Phase control method and system based on coherent combination

Abstract

The invention belongs to the technical field of laser, and discloses a phase control method and system based on coherent synthesis, and the method comprises the steps: measuring the peak intensity of a main pulse and background noise of a to-be-optimized coherent synthesis pulse, so as to calculate the contrast of the to-be-optimized coherent synthesis pulse; measuring the peak intensity of the main pulse and the background noise of each channel pulse so as to calculate the contrast of each channel pulse; based on the contrast ratio of the pulses of each channel, adopting a phase locking algorithm, and selecting any channel as a reference channel j to obtain a phase error between the pulse of the channel i and the pulse of the reference channel j; and feeding back the phase error to correct the phase of the pulse of each channel until the contrast ratio of the coherent synthesis pulse to be optimized is maximum, and realizing phase locking of the pulse of each channel. By accurately controlling the phase difference of the sub-beams, the main pulse intensity is enhanced to the maximum extent, and background noise and side lobes are suppressed, so that the pulse contrast is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of laser technology, and more specifically, relates to a phase control method and system based on coherent synthesis. Background Art

[0002] In multi-beam coherent combining, multiple sub-beams must be precisely phase-synchronized in both time and space to form a high-intensity main pulse. However, due to environmental disturbances (such as temperature changes and mechanical vibrations) and the non-ideal properties of optical components, phase errors between sub-beams can lead to a decrease in pulse contrast, manifesting as increased noise and enhanced sidelobes.

[0003] While conventional phase control methods (such as direct interferometry or heterodyne detection) can partially address the phase synchronization issue, they are insufficient in providing feedback on pulse contrast, and low pulse contrast can severely impact beam quality. Therefore, an efficient and stable phase control method is urgently needed to improve pulse contrast in multi-beam coherent combining. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a phase control method and system based on coherent synthesis, the purpose of which is to improve the contrast of laser pulses.

[0005] To achieve the above object, the present invention provides a phase control method based on coherent combining, comprising:

[0006] Measuring the peak intensities of the main pulse and background noise of the coherent synthesis pulse to be optimized to calculate the contrast of the coherent synthesis pulse to be optimized; measuring the peak intensities of the main pulse and background noise of the pulses of each channel to calculate the contrast of the pulses of each channel; wherein the coherent synthesis pulse to be optimized is obtained by coherently combining the pulses of each channel;

[0007] Based on the contrast of the pulses of each channel, the Phase-locking algorithm, and select any channel as the reference channel j, get the phase error between the pulse of channel i and the pulse of reference channel j, i, j∈{1, 2, …, n}, and i≠j, n is the total number of channels;

[0008] Feedback is performed on the phase error to correct the phase of each channel pulse until the contrast of the coherent synthesis pulse to be optimized is maximized, thereby achieving phase locking of the pulses of each channel.

[0009] Furthermore, the phase error between the pulse of channel i and the pulse of reference channel j is for:

[0010]

[0011] Among them, β Ti and β Ri They are The synthetic coherence coefficient of the transmitted pulse and the synthetic coherence coefficient of the reflected pulse corresponding to channel i in the phase-locked system; is the average value of the pulse contrast of n channels; k i is the pulse contrast of channel i, k j is the pulse contrast of reference channel j.

[0012] Furthermore, β Ti and β Ri The calculation method is:

[0013]

[0014] in, and are the coherent synthesis pulses to be optimized and input to Transmission path coherent synthesis pulse contrast and reflection path coherent synthesis pulse contrast in phase-locked system; and are the main pulse peak intensity and background noise intensity of the coherent synthesis pulse in the transmission path respectively; and are the main pulse peak intensity and background noise intensity of the coherent synthesis pulse in the reflection path, respectively.

[0015] Furthermore, the contrast k of the coherent synthesis pulse to be optimized is c The contrast ratio of each channel pulse is calculated as follows:

[0016]

[0017] in, is the peak intensity of the main pulse of the coherent synthesis pulse to be optimized, k is the background noise intensity of the coherent synthesis pulse to be optimized; i is the pulse contrast of channel i, is the peak intensity of the main pulse of channel i, is the background noise intensity of the pulse in channel i.

[0018] The present invention also provides a phase control system based on coherent synthesis, comprising:

[0019] a contrast calculation module, configured to measure the peak intensities of the main pulse and background noise of the coherent synthesis pulse to be optimized, so as to calculate the contrast of the coherent synthesis pulse to be optimized; and to measure the peak intensities of the main pulse and background noise of the pulses of each channel, so as to calculate the contrast of the pulses of each channel; wherein the coherent synthesis pulse to be optimized is obtained by coherently combining the pulses of each channel;

[0020] The phase error calculation module uses the contrast of the pulses of each channel to calculate the phase error. Phase-locking algorithm, and select any channel as the reference channel j, get the phase error between the pulse of channel i and the pulse of reference channel j, i, j∈{1, 2, …, n}, and i≠j, n is the total number of channels;

[0021] The phase modulator is used to feed back the phase error to correct the phase of each channel pulse until the contrast of the coherent synthesis pulse to be optimized is maximized, thereby achieving phase locking of the pulses of each channel.

[0022] Furthermore, in the contrast calculation module, a photodetector with a time gating device is used to measure the peak intensity.

[0023] The present invention also provides an electronic device comprising a computer-readable storage medium and a processor;

[0024] The computer-readable storage medium is used to store executable instructions;

[0025] The processor is configured to read the executable instructions stored in the computer-readable storage medium to execute any one of the above-mentioned phase control methods based on coherent synthesis.

[0026] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the phase control method based on coherent synthesis as described in any one of the above items is implemented.

[0027] The present invention also provides a computer program product, comprising a computer program, which enables the computer to execute any of the above-mentioned phase control methods based on coherent synthesis when the computer program is run on the computer.

[0028] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0029] (1) The present invention is based on Phase-locked technology improves pulse contrast while achieving high-precision phase locking. Specifically, by measuring the peak intensity of the main pulse and background noise in the coherent synthesis pulse to be optimized and the pulses of each channel, the corresponding pulse contrast is calculated and the contrast information is input into the In the phase-locked system, the phase error obtained in each channel can represent the contrast information of the coherent synthesized pulse to be optimized, and then the phase error of each channel is feedback controlled. When the pulse contrast of each channel reaches the maximum value, the contrast of the coherent synthesized pulse to be optimized also reaches the maximum value accordingly. In this way, while achieving precise control of the phase of each channel light beam, the main pulse intensity is maximized while suppressing noise and sidelobes.

[0030] at the same time, Phase-locked technology is a high-precision phase-locked technology based on the principle of polarization interference. It has high sensitivity and strong anti-interference ability, and can improve beam combining efficiency and phase-locking efficiency.

[0031] In summary, the present invention utilizes improved Phase-locked technology significantly improves pulse contrast by precisely controlling the phase of each sub-beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of a phase control method based on coherent combining in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0034] Example 1

[0035] like Figure 1 As shown, an embodiment of the present invention provides a phase control method based on coherent combining, which mainly includes:

[0036] The peak intensities of the main pulse and background noise of the coherently synthesized pulse to be optimized are measured to calculate the contrast of the coherently synthesized pulse to be optimized. The peak intensities of the main pulse and background noise of the pulses of each channel are measured to calculate the contrast of the pulses of each channel. The coherently synthesized pulse to be optimized is obtained by coherently combining the pulses of each channel. Preferably, a photodetector with a time gating device is used to capture the coherently synthesized pulse to be optimized and the pulses of each channel, and the peak intensities of the corresponding main pulse and background noise are measured respectively to improve detection accuracy.

[0037] Based on the contrast of each channel pulse, Phase-locking algorithm is used, and any channel is selected as reference channel j to obtain the phase error between the pulse of channel i and the pulse of reference channel j, i, j∈{1, 2, …, n}, and i≠j, n is the total number of channels, n≥2.

[0038] Feedback is provided on the phase error between each channel and the reference channel to correct the phase of each channel's pulse until the contrast of the coherently synthesized pulse to be optimized is maximized, achieving phase lock of the pulses in each channel. In this embodiment of the present invention, feedback is provided on the phase error between each channel and the reference channel via a phase modulator; when the contrast of the coherently synthesized pulse to be optimized does not vary within a certain range, it can be considered that the contrast of the coherently synthesized pulse to be optimized is maximized.

[0039] In the embodiment of the present invention, the constructed pulse contrast model is:

[0040]

[0041] β=k c -k

[0042] Where, k is the single pulse contrast, I m is the peak intensity of the main pulse of a single pulse, I n is the background noise intensity of a single pulse, k c is the coherent synthesis pulse contrast, is the peak intensity of the main pulse of the coherently combined pulse, is the background noise intensity of the coherent synthesis pulse, and β is the pulse synthesis coherence coefficient.

[0043] In the embodiment of the present invention, the pulse contrast model is introduced into Phase-locked algorithm;

[0044]

[0045] Where, is the peak intensity of the main pulse of the coherent synthesis pulse in the transmission path, is the background noise intensity of the coherent synthesis pulse in the transmission path, For the transmission path coherent synthesis pulse contrast, is the peak intensity of the main pulse of the coherent synthesis pulse in the reflection path, is the background noise intensity of the coherent synthesis pulse in the reflection path, It is the coherent synthesis pulse contrast of the reflection path; is the peak intensity of the main pulse of channel i, is the background noise intensity of the pulse in channel i, k i is the pulse contrast of channel i, i∈{1, 2,…, n}; is the average value of the pulse contrast of n channels, βT is the synthetic coherence coefficient of the transmitted pulse, β R is the synthetic coherence coefficient of the reflected pulse.

[0046] The laser to be optimized is coherently combined by n beams of vertically polarized lasers from n channels. The phase-locked system consists of a quarter-wave plate, a polarization beam splitter cube, and a photodetector. The transmitted laser and reflected laser light passing through the polarization beam splitter cube are received by two photodetectors, respectively. Taking n=2 as an example, the detection results are:

[0047]

[0048] Where k1 is the pulse contrast of channel 1, k2 is the pulse contrast of channel 2, β T is the synthetic coherence coefficient of the transmitted pulse, β R is the synthetic coherence coefficient of the reflected pulse, is the phase difference to be corrected.

[0049] After calculation, we can get:

[0050]

[0051] For multiple channels, any one channel is selected as the reference channel j. Based on the contrast of the pulses of each channel, the detection results of the transmitted laser and reflected laser corresponding to channel i and reference channel j are:

[0052]

[0053] Where k i is the pulse contrast of channel i, k j is the pulse contrast of reference channel j, β Ti is the synthetic coherence coefficient of the transmission path pulse corresponding to channel i, β Ri is the synthetic coherence coefficient of the reflected pulse corresponding to channel i, is the phase error between channel i and reference channel j, is the phase difference to be corrected, i, j∈{1, 2, …, n}, and i≠j.

[0054] After calculation, we can get:

[0055]

[0056] The calculated phase difference to be corrected is fed back to the phase controller, and the phase controller corrects the phase, thereby improving the pulse contrast.

[0057] Example 2

[0058] The embodiment of the present invention provides a phase control system based on coherent combining, which mainly includes:

[0059] The contrast calculation module is used to measure the peak intensity of the main pulse and background noise of the coherent synthesis pulse to be optimized to calculate the contrast of the coherent synthesis pulse to be optimized, and to measure the peak intensity of the main pulse and background noise of each channel pulse to calculate the contrast of each channel pulse.

[0060] Phase error calculation module, used for contrast based on pulses of each channel, using Phase-locking algorithm is used, and any channel is selected as the reference channel j. The phase error between channel i and reference channel j is obtained, i, j∈{1, 2, …, n}, and i≠j, n is the total number of channels, n≥2.

[0061] The phase modulator is used to provide feedback on the phase error between each channel and the reference channel to correct the phase of the pulse of each channel until the contrast of the coherent synthesis pulse to be optimized is maximized, thereby achieving phase locking of the pulses of each channel.

[0062] The relevant technical solutions are the same as above and will not be repeated here.

[0063] Example 3

[0064] An embodiment of the present invention provides an electronic device including a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the steps of the phase control method based on coherent synthesis in the above-mentioned embodiment 1 are implemented.

[0065] The relevant technical solutions are the same as above and will not be repeated here.

[0066] Example 4

[0067] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the phase control method based on coherent synthesis in the above-mentioned embodiment 1 are implemented.

[0068] Specifically, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0069] The relevant technical solutions are the same as above and will not be repeated here.

[0070] Example 5

[0071] An embodiment of the present invention provides a computer program product, including a computer program. When the computer program is run on a computer, the computer is caused to execute the steps of the phase control method based on coherent synthesis in the above-mentioned embodiment 1.

[0072] The relevant technical solutions are the same as above and will not be repeated here.

[0073] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A phase control method based on coherent combining, characterized in that: include: measuring the peak intensities of the main pulse and background noise of the coherent synthesis pulse to be optimized to calculate the contrast of the coherent synthesis pulse to be optimized; Measuring the peak intensity of the main pulse and background noise of each channel pulse to calculate the contrast of each channel pulse; wherein the coherent synthesis pulse to be optimized is obtained by coherently combining the pulses of each channel; Based on the contrast of the pulses of each channel, the - Couillaud phase-locking algorithm, and select any channel as the reference channel j, and obtain the phase error between the pulse of channel i and the pulse of reference channel j, i, j ∈ {1, 2, …, n}, and i ≠ j, n is the total number of channels; Feedback is performed on the phase error to correct the phase of each channel pulse until the contrast of the coherent synthesis pulse to be optimized is maximized, thereby achieving phase locking of the pulses of each channel.

2. The phase control method based on coherent combining according to claim 1, characterized in that: Phase error between the pulse of channel i and the pulse of reference channel j for: Among them, β Ti and β Ri They are -The synthetic coherence coefficient of the transmitted pulse and the synthetic coherence coefficient of the reflected pulse corresponding to channel i in the Couillaud phase-locked system; is the average value of the pulse contrast of n channels; k i is the pulse contrast of channel i, k j is the pulse contrast of reference channel j.

3. The phase control method based on coherent synthesis according to claim 2, characterized in that: β Ti and β Ri The calculation method is: in, and are the coherent synthesis pulses to be optimized and input to -Contrast ratio of coherent synthesis pulses in the transmission path and the reflection path in the Couillaud phase-locked system; and are the main pulse peak intensity and background noise intensity of the coherent synthesis pulse in the transmission path respectively; and are the main pulse peak intensity and background noise intensity of the coherent synthesis pulse in the reflection path, respectively.

4. The phase control method based on coherent combining according to claim 1, characterized in that: The contrast k of the coherent synthesis pulse to be optimized is c The contrast ratio of each channel pulse is calculated as follows: in, is the peak intensity of the main pulse of the coherent synthesis pulse to be optimized, k is the background noise intensity of the coherent synthesis pulse to be optimized; i is the pulse contrast of channel i, is the peak intensity of the main pulse of channel i, is the background noise intensity of the pulse in channel i.

5. A phase control system based on coherent synthesis, characterized in that: include: A contrast calculation module, used to measure the peak intensity of the main pulse and background noise of the coherent synthesis pulse to be optimized, so as to calculate the contrast of the coherent synthesis pulse to be optimized; Measuring the peak intensity of the main pulse and background noise of each channel pulse to calculate the contrast of each channel pulse; wherein the coherent synthesis pulse to be optimized is obtained by coherently combining the pulses of each channel; The phase error calculation module uses the contrast of the pulses of each channel to calculate the phase error. Phase-locking algorithm, and select any channel as the reference channel j, get the phase error between the pulse of channel i and the pulse of reference channel j, i, j∈{1, 2, …, n}, and i≠j, n is the total number of channels; The phase modulator is used to feed back the phase error to correct the phase of each channel pulse until the contrast of the coherent synthesis pulse to be optimized is maximized, thereby achieving phase locking of the pulses of each channel.

6. The phase control system based on coherent synthesis according to claim 5, characterized in that: In the contrast calculation module, a photoelectric detector with a time gating device is used to measure the peak intensity.

7. An electronic device, characterized in that: comprising a computer-readable storage medium and a processor; The computer-readable storage medium is used to store executable instructions; The processor is configured to read the executable instructions stored in the computer-readable storage medium to execute the phase control method based on coherent combination according to any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the phase control method based on coherent synthesis as described in any one of claims 1 to 4 is implemented.

9. A computer program product, characterized in that The invention comprises a computer program, which, when running on a computer, enables the computer to execute the phase control method based on coherent synthesis according to any one of claims 1 to 4.

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