂₁ , that is, the light intensity A _L15a , a decrease in a% and an increase in b% from the normal state are allowed. The parameter P ₂₁ and the current I ₁ are allowed within the following predetermined allowable range.

Similarly, if the output state of the laser device 10 is normal, A _L11 can be expressed as A _L11 = I ₂ / (c (1−B ₁ ) B ₂ ) by the current I ₂ . At this time, for example, _regarding the change in the determination parameter P ₂₂ , that is, the light intensity A _L15a , a decrease in a% and an increase in b% from the normal state are allowed. parameter P ₂₂ and the current I ₁ becomes to be allowed within a predetermined tolerance range below.

Here, the determination unit is in a normal state when all of the determination parameter P ₂₁ and the determination parameter P ₂₂ are values within a predetermined allowable range expressed by the expressions (3) and (4). And when at least one of the determination parameter P ₂₁ and the determination parameter P ₂₂ is a value outside the predetermined allowable range expressed by the equations (3) and (4), it is in an abnormal state. May be determined. At this time, the output state of the laser device 10 is determined by two photodetectors until one of the photodetectors 13 and 16 fails, so even if either one of the photodetectors fails. It is a highly reliable laser device that can maintain reliability. Furthermore, since the output is stopped in a state in which one of the photodetector 13 and the photodetector 16 is functioning normally, the output laser beam having an unintended light intensity is not output and is highly reliable. It is a laser device.

The determination unit, when at least one determination parameter P ₂₁ and determination parameter P _22, a value within a predetermined tolerance range expressed out with Formula (3) and (4), the normal state If all of the determination parameter P ₂₁ and the determination parameter P ₂₂ are values outside the predetermined allowable range expressed by the equations (3) and (4), the abnormal state is determined. The structure which determines may be sufficient. At this time, the laser device 10 determines the output state of the laser device 10 with the two photodetectors until one of the photodetector 13 and the photodetector 16 breaks down. This is a highly reliable laser device that can maintain reliability even if the device breaks down. In addition, since the laser device 10 can be used until both the photodetector 13 and the photodetector 16 fail, the laser device 10 can maintain a reliable output state for a long time without failure. It is a highly reliable laser device that can be maintained.

(Judgment example 3)
As a determination example 3, a case where the determination parameter is a ratio of the light intensity of each branched light detected by a plurality of photodetectors will be described. First, the determination parameter P ₃ is a ratio of the light intensity A _L12b and the light intensity A _L15b detected by the light detector 13 and the light detector 16, and _therefore P ₃ = A _L12b / A _L15b . Furthermore, A _L12b = I ₁ / c and A _L15b = I ₂ / c, that is, P ₃ = I ₁ / I ₂ . Similarly to the case of the determination example 1, when expressed by the light intensity A _L11 , the branching rate B _1, and the branching rate B ₂ , P ₃ = I ₁ / I ₂ = B ₁ / ((1-B ₁ ) B ₂ ). As in the case of the determination example 1, the determination parameter P ₃ is allowed to have a reduction of a% and an increase of b% from the normal state. When set as a predetermined allowable range, the determination parameter P ₃ is It is allowed within the predetermined allowable range.

At this time, the determination unit 14, a predetermined determination parameter P ₃ and normal state when within a predetermined tolerance of the formula (5), the determination parameter P ₃ is expressed by formula (5) If it is within the allowable range of At this time, the laser device 10 determines the output state of the laser device 10 with the two photodetectors until one of the photodetector 13 and the photodetector 16 breaks down. This is a highly reliable laser device that can maintain reliability even if the device breaks down. Further, since the laser device 10 stops the output in a state where either the photodetector 13 or the photodetector 16 is functioning normally, an output laser beam having an unintended light intensity may be output. There is no highly reliable laser device.

(Judgment example 4)
As a determination example 4, a case where the determination parameter is a difference in the light intensity of each branched light detected by a plurality of photodetectors will be described. First, the determination parameter P ₄ is the difference between the light intensity A _L12b and the light intensity A _L15b detected by the photodetector 13 and the photodetector 16, and _therefore P ₄ = A _L12b −A _L15b . Furthermore, since A _L12b = I ₁ / c and A _L15b = I ₂ / c, that is, P ₄ = (I ₁ −I ₂ ) / c. When this is expressed by the light intensity A _L11 , the branching rate B ₁ and the branching rate B ₂ as in the case of the determination example 1, P ₄ = (I ₁ −I ₂ ) / c = ((B ₁ −1 + B ₁ the _{B 2) a L11) / c} . As in the case of the determination example 1, the determination parameter P ₄ is allowed to have a decrease of a% and an increase of b% from a normal state. When set as a predetermined allowable range, the determination parameter P ₄ is It is allowed within the predetermined allowable range.

At this time, the determination unit 14 sets a normal state when the determination parameter P ₄ is within a predetermined allowable range represented by the equation (6), and the determination parameter P ₄ is a predetermined state represented by the equation (6). If it is within the allowable range of At this time, the laser device 10 determines the output state of the laser device 10 with the two photodetectors until one of the photodetector 13 and the photodetector 16 breaks down. This is a highly reliable laser device that can maintain reliability even if the device breaks down. Further, since the laser device 10 stops the output in a state where either the photodetector 13 or the photodetector 16 is functioning normally, an output laser beam having an unintended light intensity may be output. There is no highly reliable laser device.

  As described above, the laser apparatus 10 according to the first embodiment is a highly reliable laser apparatus.

(Modification 1)
Next, a laser device according to Modification 1 of the present invention will be described. Since the laser device according to Modification 1 has a configuration in which only the laser unit 11 of the laser device 10 according to Embodiment 1 is replaced, the configuration of the laser unit 11 will be described below. FIG. 3 is a schematic configuration diagram of a laser unit of the laser device according to the first modification of the present invention. As shown in FIG. 3, the optical laser unit 11 includes a light source 201 that oscillates seed light that is amplified in an amplification optical fiber, and a plurality of pumps that receive drive current E17 from the control unit 17 and oscillate pump light. A light source 202, a TFB (Tapered Fiber Bundle) 203 that combines a plurality of pump lights output from a plurality of pump light sources 101, and a rare earth that is a double clad optical fiber in which a rare earth element is added to the core as an amplification optical fiber An additive optical fiber 204 and a single mode optical fiber 206 are included. The light source 201 may receive the drive current E17a from the control unit 17, or may be configured to be separately applied with a drive current from a power source for the light source 201. An optical filter 205 is formed in the vicinity of the output end of the rare earth-doped optical fiber 204, and the excitation light is removed from the output light. However, the optical filter 205 is not formed, and the remaining excitation light that is not used for optical amplification is also output. It may be a configuration. The rare earth-doped optical fiber 204 and the single mode optical fiber 206 are fusion spliced by a fusion splicing part 207. One end of the single mode optical fiber 206 is connected to the branching section 12 and outputs laser light L11.

The optical laser unit 11 has a so-called double clad excitation structure. Then, for example, by supplying excitation light having a wavelength of 915 nm to a rare earth-doped optical fiber 204 in which ytterbium (Yb) is added as a rare earth element to the core, seed light in a 1.1 μm wavelength band input from the light source 201, for example. Can be amplified to a 1.1 μm wavelength laser beam L11 having a light intensity of several watts to several tens of watts and output to the branching section 12. Thus, although the laser apparatus of the modification 1 is a structure from which the laser part 11 differs from the laser part of Embodiment 1, other structures may be the same. Therefore, the laser device according to the modified example 1 is a highly reliable laser device because it performs the same operation as the laser device of the first embodiment.

(Embodiment 2)
Next, a laser apparatus according to Embodiment 2 of the present invention will be described. FIG. 4 is a schematic configuration diagram of a laser apparatus according to Embodiment 2 of the present invention. As shown in FIG. 4, in the laser device 20 according to the second embodiment, the branching section 22 and the branching section 25 are made of optical couplers, and all of the laser beams L21, L22a, L22b, L25a, and L25b pass through the optical fiber. It is a configuration that propagates. Other configurations may be the same as those in the first embodiment, and the laser unit 11, the laser unit 21, the photodetector 13, the photodetector 23, the photodetector 16, the photodetector 26, and the determination, respectively. The unit 14, the determination unit 24, the control unit 17, and the control unit 27 correspond to each other.

  In the laser device 20, first, the laser beam L 21 output from the laser unit 21 is branched into a laser beam L 22 a and a laser beam L 22 b at the branching unit 22, and the laser beam L 22 b is input to the photodetector 23. Further, the laser beam L22a is branched into the laser beam L25a and the laser beam L25b at the branching unit 25, and the laser beam L25b is input to the photodetector 26. The photodetector 23 outputs an electric signal E23 having a current proportional to the light intensity of the laser beam L22b. The photodetector 26 outputs an electric signal E26 having a current proportional to the light intensity of the laser beam L25b. As in the first embodiment, the determination unit 24 has a configuration in which the first determination unit and the second determination unit are integrated. For example, the electric signal E23 and the electric signal are determined by the determination methods of the determination examples 1 to 4. Based on E26, it is determined whether the output state of the laser device 20 is a normal state or an abnormal state, and the determination result is output as an electric signal E24. The control unit 27 outputs a drive current E27 so that the laser device 20 is output if the electrical signal E24 is in a normal state, and drives so that the laser device 20 is not output if the electrical signal E24 is in an abnormal state. The current E27 is not output. Thus, the laser device 20 according to the second embodiment is a highly reliable laser device because it performs the same operation as the laser device of the first embodiment.

  The branching ratio of the optical coupler is about −20 dB at the maximum, and when the light branched from the branching section is directly input to the photodetector without passing through a filter or the like, the output light intensity of the laser section is about several watts. It should be noted that there is a need to do. Conversely, when the output light intensity of the laser unit is high, the light intensity of the light branched by the branching part is input to the photodetector after being weakened by a filter or the like, or the light branched by the branching part is reflected once It is necessary to configure such that the plate is irradiated and a part of the scattered light is detected by a photodetector. However, such a configuration is not preferable because it hinders downsizing of the laser device.

(Embodiment 3)
Next, a laser apparatus according to Embodiment 3 of the present invention will be described. FIG. 5 is a schematic configuration diagram of a laser apparatus according to Embodiment 3 of the present invention. As shown in FIG. 5, in the laser device 30 according to the third embodiment, the branching section 32 and the branching section 33 are made of optical couplers, and the branching section 32 and the branching section 33 are part of the branched laser light. Is a laser beam L31a of reflected light returning from the output side of the laser device 30 to the laser unit side. Other configurations may be the same as those in the second embodiment.

  In the laser device 30, first, the laser light L 31 output from the laser unit 31 passes through the branching unit 32 and the branching unit 33 and is output from the laser device 30. The output laser beam L31 is irradiated, for example, on an object to be processed, and a part of the laser beam L31 is reflected on the surface of the object. Then, a part of the reflected light is input from the output end of the laser device 30 as laser light L31a which is return light that returns to the laser device 30. The laser beam L31a is branched into the laser beam L33a and the laser beam L33b by the branching unit 33, and the laser beam is input to the photodetector 34. Further, the laser beam L33a is branched at the branching section 32 as the laser beam L32. In the branching section 32, there may be a component that transmits the laser light L33a in the direction of the laser section 31, but the transmitted light may make the operation of the laser section 31 unstable. It is not preferable that there is. The laser beam L32 is input to the photodetector 36.

  The photodetector 34 outputs an electric signal E34 having a current proportional to the light intensity of the laser beam L33b. The photodetector 36 outputs an electric signal E36 having a current proportional to the light intensity of the laser beam L32. The determination unit 36 determines whether the output state of the laser device 30 is a normal state or an abnormal state based on the electric signal E34 and the electric signal E36, and outputs the determination result as an electric signal E35. As in the first embodiment, the control unit 37 has a configuration in which the first determination unit and the second determination unit are integrated. For example, the electrical signal E35 is in a normal state by the determination methods of determination examples 1 to 4. If so, the drive current E37 is output so that the laser device 30 is output, and if the electrical signal E35 is in an abnormal state, the drive current E37 is not output so that the laser device 30 is not output. As described above, the laser device 30 according to the third embodiment is a highly reliable laser device because it performs the same operation as the laser device according to the first embodiment.

  In Embodiment 3, since the light intensity of the return light is sufficiently weak, a highly reliable laser device can be realized even if the output light intensity of the laser unit is several hundred W, for example.

(Embodiment 4)
Next, a laser apparatus according to Embodiment 4 of the present invention will be described. FIG. 6 is a schematic configuration diagram of a laser apparatus according to Embodiment 4 of the present invention. As shown in FIG. 6, the laser device 40 according to the fourth embodiment has a configuration in which one branch portion 42 includes three branch surfaces 42 a, 42 b, and 42 c. Furthermore, the photodetector has a configuration in which three photodetectors 43, 45, and 46 are disposed. And the determination part 44 consists of 1st determination part 44aa, 44ab, 44ac separately provided for every some photodetector, and the 2nd determination part into which the output of each 1st determination part is input. As described above, the determination unit may include a plurality of devices in which the first determination unit is separately provided, and the first determination unit and the second determination unit may be provided separately. In addition, a display unit 48 and a light blocking unit 49 are connected to the control unit 47.

  In the laser device 40, first, the laser beam L 41 output from the laser unit 41 is branched into the laser beam L 42 aa and the laser beam L 42 ab at the branch surface 42 a of the branch unit 42, and the laser beam L 42 ab is input to the photodetector 43. The Further, the laser beam L42aa is branched into the laser beam L42ba and the laser beam L42bb at the branch surface 42b, and the laser beam L42bb is input to the photodetector 45. The laser beam L42ba is branched into the laser beam L42ca and the laser beam L42cb at the branch surface 42c, and the laser beam L42cb is input to the photodetector 46.

  The photodetector 43 outputs an electric signal E43 having a current proportional to the light intensity of the laser beam L42ab. Then, the first determination unit 44aa to which the electric signal E43 is input determines whether the determination parameter is a value within a predetermined allowable range by the determination method 1 or 2, for example. And 1st determination part 44aa outputs the 1st determination result which is the determination result as electric signal E44aa. Similarly, the photodetector 45 outputs an electric signal E45 having a current proportional to the light intensity of the laser beam L42bb, and the first determination unit 44ab to which the electric signal E45 is input has a determination parameter within a predetermined allowable range. It is determined whether the value is in the range. And the 1st determination part 44ab outputs the 1st determination result which is the determination result as the electrical signal E44ab. Further, the photodetector 46 outputs an electric signal E46 having a current proportional to the light intensity of the laser beam L42cb. The first determination unit 44ac to which the electric signal E46 is input has a determination parameter within a predetermined allowable range. It is determined whether it is the value of. And the 1st determination part 44ac outputs the 1st determination result which is the determination result as the electrical signal E44ac.

  At this time, the electrical signals E43, E45, and E46 are electrical signals having information on the first determination result that is the determination result of each first determination unit. However, the electrical signals E43, E45, and E46 are electrical signals having information on the light intensity of the laser light L49 that is the final output laser light of the laser device 40 calculated from the light intensity of the branched light detected by each photodetector. It is preferable that This is because the information is necessary for the control unit 47 to control the light intensity of the laser light L49, which is the final output laser light of the laser device 40.

  Here, all of the electrical signals E43, E45, E46 may be electrical signals having information on the light intensity of the laser beam L49. Further, any one of the electrical signals E43, E45, E46 may be an electrical signal having information on the light intensity of the laser light L49. At this time, one first determination unit out of the first determination units outputs an electrical signal having the first determination result and the light intensity information of the laser beam L49, and other than the first determination unit. The first determination unit may be configured to output only the first determination result. As a result, the configuration other than the first determination unit that outputs the electrical signal having the light intensity information of the laser beam L49 can be simplified.

  The electrical signals E43, E45, E46 are the first determination result and the light intensity of the laser beam L49 when each first determination unit determines that the determination parameter is a value within a predetermined allowable range. The first determination unit may output only the first determination result when each of the first determination units determines that the determination parameter is outside a predetermined allowable range. . At this time, the control unit 47 does not erroneously recognize the light intensity information of the laser beam L49 due to a failure of each photodetector or the like, and the laser device is highly reliable.

  Thus, the three first determination results are given to the second determination unit 44b from the electric signal E44aa, the electric signal E44ab, and the electric signal E44ac. At this time, the second determination unit 44b is in a state where all the three first determination results are in a normal state, that is, all the three determination parameters obtained by the three photodetectors are values within a predetermined allowable range. In addition, the final determination result may be determined as a normal state. At this time, the laser device 40 determines the output state of the laser device 40 with three photodetectors until any one of the photodetectors 43, 45, and 46 fails, so any one photodetector. This is a highly reliable laser device that can maintain reliability even if a failure occurs. Furthermore, since the laser device 40 stops the output in a state where any two of the photodetectors 43, 45, and 46 are functioning normally, an output laser beam having an unintended light intensity is not output. It is a highly reliable laser device.

  The second determination unit 44b has at least one of the three first determination results in a normal state, that is, at least one of the three determination parameters obtained by the three photodetectors is a value within a predetermined allowable range. In such a case, the final determination result may be determined as a normal state. At this time, the laser device 40 determines the output state of the two light detectors until any two of the light detectors 43, 45, and 46 fail. This is a highly reliable laser device that can maintain reliability even if one photodetector fails. Further, the laser device 40 can use the laser device 10 until all of the photodetectors 43, 45, and 46 have failed, so that an output state in which reliability is maintained for a long time without failure is maintained. This is a highly reliable laser device.

  Furthermore, the second determination unit 44b is in a state where any two of the three first determination results are in a normal state, that is, any two of the three determination parameters obtained by the three photodetectors have a predetermined tolerance. When the value is within the range, the final determination result may be determined as a normal state. At this time, the laser device 40 determines the output state of the laser device 10 with the two photodetectors until any two of the photodetectors 43, 45, and 46 fail. This is a highly reliable laser device that can maintain reliability even if the detector fails. Furthermore, since the laser device 40 stops the output in a state where any one of the photodetectors 43, 45, and 46 is functioning normally, an output laser beam having an unintended light intensity is not output. It is a highly reliable laser device. In addition, since the laser device 10 can be used until any two of the photodetectors 43, 45, and 46 fail, it is possible to maintain a reliable output state for a long time without failure. It is a highly reliable laser device capable of

  Then, the second determination unit 44b outputs the determination result as an electric signal E44b. The controller 47 applies a drive current E47a so that the laser device 40 is output when the input electric signal E44b is in a normal state. If the input electric signal E44b is in an abnormal state, the laser device 40 is The drive current E47a may not be applied so as not to be output. Further, the control unit 47 outputs an electric signal E47b to the display unit 48 and outputs an electric signal E47c to the light blocking unit 49.

  Note that the current value of the drive current E47a is the final output laser light of the laser device 40 calculated from the light intensity of the branched light detected by each photodetector included in the electrical signal E44b input from the determination unit 44. The light intensity of the laser beam L49 is controlled to be a desired light intensity by the information on the light intensity of the laser beam L49. Here, it is assumed that the light intensity information of the three laser beams L49 is input by the three photodetectors. At this time, when the first determination unit determines that one or more of the determination parameters are outside the predetermined allowable range, the control unit 47 determines that the determination parameter is out of the predetermined allowable range by the first determination unit. The output state of the laser device 40 may be controlled using the light intensity detected by a light detector other than the light detector that has detected the light intensity for obtaining the determination parameter. As a result, the control unit 47 does not erroneously recognize the light intensity information of the laser beam L49 due to a failure of the photodetector or the like, and the laser device is highly reliable.

  The display unit 48 displays the determination result determined by the determination unit 44, that is, the final determination result of the second determination unit 44b, and further the first determination results of the three first determination units 44aa, 44ab, and 44ac. . Further, the light intensity of each branched light detected by each light detector, each determination parameter, the output state of the laser device 40, and the like may be displayed. Thereby, it is possible not only to monitor the output state of the laser device 40 but also to confirm which of the three photodetectors is malfunctioning. Therefore, by replacing the failed photodetector with a non-failed photodetector, the output state of the laser device 40 can be managed with two or more normal photodetectors at all times. A highly reliable laser device can be realized.

  When the determination unit 44 determines that the output state of the laser device 40 is normal, the light blocking unit 49 passes the laser light L42ca output from the laser unit 41 as the laser light L49, and the laser light is emitted from the laser device 40. The output state. On the other hand, when the determination unit 44 determines that the output state of the laser device 40 is an abnormal state, the laser beam L42ca output from the laser unit 41 is blocked and the laser device 40 is not outputting the laser beam. As described above, since the laser beam L42ca is directly cut off based on the determination result, the control unit 47 controls the drive current E47a to output the laser unit 41, that is, the output of the laser device 40 more reliably. Can be cut off. Therefore, the laser device 40 is a more reliable laser device that prevents an unintended output laser beam from being output.

  Note that both the control unit 47 and the light blocking unit 49 may be configured to control the output of the laser device 40, or either one may be configured to control the output of the laser device 40. That is, the control unit 47 always applies a constant drive current E47a regardless of the determination result of the determination unit, and when the determination result of the determination unit 44 is in an abnormal state, the light blocking unit 49 causes the laser beam to be The structure which interrupts | blocks L42ca may be sufficient.

  As described above, according to this embodiment, a highly reliable laser device can be provided.

  In the above embodiment, the laser apparatus including two or three photodetectors has been described. However, the present invention provides a redundant monitoring mechanism that monitors the output state of the laser apparatus using a plurality of photodetectors. What is necessary is just to be set as a structure. That is, a plurality of photodetectors may be further provided and a multi-stage redundant configuration may be employed. At this time, needless to say, a more reliable laser device is realized.

Moreover, in the said embodiment, although the determination method of the determination examples 1-4 was demonstrated, the determination method is not restricted to these. The determination parameter may be any value obtained from the light intensity detected by the photodetector, and may be, for example, the current I ₁ itself or the light intensity of the laser unit 11 obtained from the current I ₁ . Furthermore, a ratio or difference between three or more light intensities among the light intensities detected by the three or more photodetectors may be used.

  The laser device may include an isolator, a wavelength filter, and the like. For example, when the laser unit is a semiconductor laser and the wavelength of the output laser light is variable, a wavelength monitoring mechanism and a wavelength control mechanism may be further provided. The output end of the laser device may be an optical fiber, but may include a condensing unit that condenses the target laser beam to be output, or may be connected to another device. A connector that can be used may be provided. Further, except for the third embodiment, an antireflection mechanism may be formed at the output end of the laser device in order to prevent the laser unit from being damaged by the return light.

  In the above-described embodiment, it has been described that the laser device is highly reliable against a failure of the photodetector, but the present invention is not limited to this. For example, it is a highly reliable laser device even when a branching unit, an optical element arranged between the branching unit and the photodetector, or any of the first determination units or the like fails. In other words, even if any one of the plurality of monitor systems from the branching unit to the determination unit is out of order, the operation as a reliable laser device is possible if there is another monitor system. Can be realized.

  Further, the present invention is not limited by the above embodiment. What was comprised combining each component mentioned above suitably is also contained in this invention. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

10, 20, 30, 40 Laser device 11, 21, 31, 41 Laser part 12, 15, 22, 25, 32, 33, 42 Branch part 42a, 42b, 42c Branch surface 13, 16, 23, 26, 34, 36, 43, 45, 46 Photodetector 14, 24, 35, 44 Determination unit 17, 27, 37, 47 Control unit 44aa, 44ab, 44ac First determination unit 44b Second determination unit 48 Display unit 49 Light blocking unit 101 , 202 Excitation light source 102, 203 TFB
103, 105 double clad optical fiber 103a, 105a FBG
104, 204 Rare earth doped optical fiber 106, 206 Single mode optical fiber 107, 207 Fusion splicer 201 Light source 205 Optical filter L11, L12a, L12b, L15a, L15b, L21, L22a, L22b, L25a, L25b, L31, L31a, L32, L33a, L33b, L41, L42aa, L42ab, L42ba, L42bb, L42ca, L42cb, L49 Laser light E13, E14, E16, E23, E24, E26, E27, E34, E35, E36, E43, E45, E46, E44aa , E44ab, E44ac, E44b, E47b, E47c, E48, E49 Electrical signal E17, E17a, E27, E37, E47a Drive current

Claims (16)

A laser unit;
A plurality of branch portions which branches a part of the output laser beam from the laser unit,
A plurality of photodetectors for detecting the light intensity of each branched light branched from the plurality of branch parts ;
Based on one or more determination parameters obtained from the light intensity of each branched light detected by the plurality of photodetectors, it is determined whether the output state of the laser device is in a normal state or an abnormal state. And a determination unit for determining whether or not each of the photodetectors is abnormal ,
When the determination unit determines that the output state of the laser device is the normal state, control is performed to output laser light from the laser device, and the determination unit sets the output state of the laser device to the abnormal state. A controller that controls the laser device not to output a laser beam when determined ,
The laser unit is an optical fiber laser including an excitation light source and an amplification optical fiber,
The control unit controls to apply a driving current to the excitation light source when the determination unit determines that the output state of the laser device is the normal state, and the determination unit outputs the output state of the laser device. If it is determined that the abnormal state of the laser device, characterized in that that control so as not to apply a driving current to the pumping light source.   The determination unit determines whether the determination parameter is a value within a predetermined allowable range, and outputs a first determination result that is the determination result, and the first determination result, 2. A second determination unit that determines whether an output state of the laser device is the normal state or the abnormal state, and outputs the determination result. Laser equipment.   The second determination unit determines the normal state when all of the determination parameters are values within the predetermined tolerance in the first determination result, and at least one of the determination parameters is the The laser apparatus according to claim 2, wherein the abnormal state is determined when the value is outside a predetermined allowable range.   The second determination unit determines the normal state when at least one of the determination parameters is a value within the predetermined allowable range in the first determination result, and all of the determination parameters are The laser apparatus according to claim 2, wherein the abnormal state is determined when the value is outside a predetermined allowable range.   The photodetector includes three or more first determination units, the first determination unit outputs three or more first determination results, and the second determination unit includes three or more first determination units. In one determination result, when at least two of the determination parameters are values within the predetermined allowable range, it is determined as the normal state, and 0 or one of the three or more determination parameters is the predetermined value. 3. The laser device according to claim 2, wherein the laser device is determined to be in the abnormal state when the value is within a permissible range.   When the first determination unit determines that one or more of the determination parameters are outside the predetermined allowable range, the control unit determines that the first determination unit determines that the parameter is out of the predetermined allowable range. 6. The output state of the laser device is controlled using the light intensity detected by the photodetector other than the photodetector that detects the light intensity for obtaining the determination parameter. The laser device according to any one of the above.   The laser apparatus according to claim 2, wherein the first determination unit is provided separately for each of the plurality of photodetectors.   Of the first determination units, one first determination unit outputs the first determination result and the light intensity, and the first determination unit other than the one first determination unit is the first determination result. The laser apparatus according to claim 2, wherein only the laser beam is output.   The laser device according to claim 1, wherein the determination parameter is light intensity of each branched light detected by the plurality of photodetectors.   9. The determination parameter according to claim 1, wherein the determination parameter is a value obtained by calculating a laser light intensity output from the laser device based on a light intensity of each branched light detected by the plurality of photodetectors. The laser apparatus as described in any one.   The laser apparatus according to claim 1, wherein the determination parameter is a ratio of light intensity of each branched light detected by the plurality of photodetectors.   The laser apparatus according to claim 1, wherein the determination parameter is a difference in light intensity of each branched light detected by the plurality of photodetectors.   13. The laser according to claim 1, wherein a part of the laser beam branched by the branching unit is reflected light that returns from the output side of the laser device to the laser unit side. apparatus.   The control unit controls the laser unit to output a laser beam when the determination unit determines that the output state of the laser device is the normal state, and the determination unit controls the output state of the laser device. The laser apparatus according to claim 1, wherein when the laser beam is determined to be in the abnormal state, control is performed so that laser light is not output from the laser unit. When the determination unit determines that the output state of the laser device is the normal state, the laser beam output from the laser unit is allowed to pass, and when the output state of the laser device is determined to be the abnormal state, the laser the laser apparatus according to any one of claims 1 to 1 4, characterized in that a light blocking section that blocks the laser light outputted from the section. The determination result determined by the determination unit, the light intensity detected by the photodetector, the current value input from the photodetector to the determination unit, the current value input from the determination unit to the control unit, the determination use parameters, laser apparatus according to any one of claims 1 to 1 5, characterized in that it comprises a display unit for displaying any one or more of the output state of the laser device.

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