Optical amplification device and laser
By using the optical shaping, modulation, and reshaping modules in the optical amplification device, beams from different oscillators are converged and modulated to form variable laser pulses, solving the problem of insufficient laser flexibility and improving the flexibility and efficiency of laser material processing.
Patent Information
- Application Number
- CN202410819909.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2025-12-26
AI Technical Summary
Existing lasers lack flexibility in laser material processing, making it difficult to flexibly adjust the pulse length and pulse shape to meet the requirements of different processes.
An optical amplification device, consisting of an optical shaping module, a first modulation module, an optical shaping module, and an amplification module, achieves coaxial superposition and energy amplification of light beams by converging, diffracting, and modulating light beams emitted from different oscillators, thereby forming laser pulses with variable pulse length and shape.
It enables flexible adjustment of laser pulse length and shape, meets diverse needs in laser material processing, and improves the applicability and processing efficiency of lasers.
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Figure CN121209112A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of optics, in particular to an optical amplification device and a laser. BACKGROUND
[0002] Laser material processing is a key technology for more and more production processes, one of its features is flexibility; it is known that applicability, processing quality and speed depend on the material to be processed on the one hand and on the laser parameters such as pulse length and pulse shape on the other hand. In order to further improve flexibility, it is important to develop laser beam sources whose pulse length and pulse shape can be adapted to the process requirements.
[0003] Some lasers have different temporal behavior, however, in most cases the achievable pulse length and pulse shape are defined discretely. How to make the pulse length and pulse shape of the laser meet the flexible process requirements has become one of the problems to be solved by those skilled in the art.
[0004] It should be noted that the above introduction to the technical background is only to facilitate the clear and complete description of the technical scheme of the present application, and to facilitate the understanding of those skilled in the art. The above technical scheme cannot be considered as known to those skilled in the art only because it is described in the background section of the present application. SUMMARY
[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an optical amplification device and a laser, which can solve the problem of insufficient flexibility of the laser in the prior art.
[0006] To achieve the above-mentioned purpose and other related purposes, the present application provides an optical amplification device, which at least comprises:
[0007] an optical shaping module, a first modulation module, an optical shaping module, an amplification module and N oscillators, N is a natural number greater than or equal to 2;
[0008] Each oscillator emits a light beam;
[0009] The optical shaping module is arranged at the exit end of the N oscillators, converges each light beam on a common focal point, and the focal point size of each light beam is the same;
[0010] The first modulation module is arranged at the focal point of each light beam output by the optical shaping module, diffracts and modulates each light beam to make at least one non-zero diffraction order light of each light beam coaxially superimposed;
[0011] The optical shaping module is arranged at the exit end of the first modulation module, and the coaxially overlapped light beams emitted by the first modulation module are coupled into the amplification module.
[0012] The amplification module amplifies the power and pulse energy of the light beams outputted by the optical shaping module.
[0013] Optionally, the pulse characteristics provided by each oscillator include at least one of pulse duration, pulse shape, wavelength, and pulse repetition rate.
[0014] Optionally, each oscillator is at least one of a continuous wave oscillator, a Q-switched oscillator, a gain-switched oscillator, and a mode-locked oscillator.
[0015] Optionally, the optical shaping module includes N sets of optical modules corresponding to the N oscillators respectively, each optical module including a deflection mirror and a first lens.
[0016] The deflection mirror adjusts the propagation direction and / or position of the light beam emitted by the corresponding oscillator.
[0017] The first lens is arranged at the exit end of the corresponding deflection mirror to converge the light beam emitted by the corresponding deflection mirror.
[0018] Optionally, the optical shaping module includes a second lens and N sets of optical elements corresponding to the N oscillators respectively.
[0019] Each optical element adjusts the light beam emitted by the corresponding oscillator so that the N light beams are emitted in parallel and collimated, each collimated light beam having the same size and divergence angle.
[0020] The second lens is arranged at the exit end of each optical element to converge the collimated light beams into the first modulation module.
[0021] Optionally, the exit directions of the N oscillators are arranged in parallel.
[0022] Optionally, the exit directions of the N oscillators intersect; the optical shaping module includes N sets of third lenses corresponding to the N oscillators respectively, the third lenses being arranged at the exit ends of the corresponding oscillators to converge the light beams emitted by the corresponding oscillators into the first modulation module.
[0023] Optionally, the first modulation module includes a driver and an acousto-optic modulator.
[0024] The driver provides N high-frequency power signals.
[0025] The acousto-optic modulator diffractively modulates each light beam outputted by the optical shaping module based on the N high-frequency power signals, the optical shaping module and the frequencies of the N high-frequency power signals being arranged so that at least one non-zero diffraction order of each light beam is coaxially superimposed.
[0026] Wherein, the N high-frequency power signals vary with time according to requirements to realize modulation of each light beam.
[0027] More optionally, the light beam wavelength, light beam incidence angle in the first modulation module and the frequency of the high-frequency power signal in the driver are matched, so that at least one light beam satisfies the blaze angle diffraction condition of the grating in the first modulation module.
[0028] Optionally, the optical shaping module is realized by a convex lens.
[0029] Optionally, the amplification module is pumped with constant power, and the energy of the coaxial overlapping light beams extracted in the amplification module remains constant within a time constant equal to the reciprocal of the characteristic frequency.
[0030] More optionally, the optical amplification device further comprises a second modulation module arranged at the exit end of the amplification module, for shaping and / or modulating the pulse time sequence of the optical signal output by the amplification module.
[0031] To achieve the above object and other related objects, the present application further provides a laser, which comprises at least the above optical amplification device.
[0032] As described above, the optical amplification device and the laser of the present application have the following beneficial effects:
[0033] The optical amplification device and the laser of the present application combine lasers with different optical characteristics into a required pulse time sequence, to obtain laser pulses with variable and free triggerable pulse length and / or pulse shape, which meet the flexible process requirements of laser material processing. BRIEF DESCRIPTION OF DRAWINGS
[0034] Figure 1 A first structural schematic diagram of the optical amplification device of the present application is shown.
[0035] Figure 2 A second structural schematic diagram of the optical amplification device of the present application is shown.
[0036] Figure 3 A third structural schematic diagram of the optical amplification device of the present application is shown.
[0037] Figure 4 A fourth structural schematic diagram of the optical amplification device of the present application is shown.
[0038] Figure 5 A fifth structural schematic diagram of the optical amplification device of the present application is shown.
[0039] ELEMENT NUMBER EXPLANATION
[0040] 1 optical amplification device
[0041] 11 Oscillators
[0042] 11a First Oscillator
[0043] 11b Second Oscillator
[0044] 12 Optical Shaping Module
[0045] 12a First Optical Module
[0046] 12b Second Optical Module
[0047] 121 Deflecting Mirror
[0048] 122 First Lens
[0049] 123 Optical Components
[0050] 124 Second Lens
[0051] 125 Third Lens
[0052] 13 First Modulation Module
[0053] 131 drive
[0054] 132 Acousto-optic modulator
[0055] 14 Optical Shaping Module
[0056] 15 Amplification Modules
[0057] 16 Second Modulation Module Detailed Implementation
[0058] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0059] Please see Figures 1-5 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0060] like Figure 1 As shown, the present invention provides an optical magnification device 1, comprising:
[0061] N oscillators 11, an optical shaping module 12, a first modulation module 13, an optical reshaping module 14, and an amplification module 15. Wherein, N is a natural number greater than or equal to 2, which can be set according to the needs, in this embodiment, N is set to 2, denoted as a first oscillator 11a and a second oscillator 11b.
[0062] As shown in Figure 1 , each oscillator 11 emits a beam, and the pulse characteristics of each beam are different.
[0063] Specifically, the pulse characteristics of each beam are the same or different. In this example, the pulse characteristics of each beam provided by each oscillator 11 include pulse duration (pulse length), pulse shape, wavelength, and pulse repetition rate, at least one of which is configured to be different. Each oscillator 11 includes, but is not limited to, one or a combination of at least two of a continuous wave oscillator, a Q-switched oscillator, a gain-tunable oscillator, and a mode-locked oscillator; wherein the continuous wave oscillator emits laser light with continuous and constant power; the Q-switched oscillator emits laser pulses, and the pulse length is usually in the range of several ns (nanoseconds) to one hundred ns; the pulse duration of the gain-tunable oscillator can be extended to ms (milliseconds); the mode-locked oscillator can be used to generate pulses with a pulse length of several tens of fs (femtoseconds) to one hundred ps (picoseconds). As an example, the first oscillator 11a provides a continuous laser beam at the ns level, and the second oscillator 11b provides a pulsed laser beam at the ps level.
[0064] As shown in Figure 1 , the optical shaping module 12 is arranged at the exit end of the N oscillators 11, converges each beam at a common focal point, and the focal point size of each beam is the same.
[0065] Specifically, in this embodiment, the optical shaping module 12 receives two beams and converges the two beams to the same point, and the focal point size of the two beams is also the same; any design and arrangement of the oscillators 11 and the optical shaping module 12 can be used to make each beam have a focal point, and each beam has a focal point with the same size and is located at a common intersection, which is applicable to the present application, and is not limited to the following several ways.
[0066] As an example, as shown in Figure 2As shown, the optical shaping module 12 includes N sets of optical modules corresponding one-to-one with each oscillator 11. Each optical module includes a deflector and a first lens. In this embodiment, the optical shaping module 12 includes a first optical module 12a and a second optical module 12b. The first optical module 12a includes a deflector 121 and a first lens 122. The input beam of the deflector 121 comes from the first oscillator 11a and can be used to adjust the propagation direction, position, and / or adjust the optical path tilt error of the input beam. In this example, it is mainly used to adjust the propagation direction and / or position of the input beam so that the beam can converge to a common focal point. The first lens 122 is disposed at the output end of the deflector 121 and converges the beam after adjusting the propagation direction to a common focal point. In this example, the first lens 122 is implemented using a convex lens. In actual use, any lens structure that can achieve a converging effect is applicable. The structure of the second optical module 12b is the same as that of the first optical module 12a, only the placement is different, and will not be described in detail here. The light beams emitted from the first optical module 12a and the second optical module 12b converge at the same position in the optical path, and the focal point is the same size. Due to the presence of the deflection mirror 121, the positions of the first oscillator 11a and the second oscillator 11b can be set as needed. In this example, the emission directions of the first oscillator 11a and the second oscillator 11b are parallel (i.e., the emitted light beams propagate in parallel). Further, as an example, the emission directions of the first oscillator 11a and the second oscillator 11b are perpendicular to the direction of the output light beam of the first modulation module 13.
[0067] As another example, such as Figure 3 As shown, the optical shaping module 12 includes a second lens 124 and N sets of optical elements 123 corresponding to each oscillator 11; in this embodiment, it includes two sets of optical elements 123. Each optical element 123 adjusts the beam emitted by the corresponding oscillator so that each beam is collimated and propagates parallel to each other. Each collimated beam has the same size (cross-sectional dimension) and divergence angle, and the distance between each beam can be set as needed. The second lens 124 is disposed at the emission end of each optical element 123 and converges each collimated beam into the first modulation module 13. In this example, the second lens 124 is implemented using a convex lens. Similarly, the second lens 124 converges two beams at the same position in the optical path, and the focal point is the same size. In this example, the emission directions of the first oscillator 11a and the second oscillator 11b are parallel; furthermore, in this example, the emission directions of the first oscillator 11a and the second oscillator 11b are parallel to the direction of the output beam of the first modulation module 13.
[0068] As yet another example, such as Figure 4As shown, the optical shaping module 12 includes N sets of third lenses 125 corresponding to each oscillator 11; in this embodiment, it includes two sets of third lenses 123. Each third lens 125 is arranged at the exit end of the corresponding oscillator to converge the light beams emitted by the corresponding oscillator. In this example, the third lens 125 is implemented as a convex lens. In this scheme, the third lens 125 is only used for light beam convergence, so the light beam incidence angle needs to be set by the position of each oscillator 11, the exit directions of each oscillator 11 intersect at a certain angle (greater than 0° and less than 180°), and the specific angle is configured according to the actual system setting needs. Two light beams can have the same size focal point after convergence and can be converged on a common focal point, which is not described here.
[0069] As shown, the first modulation module 13 is arranged at the focal point of each light beam output by the optical shaping module 12 to diffract and modulate each light beam so that at least one non-zero diffraction order of each light beam is coaxially superimposed. Figure 1 Specifically, in this embodiment, the first modulation module 13 includes a driver 131 and an acousto-optic modulator 132. The driver 131 provides N high-frequency power signals that vary with time according to requirements to achieve modulation of each light beam; in this example, the driver 131 provides two time-varying high-frequency power signals, which are a first high-frequency power signal A1(f1, t) and a second high-frequency power signal A2(f2, t), respectively. The frequency f1 of the first high-frequency power signal A1 varies with time, and the frequency f2 of the second high-frequency power signal A2 varies with time. The acousto-optic modulator 132 is arranged at the focal point of each light beam output by the optical shaping module 12 and diffracts and modulates each light beam output by the optical shaping module 12 based on the N high-frequency power signals; in this example, the first order and negative first order diffraction orders of each light beam are overlapped (in actual use, any order or multiple orders of light beam coaxial superposition are also available, not limited to this embodiment); when the acousto-optic modulator 132 receives a power signal, it generates a corresponding ultrasonic wave, which propagates in the acousto-optic medium to form a periodic refractive index change, thereby changing the direction of light propagation and producing diffraction (the diffraction angle of the corresponding light beam can be adjusted by changing the frequency), achieving modulation; in this embodiment, the ultrasonic wave is generated based on the frequency f1 to modulate the first convergent light beam emitted by the optical shaping module 12, and the ultrasonic wave is generated based on the frequency f2 to modulate the second convergent light beam emitted by the optical shaping module 12; the optical shaping module 12 and the first modulation module 13 are arranged to select appropriate incidence angles of the first convergent light beam, the second convergent light beam, the frequency f1, and the frequency f2, thereby coaxially superimposing the two light beams.
[0070]
[0071] It should be noted that, in order to achieve high diffraction efficiency, the wavelength of the light beam, the incidence angle of the light beam and the frequency of the high-frequency power signal in the first modulation module 13 are matched, so that at least one light beam satisfies the blaze angle diffraction condition of the grating in the first modulation module 13. As an example, the wavelength, the angle of incidence into the first modulation module 13 and the frequency f1 of the first beam convergent light beam are set so that it satisfies the blaze angle diffraction condition; as another example, the wavelength, the angle of incidence into the first modulation module 13 and the frequency f2 of the second beam convergent light beam are set so that it satisfies the blaze angle diffraction condition; both light beams can also satisfy the blaze angle diffraction condition, which will not be described here.
[0072] As shown in Figure 1 The optical shaping module 14 is arranged at the exit end of the first modulation module 13, and couples the coaxial overlapping light beams emitted by the first modulation module 13 into the next amplification module 15.
[0073] Specifically, in this embodiment, the optical shaping module 14 is implemented by a convex lens, which shapes the divergent coaxial overlapping light beams into parallel light beams and then transmits them into the amplification module 15, and separates the coaxial superimposed light beams from the remaining light beams (interference light beams); in actual use, any structure that can couple the coaxial overlapping light beams emitted by the first modulation module 13 into the amplification module 15 for amplification is applicable to the present application, and is not limited to this embodiment.
[0074] As shown in Figure 1 The amplification module 15 amplifies the power and pulse energy of the light beams emitted by the optical shaping module 14.
[0075] Specifically, the amplified light beams output by the amplification module 15 have higher power and pulse energy; the amplification module 15 can use one-stage amplification or multi-stage amplification cascade to achieve a preset gain, and the structure is not limited.
[0076] Specifically, the stability, beam quality and propagation characteristics of the optical amplification device 1 depend largely on the thermal state of the gain medium in the amplification module, and the two factors that determine the thermal state of the amplification medium are the pump power and the power extracted by the light beam to be amplified. In order to achieve stable laser operation, the present application uses constant power to pump the amplification medium. Further, the average power, wavelength, time distribution of power of the oscillator, the incidence angle of the first modulator 13, the frequencies f1, f2, power and time distribution are matched with each other, so that the energy of the coaxial overlapping light beams extracted from the amplifier remains constant within a time constant equal to the inverse of the characteristic frequency. In a pulse amplifier, the characteristic frequency is usually the nominal pulse repetition rate; in this way, a stable oscillator-amplifier structure with constant beam quality and constant processing behavior can be achieved, and can be externally triggered freely.
[0077] AsFigure 5 As another implementation of the present application, the optical amplification device 1 further comprises a second modulation module 16, which is arranged at the exit end of the amplification module 15, and is used to shape and / or modulate the pulse time sequence of the optical signal output by the amplification module 15. Further, the second modulation module 16 can also be used to modulate the power and pulse energy. As an example, the second modulation module 16 shields the unwanted pulse signals; the second modulation module 16 includes but is not limited to electro-optic modulators and acousto-optic modulators. Any means that can convert the optical signal output by the amplification module 15 into an output beam with a specific time distribution are suitable for the present application, and are not described here.
[0078] The present application also provides a laser, which comprises the optical amplification device 1 of the present application. The laser of the present application can expand the applicability of the laser by changing at least one of the pulse duration, pulse shape, wavelength and pulse repetition rate, and freely trigger the laser pulse with variable pulse length, pulse shape, wavelength and / or pulse repetition rate.
[0079] In summary, the present application provides an optical amplification device and a laser, which comprises an optical shaping module, a first modulation module, an optical shaping module, an amplification module and N oscillators, N being a natural number greater than or equal to 2; each oscillator emits a beam; the optical shaping module is arranged at the exit end of the N oscillators, converges each beam on a common focal point, and the focal point size of each beam is the same; the first modulation module is arranged at the focal point of each beam output by the optical shaping module, diffracts and modulates each beam to make at least one non-zero diffraction order beam coaxially superimposed; the optical shaping module is arranged at the exit end of the first modulation module, and couples the coaxially superimposed beams emitted by the first modulation module into the amplification module; the amplification module amplifies the power and / or pulse energy of the exit beam of the optical shaping module. The present application can produce laser pulses with combinable pulse length and / or pulse shape in any pulse time sequence, and meet the flexible process requirements of laser material processing. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.
[0080] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.
Claims
1. An optical magnification device, characterized in that, The optical magnification device includes at least: The system comprises an optical shaping module, a first modulation module, an optical shaping module, an amplification module, and N oscillators, where N is a natural number greater than or equal to 2. Each oscillator emits a beam of light; The optical shaping module is located at the output end of N oscillators, which converges the beams to a common focal point, and the focal point of each beam is the same size. The first modulation module is positioned at the focal point of each beam output by the optical shaping module, and diffracts and modulates each beam so that each beam has at least one non-zero diffraction order optically coaxially superimposed. The optical shaping module is disposed at the output end of the first modulation module, and couples the coaxial overlapping beam emitted by the first modulation module into the amplification module; The amplification module amplifies the power and pulse energy of the emitted beam from the optical shaping module.
2. The optical magnification device according to claim 1, characterized in that: The pulse characteristics of each beam provided by each oscillator include pulse width, pulse shape, wavelength, and pulse repetition rate, at least one of which is different.
3. The optical magnification device according to claim 1, characterized in that: Each oscillator is at least one of the following: continuous wave oscillator, Q-switched oscillator, gain-adjustable oscillator, and mode-locked oscillator.
4. The optical magnification device according to claim 1, characterized in that: The optical shaping module includes N sets of optical modules corresponding to each oscillator, and each optical module includes a deflection mirror and a first lens; The deflection mirror adjusts the propagation direction and / or position of the beam emitted by the corresponding oscillator; The first lens is disposed at the exit end of the corresponding deflector to converge the light beam emitted from the corresponding deflector.
5. The optical magnification device according to claim 1, characterized in that: The optical shaping module includes a second lens and N sets of optical elements corresponding to each oscillator; Each optical element adjusts the beam emitted by the corresponding oscillator to make the N beams of light that are emitted propagate in parallel and collimated, with each collimated beam having the same size and divergence angle. The second lens is disposed at the output end of each optical element, and converges each collimated beam into the first modulation module.
6. The optical magnification device according to claim 4 or 5, characterized in that: The emission directions of each oscillator are set in parallel.
7. The optical magnification device according to claim 1, characterized in that: The emission directions of each oscillator intersect; the optical shaping module includes N sets of third lenses corresponding to each oscillator. The third lenses are disposed at the emission end of the corresponding oscillator and converge the beam emitted by the corresponding oscillator into the first modulation module.
8. The optical magnification device according to claim 1, characterized in that: The first modulation module includes a driver and an acousto-optic modulator; The driver provides N channels of high-frequency power signals; The acousto-optic modulator performs diffraction modulation on each beam output by the optical shaping module based on N high-frequency power signals. The frequencies of the optical shaping module and each high-frequency power signal are set such that each beam has at least one non-zero diffraction order optically coaxially superimposed. Among them, N high-frequency power signals change over time as required to modulate each beam.
9. The optical magnification device according to claim 8, characterized in that: The wavelength of the beam, the incident angle of the beam, and the frequency of the high-frequency power signal in the driver are matched in the first modulation module, so that at least one beam satisfies the blaze angle diffraction condition of the grating in the first modulation module.
10. The optical magnification device according to claim 1, characterized in that: The optical shaping module is implemented using a convex lens.
11. The optical magnification device according to claim 1, characterized in that: The amplification module is pumped with constant power, and the energy of the coaxial overlapping beam extracted by the amplification module remains constant within a time constant equal to the reciprocal of the characteristic frequency.
12. The optical magnification device according to any one of claims 1-5 and 7-11, characterized in that: The optical amplification device further includes a second modulation module, which is disposed at the output end of the amplification module and is used to shape and / or modulate the pulse time sequence of the optical signal output by the amplification module.
13. A laser, characterized in that, The laser includes at least the optical amplification device as described in any one of claims 1-12.