Laser device

Abstract

To provide a laser device for synthesizing a plurality of laser beams, the laser device being capable of detecting generation timings of the respective laser beams via a small and simple optical system.SOLUTION: A laser device includes: a plurality of laser oscillators that each generate a laser beam according to each of a plurality of pulse currents; an optical unit that optically synthesizes the plurality of laser beams and outputs the synthesized laser beam; a detection unit that spectrally disperses the synthesized laser beam for each wavelength and detects a deviation in at least one of a rising timing and a falling timing between the spectrally dispersed laser beams; and an adjustment unit that generates adjustment signals for each adjusting at least one of the rising timing and the falling timing of each of the plurality of laser beams based on the deviation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laser device that outputs a plurality of laser beams using a plurality of pulse currents. [Background technology]

[0002] In recent years, technologies have been developed to process various materials using laser light (hereinafter referred to as laser processing). One example of such a material is copper. In laser processing, the higher the optical density of the laser light, the thicker the material can be processed, or the faster the processing speed can be. Therefore, there is a demand for higher output and higher quality laser light. In addition, to suppress the effects of spatter, heat, and other factors that occur during processing, there is a demand for pulsed driving, which repeatedly turns the laser light on and off over time.

[0003] Combining multiple laser beams is an effective way to increase the output power of laser beams. By adopting the Wavelength Beam Combining (WBC) method to combine multiple laser beams, it is expected that the quality of the laser beam will be improved. Pulse-driven laser beams can be achieved by adding a pulse-drive function to the power supply that drives the laser beam.

[0004] When synthesizing a single pulse waveform using multiple pulsed power sources and multiple laser beams, if there is a discrepancy in the generation timing of each laser beam due to individual differences in the pulsed power sources, signal delays, etc., the synthesized pulse waveform will differ from the originally intended desired waveform. To eliminate this discrepancy, it is necessary to monitor the discrepancy in the operation timing of the multiple laser beams and adjust the operation timing between the multiple laser beams.

[0005] The laser processing device disclosed in Patent Document 1 uses a photodiode to individually detect the generation timing of each laser beam generated by multiple pulse laser beam generating means, evaluates the timing deviation with an oscilloscope, and adjusts the timing of each pulse laser beam with a synchronization means. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5912421 Summary of the Invention [Problem to be solved by the invention]

[0007] In the laser device described in Patent Document 1, multiple laser beams are detected by different detection optical systems (mirrors, photodiodes, etc.), so the device becomes larger as the number of laser beams to be combined increases. Also, the optical system becomes more complex as the number of laser beams to be combined increases, making optical adjustment more difficult.

[0008] An object of the present disclosure is to provide a laser device that combines a plurality of laser beams and that can detect the generation timing of each laser beam using a small and simple optical system. [Means for solving the problem]

[0009] In order to solve the above problems, the laser device according to the present disclosure includes a plurality of laser oscillators that generate laser beams, respectively, in accordance with a plurality of pulse currents; an optical unit that optically combines the plurality of laser beams to output a combined laser beam; a detection unit that separates the combined laser beam into wavelengths and detects a deviation in at least one of the rise timing and fall timing of the separated laser beams; and an adjustment unit that generates an adjustment signal to adjust at least one of the rise timing and fall timing of each of the plurality of laser beams based on the deviation. [Effects of the Invention]

[0010] According to the present disclosure, in a laser device that combines a plurality of laser beams, the generation timing of each laser beam can be detected using a small and simple optical system. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic block diagram illustrating a configuration of a laser device according to an embodiment of the present disclosure; [Figure 2] FIG. 1 is a schematic diagram showing an example of the configuration of a laser oscillator and an optical unit when the laser oscillator has one laser array. [Figure 3] Schematic diagram showing an example of the configuration of a laser oscillator and an optical unit when the laser oscillator has M laser arrays (M is an integer of 2 or more). [Figure 4] FIG. 10 is a diagram showing an example of the configuration of a detection unit; [Figure 5] FIG. 1 is a diagram showing an example of wavelength components of laser light generated by four laser oscillators. [Figure 6] FIG. 1 is a diagram showing an example of wavelength components of laser light generated by four laser oscillators. [Figure 7] FIG. 1 is a diagram showing an example of wavelength components of laser light generated by four laser oscillators. [Figure 8] FIG. 10 is a diagram for explaining an example of detection by a detection unit and adjustment by an adjustment unit. [Figure 9] FIG. 10 is a diagram illustrating waveforms of individual laser beams and a waveform of a combined laser beam after various adjustments; DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, and the arrangement and connection of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0013] Furthermore, each figure is a schematic diagram and is not necessarily an exact representation. Therefore, the scales and the like do not necessarily match in each figure. In each figure, the same reference numerals are used to denote substantially the same components, and redundant explanations will be omitted or simplified.

[0014] <Overall structure> FIG. 1 is a schematic block diagram showing a configuration of a laser device 100 according to an embodiment of the present disclosure. The laser device 100 includes a command signal generating unit 1, a branching unit 2, N pulse current generating units 3, N laser oscillators 4, an optical unit 5, a detecting unit 6, and an adjusting unit 7, where N is an integer equal to or greater than 2. The laser device 100 is a device that outputs laser light for processing various materials, for example. In this embodiment, the processing target is copper, for example. To efficiently process copper, the laser device 100 according to this embodiment outputs laser light in at least one of the blue region (wavelength of 400 nm to 490 nm) and the infrared region (wavelength of 780 nm to 1700 nm). However, these are merely examples, and the present disclosure does not particularly limit the use of the laser device, the processing target, or the wavelength region of the output laser light.

[0015] The command signal generating unit 1 generates a command signal according to the object to be processed by the laser device 100. For example, when the laser device 100 performs pulse processing of a material, the command signal generating unit 1 generates an electric pulse signal corresponding to a desired pulse frequency and pulse width as a command signal and outputs it to the branching unit 2. In the present embodiment, as an example, the command signal generating unit 1 generates a command signal including an electric pulse signal corresponding to a frequency of 10 kHz and a pulse width of 20 μs.

[0016] The branching unit 2 branches one command signal and outputs it to each of the N pulse current generating units 3. For example, when N=4, the branching unit 2 branches one command signal into four and outputs them to the pulse current generating units 3. It is desirable that the branching unit 2 has a circuit designed so that the inductance and capacitance components of the branched signal lines have approximately the same values, so that the timing of the branched signals can be aligned as much as possible.

[0017] Each of the N pulse current generating units 3 generates a pulse current based on the branch signal. The N pulse current generating units 3 output a pulse current to the corresponding N laser oscillators 4. In this embodiment, when the laser oscillators 4 generate laser light in the blue region (wavelength 400 nm or more and 490 nm or less), each of the pulse current generating units 3 generates a pulse current of about 60 A.

[0018] The N pulse current generating units 3 can adjust the timing at which the pulse currents are generated based on the adjustment signal received from the adjustment unit 7. In the present disclosure, known techniques can be used for the method by which the pulse current generating units 3 adjust the timing at which the pulse currents are generated. As an example, each pulse current generating unit 3 may have a delay circuit that delays the timing at which the pulse currents are generated. The delay circuit may be configured with an RC circuit using a resistor and a capacitor. By using a voltage-controlled variable capacitor as the capacitor of the delay circuit and inputting the adjustment signal from the adjustment unit 7, the pulse generation timing of each of the N pulse current generating units 3 can be adjusted. The delay circuit may be configured with multiple buffer circuits, each with its own unique delay time. When the delay circuit is configured with multiple buffer circuits, multiple circuits with different numbers of buffer circuits are prepared, and the pulse generation timing of the pulse generating unit can be adjusted by switching the path with an electrical switch.

[0019] Each of the N laser oscillators 4 generates a pulsed laser beam based on the pulse current obtained from each of the N pulsed current generating units 3. As will be described in detail later, the laser beams generated by the N laser oscillators 4 each contain a different wavelength component. The entire wavelength components contained in the laser beams generated by the N laser oscillators 4 may be different from each other, or only some of the wavelength components may be different from each other.

[0020] Each of the laser oscillators 4 may have, for example, one or more laser arrays in which multiple laser stripes are mounted on a single chip. Such a configuration makes it possible to generate laser light having a wide wavelength range and to increase the output power of the laser light. More specifically, each of the laser oscillators 4 may have a configuration in which approximately 10 laser arrays, each having approximately 40 laser stripes mounted on a single chip, are connected in series.

[0021] The optical unit 5 outputs a combined laser beam obtained by combining the laser beams generated by the N laser oscillators 4. The optical unit 5 may be configured using, for example, a spatial combining method that combines light by combining optical mirrors, a polarization combining method that combines light using polarized light, a wavelength combining method that combines light using wavelengths, or a combination of these. More preferably, the optical unit 5 may be configured using a wavelength combining (WBC) method that utilizes external resonance. By using a wavelength combining method, it is possible to achieve both high quality and high output of the laser beam. The combined laser beam output from the optical unit 5 is sent to a processing unit (not shown) for processing a material, for example. At least a portion of the combined laser beam output from the optical unit 5 is sent to the detection unit 6.

[0022] The detection unit 6 separates the combined laser light output from the optical unit 5 into wavelength components and detects the separated laser light. As described above, the laser light before combining, i.e., the laser light output from the N laser oscillators 4, each has a different wavelength component. Therefore, by separating the combined laser light into wavelength components, the detection unit 6 can detect the laser light generated by each of the N laser oscillators 4.

[0023] The detection unit 6 detects at least one of the rising timing and the falling timing of each of the laser beams separated into wavelengths. This allows the detection unit 6 to detect a deviation in at least one of the rising timing and the falling timing of the laser beams generated by different laser oscillators 4. The detection unit 6 outputs deviation information indicating a deviation in at least one of the rising timing and the falling timing of the laser beams generated by different laser oscillators 4 to the adjustment unit 7.

[0024] Based on the deviation information, the adjustment unit 7 outputs an adjustment signal for adjusting at least one of the rise timing and fall timing of the pulse current to each of the N pulse current generation units 3. For example, if the adjustment unit 7 outputs an adjustment signal for adjusting the rise timing of the pulse current to align the rise timings of the pulse currents to each of the N pulse current generation units 3, the rise timings of the pulse currents generated by each of the N pulse current generation units 3 will be aligned, and therefore the rise timings of the laser beams generated by each of the N laser oscillators 4 that generate laser beams based on the pulse current will be aligned.

[0025] How the adjustment unit 7 adjusts the rise timing or fall timing of the pulse current may be appropriately set based on the application of the combined laser beam output by the laser device 100. For example, if it is desired to sharpen the cut surface of the material to be processed by the combined laser beam output by the laser device 100, it is necessary to make the rise timing of the combined laser beam steep. In order to make the rise timing of the combined laser beam steep, it is desirable to align the rise timing of the laser beams generated by the N laser oscillators 4, so the adjustment unit 7 may output an adjustment signal that aligns the rise timing of the pulse currents generated by the N pulse current generation units 3.

[0026] In this manner, in the laser apparatus 100 according to the embodiment of the present disclosure, the N laser oscillators 4 each output laser light having a unique wavelength component based on the pulse currents generated by the N pulse current generating units 3, and the optical unit 5 combines the laser light to output a combined laser light. By combining the laser light generated by the multiple laser oscillators 4 in this manner, it is possible to achieve both high-power and high-quality laser light. Furthermore, the detector 6 detects at least a portion of the combined laser light by wavelength, thereby detecting a difference in the rise and / or fall timing of the laser light generated by each of the N laser oscillators 4. The adjuster 7 outputs an adjustment signal to each of the N pulse current generating units 3 to correct the difference, thereby adjusting the operation timing of the N laser oscillators 4 and adjusting the combined laser light to the intended waveform. This allows the combined laser light output by the laser apparatus 100 to be used for material processing under desired processing conditions.

[0027] In the example shown in FIG. 1 , the adjustment unit 7 generates an adjustment signal that adjusts at least one of the rise timing and fall timing of the pulse currents generated by the N pulse current generation units 3. However, the present disclosure is not limited to this. In the present disclosure, for example, the adjustment unit may generate an adjustment signal for adjusting at least one of the rise timing and fall timing of the control signal output from the branching unit to the pulse current generation unit. In this case, instead of the pulse current generation unit, the branching unit may include a delay circuit or the like, and the branching unit may adjust the timing of each control signal after the command signal is branched based on the adjustment signal. Even in this case, it is possible to adjust the operation timing of the pulse current generation unit that operates based on the control signal and the laser generation timing of the laser oscillator that operates based on the pulse current.

[0028] <Configuration example of laser oscillator 4 and optical unit 5> 2 and 3, a configuration example of the laser oscillator 4 and the optical unit 5 will be described. Fig. 2 is a schematic diagram showing a configuration example of the laser oscillator 4 and the optical unit 5 when the laser oscillator 4 has one laser array. Fig. 3 is a schematic diagram showing a configuration example of the laser oscillator 4 and the optical unit 5 when the laser oscillator 4 has M laser arrays (M is an integer of 2 or more).

[0029] In the example shown in FIG. 2A, the laser oscillator 4 has one laser array 41. The laser array 41 has a number a (a is an integer equal to or greater than 2) of laser stripes 42. In the example shown in FIG. 2A, the optical unit 5 has an optical lens 51, a diffraction grating 52, and an output coupler 53. The laser light emitted from each laser stripe 42 is focused by the optical lens 51 onto a point on the diffraction grating 52, reflected by the diffraction grating 52, and incident on the output coupler 53. The output coupler 53 transmits a portion of the incident laser light and reflects the remainder. The laser light reflected by the output coupler 53 returns to the diffraction grating 52, is reflected by the diffraction grating 52, and travels the optical path in the opposite direction to enter the original laser stripe 42. By disposing a highly reflective material on the rear end surface of the laser stripe 42, an external resonator is formed between the rear end surface of the laser stripe 42 and the output coupler 53, and laser light is emitted.

[0030] The a laser stripes 42 each emit laser light of a different wavelength. In the example shown in Fig. 2A, the laser stripes 42 are arranged in a row in the laser array 41, and the wavelength of the laser light emitted from each laser stripe 42 varies depending on the arrangement position. In the following description, the wavelength of the laser light emitted by the laser stripe 42 arranged at one end of the laser array 41 in Fig. 2A is referred to as λ1, and the wavelength of the laser light emitted by the laser stripe 42 arranged at the other end is referred to as λ a When i is an integer between 1 and a, the wavelength of the laser light emitted by the i-th laser stripe 42 is set to λ i It can be expressed as:

[0031] Furthermore, each of the a laser stripes 42 is arranged in the laser array 41 so that the laser light emitted from each laser stripe 42 has a different angle of incidence on the diffraction grating 52. In the following description, the angle of incidence at which the laser light emitted from the laser stripe 42 arranged at one end is incident on the diffraction grating 52 is referred to as θ1, and the angle of incidence at which the laser light emitted from the laser stripe 42 arranged at the other end is incident on the diffraction grating 52 is referred to as θ a When i is an integer between 1 and a, the incident angle of the laser light emitted from the i-th laser stripe 42 to the diffraction grating 52 is expressed as θ i It can be expressed as:

[0032] When multiple laser beams having different wavelengths are incident at different angles of incidence, the diffraction grating 52 has the property of reflecting each laser beam at the same reflection angle θ0. As a result, the laser beams emitted from the a laser stripes 42 and incident on the diffraction grating 52 at different angles of incidence are all reflected by the diffraction grating 52 at the same reflection angle θ0. Here, if the pitch of the diffraction grating 52 is d, then the following equation (1) holds: d(sinθ i -sinθ0)=mλ i (1)

[0033] In the formula (1), m is a positive integer.

[0034] In this way, when the optical unit 5 is configured with a wavelength synthesis optical system using external resonance, a diffraction grating is used in the path of the external resonator, and therefore the oscillation wavelength of the laser light is determined by the geometrical positional relationship between the laser light and the optical system. Specifically, since d, θi, and θ0 are uniquely determined by the geometrical positional relationship between the laser light and the optical system, external resonance in the optical unit 5 is realized by determining λi to satisfy formula (1).

[0035] 2B is a schematic diagram of wavelength components of laser light obtained by the laser oscillator 4 and the optical unit 5 of the configuration example shown in FIG. 2A. As described above, the laser light emitted from each has different wavelength components λ1 to λa. The geometric positional relationship between the laser array 41 of the laser oscillator 4 and the diffraction grating 52 of the optical unit 5 may be designed so that the wavelength range of this laser light, i.e., the difference between the maximum wavelength λa and the minimum wavelength λ1 of the laser light emitted by the multiple laser stripes 42 included in one laser array 41, is, for example, 1 nm or more and 2 nm or less.

[0036] FIG. 3A shows an example in which the laser oscillator 4 has M laser arrays 41, and the M laser arrays 41 are arranged at geometrically different positions (for example, in a substantially fan-shaped configuration with respect to the diffraction grating 52). In the example shown in FIG. 3A, by arranging the multiple laser arrays 41 at geometrically different positions with respect to the diffraction grating 52, the diffraction grating 52 can reflect the laser beams incident from the multiple laser arrays 41 at the same reflection angle, and can combine the laser beams emitted from the multiple laser arrays 41 into one. With this configuration, an external resonator can be formed between each of the multiple laser stripes 42 of the multiple laser arrays 41 and the output coupler 53. Note that, for simplicity, FIG. 3A shows only one laser beam among the laser beams emitted from the multiple laser stripes 42 of each laser array 41.

[0037] An example of wavelength components of laser light in the configuration example shown in Fig. 3A is shown in Fig. 3B. In the example shown in Fig. 3B, it is assumed that each of a plurality of laser arrays 41 has a number of laser stripes 42. In the example shown in Fig. 3B, among M laser arrays arranged in a line along the fan shape as shown in Fig. 3A, the wavelength components of laser light emitted from a number of laser stripes 42 of the laser array 41 arranged at one end are defined as λ 11 ~λ 1a , and the wavelength components of the laser light emitted from the a laser stripes 42 of the laser array 41 arranged next are defined as λ 21 ~λ2a , the wavelength components of the laser light emitted from the a laser stripes 42 of the laser array 41 arranged at the other end are defined as λ M1 ~λ Ma It shows:

[0038] The difference in wavelength components of the laser light generated by each laser array 41 is determined by the position where the laser array 41 is disposed. When multiple laser arrays 41 are disposed at positions spatially separated from one another, the wavelength groups of the laser light generated by each laser array 41 have wavelengths that are separated from one another. As shown in FIG. 3B, when the laser oscillator 4 has M laser arrays 41, the wavelength components of the laser light generated by each laser oscillator 4 are wavelengths λ 11 ~λ 1a , wavelength λ 21 ~λ 2a , and wavelength λ M1 ~λ Ma 3B. By adjusting the geometrical position of the laser array 41 relative to the diffraction grating 52, it is possible to adjust the wavelength components of the laser beams generated by each laser array 41. The difference in wavelength (for example, λ ) between the laser beams emitted from the adjacent laser arrays 41 can be adjusted. 1a and λ 21 The geometrical positional relationship between the laser array 41 and the diffraction grating 52 may be designed so that the difference between the laser array 41 and the diffraction grating 52 is, for example, 1 nm or more and 2 nm or less.

[0039] In this way, when each of the N laser oscillators 4 has a plurality of laser arrays 41 as illustrated in Fig. 3A, each of the N laser oscillators 4 can generate laser light having a comb-shaped oscillation spectrum as illustrated in Fig. 3B. Furthermore, by adjusting the geometric positional relationship between the laser array 41 and the diffraction grating 52 in each of the N laser oscillators 4, it is possible to make the laser light generated by the N laser oscillators 4 have unique wavelength components. As a result, the combined laser light combined by the optical unit 5 contains at least N wavelength components that are different from one another, and when the detection unit 6 disperses the combined laser light, it is possible to identify laser light having wavelength components corresponding to each of the N laser oscillators 4.

[0040] All of the wavelength components of the N laser beams generated by the N laser oscillators 4 may be different from one another, or at least some of the wavelength components may be different from one another.

[0041] <Configuration example of detection unit 6> An example of the configuration of the detection unit 6 will be described with reference to Fig. 4. The detection unit 6 has a spectroscope 61, N photodiodes 62, a processing circuit 63, and a power supply 64.

[0042] The spectrometer 61 separates the combined laser beam into N laser beams each having a wavelength corresponding to each of the N laser oscillators 4. Since the combined laser beam contains at least N wavelength components specific to each of the N laser oscillators 4, the spectrometer 61 separates the combined laser beam into N laser beams each having a wavelength component corresponding to each of the N laser oscillators 4.

[0043] The photodiodes 62 receive the laser light separated into wavelengths and generate detection signals. The processing circuit 63 measures the deviation in the rise timing or fall timing of the laser light for each wavelength based on the detection signals for each wavelength detected by the photodiodes 62, and generates deviation information indicating the amount of deviation. The deviation information indicates the deviation in the generation timing of N laser light beams containing wavelength components corresponding to the N laser oscillators 4. The processing circuit 63 outputs the deviation information to the adjustment unit 7 shown in FIG. 1.

[0044] The power supply 64 supplies power to the plurality of photodiodes 62 and the processing circuitry 63 .

[0045] In this way, the detection unit 6 detects the laser light generated by each of the N laser oscillators 4 using a composite laser light obtained by combining the N laser light generated by the N laser oscillators 4. Therefore, the detection unit 6 can install the multiple photodiodes 62 close to each other. As a result, the detection unit 6 only needs to have one processing circuit 63 that collectively processes the detection signals detected by the multiple photodiodes 62 and one power supply 64 that supplies power to the multiple photodiodes 62. Therefore, compared to when multiple laser light generated by multiple laser oscillators is detected by multiple photodiodes that are respectively located in different positions, there is no need to provide a processing circuit and power supply for each of the multiple photodiodes, and therefore the detection unit 6, and ultimately the laser device 100, can be made smaller.

[0046] <Example of operation> An example of the operation of the laser device 100 according to the embodiment of the present disclosure will be described below. The example of the operation will be described below for the case where N=4, that is, the laser device 100 has four pulse current generating units 3 and four laser oscillators 4.

[0047] (Specific examples of wavelength components possessed by the laser beams generated by the four laser oscillators 4) 5, 6, and 7 are diagrams showing examples of wavelength components of laser beams generated by four laser oscillators 4 when N = 4. In Fig. 5, 6, and 7, the laser beams generated by the four laser oscillators 4 are designated as R1, R2, R3, and R4, respectively.

[0048] FIG. 5 shows an example in which the wavelength components of the laser beams generated by the four laser oscillators 4 are different across the entire wavelength range.

[0049] In the example shown in FIG. 5, the wavelengths of the laser beams generated by the respective laser oscillators 4 are far apart from each other. The example shown in FIG. 5 is effective when widening the wavelength range of the combined laser beam output by the entire laser device 100, because the wavelength ranges of the laser beams generated by the four laser oscillators 4 are significantly different from each other. Specifically, an example can be given in which, of the four laser oscillators 4, three laser oscillators 4 generate laser beams in the blue range, and the remaining laser oscillator 4 generates laser beams in the infrared range. In this way, by widening the wavelength range of the combined laser beam output by the laser device 100, the quality of material processing using the combined laser beam can be adjusted.

[0050] In the example shown in FIG. 6 , the wavelengths of the laser beams generated by the respective laser oscillators 4 are close to each other. Furthermore, in the short wavelength region or the long wavelength region, the laser beams generated by one laser oscillator 4 are designed to have wavelength components in a region where the laser beam generated by the other laser oscillator 4 does not have a wavelength component. Specifically, the shortest wavelength component of laser beam R1 is not included in the wavelength components of laser beams R2, R3, and R4. The shortest wavelength component of laser beam R2 is not included in the wavelength components of laser beams R1, R3, and R4. The longest wavelength component of laser beam R3 is not included in the wavelength components of laser beams R1, R2, and R4. The longest wavelength component of laser beam R4 is not included in the wavelength components of laser beams R1, R2, and R3.

[0051] 7 shows an example in which the wavelengths of the laser beams generated by the respective laser oscillators 4 have values ​​close to each other, and the laser beams generated by the respective laser oscillators 4 have the same wavelength components in a relatively short wavelength region, and have different wavelength components only in a partial region where the wavelengths are relatively long. Specifically, R1, R2, R3, and R4 have the same wavelength components except for the longest wavelength component, and each of the longest wavelength components has a unique value.

[0052] As shown in the examples of Figures 5, 6, and 7, the laser beams generated by the four laser oscillators 4 each have wavelength components that differ from each other in at least a portion of the wavelength range, so that when the detection unit 6 separates the combined laser beam into wavelengths, it is possible to identify which laser oscillator 4 generated each laser beam.

[0053] It is known that the operating wavelength of laser light varies depending on factors such as the temperature of the laser light. However, as illustrated in Figures 4 and 5, when a laser oscillator 4 and an optical unit 5 using a wavelength synthesis method utilizing external resonance are used, the operating wavelength of the laser light is determined by the geometric positional relationship between the laser light and the optical system, minimizing the effect of temperature. Therefore, by using a wavelength synthesis method utilizing external resonance in the laser oscillators 4 and the optical unit 5, the oscillation wavelength of the laser light generated by each of the multiple laser oscillators 4 can be stabilized. As a result, even if the difference in wavelength components of the laser light generated by the laser oscillators 4 is very small, the detection unit 6 can easily detect which laser light was generated by which laser oscillator 4 based on the dispersed laser light. Specifically, as long as the laser light generated by the laser oscillators 4 differs from each other by approximately 0.5 nm to 1 nm, the detection unit 6 can easily detect it.

[0054] (Specific example of detection by the detection unit 6 and adjustment by the adjustment unit 7) FIG. 8 is a diagram illustrating an example of detection by the detection unit 6 and adjustment by the adjustment unit 7. In FIG. 8, the laser beams generated by the four laser oscillators 4 are designated R1, R2, R3, and R4, respectively. FIG. 8A shows the detection unit 6 separating the combined laser beam into wavelengths and detecting the laser beams R1, R2, R3, and R4. FIG. 8B shows the detection unit 6 comparing the rising timings of the laser beams R1, R2, R3, and R4 and detecting the deviation time. FIG. 8C shows the adjustment unit 7 generating an adjustment signal based on deviation information including the deviation time, thereby aligning the rising timings of the laser beams R1, R2, R3, and R4 generated by the four laser oscillators 4 to timing T.

[0055] Although FIG. 8 shows an example in which adjustment is made to align the rising timings of the laser beams R1, R2, R3, and R4, the present disclosure is not limited to this, and various adjustments are possible as shown in FIG.

[0056] 9A and 9B are diagrams illustrating examples of the waveforms of the individual laser beams and the waveform of the combined laser beam after various adjustments. Fig. 9A shows an example of the waveforms of the laser beams R1, R2, R3, and R4 after adjustments are made to align both the rising and falling timings of the four laser beams. Fig. 9B shows the waveform of the combined laser beam after adjustments are made to align both the rising and falling timings of the four laser beams. In this case, a combined laser beam having a waveform with steep rising and falling edges can be output.

[0057] 9C shows an example of the waveforms of the laser beams R1, R2, R3, and R4 after adjustment when the rise and fall timings of the four laser beams are adjusted so that they are shifted by the same amount. 9D shows the waveform of the combined laser beam when the rise and fall timings of the four laser beams are adjusted so that they are shifted by the same amount. In this case, a combined laser beam having a waveform with smooth rises and falls can be output.

[0058] 9E shows an example of the waveforms of the laser beams R1, R2, R3, and R4 after the adjustment in which the rising timing of the four laser beams R1, R2, R3, and R4 is aligned and the falling timing of R4 is adjusted to be slower than the falling timing of R1, R2, and R3. 9F shows the waveform of the combined laser beam after the rising timing of the four laser beams R1, R2, R3, and R4 is aligned and the falling timing of R4 is adjusted to be slower than the falling timing of R1, R2, and R3. In this case, a combined laser beam having a waveform with a steep rising edge and a gradual falling edge can be output.

[0059] 9G shows an example of the waveforms of the laser beams R1, R2, R3, and R4 after the adjustment in which the fall timings of the four laser beams R1, R2, R3, and R4 are aligned and the rise timing of R2 is slower than R1, R3 is slower than R2, and R4 is slower than R3. 9H shows the waveform of the combined laser beam after the fall timings of the four laser beams R1, R2, R3, and R4 are aligned and the rise timing of R2 is slower than R1, R3 is slower than R2, and R4 is slower than R3. In this case, a combined laser beam having a waveform with a gradual rise and a steep fall can be output.

[0060] The adjustments possible with the laser device of the present disclosure are not limited to the example shown in FIG. 9 , and various adjustments may be possible as appropriate depending on the intended use of the combined laser light output by the laser device. The adjustment unit 7 generates an adjustment signal for adjusting the multiple control signals generated by the branching unit 2 or an adjustment signal for adjusting the pulse currents generated by each of the multiple pulse current generating units 3, thereby adjusting the pulse width, frequency, intensity, etc. of the laser light generated by the laser oscillator 4, and ultimately allowing the combined laser light combined by the optical unit 5 to have any waveform. If only one pulse current generating unit were used, the laser device would need to be large in size to generate a complex pulse waveform. However, by using multiple pulse current generating units 3, the laser device 100 according to the embodiment of the present disclosure can generate a complex pulse waveform with a relatively simple configuration.

[0061] <Actions and Effects> A laser device 100 according to an embodiment of the present disclosure includes a plurality of (N) laser oscillators 4 that each emit a laser beam in accordance with a plurality of pulse currents, an optical unit 5 that optically combines the plurality of (N) laser beams to output a combined laser beam, a detection unit 6 that separates the combined laser beam into wavelengths and detects a deviation in at least one of the rise timing and fall timing of the separated laser beams, and an adjustment unit 7 that generates an adjustment signal to adjust at least one of the rise timing and fall timing of each of the plurality of laser beams based on the deviation.

[0062] With this configuration, laser device 100 can appropriately adjust the waveform of the laser beams before combining according to the intended use of the output combined laser beam, and thus can appropriately adjust the waveform of the output combined laser. In laser device 100, multiple laser beams are combined once and then separated and detected for each wavelength, which allows detection unit 6 to be made smaller, and ultimately allows laser device 100 to be made smaller.

[0063] The laser device 100 according to the embodiment of the present disclosure further includes a command signal generating unit 1 that generates a command signal, a branching unit 2 that branches the command signal into multiple signals to generate multiple control signals, and a pulse current generating unit 3 that generates multiple pulse currents based on each of the multiple control signals.

[0064] With this configuration, a composite laser beam having a complex pulse waveform can be generated with a relatively simple configuration, which allows the laser device 100 to be made smaller.

[0065] According to the laser device 100 according to the embodiment of the present disclosure, the pulse current generating unit 3 adjusts at least one of the rise timing and fall timing of the plurality of pulse currents based on the adjustment signal. Alternatively, the branching unit 2 adjusts at least one of the rise timing and fall timing of the plurality of control signals based on the adjustment signal. In this way, by adjusting the signal generated by at least one of the branching unit 2 and the pulse current generating unit 3 based on the adjustment signal generated by the adjusting unit 7, the waveform of the laser light generated by the laser oscillator 4 at the downstream stage can be suitably adjusted.

[0066] According to the laser device 100 of the embodiment of the present disclosure, each of the multiple laser oscillators 4 has multiple laser arrays 41, and the optical unit 5 combines the laser light emitted from each of the multiple laser arrays 41 using a wavelength combining method that utilizes external resonance.

[0067] With this configuration, the laser light generated by each of the multiple laser oscillators has high wavelength stability, so that even if the difference in wavelength components between the laser lights is small, the detection unit 6 can reliably detect the laser light for each wavelength.

[0068] According to the laser device 100 according to the embodiment of the present disclosure, the geometric positional relationship between the diffraction grating 52 of the optical unit 5 and the laser arrays 41 differs in each of the laser oscillators 4.

[0069] With this configuration, the laser beams generated by the plurality of laser oscillators can have high wavelength stability.

[0070] According to the laser device 100 according to the embodiment of the present disclosure, the plurality of laser oscillators generate laser light having unique wavelength components, based on the geometrical positional relationship.

[0071] With this configuration, the detector 6 can reliably detect laser light of each wavelength.

[0072] According to the laser device 100 according to the embodiment of the present disclosure, the wavelength components of the laser beams generated by the laser oscillators 4 may be different from each other over the entire wavelength range. Alternatively, the wavelength components of the laser beams generated by the laser oscillators 4 may be different from each other over a part of the wavelength range.

[0073] A laser device 100 according to an embodiment of the present disclosure includes a plurality of (N) laser oscillators 4 that each emit a laser beam in accordance with a plurality of pulse currents, an optical unit 5 that optically combines the plurality of (N) laser beams to output a combined laser beam, a detection unit 6 that separates the combined laser beam into wavelengths and detects a deviation in at least one of the rise timing and fall timing between the separated laser beams, and an adjustment signal that adjusts the waveform of the laser beam generated by the laser oscillator based on the deviation so that the combined laser beam has a desired waveform.

[0074] With this configuration, the waveforms of the laser beams generated by the plurality of laser oscillators 4 are suitably adjusted by the adjustment signal.

[0075] According to the laser device 100 according to the embodiment of the present disclosure, each of the multiple laser oscillators 4 generates laser light in at least the blue region (wavelength of 400 nm or more and 490 nm or less) and the infrared region (780 nm or more and 1700 nm or less).

[0076] With this configuration, efficient machining is possible when machining copper using the combined laser beam. [Industrial Applicability]

[0077] The present disclosure is useful for laser devices that output laser light having a variety of waveforms. [Explanation of symbols]

[0078] 100 Laser device 1 Command signal generation section 2 Branch 3 Pulse current generator 4 Laser oscillator 41 Laser Array 42 Laser Stripe 5 Optics Department 51 Optical Lenses 52 Diffraction Grating 53 Output Coupler 6. Detection unit 61 Spectrometer 62 Photodiode 63 Processing circuit 64 Power supply 7 Adjustment part

Claims

1. a plurality of laser oscillators each generating a laser beam in accordance with a respective one of a plurality of pulse currents; an optical unit that optically combines the plurality of laser beams and outputs a combined laser beam; a detector that separates the combined laser beam into wavelengths and detects a difference in at least one of rise timing and fall timing between the separated laser beams; an adjustment unit that generates an adjustment signal for adjusting at least one of the rise timing and the fall timing of each of the plurality of laser beams based on the deviation; A laser device comprising:

2. a command signal generating unit that generates a command signal; a branching unit that branches the command signal into a plurality of signals to generate a plurality of control signals; a pulse current generating unit that generates the plurality of pulse currents based on each of the plurality of control signals; Further provided with 2. The laser device according to claim 1.

3. the pulse current generating unit adjusts at least one of rise timings and fall timings of the plurality of pulse currents based on the adjustment signal.

3. The laser device according to claim 2.

4. the branching unit adjusts at least one of rising timings and falling timings of the plurality of control signals based on the adjustment signal.

3. The laser device according to claim 2.

5. each of the plurality of laser oscillators has a plurality of laser arrays; the optical unit combines the laser beams emitted from the plurality of laser arrays by a wavelength combining method utilizing external resonance; 2. The laser device according to claim 1.

6. In each of the plurality of laser oscillators, a geometric positional relationship between a diffraction grating of the optical unit and the plurality of laser arrays is different.

6. The laser device according to claim 5.

7. based on the geometrical positional relationship, the plurality of laser oscillators generate the laser light having a unique wavelength component, 7. The laser device according to claim 6.

8. the wavelength components of the laser beams generated by the laser oscillators are different from each other across an entire wavelength range; 8. The laser device according to claim 7.

9. the wavelength components of the laser beams generated by the laser oscillators are different from each other in some wavelength ranges; 8. The laser device according to claim 7.

10. the adjusting unit generates the adjustment signal so that the combined laser light has a desired waveform.

2. The laser device according to claim 1.

11. Each of the plurality of laser oscillators generates the laser light in at least a blue region (wavelength: 400 nm or more and 490 nm or less) and an infrared region (780 nm or more and 1700 nm or less).

2. The laser device according to claim 1.

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