Pulse output coherent combination light source regulation and control device and method

Abstract

The invention belongs to the technical field of light beam synthesis, and particularly discloses a coherent synthesis light source regulation and control device and method for pulse output. Comprising a plurality of single-frequency lasers used for outputting single-frequency laser; the optical phase modulators are arranged in one-to-one correspondence with the single-frequency lasers and are used for performing phase adjustment on the single-frequency lasers; a plurality of polarizers which are arranged in one-to-one correspondence with the optical phase modulators and are used for carrying out polarization processing on the single-frequency laser after phase adjustment; the gathering device is used for carrying out focusing processing on the plurality of single-frequency lasers processed by the polaroid; the synthesis grating is used for coherently synthesizing the plurality of focused single-frequency lasers into a beam of pulse laser and outputting the pulse laser; the angles of the multiple single-frequency laser beams incident on the synthesis grating meet the grating diffraction synthesis relation. According to the invention, the diffractive optical element is adopted to coherently combine a plurality of continuously output single-frequency laser beams, so that high-average-power and high-peak pulse laser source output is realized, and the laser pulse width is adjustable.

Description

Technical Field

[0001] The present invention belongs to the technical field of light beam synthesis, and more specifically, relates to a pulse output coherent synthesis light source control device and method. Background Art

[0002] High-power lasers are limited in output power and brightness by factors such as thermal effects, nonlinear effects, mode instability, pump laser brightness, and material damage. In order to increase the power and brightness of the output laser beam, spectral synthesis technology, coherent synthesis technology and other technical approaches are used to synthesize high-power, high-brightness laser output. Laser spectral synthesis technology uses dispersive elements such as synthetic gratings to synthesize multiple laser arrays of different wavelengths into one laser output in the near field to obtain a high-brightness, high-beam quality laser beam. Laser coherent synthesis technology uses a laser source to generate multiple identical laser beam arrays through beam splitting, and performs the same power amplification, phase control and emission control on each laser array, so that the phase of the laser beam array in the far-field spot is basically consistent, forming a coherent superposition, thereby obtaining a high-brightness synthetic beam.

[0003] In the prior art, the multiple laser beams of laser coherent synthesis originate from the same laser source and are split into multiple laser beams. The power, power amplification optical path, transmission optical path, phase control optical path, and synthesis optical path of each laser beam need to be kept consistent. The differences between the laser beams will lead to the effect of laser coherent synthesis, which requires a laser coherent synthesis system to control and compensate.

[0004] In the prior art, the arrangement and duty cycle of the laser coherent synthesis laser beam array affect the concentration of the laser beam spot energy in the far-field. However, it is impossible to achieve complete overlap of the laser beam array spots in the far field for any beam array arrangement, resulting in uneven and dynamically changing energy distribution of the coherent synthesis far-field spot, which requires control by the laser coherent synthesis system.

[0005] In the prior art, the coherence time of the laser source for laser coherent synthesis is short, and there are errors such as optical path error, power error, and emission beam pointing error among the laser beam arrays for coherent synthesis. At the same time, any inconsistency between the laser beams of each path may affect the effect of laser coherent synthesis, requiring a laser coherent synthesis system to control and compensate. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the present invention provides a control device and method for a pulsed coherent synthesis light source, which uses a diffractive optical element to coherently synthesize multiple continuously output single-frequency laser beams to achieve coherent synthesis pulse laser output, and the laser pulse width is adjustable. The coherent synthesis light source breaks through the technical route of traditional coherent synthesis and pulse laser generation, and can be applied to the development of high-energy laser systems, as well as in the fields of optoelectronic countermeasures, laser processing, laser measurement, etc.

[0007] To achieve the above object, according to one aspect of the present invention, a pulse output coherent synthesis light source control device is provided, comprising:

[0008] A plurality of single-frequency lasers for outputting single-frequency lasers;

[0009] A plurality of optical phase modulators arranged in one-to-one correspondence with each single-frequency laser and used for adjusting the phase of the single-frequency laser;

[0010] A plurality of polarizers arranged in one-to-one correspondence with each optical phase modulator and used for performing polarization processing on the single-frequency laser after phase adjustment;

[0011] A focusing device, used for focusing the multiple single-frequency lasers processed by the polarizer;

[0012] A synthetic grating, used for coherently synthesizing a plurality of single-frequency laser beams after focusing processing into a pulse laser beam for output;

[0013] The angles at which the multiple single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

[0014] As a further preference, the optical phase modulator further includes a collimating device arranged between the optical phase modulator and a polarizing plate arranged corresponding to the optical phase modulator.

[0015] As a further preferred embodiment, a detection module is also included, which includes a beam sampling mirror, a sampling polarizer, an attenuation plate and a photodetector arranged in sequence along the optical path. The beam sampling mirror is used to split the pulse laser, one of which is output as an output light source, and the other is input to the sampling polarizer as a detection light.

[0016] As a further preferred embodiment, a controller is also included, which is connected to the multiple optical phase modulators and photodetectors, and is used to collect detection information of the photodetectors, and based on the detection information, coordinately adjust the polarization directions of multiple polarizers and the phase delays output by the multiple optical phase modulators, so that the intensity characteristics of the synthesized pulsed laser remain stable.

[0017] As further preferred, the grating diffraction synthesis relationship includes:

[0018]

[0019] Among them, a k is the incident angle between the single-frequency laser and the normal line of the synthetic grating, β is the output diffraction angle between the combined pulsed laser and the normal line of the synthetic grating, m is the synthetic diffraction order of the single-frequency laser beam, λ k is the wavelength of the input single-frequency laser, and d is the grating period of the synthetic grating.

[0020] As a further preferred embodiment, the light field of the single-frequency laser after being processed by the polarizer is:

[0021]

[0022] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively.

[0023] As a further preferred embodiment, the light field of the pulsed laser after being combined by the synthetic grating is:

[0024]

[0025] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively, n is the number of single-frequency lasers, n is an integer greater than or equal to 2, and A and C are constant terms.

[0026] As further preferred, the step of maintaining the intensity characteristics of the synthesized pulsed laser stable includes:

[0027] The frequency relationship between the outputs of single-frequency lasers is ω k -ω k-1 =Δω, when the phase of the single-frequency laser beam is adjusted by multiple optical phase modulators, the phase difference of each single-frequency laser beam is stabilized, that is: When , the light field of the output combined laser beam can be expressed as:

[0028]

[0029] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, A and C are constant terms, Δφ is the phase difference, and φ0 is the initial phase;

[0030] The pulse period of the coherently combined pulse laser output is expressed as By changing the phase difference between each single frequency laser To achieve the regulation of the pulse width of the output pulse laser.

[0031] According to another aspect of the present invention, a method for controlling a pulsed output coherent synthesis light source is provided, comprising:

[0032] After phase adjustment, collimation and polarization of multiple single-frequency laser beams in sequence, the multiple single-frequency laser beams are focused, and the focused light beams are coherently synthesized into a pulsed laser output using a synthetic grating, wherein the angles at which the multiple single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

[0033] Preferably, the grating diffraction synthesis relationship includes:

[0034]

[0035] Among them, a k is the incident angle between the single-frequency laser and the normal line of the synthetic grating, β is the output diffraction angle between the combined pulsed laser and the normal line of the synthetic grating, m is the synthetic diffraction order of the single-frequency laser beam, λ k is the wavelength of the input single-frequency laser, d is the grating period of the synthetic grating;

[0036] Preferably, the light field of the single-frequency laser after polarization is:

[0037]

[0038] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively;

[0039] Preferably, the light field of the pulsed laser after being combined by the synthetic grating is:

[0040]

[0041] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, and A and C are constant terms;

[0042] Preferably, the control method further comprises:

[0043] Splitting the pulsed laser light, with one path being used as an output light source and the other path being used as a detection light;

[0044] Detecting the detection light, and according to the detection information, cooperatively adjusting the polarization directions of multiple polarizers and the phase delays output by multiple optical phase modulators, so that the intensity characteristics of the synthesized pulsed laser remain stable;

[0045] Preferably, the step of maintaining the intensity characteristics of the synthesized pulsed laser stable comprises:

[0046] The frequency relationship between the outputs of single-frequency lasers is ω k -ω k-1 =Δω, when the phase of the single-frequency laser beam is adjusted by multiple optical phase modulators, the phase difference of each single-frequency laser beam is stabilized, that is: When , the light field of the output combined laser beam can be expressed as:

[0047]

[0048] λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, A and C are constant terms, Δφ is the phase difference, and φ0 is the initial phase;

[0049] The pulse period of the coherently combined pulse laser output is expressed as By changing the phase difference between each single frequency laser To achieve the regulation of the pulse width of the output pulse laser.

[0050] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0051] 1. The present invention combines multiple single-frequency laser beams through a grating, and by adjusting the phases between the multiple single-frequency laser beams, the phases between the single-frequency laser beams are relatively stable, and the single-frequency laser beams are coherently combined to form a pulse laser beam output. That is, the present invention can adjust the output pulse width and power by changing the power and number of laser beams according to application requirements, and can be used as a pulse light source in high-energy laser systems, optoelectronic countermeasures, laser processing, laser measurement and other fields.

[0052] 2. The present invention adopts an array of single-frequency laser beams of different wavelengths, utilizes the long coherence time of the single-frequency laser beam, and adopts a synthetic grating to realize the coherent synthesis of multiple single-frequency laser beams in the near field. Compared with the far-field coherent synthesis method, it has the advantages of simpler system, higher reliability, higher phase control accuracy, and more stable coherent synthesis effect.

[0053] 3. The present invention realizes a new laser coherent synthesis method, which can realize the synthesis of multiple single-frequency laser beams in the near field through a grating. It breaks through the traditional coherent synthesis method of using the same light source to split into multiple coherent sub-beams, and then amplifying the power and phase of the sub-beams to perform coherent synthesis in the far field.

[0054] 4. The present invention can obtain a pulsed laser beam with high average power and high peak power by increasing the power and number of single-frequency laser beams. It has a higher average power than traditional Q-switched and mode-locked pulsed lasers, and has a higher peak power than traditional electrically modulated pulsed lasers.

[0055] 5. The present invention realizes coherent synthesis of single-frequency laser beam arrays in the near field, and each single-frequency laser beam array realizes laser synthesis output in the near field. The synthesized light spots completely overlap and the energy distribution of the light spots is not affected by the phase control frequency and transmission distance between the single-frequency laser beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a structural schematic diagram of a pulse output coherent synthesis light source control device involved in an embodiment of the present invention;

[0057] Figure 2 A schematic diagram of a synthetic grating beam combining arrangement of a coherent synthetic light source according to an embodiment of the invention;

[0058] Figure 3 A schematic diagram of polarization direction control of a single-frequency laser beam array according to an embodiment of the invention;

[0059] Figure 4 A schematic diagram of phase control of a single-frequency laser beam array according to an embodiment of the invention;

[0060] Figure 5 This is a diagram showing the output result of coherent synthesis of two single-frequency laser beams involved in an embodiment of the invention;

[0061] Figure 6 Schematic diagram of pulse width control of a coherently synthesized output light beam according to an embodiment of the invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain 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 can be combined with each other as long as they do not conflict with each other.

[0063] Example 1

[0064] like Figures 1 to 6As shown, an embodiment of the present invention provides a pulse output coherent synthesis light source control device, comprising: a plurality of single-frequency lasers for outputting single-frequency lasers; a plurality of optical phase modulators arranged in a one-to-one correspondence with each single-frequency laser and used for performing phase adjustment on the single-frequency lasers; a plurality of polarizers arranged in a one-to-one correspondence with each optical phase modulator and used for performing polarization processing on the single-frequency lasers after phase adjustment; a focusing device for focusing the plurality of single-frequency lasers processed by the polarizers; a synthetic grating for coherently synthesizing the plurality of single-frequency lasers after focusing processing into a beam of pulsed laser output; wherein the angles at which the plurality of single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

[0065] A plurality of single-frequency lasers constitute a single-frequency laser array, a plurality of optical phase modulators constitute an optical phase modulator array, and a plurality of polarizers constitute a polarizer array.

[0066] Optionally, a collimating device is further included between the optical phase modulator and a polarizing plate corresponding to the optical phase modulator. A plurality of collimating devices constitute a collimating device array.

[0067] Optionally, the detection module includes a beam sampling mirror, a sampling polarizer, an attenuation plate and a photodetector arranged in sequence along the optical path, and the beam sampling mirror is used to split the pulse laser, one of which is output as an output light source and the other is input to the sampling polarizer as detection light.

[0068] Optionally, the above-mentioned control device also includes a controller, which is connected to the multiple optical phase modulators and photodetectors, and is used to collect detection information of the photodetectors, and based on the detection information, coordinately adjust the polarization directions of multiple polarizers and the phase delays output by multiple optical phase modulators to keep the intensity characteristics of the synthesized pulsed laser stable.

[0069] Based on any of the above embodiments or a combination of multiple embodiments, a control method of the above control device is also provided:

[0070] After phase adjustment, collimation and polarization of multiple single-frequency laser beams in sequence, the multiple single-frequency laser beams are focused, and the focused light beams are coherently synthesized into a pulsed laser output using a synthetic grating, wherein the angles at which the multiple single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

[0071] The grating diffraction synthesis relationship includes:

[0072]

[0073] Among them, a kis the incident angle between the single-frequency laser and the normal line of the synthetic grating, β is the output diffraction angle between the combined pulsed laser and the normal line of the synthetic grating, m is the synthetic diffraction order of the single-frequency laser beam, λ k is the wavelength of the input single-frequency laser, d is the grating period of the synthetic grating;

[0074] Preferably, the light field of the single-frequency laser after polarization is:

[0075]

[0076] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively;

[0077] Preferably, the light field of the pulsed laser after being combined by the synthetic grating is:

[0078]

[0079] Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, and A and C are constant terms;

[0080] Preferably, the control method further comprises:

[0081] Splitting the pulsed laser light, with one path being used as an output light source and the other path being used as a detection light;

[0082] Detecting the detection light, and according to the detection information, cooperatively adjusting the polarization directions of multiple polarizers and the phase delays output by multiple optical phase modulators, so that the intensity characteristics of the synthesized pulsed laser remain stable;

[0083] Preferably, the step of maintaining the intensity characteristics of the synthesized pulsed laser stable comprises:

[0084] The frequency relationship between the outputs of single-frequency lasers is ω k -ω k-1 =Δω, when the phase of the single-frequency laser beam is adjusted by multiple optical phase modulators, the phase difference of each single-frequency laser beam is stabilized, that is: When , the light field of the output combined laser beam can be expressed as:

[0085]

[0086] λ k ,ω k ,φ kare the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, A and C are constant terms, Δφ is the phase difference, and φ0 is the initial phase;

[0087] The pulse period of the coherently combined pulse laser output is expressed as By changing the phase difference between each single frequency laser To achieve the regulation of the pulse width of the output pulse laser.

[0088] That is, in this embodiment, the grating can be used to achieve the synthesis of multiple single-frequency laser beams in the near field, breaking through the traditional coherent synthesis method of using the same light source to split into multiple coherent sub-beams, and then amplifying the power and phase of the sub-beams to perform coherent synthesis in the far field. In addition, this embodiment can achieve coherently synthesized pulsed laser output, and proposes a new technical approach for lasers to generate pulsed lasers. Through the technical method of the present invention, by increasing the power and number of single-frequency laser beams, a pulsed laser beam with high average power and high peak power can be obtained. Compared with traditional Q-switched and mode-locked pulsed lasers, it has a higher average power, and compared with traditional electrically modulated pulsed lasers, it has a higher peak power. Furthermore, this embodiment can adjust the output pulse width and power by changing the power and number of input laser beams according to application requirements. As a pulse light source, it can be applied to high-energy laser systems, optoelectronic countermeasures, laser processing and other fields.

[0089] Example 2

[0090] like Figure 1 As shown, this embodiment provides a pulse-output coherent synthesis light source control device, including a single-frequency laser array, an optical phase modulator array, a collimation device array, a polarizer array, a focusing device 105, a synthetic grating 106, a combined laser beam 107, a beam sampling mirror 108, a polarizer 109, an attenuation plate 110, a photodetector 111, and a controller 112.

[0091] The single-frequency laser array includes n single-frequency lasers, namely single-frequency laser 1011, single-frequency laser 1012, single-frequency laser 101m, and single-frequency laser 101n. The optical phase modulator includes n optical phase modulators, namely optical phase modulator 1021, optical phase modulator 1022, optical phase modulator 102m, and optical phase modulator 102n. The collimator array includes n collimators, namely collimator 1031, collimator 1032, collimator 103m, and collimator 103n. The polarizer array includes n polarizers, namely polarizer 1041, polarizer 1041, polarizer 104m, and polarizer 104n. The single-frequency laser array is connected to the optical phase modulator array, and the optical phase modulator array regulates the phase of the single-frequency laser output by the single-frequency laser array. The polarizer array is placed after the collimator array, and the polarizer array performs polarization output and polarization direction control on the single-frequency laser output by the collimator array. The focusing device 105 focuses the single-frequency laser output by the single-frequency laser array. The synthetic grating 106 combines the single-frequency lasers of the single-frequency laser array focused by the focusing device 105 to form the combined laser beam 107. The beam sampling mirror 108 and the photodetector 111 are placed after the synthetic grating 106, and the beam sampling mirror 108 samples the combined laser beam 107, and the photodetector 110 detects the sampled beam of the combined laser beam 107. The photodetector 111 is placed behind the polarizer 108. The photodetector 110 detects the intensity of the polarized light beam output by the polarizer 108, adjusts the polarization direction of each polarizer in the polarizer array, adjusts the polarization direction of the polarizer 1041, and maximizes the intensity of the polarized light beam detected by the photodetector 110, so that the polarization direction of the polarizer 1041 is consistent with the polarization direction of the polarizer 108. The photodetector 111 is placed behind the polarizer 108. The photodetector 110 detects the intensity of the polarized light beam output by the polarizer 108, adjusts the polarization direction of each polarizer in the polarizer array, adjusts the polarization direction of the polarizer 1042, and maximizes the intensity of the polarized light beam detected by the photodetector 110, so that the polarization direction of the polarizer 1042 is consistent with the polarization direction of the polarizer 108. The photodetector 111 is placed after the polarizer 108. The photodetector 110 detects the intensity of the polarized light beam output by the polarizer 108, and adjusts the polarization direction of each polarizer in the polarizer array respectively, and adjusts the polarization direction of the polarizer 104m. The intensity of the polarized light beam detected by the photodetector 110 is the maximum, so that the polarization direction of the polarizer 104m is consistent with the polarization direction of the polarizer 108.The photodetector 111 is placed behind the polarizer 108. The photodetector 110 detects the intensity of the polarized light beam output by the polarizer 108, and adjusts the polarization direction of each polarizer in the polarizer array, and adjusts the polarization direction of the polarizer 104n. The intensity of the polarized light beam detected by the photodetector 110 is the maximum, and the polarization direction of the polarizer 104n is consistent with the polarization direction of the polarizer 108. The photodetector 111 is connected to the controller 112. The photodetector 110 detects the sampling light beam of the combined laser beam 107, and the controller 111 collects the detection information of the photodetector 110. The controller 112 is connected to the optical phase modulator array, and the controller 112 collects detection information of the photodetector 111. The controller 112 controls the phase delay output by the optical phase modulator 1021, the optical phase modulator 1022, the optical phase modulator 102m, and the optical phase modulator 102n, so that the sampling beam intensity characteristics of the combined laser beam 107 detected by the photodetector 111 remain stable.

[0092] Example 3

[0093] like Figure 2 As shown, this embodiment provides a synthetic grating combining part of a coherent synthetic light source in a coherent synthetic light source control device with a pulse output, which includes a single-frequency laser 201, a single-frequency laser 202, a single-frequency laser beam 203, a single-frequency laser beam 204, a focusing device 205, a focused single-frequency laser beam 206, a focused single-frequency laser beam 207, a synthetic grating 208, and a combined laser beam 209.

[0094] The central wavelength of the single-frequency laser beam 203 is λ1, and the single-frequency laser beam 203 is formed into the focused single-frequency laser beam 206 through the focusing device 205. The focused single-frequency laser beam 206 is dispersed and diffracted by the synthetic grating 208 to output the combined laser beam 209, and the angle relationship between the focused single-frequency laser beam 206 and the combined laser beam 209 is:

[0095]

[0096] Wherein, a1 is the incident angle of the focused single-frequency laser beam 206 and the normal of the synthetic grating 208, β is the diffraction angle of the combined laser beam 209 and the normal of the synthetic grating 208, m is the diffraction order, whose value is usually 1, and d is the grating period of the synthetic grating 208.

[0097] The central wavelength of the single-frequency laser beam 204 is λ2, and the single-frequency laser beam 204 forms the focused single-frequency laser beam 207 through the focusing device 205. The focused single-frequency laser beam 207 is dispersed and diffracted by the synthetic grating 208 to output the combined laser beam 209, and the angle relationship between the focused single-frequency laser beam 207 and the combined laser beam 209 is:

[0098]

[0099] Among them, a2 is the incident angle of the focused single-frequency laser beam 207 and the normal of the synthetic grating 208, β is the diffraction angle of the combined laser beam 209 and the normal of the synthetic grating 208, m is the diffraction order, whose value is usually 1, and d is the grating period of the synthetic grating 208.

[0100] Example 4

[0101] like Figure 3 As shown, this embodiment provides a single-frequency laser beam array polarization direction control part involved in a pulse output coherent synthesis light source control device, and the single-frequency laser beam array polarization direction control includes a single-frequency laser beam 301, a single-frequency laser beam 302, a polarizer 303, a polarizer 304, a focusing device 305, a synthetic grating 306, a combined laser beam 307, a beam sampling mirror 308, a polarizer 309, an attenuation plate 310, and a photodetector 311.

[0102] The polarizer 303 performs polarization adjustment on the single-frequency laser beam 301, and the polarization direction of the single-frequency laser beam 301 remains unchanged after passing through the focusing device 305 and the synthetic grating 306; the polarizer 304 performs polarization adjustment on the single-frequency laser beam 302, and the polarization direction of the single-frequency laser beam 302 remains unchanged after passing through the focusing device 305 and the synthetic grating 306; the beam sampling mirror 308 performs spectroscopic sampling detection on the combined laser beam 307, and the spectroscopic sampling beam of the combined laser beam 307 enters the photodetector 311 for intensity detection after passing through the polarizer 309 and the attenuation plate 310; after the polarization direction of the polarizer 309 is fixed, the polarization direction of the polarizer 303 is adjusted so that the single-frequency laser beam 301 passes through the polarizer 303, the beam sampling mirror 308 and the polarizer 309. The photodetector 311 performs intensity detection, and when the photodetector 311 detects that the intensity is maximum, it is determined that the polarization direction of the polarizer 303 is consistent with the polarization direction of the beam sampling mirror 308; after the polarization direction of the polarizer 309 is fixed, the polarization direction of the polarizer 304 is adjusted so that the single-frequency laser beam 302 passes through the polarizer 304, the beam sampling mirror 308 and the polarizer 309 and is intensity detected by the photodetector 311, and when the photodetector 311 detects that the intensity is maximum, it is determined that the polarization direction of the polarizer 304 is consistent with the polarization direction of the beam sampling mirror 308; through the detection of the polarizer 309 and the photodetector 311, the polarization directions of the polarizer 303 and the polarization directions of the polarizer 304 are consistent with the polarization direction of the polarizer 309.

[0103] Example 5

[0104] like Figure 4 As shown, this embodiment provides a single-frequency laser beam array phase control part involved in a pulse-output coherent synthesis light source control device, and the single-frequency laser beam array phase control includes a single-frequency laser 401, a single-frequency laser 402, an optical phase modulator 403, an optical phase modulator 404, a polarizer 405, a polarizer 406, a focusing device 407, a polarized single-frequency laser 408, a polarized single-frequency laser 409, a synthetic grating 410, a combined laser beam 411, a beam sampling mirror 412, a photodetector 413, and a controller 414.

[0105] After the single-frequency laser 401 passes through the polarizer 405 and the focusing device 407, the polarized single-frequency laser 408 is focused, and the polarization direction of the polarized single-frequency laser 408 is consistent with the polarization direction of the polarizer 405; after the single-frequency laser 402 passes through the polarizer 406 and the focusing device 407, the polarized single-frequency laser 409 is focused, and the polarization direction of the polarized single-frequency laser 409 is consistent with the polarization direction of the polarizer 406; the coherence time of the polarized single-frequency laser 408 is is the line width of the polarized single-frequency laser 408; the coherence time of the polarized single-frequency laser 409 is is the line width of the polarized single-frequency laser 409; the polarized single-frequency laser 408 and the polarized single-frequency laser 409 are diffracted and combined by the synthetic grating 410 to form the combined laser beam 411, the polarized single-frequency laser 408 and the polarized single-frequency laser 409 are coherently superimposed on the synthetic grating 410, and the combined laser beam 411 is the combined laser beam coherently formed by the polarized single-frequency laser 408 and the polarized single-frequency laser 409; the combined laser beam 411 passes through the beam sampling mirror 41 2 performs beam splitting sampling, and the sampling light of the combined laser beam 411 is detected by the photodetector 413; the controller 414 is connected to the photodetector 413, the optical phase modulator 403, and the optical phase modulator 404, and the controller 414 collects the detection signal of the photodetector 413. The controller 414 controls the phase delay of the optical phase modulator 403 and the optical phase modulator 404, so that the laser intensity characteristics detected by the photodetector 413 remain stable.

[0106] Example 6

[0107] like Figure 5 As shown, this embodiment provides a pulse output coherent synthesis light source control device involving two single-frequency laser beams coherent synthesis output beam part, the coherent synthesis output result of the two single-frequency laser beams is Figure 4 The single-frequency laser 401 and the single-frequency laser 401 are coherently synthesized to form the light intensity distribution detection result of the combined laser beam 411, the wavelength of the single-frequency laser 401 is λ1, the line width of the single-frequency laser 401 is Δυ1=2khz, the wavelength of the single-frequency laser 402 is λ2, and the line width of the single-frequency laser 402 is Δυ2=2khz.

[0108] Example 7

[0109] like Figure 6 As shown, this embodiment provides a pulse output coherent synthesis light source control device, which includes a coherent synthesis output light beam pulse width control part.

[0110] The pulse width control of the coherent synthesis output light beam includes a single-frequency laser array, an optical phase modulator array, a polarizer array, a focusing device 604, a polarized single-frequency laser array, a synthetic grating 606, a combined laser beam 607, a beam sampling mirror 608, a photodetector 609, and a controller 610.

[0111] The single-frequency laser array includes a single-frequency laser beam 6011, a single-frequency laser beam 6012, a single-frequency laser beam 601m, a single-frequency laser beam 601n, etc.; the optical phase modulator array includes an optical phase modulator 6021, an optical phase modulator 6022, an optical phase modulator 602m, an optical phase modulator 602n, etc.; the polarizer array includes a polarizer 6031, a polarizer 6032, a polarizer 603m, a polarizer 603n, etc.; the polarized single-frequency laser array includes n polarized single-frequency lasers, namely a polarized single-frequency laser 6051, a polarized single-frequency laser 6052, a polarized single-frequency laser 605m, and a polarized single-frequency laser 605n; the wavelength of the single-frequency laser beam 6011 is λ1, the frequency is ω1, and the phase is The single-frequency laser beam 6011 is transformed into the polarized single-frequency laser 6051 after passing through the polarizer 6031 and the focusing device 604 .

[0112] The light field of the polarized single-frequency laser 6051 can be expressed as:

[0113]

[0114] The wavelength of the single-frequency laser beam 6012 is λ2, the frequency is ω2, and the phase is The single-frequency laser beam 6012 is transformed into the polarized single-frequency laser 6052 after passing through the polarizer 6032 and the focusing device 604 .

[0115] The light field of the polarized single-frequency laser 6052 can be expressed as:

[0116]

[0117] Wherein, the wavelength of the single-frequency laser beam 601m is λ m , frequency is ω m , the phase is The single-frequency laser beam 601m is transformed into the polarized single-frequency laser 605m after passing through the polarizer 603m and the focusing device 604.

[0118] The light field of the polarized single-frequency laser 605m can be expressed as:

[0119]

[0120] The wavelength of the single-frequency laser beam 601n is λ n, frequency is ω n , the phase is The single-frequency laser beam 601n is transformed into the polarized single-frequency laser 605n after passing through the polarizer 603n and the focusing device 604.

[0121] The light field of the polarized single-frequency laser 605n can be expressed as:

[0122]

[0123] The polarized single-frequency laser 6051, the polarized single-frequency laser beam 6052, the polarized single-frequency laser beam 605m and the polarized single-frequency laser beam 605n are output as the combined laser beam 607 after passing through the synthetic grating 606. The light field of the combined laser beam 607 can be expressed as:

[0124]

[0125] The output wavelengths of the polarized single-frequency laser 6051, the polarized single-frequency laser beam 6052, the polarized single-frequency laser beam 605m and the polarized single-frequency laser beam 605n are controlled so that the frequency relationship of the single-frequency laser satisfies ω k -ω k-1 =Δω, the light field of the combined laser beam 607 can be expressed as:

[0126]

[0127] The combined laser beam 607 is detected by the photodetector 609 after being split and sampled by the beam sampling mirror 608 .

[0128] The controller 610 collects detection information of the photodetector 609, and the controller 610 is connected to the optical phase modulator array. The controller 610 uses the detection information of the photodetector 609 to close-loop control the phase delay of the optical phase modulator array to the single-frequency laser array. The light field of the combined laser beam 607 can be expressed as:

[0129]

[0130] The average power output by the combined laser beam 607 can be expressed as I=nA 2 By increasing the number of single-frequency laser beams in the single-frequency laser array, the average power output by the combined laser beam 607 can be increased.

[0131] The peak power of the output pulse of the combined laser beam 607 can be expressed as:

[0132]

[0133] The peak power of the pulse output by the combined laser beam 607 is in square relation to the number of single-frequency laser beams in the single-frequency laser array. The peak power of the pulse output by the combined laser beam 607 can be increased by increasing the number of single-frequency laser beams in the single-frequency laser array.

[0134] The output pulse period of the combined laser beam 607 can be expressed as: By adjusting the phase delay of the optical phase modulator array to the single-frequency laser array The output pulse period of the combined laser beam 607 can be adjusted.

[0135] The output pulse period of the combined laser beam 607 can be expressed as: The output pulse period of the combined laser beam 607 can be regulated by regulating the frequency difference Δω of the single-frequency laser array.

[0136] In summary, the present invention uses single-frequency laser beam arrays of different wavelengths, utilizes the characteristics of the long coherence time of single-frequency laser beams, and uses synthetic gratings to achieve coherent synthesis of multiple single-frequency laser beams in the near field. Compared with the far-field coherent synthesis method, it has the advantages of simpler system, higher reliability, higher phase control accuracy, and more stable coherent synthesis effect. Furthermore, the present invention realizes the coherent synthesis of single-frequency laser beam arrays in the near field. Each single-frequency laser beam array forms a pulse laser output through the coherent superposition of the light field. The light intensity of the output beam is the square of the sum of the amplitudes of the light fields of each single-frequency laser beam array. Compared with traditional coherent synthesis, a higher spot power density can be obtained. At the same time, by increasing the power and number of single-frequency laser beams, the average power, pulse width, and pulse power of the coherent synthesis output pulse laser can be regulated. Compared with traditional Q-switched and mode-locked pulse lasers, it has a higher average power, and compared with traditional electrically modulated pulse lasers, it has a higher peak power. Furthermore, the present invention realizes coherent synthesis of single-frequency laser beam arrays in the near field, and each single-frequency laser beam array realizes laser synthesis output in the near field, the synthetic light spots completely overlap and the light spot energy distribution is not affected by the phase control frequency and transmission distance between the single-frequency laser beams.

[0137] It will be easily understood by those skilled in the art that the above description is only 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 protection scope of the present invention.

Claims

1. A pulse output coherent synthesis light source control device, characterized in that: include: A plurality of single-frequency lasers for outputting single-frequency lasers; A plurality of optical phase modulators arranged in one-to-one correspondence with each single-frequency laser and used for adjusting the phase of the single-frequency laser; A plurality of polarizers arranged in one-to-one correspondence with each optical phase modulator and used for performing polarization processing on the single-frequency laser after phase adjustment; A focusing device, used for focusing the multiple single-frequency lasers processed by the polarizer; A synthetic grating, used for coherently synthesizing a plurality of single-frequency laser beams after focusing processing into a pulse laser beam for output; The angles at which the multiple single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

2. A pulse output coherent synthesis light source control device according to claim 1, characterized in that: It also includes a collimating device arranged between the optical phase modulator and a polarizing plate arranged corresponding to the optical phase modulator.

3. The pulse output coherent synthesis light source control device according to claim 1, characterized in that: It also includes a detection module, which includes a beam sampling mirror, a sampling polarizer, an attenuation plate and a photodetector arranged in sequence along the optical path. The beam sampling mirror is used to split the pulse laser, one of which is output as an output light source and the other is input to the sampling polarizer as a detection light.

4. The pulse output coherent synthesis light source control device according to claim 3, characterized in that: It also includes a controller, which is connected to the multiple optical phase modulators and photodetectors, and is used to collect detection information from the photodetectors, and based on the detection information, coordinately adjust the polarization directions of the multiple polarizers and the phase delays output by the multiple optical phase modulators, so that the intensity characteristics of the synthesized pulsed laser remain stable.

5. The pulse output coherent synthesis light source control device according to claim 1, characterized in that: The grating diffraction synthesis relationship includes: Among them, a k is the incident angle between the single-frequency laser and the normal line of the synthetic grating, β is the output diffraction angle between the combined pulsed laser and the normal line of the synthetic grating, m is the synthetic diffraction order of the single-frequency laser beam, λ k is the wavelength of the input single-frequency laser, and d is the grating period of the synthetic grating.

6. The pulse output coherent synthesis light source control device according to claim 1, characterized in that: The light field of the single-frequency laser after polarization is: Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively.

7. A pulse output coherent synthesis light source control device according to any one of claims 1 to 6, characterized in that: The light field of the pulsed laser after beam combining by the synthetic grating is: Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively, n is the number of single-frequency lasers, n is an integer greater than or equal to 2, and A and C are constant terms.

8. The pulse output coherent synthesis light source control device according to claim 4, characterized in that: The step of maintaining the intensity characteristics of the synthesized pulsed laser stable comprises: The frequency relationship between the outputs of single-frequency lasers is ω k -ω k-1 =Δω, when the phase of the single-frequency laser beam is adjusted by multiple optical phase modulators, the phase difference of each single-frequency laser beam is stabilized, that is: When , the light field of the output combined laser beam can be expressed as: Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, A and C are constant terms, Δφ is the phase difference, and φ0 is the initial phase; The pulse period of the coherently combined pulse laser output is expressed as By changing the phase difference between each single frequency laser To achieve the regulation of the pulse width of the output pulse laser.

9. A method for controlling a pulsed coherent synthesis light source, characterized in that: include: After phase adjustment, collimation and polarization of multiple single-frequency laser beams in sequence, the multiple single-frequency laser beams are focused, and the focused light beams are coherently synthesized into a pulsed laser output using a synthetic grating, wherein the angles at which the multiple single-frequency laser beams are incident on the synthetic grating satisfy the grating diffraction synthesis relationship.

10. The control method of a pulse output coherent synthesis light source according to claim 9, characterized in that: The grating diffraction synthesis relationship includes: Among them, a k is the incident angle between the single-frequency laser and the normal line of the synthetic grating, β is the output diffraction angle between the combined pulsed laser and the normal line of the synthetic grating, m is the synthetic diffraction order of the single-frequency laser beam, λ k is the wavelength of the input single-frequency laser, d is the grating period of the synthetic grating; Preferably, the light field of the single-frequency laser after polarization is: Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser respectively; Preferably, the light field of the pulsed laser after being combined by the synthetic grating is: Among them, λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, and A and C are constant terms; Preferably, the control method further comprises: Splitting the pulsed laser light, with one path being used as an output light source and the other path being used as a detection light; Detecting the detection light, and according to the detection information, cooperatively adjusting the polarization directions of multiple polarizers and the phase delays output by multiple optical phase modulators, so that the intensity characteristics of the synthesized pulsed laser remain stable; Preferably, the step of maintaining the intensity characteristics of the synthesized pulsed laser stable comprises: The frequency relationship between the outputs of single-frequency lasers is ω k -ω k-1 =Δω, when the phase of the single-frequency laser beam is adjusted by multiple optical phase modulators, the phase difference of each single-frequency laser beam is stabilized, that is: When , the light field of the output combined laser beam can be expressed as: λ k ,ω k ,φ k are the wavelength, frequency and phase of the kth single-frequency laser, respectively; n is the number of single-frequency lasers, n is an integer greater than or equal to 2, A and C are constant terms, Δφ is the phase difference, and φ0 is the initial phase; The pulse period of the coherently combined pulse laser output is expressed as By changing the phase difference between each single frequency laser To achieve the regulation of the pulse width of the output pulse laser.

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