Seed laser for implementing optical path regulation and optical fiber laser coherent combination system

Abstract

The invention discloses a seed laser for implementing optical path regulation and control and an optical fiber laser coherent combination system. The seed laser comprises a picosecond pulse source, a high-speed photoelectric detector, an intensity modulator, a single-frequency laser and a phase modulation unit, the picosecond pulse source is connected with the high-speed photoelectric detector, the single-frequency laser is connected with the intensity modulator, the high-speed photoelectric detector converts a detected pulse optical signal into a pulse electric signal and loads the pulse electric signal to the intensity modulator, and the intensity modulator performs intensity modulation on laser output by the single-frequency laser to convert the laser into a pulse optical signal; and the intensity modulator is connected with the phase modulation unit and outputs the pulse light signal output by the intensity modulator after performing phase modulation on the pulse light signal. The seed laser is used for an optical fiber laser coherent combination system, and when optical path adjustment is implemented, the seed laser has the remarkable advantage that the central wavelength of a picosecond pulse source does not need to be kept consistent with the central wavelength of single-frequency seed laser in the coherent combination system, that is, one picosecond pulse source can be used for a plurality of coherent combination systems with different central wavelengths from the picosecond pulse source.

Description

Technical Field

[0001] The present invention mainly relates to the field of optical fiber laser technology, in particular to a seed laser and an optical fiber laser coherent synthesis system for implementing optical path control. Background Art

[0002] As an important high-brightness light source, the power enhancement capability of high-power narrow-linewidth linearly polarized fiber lasers has always been a research hotspot in the laser field. Existing studies have shown that the output power of fiber lasers is limited by physical factors such as nonlinear effects and mode instability effects, and these limiting factors are related to polarization. Therefore, it is more difficult to increase the power of high-power narrow-linewidth linearly polarized fiber lasers.

[0003] Multi-channel laser coherent synthesis based on active phase control is an effective technical means to break through the output power of single-channel fiber lasers, and has now achieved a power output of 10,000 watts. In a coherent synthesis system, in order to obtain a good coherent synthesis effect, the optical path difference of the multi-channel lasers involved in the synthesis must be accurately controlled so that it is within the coherence length. The coherence length of a single-frequency laser is more than several thousand meters, which is an ideal light source for a coherent synthesis system. However, due to the serious influence of nonlinear effects and mode instability effects, the power of a single-frequency laser is currently only at a kilowatt output. In order to achieve high-power output while effectively suppressing nonlinear effects, phase modulation technology is usually used to widen the line width of a single-frequency seed laser to obtain a narrow line width seed with a line width of the order of 0.1nm, and then the narrow line width seed laser is injected into an all-fiber multi-stage amplification link for power amplification. The coherence length of the narrow line width seed is only a few centimeters, and when building an actual system, the optical path difference of each laser involved in the synthesis is difficult to control within this range, and factors such as output power fluctuations, external environmental disturbances, and jitter introduced by the water cooling system will also affect the fluctuation of the optical path difference. Therefore, high-precision optical path adjustment and control is one of the key technologies of coherent combining system.

[0004] At present, the common way to adjust the optical path is to replace the single-frequency seed laser in the coherent combining system with a picosecond pulse source, use a high-speed photodetector to measure the time delay Δτ between each light beam at the output end of the synthesized laser, and then calculate the optical path difference and perform optical path compensation based on this. This method requires the use of a picosecond pulse source with a strictly identical central wavelength to the seed laser of the coherent combining system. At the same time, since the central wavelength of the optical fiber device in the subsequent optical fiber amplification link is consistent with the seed laser wavelength, it means that different seed laser wavelengths need to use a picosecond pulse source with a corresponding wavelength, which is not conducive to the construction and experimental testing of the actual system. Therefore, the development of a precise control device for the optical path of fiber laser coherent combination that is independent of the central wavelength of the picosecond pulse source is of great significance for improving the efficiency of experimental testing. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention proposes a seed laser and a fiber laser coherent synthesis system for implementing optical path control.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a seed laser for implementing optical path control, comprising: a picosecond pulse source, a high-speed photodetector, an intensity modulator, a single-frequency laser, and a phase modulation unit; the output tail fiber of the picosecond pulse source is connected to the high-speed photodetector, and the high-speed photodetector converts the detected pulse light signal into a pulse electrical signal and loads it into the intensity modulator; the intensity modulator is connected to the single-frequency laser, and the intensity modulator performs intensity modulation on the laser output by the single-frequency laser to convert the laser into a pulse light signal; the phase modulation unit is connected to the intensity modulator, and the phase modulation unit performs phase modulation on the pulse light signal output by the intensity modulator and then outputs it.

[0008] According to the seed laser for implementing optical path control provided by the present invention, the phase modulation unit includes a modulation signal source, a radio frequency signal amplifier, and an electro-optical phase modulator; the modulation signal source is connected to the radio frequency signal amplifier, and the radio frequency signal amplifier amplifies the modulation signal output by the modulation signal source and then loads it into the electro-optical phase modulator; the intensity modulator is connected to the electro-optical phase modulator, and the electro-optical phase modulator phase modulates the pulse light signal output by the intensity modulator.

[0009] According to the seed laser for implementing optical path control provided by the present invention, the seed laser also includes: a power preamplifier; an electro-optical phase modulator is connected to the power preamplifier, and the pulse light signal output by the electro-optical phase modulator is output after power amplification by the power preamplifier.

[0010] In a second aspect, the present invention further provides a fiber laser coherent combining system, comprising: a seed laser, wherein the seed laser is any of the seed lasers described above for implementing optical path control.

[0011] According to the fiber laser coherent synthesis system provided by the present invention, the system also includes: a beam splitter, a phase modulator array, a fiber delay line array, an amplifier array, a laser output end cap array, a beam synthesis device, a plurality of beam splitters, a spot analyzer, an output end photodetector, an oscilloscope, a phase controller, and a dynamic fiber delay line controller;

[0012] The output end of the seed laser is connected to a beam splitter, which divides the seed laser into N beams;

[0013] The phase modulator array includes N phase modulators, the fiber delay line array includes N fiber delay lines, the amplifier array includes N fiber laser amplification links, and the laser output end cap array includes N fiber end caps; each unit light beam output by the beam splitter is correspondingly connected to a phase modulator, a fiber delay line, a fiber laser amplification link, and a fiber end cap, and each fiber delay line is connected to a dynamic fiber delay line controller, and the dynamic fiber delay line controller controls the optical path by controlling the fiber delay line;

[0014] Each unit beam output by the beam splitter is phase modulated by the corresponding phase modulator, optical path controlled by the fiber delay line, power amplified by the fiber laser amplifier link, and then output to the beam combining device through the fiber end cap. The beam combining device combines N unit beams and outputs them.

[0015] The laser output by the beam synthesis device is split by multiple beam splitters, and a part of the laser is transmitted to the spot analyzer for observing the far-field spot and evaluating the coherent synthesis effect. A part of the laser is transmitted to the output end photodetector, and the signal detected by the output end photodetector is transmitted to the oscilloscope and the phase controller;

[0016] The phase controller is connected to each phase modulator in the phase modulator array and is used for controlling the phase of each unit light beam.

[0017] According to the fiber laser coherent synthesis system provided by the present invention, the multiple beam splitters include: a first beam splitter and a second beam splitter; the laser output by the beam synthesis device is split by the first beam splitter, wherein a part of the laser is output to the free space, and a part of the laser is incident on the second beam splitter and split by the second beam splitter; the second beam splitter splits a part of the laser and transmits it to the spot analyzer, and the second beam splitter splits another part of the laser and transmits it to the output end photoelectric detector.

[0018] The fiber laser coherent combining system provided by the present invention also includes: a lens arranged between the second beam splitter and the spot analyzer; the second beam splitter splits a part of the laser beam and transmits it to the spot analyzer through the lens.

[0019] The present invention proposes a seed laser for implementing optical path control, which is mainly composed of a picosecond pulse source, a high-speed photodetector, an intensity modulator and a single-frequency laser. Based on the seed laser for optical path control of the fiber laser coherent synthesis system, the optical path difference measurement of the optical path of the fiber laser coherent synthesis system is implemented, and combined with the optical path compensation of the energy transmission fiber fusion and the optical path compensation of the dynamic fiber delay line, the goal of fine adjustment of the optical path of each fiber laser link in the coherent synthesis system can be achieved. When implementing the optical path adjustment, the significant advantage of the seed laser is that the central wavelength of the picosecond pulse source does not need to be consistent with the central wavelength of the single-frequency seed laser in the coherent synthesis system, that is, a high-performance picosecond pulse source can be used for multiple high-power coherent synthesis systems with different central wavelengths. The construction, operation and dismantling of the present invention are simple and easy to operate, and have very little impact on the structure of the coherent synthesis system, which will greatly save experimental costs and improve experimental efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic structural diagram of a seed laser for implementing optical path control in an embodiment;

[0022] Figure 2 is a schematic structural diagram of a fiber laser coherent synthesis system in one embodiment;

[0023] Figure 3 is a structural diagram of a seed laser based on single-frequency phase modulation provided by an embodiment;

[0024] Figure 4 is a schematic structural diagram of a laser for implementing optical path control in an embodiment;

[0025] Wherein, the accompanying drawings are marked as follows:

[0026] 1: Picosecond pulse source; 2: High-speed photodetector; 3: Single-frequency laser; 4: Intensity modulator; 5: Electro-optic phase modulator; 6: Modulation signal source; 7: RF signal amplifier; 8: Power pre-amplifier; 9: Single-frequency seed laser;

[0027] 1-1: seed laser; 1-2: beam splitter; 1-3: phase modulator array; 1-4: fiber delay line array; 1-5: amplifier array; 1-6: laser output end cap array; 1-7: beam synthesizer; 1-8: first beam splitter; 1-9: second beam splitter; 1-10: lens; 1-11: spot analyzer; 1-12: output photodetector; 1-13: oscilloscope; 1-14: phase controller; 1-15: dynamic fiber delay line controller. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that, in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0030] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0031] Reference Figure 1 As an optional embodiment, a seed laser for implementing optical path control is provided, comprising a picosecond pulse source 1, a high-speed photodetector 2, an intensity modulator 4, a single-frequency laser 3, and a phase modulation unit;

[0032] The output pigtail of the picosecond pulse source 1 is connected to the high-speed photodetector 2, and the single-frequency laser 3 is connected to the intensity modulator 4. The high-speed photodetector 2 converts the detected pulse light signal into a pulse electrical signal and loads it into the intensity modulator 4. The intensity modulator 4 modulates the intensity of the output laser of the single-frequency laser 3 to convert it into a pulse light signal.

[0033] The intensity modulator 4 is connected to the phase modulation unit, and the phase modulation unit performs phase modulation on the pulse light signal output by the intensity modulator 4 and then outputs the signal.

[0034] Furthermore, the phase modulation unit includes a modulation signal source 6, a radio frequency signal amplifier 7, and an electro-optical phase modulator 5;

[0035] The modulation signal source 6 is connected to the RF signal amplifier 7, which amplifies the modulation signal output by the modulation signal source 6 and loads it to the electro-optical phase modulator 5; the intensity modulator 4 is connected to the electro-optical phase modulator 5, which phase modulates the pulse light signal output by the intensity modulator 4.

[0036] Furthermore, the seed laser further comprises a power preamplifier 8, the electro-optical phase modulator 5 is connected to the power preamplifier 8, and the pulse optical signal output by the electro-optical phase modulator 5 is output after being power-amplified by the power preamplifier 8.

[0037] The basic principle of the fiber laser coherent synthesis system is to divide the same seed laser into N sub-beams, and the N sub-beams enter N fiber laser transmission links for phase modulation, optical path control, and power amplification in the power amplifier link. Then, the output beams of the N fiber laser transmission links are spatially spliced ​​through a beam synthesis device, and the purpose of high-brightness synthetic laser output is achieved by precisely controlling parameters such as the phase and optical path of each beam.

[0038] Specifically, see Figure 2 , a fiber laser coherent synthesis system, including a seed laser 1-1, a beam splitter 1-2, a phase modulator array 1-3, a fiber delay line array 1-4, an amplifier array 1-5, a laser output end cap array 1-6, a beam synthesis device 1-7, a first beam splitter 1-8, a second beam splitter 1-9, a lens 1-10, a spot analyzer 1-11, an output end photodetector 1-12, an oscilloscope 1-13, a phase controller 1-14, and a dynamic fiber delay line controller 1-15;

[0039] The output end of the seed laser 1-1 is connected to the beam splitter 1-2, and the beam splitter 1-2 splits the seed laser into N beams;

[0040] The phase modulator array 1-3 includes N phase modulators, the fiber delay line array 1-4 includes N fiber delay lines, and the amplifier array 1-5 includes N fiber laser amplification links; the laser output end cap array 1-6 includes N fiber end caps; each unit light beam output by the beam splitter 1-2 is correspondingly connected to a phase modulator, a fiber delay line, a fiber laser amplification link and a fiber end cap, and each fiber delay line is connected to a dynamic fiber delay line controller 1-15, and the dynamic fiber delay line controller 1-15 controls the optical path by controlling the fiber delay line;

[0041] Each unit beam output by the beam splitter 1-2 is phase modulated by a correspondingly connected phase modulator, optical path controlled by an optical fiber delay line, power amplified by an optical fiber laser amplifier link, and then output to the beam combiner 1-7 through an optical fiber end cap. The beam combiner 1-7 combines N unit beams and outputs them;

[0042] The laser beam outputted by the beam combining device 1-7 is split by a plurality of beam splitters, and a part of the laser beam is transmitted to the spot analyzer 1-11 for observing the far-field spot and evaluating the coherent combining effect, and a part of the laser beam is transmitted to the output end photodetector 1-12, and the signal detected by the output end photodetector is transmitted to the oscilloscope 1-13 and the phase controller 1-14;

[0043] The phase controller 1-14 is connected to each phase modulator in the phase modulator array 1-3 and is used for controlling the phase of each unit light beam.

[0044] Optionally, the plurality of beam splitters include: a first beam splitter 1-8 and a second beam splitter 1-9;

[0045] The laser output by the beam synthesizer 1-7 passes through the first beam splitter 1-8, and the laser output by the beam synthesizer 1-7 is split by the first beam splitter 1-8, wherein most of the main laser power is output to the free space, and a small part of the laser power is incident on the second beam splitter 1-9, and is split by the second beam splitter 1-9. A part of the laser is split by the second beam splitter 1-9 and transmitted to the spot analyzer 1-11 after passing through the lens 1-10, which is used to observe the far-field spot and evaluate the coherent synthesis effect. A part of the laser is split by the second beam splitter 1-9 and is transmitted to the output end photodetector 1-12. The signal detected by the output end photodetector 1-12 is transmitted to the oscilloscope 1-13 and the phase controller 1-14. The phase controller 1-14 is connected to each phase modulator in the phase modulator array 1-3, and is used to control the phase of each unit light beam.

[0046] For the active phase control system, the output end photodetector 1-12 converts the detected optical signal into an electrical signal, and the phase controller 1-14 is used to achieve phase locking of each laser in the system. There are many methods for active phase control, which will not be introduced in the present invention.

[0047] Reference Figure 3 , a structural diagram of a seed laser based on single-frequency phase modulation provided by an embodiment, Figure 2 The seed laser originally used Figure 3 The seed laser based on single-frequency phase modulation shown in the figure includes a single-frequency seed laser 9, a modulation signal source 6, a radio frequency signal amplifier 7, an electro-optical phase modulator 5 and a power pre-amplifier 8. The phase modulation unit includes a modulation signal source 6, a radio frequency signal amplifier 7 and an electro-optical phase modulator 5. The modulation signal source 6 is connected to the radio frequency signal amplifier 7, and the radio frequency signal amplifier 7 amplifies the modulation signal output by the modulation signal source 6 and then loads it to the electro-optical phase modulator 5. The seed laser output by the single-frequency seed laser 9 passes through the electro-optical phase modulator 5 and the power pre-amplifier 8 and enters the beam splitter 1-2. Figure 2 The fiber laser coherent combining system shown.

[0048] exist Figure 2 When the fiber laser coherent combining system shown in the figure performs optical path control, Figure 2 The seed laser 1-1 in (using a single-frequency seed laser) is replaced by Figure 4 Picosecond pulse source 1 is shown. Figure 4 , Figure 4 1 is a schematic diagram of the structure of a laser for implementing optical path control in an embodiment, comprising a picosecond pulse source 1, a modulation signal source 6, a radio frequency signal amplifier 7, and an electro-optical phase modulator 5. The radio frequency signal amplifier 7 amplifies the modulation signal output by the modulation signal source 6 and then loads it to the electro-optical phase modulator 5. It is required that the picosecond pulse source 1 and the Figure 2 The central wavelength of the single-frequency seed laser used by Zhongyuan is the same. Picosecond pulse source 1 passes through the electro-optic phase modulator 5 and the power pre-amplifier 8, and then enters the beam splitter 1-2 Figure 2 The fiber laser coherent combining system shown in the figure. The specific process of optical path control is: Figure 2 The output end photoelectric detector 1-12 converts the detected optical signal into an electrical signal. After the electrical signal is analyzed and processed by the oscilloscope 1-13, the transmission time delay Δτ of the other N-1 fiber laser transmission links is obtained based on the fiber laser link with the longest optical path in the fiber laser coherent synthesis system. Then, the optical path of each laser in the fiber laser coherent synthesis system is precisely controlled by combining the coarse optical path adjustment of the fused energy transfer fiber and the fine adjustment of the dynamic fiber delay line controller 1-15.

[0049] However, for the construction and verification testing of actual synthetic systems, Figure 3 When the picosecond pulse source in the system is inconsistent with the central wavelength of the single-frequency seed laser, due to the filtering and isolation effect of the narrow linewidth fiber device in the fiber laser link, the picosecond pulse source signal cannot be transmitted in the fiber laser amplification link in the system. In order to achieve the purpose of optical path adjustment, the picosecond pulse source can only be replaced or a wavelength tunable picosecond pulse source can be selected, which increases the experimental test cost. To this end, the present invention proposes the following method: Figure 1 The wavelengths shown can be flexibly switched for Figure 2 The fiber laser coherent combining system shown here is a seed laser for optical path control.

[0050] based on Figure 2 The fiber laser coherent combining system shown in the figure is Figure 1 The seed laser shown for implementing optical path control can be applied to the fiber laser coherent synthesis system. When the fiber laser coherent synthesis system implements optical path control, its significant advantage is that the central wavelength of the picosecond pulse source does not need to be consistent with the central wavelength of the single-frequency seed laser in the coherent synthesis system, that is, one picosecond pulse source can be used for multiple coherent synthesis systems with different central wavelengths.

[0051] In one embodiment, a fiber laser coherent synthesis system is provided, and its structure diagram is as follows: Figure 2 As shown, the seed laser 1-1 adopts Figure 1 The seed laser used to implement optical path control is shown in FIG. The optical path measurement and control process of the fiber laser coherent synthesis system is as follows: Figure 3 As shown, the single-frequency seed laser in the fiber laser coherent synthesis system is replaced with a picosecond pulse source. Figure 1 The seed laser shown in the figure is to connect the picosecond pulse source output laser directly to the high-speed photodetector through the pigtail. The high-speed photodetector converts the detected pulse light signal into a pulse electrical signal and loads it into the intensity modulator. The intensity modulator then modulates the intensity of the single-frequency laser to convert it into a pulse light signal, which then enters the beam splitter 1-2. Figure 2The fiber laser coherent synthesis system shown in the figure detects the laser signal output from the beam synthesis end to obtain the transmission delay time Δτ between the other (N-1) fiber lasers and the reference laser link, and uses this as a basis for precise optical path control. The significant advantage of this solution is that the central wavelength of the picosecond pulse source does not need to be consistent with the central wavelength of the single-frequency seed laser in the original fiber laser coherent synthesis system, that is, a high-performance picosecond pulse source can be used for multiple high-power coherent synthesis systems with different central wavelengths, achieving the goal of flexibly adjusting the optical path of fiber laser coherent synthesis systems with different seed laser central wavelengths. In addition, during the construction, operation and dismantling of the optical path adjustment device, the impact on the existing system structure is very small, which will greatly save experimental costs and improve experimental efficiency.

[0052] based on Figure 1 The process of finely controlling the optical path of the fiber laser coherent synthesis system using the seed laser for optical path control is as follows:

[0053] Step 1: Figure 1 Seed laser replacement for implementing optical path control Figure 2 Seed laser for the fiber laser coherent combining system shown.

[0054] Step 2: Connect the picosecond pulse source output laser directly to the high-speed photodetector through the pigtail. The high-speed photodetector converts the detected pulse light signal into a pulse electrical signal and loads it into the intensity modulator. The intensity modulator then modulates the intensity of the single-frequency laser to convert it into a pulse light signal. The phase-modulated pulse light signal enters the power preamplifier for power amplification. The power-amplified pulse light signal enters the beam splitter through the beam splitter. Figure 2 The fiber laser coherent combining system shown.

[0055] Step 3: In Figure 2 At the combined laser output end of the fiber laser coherent combining system shown, the output end photodetector 1-12 converts the synthesized output optical signal into an electrical signal. After analyzing and processing the electrical signal using an oscilloscope, the fiber laser link with the longest optical path in the coherent combining system is determined according to the signal transmission time, and the fiber laser link with the longest optical path is used as a benchmark to obtain the transmission time delay Δτ of the other N-1 fiber laser links compared with it.

[0056] Step 4: According to the formula L=cΔτ / n, first calculate the energy transfer fiber length L that needs to be compensated for the other N-1 fiber laser links, where c represents the propagation speed of light in a vacuum and n represents the refractive index of the fiber core. Then, in the other N-1 fiber laser links, a power transfer fiber with a length of L=cΔτ / n is fused. This method can compensate the optical path difference between each light beam to 1-2 cm, so that the optical path between each fiber laser link in the fiber laser coherent combining system is basically matched.

[0057] Step 5: Based on the fourth step, a dynamic fiber delay line controller is used to adjust the fiber delay lines on each fiber laser transmission link to further fine-tune the optical path of each laser. Currently, the control accuracy of commercial fiber delay lines can reach 0.1ps, which can adjust the coherence between each light beam to the optimal state as much as possible, thereby maintaining efficient coherent synthesis laser output.

[0058] Matters not covered by the present invention are known technologies.

[0059] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present invention. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements may be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A seed laser for implementing optical path control, characterized in that: include: Picosecond pulse source, high-speed photodetector, intensity modulator, single-frequency laser, phase modulation unit; The output pigtail of the picosecond pulse source is connected to a high-speed photodetector, which converts the detected pulse light signal into a pulse electrical signal and loads it into an intensity modulator; The intensity modulator is connected to the single-frequency laser, and the intensity modulator modulates the intensity of the laser output by the single-frequency laser to convert the laser into a pulse light signal; The phase modulation unit is connected to the intensity modulator, and the phase modulation unit performs phase modulation on the pulse light signal output by the intensity modulator and then outputs the signal.

2. The seed laser for implementing optical path control according to claim 1, characterized in that: The phase modulation unit includes a modulation signal source, a radio frequency signal amplifier, and an electro-optical phase modulator; The modulation signal source is connected to the radio frequency signal amplifier, and the radio frequency signal amplifier amplifies the modulation signal output by the modulation signal source and then loads it to the electro-optical phase modulator; The intensity modulator is connected to the electro-optical phase modulator, and the electro-optical phase modulator performs phase modulation on the pulse light signal output by the intensity modulator.

3. The seed laser for implementing optical path control according to claim 2, characterized in that: The seed laser also includes: a power pre-amplifier; The electro-optic phase modulator is connected to the power pre-amplifier, and the pulse optical signal output by the electro-optic phase modulator is output after being power-amplified by the power pre-amplifier.

4. A fiber laser coherent synthesis system, characterized in that: The invention comprises a seed laser, wherein the seed laser is the seed laser for implementing optical path control as described in any one of claims 1 to 3.

5. The fiber laser coherent combining system according to claim 4, characterized in that: The system also includes: a beam splitter, a phase modulator array, an optical fiber delay line array, an amplifier array, a laser output end cap array, a beam synthesis device, a plurality of beam splitters, a spot analyzer, an output end photodetector, an oscilloscope, a phase controller, and a dynamic optical fiber delay line controller; The output end of the seed laser is connected to a beam splitter, which divides the seed laser into N beams; The phase modulator array includes N phase modulators, the fiber delay line array includes N fiber delay lines, the amplifier array includes N fiber laser amplification links, and the laser output end cap array includes N fiber end caps; each unit light beam output by the beam splitter is correspondingly connected to a phase modulator, a fiber delay line, a fiber laser amplification link, and a fiber end cap, and each fiber delay line is connected to a dynamic fiber delay line controller, and the dynamic fiber delay line controller controls the optical path by controlling the fiber delay line; Each unit beam output by the beam splitter is phase modulated by the corresponding phase modulator, optical path controlled by the fiber delay line, power amplified by the fiber laser amplifier link, and then output to the beam combining device through the fiber end cap. The beam combining device combines N unit beams and outputs them. The laser output by the beam synthesis device is split by multiple beam splitters, and a part of the laser is transmitted to the spot analyzer for observing the far-field spot and evaluating the coherent synthesis effect. A part of the laser is transmitted to the output end photodetector, and the signal detected by the output end photodetector is transmitted to the oscilloscope and the phase controller; The phase controller is connected to each phase modulator in the phase modulator array and is used for controlling the phase of each unit light beam.

6. The fiber laser coherent combining system according to claim 5, characterized in that: The plurality of beam splitters include: a first beam splitter and a second beam splitter; The laser light outputted by the beam combining device is split by the first beam splitter, wherein a part of the laser light is outputted to the free space, and a part of the laser light is incident on the second beam splitter and is split by the second beam splitter; The second beam splitter splits a part of the laser beam and transmits it to the spot analyzer, and the second beam splitter splits another part of the laser beam and transmits it to the output end photoelectric detector.

7. The fiber laser coherent combining system according to claim 6, characterized in that: Also includes: A lens disposed between the second beam splitter and the spot analyzer; The second beam splitter splits a part of the laser beam and transmits it to the spot analyzer through a lens.

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