Beam-to-beam time delay regulation and control device and method for multi-beam high-energy pat-watt laser system

Abstract

The invention discloses an inter-beam time delay regulation and control device and method for a multi-beam high-energy petawatt laser system, and relates to the technical field of high-energy petawatt lasers, and the device comprises a coarse delay regulation and control part, a fine delay regulation and control part and a control part, the thick delay regulation and control part regulates and controls the delay time between a first beam line and a second beam line by regulating and controlling the round-trip times of the first beam line and the second beam line in the multi-beam high-energy Patwatt laser system, and the thin delay regulation and control part regulates and controls the delay time between the first beam line and the second beam line by regulating and controlling the optical path of the first beam line and the optical path of the second beam line. The control component controls the coarse delay regulation and control component and the fine delay regulation and control component to work based on the delay time demand quantity between the first bunch and the second bunch, so that the delay time between the first bunch and the second bunch reaches the delay time demand quantity. According to the invention, the relative delay time can be continuously adjusted in a super-large time interval, and the structure is simple.

Description

Technical Field

[0001] The present application relates to the technical field of high-energy petawatt lasers, and particularly to an inter-beam time delay control device and method for a multi-beam high-energy petawatt laser system. Background Art

[0002] Ultra-short, ultra-intense high-energy petawatt lasers based on chirped-pulse amplification (CPA) or optical parametric chirped-pulse amplification (OPCPA) can provide ultra-strong fields, create extreme material conditions, and play an increasingly important role in the field of strong-field physics research, such as quantum electrodynamics, secondary radiation source generation, laboratory astrophysics, etc. By using the homologous seed technology, ultra-strong laser synchronization shooting at different time scales can be realized, so as to meet the requirements of certain specific loading-detection experiments. For example, the Xingguang III laser device can meet the synchronous shooting requirements of femtosecond, picosecond, and nanosecond laser beams. Among them, the nanosecond beam is used as the loading, while the femtosecond beam and the picosecond beam are used as probes, and dynamic detection of ultrafast physical processes can be realized.

[0003] However, in some physical experiment requirements, it is required to sort the arrival times of multi-beam high-energy petawatt laser pulses within a very large time interval of dozens of nanoseconds or even hundreds of nanoseconds, that is, the relative delay time between any pair of arriving pulses is continuously adjustable within a very large time interval of dozens of nanoseconds or even hundreds of nanoseconds, so as to realize multi-angle and multi-amplitude detection of extreme physical processes. The homologous seed technology can meet the synchronous arrival of multi-beam pulses at the target. With the assistance of the optical path adjustment method, the relative delay time of the arriving pulses can be continuously adjusted within the range of several nanoseconds. When the required time interval is dozens of nanoseconds or even hundreds of nanoseconds, for example, the delay interval is 100 nanoseconds, the corresponding optical path difference of the beam transmission is 30 meters. At this time, simply relying on the optical path difference adjustment method to realize the delay adjustment of the relative delay time within the range of hundreds of nanoseconds is extremely complex in engineering design. Summary of the Invention

[0004] The purpose of the present application is to provide an inter-beam time delay control device and method for a multi-beam high-energy petawatt laser system, which can realize continuous adjustment of the relative delay time within a very large time interval and has a simple structure.

[0005] To achieve the above object, the present application provides the following solutions:

[0006] In a first aspect, the present application provides an inter-beam time delay control device for a multi-beam high-energy petawatt laser system. The inter-beam time delay control device for a multi-beam high-energy petawatt laser system includes: a coarse delay control component, a fine delay control component, and a control component;

[0007] The coarse delay control component is located behind the beam splitter in the multi-beam high-energy petawatt laser system. The coarse delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the number of round trips of the first beam line and the second beam line in the multi-beam high-energy petawatt laser system;

[0008] The fine delay control component is located behind the coarse delay control component. The fine delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the optical path lengths of the first beam line and the second beam line; the maximum delay time that the fine delay control component can bring is the same as the delay time that the coarse delay control component can bring in one round trip;

[0009] The control component is used to control the operation of the coarse delay control component and the fine delay control component based on the required delay time between the first beam line and the second beam line, so that the delay time between the first beam line and the second beam line reaches the required delay time.

[0010] Optionally, the coarse delay control component includes a first coarse delay component and a second coarse delay component. The first coarse delay component is located in the optical path of the first beam line, and the second coarse delay component is located in the optical path of the second beam line;

[0011] The first coarse delay component and the second coarse delay component have the same structure; the first coarse delay component includes a first thin-film polarizer, a second thin-film polarizer, a first half-wave plate, a Faraday rotator, and a round-trip cavity arranged in sequence along the optical path direction of the first beam line;

[0012] The first beam line with S polarization is incident on the first thin-film polarizer, reflected to the second thin-film polarizer after passing through the first thin-film polarizer, reflected to the first half-wave plate after passing through the second thin-film polarizer, transmitted to the Faraday rotator after passing through the first half-wave plate, and becomes the first beam line with P polarization after passing through the Faraday rotator. The first beam line with P polarization is incident on the round-trip cavity. When the number of round trips in the round-trip cavity reaches the preset number of round trips, the first beam line with P polarization emitted from the round-trip cavity is incident on the Faraday rotator, and is transmitted to the subsequent optical path after passing through the Faraday rotator, the first half-wave plate, and the second thin-film polarizer in sequence.

[0013] Optionally, the round-trip cavity includes a first plane mirror, a first Pockels cell electro-optic switch, a quarter-wave plate, a first imaging lens, a second imaging lens, a third thin-film polarizer, a fourth thin-film polarizer, and a second plane mirror;

[0014] The first beam of P-polarized light is incident on the third thin-film polarizer, and successively passes through the third thin-film polarizer, the second imaging lens, the first imaging lens, the quarter-wave plate, and the first Pockels cell electro-optic switch, and then is transmitted to the first plane mirror. After being reflected by the first plane mirror, it is reflected to the first Pockels cell electro-optic switch. After passing through the first Pockels cell electro-optic switch, it is transmitted to the quarter-wave plate. After passing through the quarter-wave plate, it becomes the first beam of S-polarized light. The first Pockels cell electro-optic switch is loaded with a quarter-wavelength voltage. The first beam of S-polarized light starts to travel back and forth along the path of successively passing through the first imaging lens, the second imaging lens, the third thin-film polarizer, the fourth thin-film polarizer, the second plane mirror, the fourth thin-film polarizer, the third thin-film polarizer, the second imaging lens, the first imaging lens, the quarter-wave plate, the first Pockels cell electro-optic switch, the first plane mirror, the first Pockels cell electro-optic switch, and the quarter-wave plate. When the number of round trips reaches the preset number of round trips, the first Pockels cell electro-optic switch is no longer loaded with a quarter-wavelength voltage. The first beam of S-polarized light becomes the first beam of P-polarized light after passing through the quarter-wave plate. The first beam of P-polarized light is incident on the Faraday rotator after successively passing through the first imaging lens, the second imaging lens, and the third thin-film polarizer.

[0015] Optionally, the first imaging lens and the second imaging lens have the same focal length. The first plane mirror is located in the focal plane of the first imaging lens, and the second plane mirror is located in the focal plane of the second imaging lens. The distance between the first imaging lens and the second imaging lens is 2 times the focal length.

[0016] Optionally, the fine delay control component includes a first fine delay component and a second fine delay component. The first fine delay component is located in the optical path of the first beam of light, and the second fine delay component is located in the optical path of the second beam of light;

[0017] The first fine delay component and the second fine delay component have the same structure; the first fine delay component includes a motor, a first mirror, a second mirror, a third mirror, and a fourth mirror. The motor is drivingly connected to the third mirror and the fourth mirror. The motor is used to drive the third mirror and the fourth mirror to move, change the positions of the third mirror and the fourth mirror, and thus regulate the optical path of the first beam of light;

[0018] The first beam of light is reflected to the subsequent optical path after successively passing through the first mirror, the second mirror, the third mirror, and the fourth mirror.

[0019] Optionally, the maximum length when the motor drives the third mirror and the fourth mirror to move is 4 times the focal length; the motor is a stepper motor.

[0020] Optionally, the coarse time delay control component includes a plurality of coarse time delay components, and the fine time delay control component includes a plurality of fine time delay components. The number of the coarse time delay components and the number of the fine time delay components are both the same as the number of beam lines in the multi-beam high-energy petawatt laser system. One beam line corresponds to one coarse time delay component and one fine time delay component. The coarse time delay component corresponding to the first beam line is selected as the first coarse time delay component, the fine time delay component corresponding to the first beam line is selected as the first fine time delay component, the coarse time delay component corresponding to the second beam line is selected as the second coarse time delay component, and the fine time delay component corresponding to the second beam line is selected as the second fine time delay component.

[0021] Optionally, the multi-beam high-energy petawatt laser system includes a seed source, a picosecond optical parametric amplifier, a time domain stretcher, a nanosecond optical parametric chirped pulse amplifier, a beam splitter, and a plurality of branches. The number of branches is the same as the number of beam lines split by the beam splitter. Each branch includes a chirped pulse amplifier and a time domain compressor.

[0022] The laser emitted by the seed source is amplified by the picosecond optical parametric amplifier and then incident on the time domain stretcher. After being stretched by the time domain stretcher, it is incident on the nanosecond optical parametric chirped pulse amplifier. After being amplified by the nanosecond optical parametric chirped pulse amplifier, it is incident on the beam splitter. After being split by the beam splitter, a plurality of beam lines are obtained. Each beam line is respectively incident on the corresponding branch of the beam line. The beam line is amplified by the chirped pulse amplifier and then incident on the time domain compressor, and then exits after being compressed by the time domain compressor.

[0023] Among them, the coarse time delay component is located between the beam splitter and the chirped pulse amplifier, and the fine time delay component is located between the chirped pulse amplifier and the time domain compressor.

[0024] Optionally, the inter-beam time delay control device for the multi-beam high-energy petawatt laser system further includes: a leakage pulse suppression component. The leakage pulse suppression component is located between the coarse time delay component and the chirped pulse amplifier, and the leakage pulse suppression component is used to suppress the leakage pulse of the coarse time delay component.

[0025] The leakage pulse suppression component includes a plurality of suppression units arranged in sequence along the optical path direction. Each suppression unit includes a first Glan prism, a second Pockels cell electro-optic switch, a second Glan prism, and a second half-wave plate arranged in sequence along the optical path direction. The second Pockels cell electro-optic switch is loaded with a half-wavelength voltage.

[0026] In a second aspect, the present application provides an inter-beam time delay control method for a multi-beam high-energy petawatt laser system, which is applied to the above-mentioned inter-beam time delay control device for the multi-beam high-energy petawatt laser system. The inter-beam time delay control method for the multi-beam high-energy petawatt laser system includes:

[0027] Determine whether the required delay time between the first beam of light and the second beam of light is greater than the maximum delay time that the fine delay control component can provide;

[0028] If not, determine the required delay time between the first beam of light and the second beam of light as the first fine delay time, and issue a first control command based on the first fine delay time; the first control command is used to control the operation of the fine delay control component so that the delay time between the first beam of light and the second beam of light reaches the required delay time;

[0029] If so, determine the coarse delay time and the fine delay time respectively based on the required delay time between the first beam of light and the second beam of light; the coarse delay time is N times the maximum delay time that the fine delay control component can provide, the fine delay time is the difference between the required delay time and the coarse delay time, and the fine delay time is less than the maximum delay time that the fine delay control component can provide, and N is a positive integer;

[0030] Issue a second control command based on the coarse delay time and the fine delay time; the second control command is used to control the operation of the coarse delay control component so that the delay time between the first beam of light and the second beam of light is equal to the coarse delay time, and then control the operation of the fine delay control component so that the delay time between the first beam of light and the second beam of light reaches the required delay time.

[0031] According to the specific embodiments provided in this application, this application has the following technical effects:

[0032] This application provides an inter-beam time delay control device and method for a multi-beam high-energy petawatt laser system, including: a coarse delay control component, a fine delay control component, and a control component. The coarse delay control component adjusts the round-trip times of the first beam of light and the second beam of light in the multi-beam high-energy petawatt laser system to adjust the delay time between the first beam of light and the second beam of light. The fine delay control component adjusts the optical path of the first beam of light and the second beam of light to adjust the delay time between the first beam of light and the second beam of light. The control component controls the operation of the coarse delay control component and the fine delay control component based on the required delay time between the first beam of light and the second beam of light, so that the delay time between the first beam of light and the second beam of light reaches the required delay time. By setting the coarse delay control component and the fine delay control component, this application can couple two methods of round-trip times and optical path to adjust the delay time, and can realize continuous adjustment of the relative delay time within an ultra-large time interval. The ultra-large time interval is at least hundreds of nanoseconds. And by introducing the adjustment method of round-trip times, compared with the method of simply using optical path difference, there is no need to design a complex optical path, and the structure is simple. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 FIG. is a schematic structural diagram of an inter-beam time delay control device for a multi-beam high-energy petawatt laser system provided in Embodiment 1 of the present application.

[0035] Figure 2 FIG. is a schematic diagram of delayed target shooting for a multi-beam high-energy petawatt laser system provided in Embodiment 1 of the present application.

[0036] Figure 3 FIG. is a schematic flowchart of a method for inter-beam time delay control for a multi-beam high-energy petawatt laser system provided in Embodiment 2 of the present application.

[0037] Figure 4 FIG. is a schematic structural diagram of a computer device provided in Embodiment 3 of the present application. Detailed Embodiments

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0039] Embodiment 1

[0040] This embodiment provides an inter-beam time delay control device for a multi-beam high-energy petawatt laser system. As Figure 1 shown, the inter-beam time delay control device for a multi-beam high-energy petawatt laser system includes: a coarse delay control component, a fine delay control component, and a control component. The coarse delay control component and the fine delay control component are both communicatively connected to the control component.

[0041] The coarse delay control component is located after the beam splitter in the multi-beam high-energy petawatt laser system. The coarse delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the number of round trips of the first beam line and the second beam line in the multi-beam high-energy petawatt laser system.

[0042] The fine delay control component is located behind the coarse delay control component. The fine delay control component is used to control the delay time between the first beam of light and the second beam of light by adjusting the optical path of the first beam of light and the second beam of light. The maximum delay time that the fine delay control component can bring is the same as the delay time that the coarse delay control component can bring in one round trip.

[0043] The control component is used to control the operation of the coarse delay control component and the fine delay control component based on the required delay time between the first beam of light and the second beam of light, so that the delay time between the first beam of light and the second beam of light reaches the required delay time.

[0044] As Figure 2 shown, it is a schematic diagram of delayed target shooting for a multi-beam high-energy petawatt laser system. It is required that there is a specific time delay (or time sorting) between the target shooting pulses. For example, the time delay between beam line (i.e., laser beam) 1 and beam line m is Δt 1m , and the time delay between beam line m and beam line n is Δt mn . Before the inter-beam time delay control device is introduced, beam lines 1 to n originate from the same seed source, and an equal optical path design is carried out for all beam lines to achieve synchronous target shooting of all beam lines, that is, the time delay Δt ij between any two beam lines (beam line i and beam line j) is 0, where i, j = 1, 2, … n, i ≠ j. In order to make the target shooting pulses satisfy a specific time delay, an inter-beam time delay control device needs to be introduced. However, the current inter-beam time delay control device cannot adapt to the time delay in an ultra-large time interval. Therefore, it is necessary to design an ultra-large time interval inter-beam time delay precision control device for a multi-beam high-energy petawatt laser system. In this embodiment, the specifically designed inter-beam time delay precision control device consists of Figure 1 the coarse delay control part and the fine delay control part in it, that is, in order to solve this problem, the inter-beam time delay precision control device designed in this embodiment includes a coarse delay control component, a fine delay control component and a control component.

[0045] The following is a detailed introduction to each component in the inter-beam time delay control device:

[0046] (I) Coarse delay control component

[0047] The coarse delay control component is used to control the delay time between the first beam of light and the second beam of light in a multi-beam high-energy petawatt laser system by adjusting the number of round trips of the first beam of light and the second beam of light.

[0048] The coarse delay control component includes a first coarse delay component and a second coarse delay component. The first coarse delay component is located in the optical path of the first beam of light, and the second coarse delay component is located in the optical path of the second beam of light.

[0049] The structures of the first coarse delay component and the second coarse delay component are the same. The coarse delay component is composed of a round-trip cavity formed by M1-PC1-QWP-L1-L2-TFP3-TFP4-M2, as Figure 1 shown. The first coarse delay component includes a first thin-film polarizer TFP1, a second thin-film polarizer TFP2, a first half-wave plate HWP1, a Faraday rotator FR, and a round-trip cavity arranged in sequence along the optical path direction of the first beam. The first beam with S polarization is incident on the first thin-film polarizer TFP1, reflected to the second thin-film polarizer TFP2 after passing through the first thin-film polarizer TFP1, reflected to the first half-wave plate HWP1 after passing through the second thin-film polarizer TFP2, transmitted to the Faraday rotator FR after passing through the first half-wave plate HWP1, and becomes the first beam with P polarization after passing through the Faraday rotator FR. The first beam with P polarization is incident on the round-trip cavity and makes a round trip in the round-trip cavity. When the number of round trips in the round-trip cavity reaches the preset number of round trips, the first beam with P polarization emitted from the round-trip cavity is incident on the Faraday rotator FR, and after passing through the Faraday rotator FR, the first half-wave plate HWP1, and the second thin-film polarizer TFP2 in sequence, it is transmitted to the subsequent optical path.

[0050] Among them, the round-trip cavity includes a first plane mirror M1, a first Pockels cell electro-optic switch PC1, a quarter-wave plate QWP, a first imaging lens L1, a second imaging lens L2, a third thin-film polarizer TFP3, a fourth thin-film polarizer TFP4, and a second plane mirror M2. When the first P-polarized beam of light is incident on the round-trip cavity, the first P-polarized beam of light is incident on the third thin-film polarizer TFP3, and after passing through the third thin-film polarizer TFP3, the second imaging lens L2, the first imaging lens L1, the quarter-wave plate QWP, and the first Pockels cell electro-optic switch PC1 in sequence, it is transmitted to the first plane mirror M1. After being reflected by the first plane mirror M1, it is reflected to the first Pockels cell electro-optic switch PC1. After passing through the first Pockels cell electro-optic switch PC1, it is transmitted to the quarter-wave plate QWP. After passing through the quarter-wave plate QWP, it becomes the first S-polarized beam of light. At this time, the first Pockels cell electro-optic switch PC1 is loaded with a quarter-wavelength voltage (i.e., the voltage corresponding to a quarter wavelength of the beam of light). The first S-polarized beam of light starts to make round trips along the path of passing through the first imaging lens L1, the second imaging lens L2, the third thin-film polarizer TFP3, the fourth thin-film polarizer TFP4, the second plane mirror M2, the fourth thin-film polarizer TFP4, the third thin-film polarizer TFP3, the second imaging lens L2, the first imaging lens L1, the quarter-wave plate QWP, the first Pockels cell electro-optic switch PC1, the first plane mirror M1, the first Pockels cell electro-optic switch PC1, and the quarter-wave plate QWP. When the number of round trips reaches the preset number of round trips, at this time, the first Pockels cell electro-optic switch PC1 is no longer loaded with a quarter-wavelength voltage. The first S-polarized beam of light becomes the first P-polarized beam of light after passing through the quarter-wave plate QWP. The first P-polarized beam of light is incident on the Faraday rotator FR after passing through the first imaging lens L1, the second imaging lens L2, and the third thin-film polarizer TFP3 in sequence.

[0051] The focal lengths of the first imaging lens L1 and the second imaging lens L2 are the same, that is, the first imaging lens L1 and the second imaging lens L2 have the same focal length, and the focal length is f. The first plane mirror M1 is located in the focal plane of the first imaging lens L1, and the second plane mirror M2 is located in the focal plane of the second imaging lens L2. The distance between the first imaging lens L1 and the second imaging lens L2 is 2 times the focal length, that is, the spacing is 2f, so that the round-trip cavity composed of M1-PC1-QWP-L1-L2-TFP3-TFP4-M2 forms a 4f imaging system. At this time, after the beam of light makes multiple round trips in the round-trip cavity, the object plane of the incident beam of light and the image plane of the outgoing beam of light are strictly conjugate and coincide, that is, the beam of light satisfies a strict image transfer relationship during multiple round trips in the round-trip cavity, and does not affect the near-field quality of the long-distance transmission of the light beam.

[0052] The single round-trip time for the beam of light to travel in the round-trip cavity is denoted as T R , T R= 8f / c, where c is the speed of light. At this time, if it is set that the first beam line makes n fewer round trips than the second beam line, the delay time between the first beam line and the second beam line can reach nT R .

[0053] The number of round trips of the beam line in the return cavity is controlled by the first Pockels cell electro-optical switch PC1. The working mode is as follows: the incident beam line is S-polarized, and after being reflected by the first thin-film polarizer TFP1 and the second thin-film polarizer TFP2, it enters the first half-wave plate HWP1 and the Faraday rotator FR, and the beam line becomes P-polarized. The P-polarized beam line passes through the third thin-film polarizer TFP3, the second imaging lens L2, the first imaging lens L1, the quarter-wave plate QWP and the first Pockels cell electro-optical switch PC1 in sequence, and then is reflected by the first plane mirror M1 and returns along the original optical path. After passing through the first Pockels cell electro-optical switch PC1, it is incident on the quarter-wave plate QWP. After passing through the quarter-wave plate QWP, the beam line becomes S-polarized. The S-polarized beam line then returns along the optical path L1 - L2 - TFP3 - TFP4 - M2 - TFP4 - TFP3 - L2 - L1 - QWP. Before the return light passes through the first Pockels cell electro-optical switch PC1, a quarter-wavelength voltage is applied to the first Pockels cell electro-optical switch PC1, so as to form a half-wave plate with the quarter-wave plate QWP. At this time, when the beam line makes a round trip in the return cavity along L1 - L2 - TFP3 - TFP4 - M2 - TFP4 - TFP3 - L2 - L1 - QWP - PC1 - M1 - PC1 - QWP - L1, it is equivalent to the beam line passing through a full-wave plate, and the polarization state of the beam line remains unchanged. Thus, the beam line makes round trips in the return cavity without being exported. When the designed number of round trips is reached, the quarter-wavelength voltage is removed from the first Pockels cell electro-optical switch PC1, and the polarization state of the beam line becomes P-polarized. The P-polarized beam line is exported from the third thin-film polarizer TFP3, and after passing through the Faraday rotator FR and the first half-wave plate HWP1, the polarization state of the beam line remains unchanged and is output along the second thin-film polarizer TFP2.

[0054] (2) Fine delay control component

[0055] The fine delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the optical paths of the first beam line and the second beam line. The maximum delay time that the fine delay control component can bring is the same as the delay time that the coarse delay control component can bring in one round trip.

[0056] The fine delay control component includes a first fine delay component and a second fine delay component. The first fine delay component is located in the optical path of the first beam line, and the second fine delay component is located in the optical path of the second beam line.

[0057] The structures of the first fine delay component and the second fine delay component are the same. The fine delay component consists of a high-precision stepper motor. The adjustable length of the stepper motor is 4f, and the round-trip adjustable length is 8f. Therefore, the adjustable time delay amount is also T R , T R = 8f / c. The delay adjustment accuracy and adjustment step size are determined by the stepping accuracy and step size of the stepper motor. The first fine delay component includes a motor, a first mirror, a second mirror, a third mirror, and a fourth mirror. The motor is drivingly connected to the third mirror and the fourth mirror. The motor is used to drive the third mirror and the fourth mirror to move, changing the positions of the third mirror and the fourth mirror to regulate the optical path of the first beam of light. The first beam of light is reflected to the subsequent optical path after passing through the first mirror, the second mirror, the third mirror, and the fourth mirror in sequence

[0058] Among them, the maximum length when the motor drives the third mirror and the fourth mirror to move is 4 times the focal length, and the motor can be a stepper motor

[0059] (3) Control component

[0060] The control component is used to control the operation of the coarse delay regulation component and the fine delay regulation component based on the delay time requirement between the first beam of light and the second beam of light, so that the delay time between the first beam of light and the second beam of light reaches the delay time requirement

[0061] According to the physical experiment requirements, clarify the target shooting time delay amount (i.e., relative delay time) between beam m and beam n, denoted as Δt mn . When Δt mn ≤T R , the number of round trips of beam m and beam n in the reciprocating cavity is the same, and the relative delay time Δt mn is determined by the optical path difference controlled by the high-precision stepper motor. The delay time range is 0 ≤ Δt mn ≤T R . When Δt mn >T R , that is, Δt mn = NT R +t mn , at this time, control the number of round trips of beam m and beam n in the reciprocating cavity to be N m and N n , so that N = N m -N m , and t mn is determined by the optical path difference controlled by the high-precision stepper motor. Control the number of round trips N m and N n of beam m and beam n in the reciprocating cavity, combined with the fine delay control of the high-precision stepper motor, so that the relative delay time Δt mn of any two beams of light can be from 0 to NTR continuously adjustable within an extremely large time interval.

[0062] In this embodiment, as Figure 2 shown, the coarse delay control component includes multiple coarse delay components, and the fine delay control component includes multiple fine delay components. The number of coarse delay components and the number of fine delay components are both the same as the number of beam lines in the multi-beam high-energy petawatt laser system. One beam line corresponds to one coarse delay component and one fine delay component. Select the coarse delay component corresponding to the first beam line as the first coarse delay component, select the fine delay component corresponding to the first beam line as the first fine delay component, select the coarse delay component corresponding to the second beam line as the second coarse delay component, and select the fine delay component corresponding to the second beam line as the second fine delay component.

[0063] The multi-beam high-energy petawatt laser system includes a seed source, a picosecond optical parametric amplifier, a temporal stretcher, a nanosecond optical parametric chirped pulse amplifier, a beam splitter, and multiple branches. The number of branches is the same as the number of beam lines split by the beam splitter. Each branch includes a chirped pulse amplifier and a temporal compressor. The laser emitted by the seed source is amplified by the picosecond optical parametric amplifier and then incident on the temporal stretcher. After being stretched by the temporal stretcher, it is incident on the nanosecond optical parametric chirped pulse amplifier. After being amplified by the nanosecond optical parametric chirped pulse amplifier, it is incident on the beam splitter. After being split by the beam splitter, multiple beam lines are obtained. Each beam line is respectively incident on the branch corresponding to the beam line. After being amplified by the chirped pulse amplifier, the beam line is incident on the temporal compressor and then exits after being compressed by the temporal compressor.

[0064] Among them, the coarse delay component is located between the beam splitter and the chirped pulse amplifier, and the fine delay component is located between the chirped pulse amplifier and the temporal compressor.

[0065] The inter-beam time delay control device for the multi-beam high-energy petawatt laser system in this embodiment further includes: a leakage pulse suppression component. The leakage pulse suppression component is located between the coarse delay component and the chirped pulse amplifier, and the leakage pulse suppression component is used to suppress the leakage pulses of the coarse delay component.

[0066] Among them, the leakage pulse suppression component includes several suppression units arranged in sequence along the optical path direction. Each suppression unit includes a first Glan prism GP1, a second Pockels cell electro-optic switch PC2, a second Glan prism GP2, and a second half-wave plate HWP2 arranged in sequence along the optical path direction. The second Pockels cell electro-optic switch PC2 is loaded with a half-wavelength voltage (i.e., the voltage corresponding to half the wavelength of the beam line). The second Pockels cell electro-optic switch PC2 is used to suppress the leakage pulses of the round-trip cavity and improve the temporal contrast of the target pulse.

[0067] When the required delay interval is dozens of nanoseconds or even hundreds of nanoseconds, simply relying on the adjustment method of optical path difference to achieve a delay adjustment with a relative delay time in the range of hundreds of nanoseconds is extremely complex in engineering design. At the same time, it is impossible to meet the beam image transfer design throughout the delay optical path, which will deteriorate the near-field quality of the beam. In view of this, this embodiment invents a device for precise control of inter-beam time delay with an ultra-large time interval for a multi-beam high-energy petawatt laser system, which has the advantages of a large delay interval, high delay adjustment accuracy, and little influence on the near-field quality of the beam, and has important application value in the field of strong-field physics research based on multi-beam high-energy petawatt lasers.

[0068] In the field of high-power laser applications, to meet the requirements of specific physical experiments, it is necessary to sort the arrival times of laser pulses of a multi-beam high-energy petawatt laser system to the target, that is, it is required to precisely control the inter-beam arrival time delay of the multi-beam high-energy petawatt laser system, and the time delay interval is dozens of nanoseconds or even hundreds of nanoseconds. This embodiment proposes a device for precise control of inter-beam time delay with an ultra-large time interval for a multi-beam high-energy petawatt laser system, which has the following main advantages:

[0069] (1) Large delay interval. The relative delay time Δt between any two beams is theoretically mn continuously adjustable within an ultra-large time interval from 0 to NT. R

[0070] (2) High delay adjustment accuracy. The delay adjustment accuracy and adjustment step size are determined by the stepping accuracy and step size of the stepping motor, and the adjustment accuracy can reach several picoseconds or even femtoseconds.

[0071] (3) Little influence on the near-field quality of the beam. In the round-trip cavity, the object plane of the incident beam line and the image plane of the outgoing beam line are strictly conjugate and coincide, that is, the beam line satisfies a strict image transfer relationship during multiple round trips in the round-trip cavity, which does not affect the near-field quality of the long-distance transmission of the beam. The fine delay adjustment is located after the CPA after beam expansion. Under a large-aperture beam, the optical path difference introduced by the stepping motor has a negligible influence on the near-field of the beam.

[0072] Embodiment 2

[0073] This embodiment provides a method for controlling the inter-beam time delay of a multi-beam high-energy petawatt laser system, which is applied to the device for controlling the inter-beam time delay of a multi-beam high-energy petawatt laser system described in Embodiment 1, as Figure 3 shown. The method for controlling the inter-beam time delay of a multi-beam high-energy petawatt laser system includes:

[0074] S1: Determine whether the required delay time between the first beam line and the second beam line is greater than the maximum delay time that the fine delay control component can bring.

[0075] S2: If not, determine the delay time requirement between the first beam of wires and the second beam of wires as the first fine delay time, and issue a first control command based on the first fine delay time; the first control command is used to control the operation of the fine delay adjustment component so that the delay time between the first beam of wires and the second beam of wires reaches the delay time requirement.

[0076] S3: If so, determine the coarse delay time and the fine delay time respectively based on the delay time requirement between the first beam of wires and the second beam of wires; the coarse delay time is N times the maximum delay time that the fine delay adjustment component can bring, the fine delay time is the difference between the delay time requirement and the coarse delay time, and the fine delay time is less than the maximum delay time that the fine delay adjustment component can bring, where N is a positive integer.

[0077] S4: Issue a second control command based on the coarse delay time and the fine delay time; the second control command is used to control the operation of the coarse delay adjustment component so that the delay time between the first beam of wires and the second beam of wires is equal to the coarse delay time, and then control the operation of the fine delay adjustment component so that the delay time between the first beam of wires and the second beam of wires reaches the delay time requirement.

[0078] Embodiment 3

[0079] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 4 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a method for inter-beam time delay adjustment of a multi-beam high-energy petawatt laser system.

[0080] Those skilled in the art can understand, Figure 4The structure shown is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.

[0081] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the method for inter-beam time delay regulation of a multi-beam high-energy petawatt laser system in Embodiment 2.

[0082] Embodiment 4

[0083] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, it implements the method for inter-beam time delay regulation of a multi-beam high-energy petawatt laser system in Embodiment 2.

[0084] Embodiment 5

[0085] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, it implements the method for inter-beam time delay regulation of a multi-beam high-energy petawatt laser system in Embodiment 2.

[0086] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0087] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this specification.

[0088] Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, based on the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on this application.

Claims

1. An inter-beam time delay control device for a multi-beam high-energy petawatt laser system, characterized in that, The inter-beam time delay control device for a multi-beam high-energy petawatt laser system includes: a coarse delay control component, a fine delay control component, and a control component; The coarse delay control component is located behind the beam splitter in the multi-beam high-energy petawatt laser system. The coarse delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the number of round trips of the first beam line and the second beam line in the multi-beam high-energy petawatt laser system; The fine delay control component is located behind the coarse delay control component. The fine delay control component is used to control the delay time between the first beam line and the second beam line by adjusting the optical path lengths of the first beam line and the second beam line; the maximum delay time that the fine delay control component can bring is the same as the delay time that the coarse delay control component can bring in one round trip; The control component is used to control the operation of the coarse delay control component and the fine delay control component based on the required delay time between the first beam line and the second beam line, so that the delay time between the first beam line and the second beam line reaches the required delay time.

2. The beam - to - beam time delay control device for a multi - beam high - energy petawatt laser system according to claim 1, wherein, The coarse delay control component includes a first coarse delay component and a second coarse delay component. The first coarse delay component is located in the optical path of the first beam line, and the second coarse delay component is located in the optical path of the second beam line; The structures of the first coarse delay component and the second coarse delay component are the same; the first coarse delay component includes a first thin film polarizer, a second thin film polarizer, a first half-wave plate, a Faraday rotator, and a round-trip cavity arranged in sequence along the optical path direction of the first beam line; The first beam line with S polarization is incident on the first thin film polarizer, reflected to the second thin film polarizer after passing through the first thin film polarizer, reflected to the first half-wave plate after passing through the second thin film polarizer, transmitted to the Faraday rotator after passing through the first half-wave plate, and becomes the first beam line with P polarization after passing through the Faraday rotator. The first beam line with P polarization is incident on the round-trip cavity. When the number of round trips in the round-trip cavity reaches the preset number of round trips, the first beam line with P polarization emitted from the round-trip cavity is incident on the Faraday rotator, and after passing through the Faraday rotator, the first half-wave plate, and the second thin film polarizer in sequence, it is transmitted to the subsequent optical path.

3. The beam - to - beam time - delay control device for a multi - beam high - energy petawatt laser system according to claim 2, characterized in that, The round-trip cavity includes a first plane mirror, a first Pockels cell electro-optic switch, a quarter-wave plate, a first imaging lens, a second imaging lens, a third thin film polarizer, a fourth thin film polarizer, and a second plane mirror; The first beam of P-polarized light is incident on the third thin-film polarizer, and successively passes through the third thin-film polarizer, the second imaging lens, the first imaging lens, the quarter-wave plate, and the first Pockels cell electro-optic switch, and then is transmitted to the first plane mirror. After being reflected by the first plane mirror, it is reflected to the first Pockels cell electro-optic switch. After passing through the first Pockels cell electro-optic switch, it is transmitted to the quarter-wave plate. After passing through the quarter-wave plate, it becomes the first beam of S-polarized light. The first Pockels cell electro-optic switch is loaded with a quarter-wavelength voltage. The first beam of S-polarized light starts to travel back and forth along the path of successively passing through the first imaging lens, the second imaging lens, the third thin-film polarizer, the fourth thin-film polarizer, the second plane mirror, the fourth thin-film polarizer, the third thin-film polarizer, the second imaging lens, the first imaging lens, the quarter-wave plate, the first Pockels cell electro-optic switch, the first plane mirror, the first Pockels cell electro-optic switch, and the quarter-wave plate. When the number of round trips reaches the preset number of round trips, the first Pockels cell electro-optic switch is no longer loaded with a quarter-wavelength voltage. The first beam of S-polarized light becomes the first beam of P-polarized light after passing through the quarter-wave plate. The first beam of P-polarized light is incident on the Faraday rotator after successively passing through the first imaging lens, the second imaging lens, and the third thin-film polarizer.

4. The beam - to - beam time - delay control device for a multi - beam high - energy petawatt laser system according to claim 3, characterized in that, The focal lengths of the first imaging lens and the second imaging lens are the same. The first plane mirror is located in the focal plane of the first imaging lens. The second plane mirror is located in the focal plane of the second imaging lens. The distance between the first imaging lens and the second imaging lens is 2 times the focal length.

5. The beam - to - beam time delay control device for a multi - beam high - energy petawatt laser system according to claim 4, wherein, The fine delay control component includes a first fine delay component and a second fine delay component. The first fine delay component is located in the optical path of the first beam of light. The second fine delay component is located in the optical path of the second beam of light. The structures of the first fine delay component and the second fine delay component are the same. The first fine delay component includes a motor, a first mirror, a second mirror, a third mirror, and a fourth mirror. The motor is drivingly connected to the third mirror and the fourth mirror. The motor is used to drive the third mirror and the fourth mirror to move, change the positions of the third mirror and the fourth mirror, and thus regulate the optical path of the first beam of light. The first beam of light is reflected to the subsequent optical path after successively passing through the first mirror, the second mirror, the third mirror, and the fourth mirror.

6. The beam - to - beam time delay control device for a multi - beam high - energy petawatt laser system according to claim 5, wherein, The maximum length when the motor drives the third mirror and the fourth mirror to move is 4 times the focal length. The motor is a stepper motor.

7. The inter-beam time delay control device for a multi-beam high-energy petawatt laser system according to claim 5, characterized in that The coarse delay control component includes a plurality of coarse delay components. The fine delay control component includes a plurality of fine delay components. The number of coarse delay components and the number of fine delay components are both the same as the number of beams in the multi-beam high-energy petawatt laser system. One beam corresponds to one coarse delay component and one fine delay component. The coarse delay component corresponding to the first beam is selected as the first coarse delay component. The fine delay component corresponding to the first beam is selected as the first fine delay component. The coarse delay component corresponding to the second beam is selected as the second coarse delay component. The fine delay component corresponding to the second beam is selected as the second fine delay component.

8. The inter-beam time delay control device for a multi-beam high-energy petawatt laser system according to claim 7, wherein, The multi-beam high-energy petawatt laser system includes a seed source, a picosecond optical parametric amplifier, a time-domain stretcher, a nanosecond optical parametric chirped pulse amplifier, a beam splitter, and multiple branches. The number of branches is the same as the number of beam lines split by the beam splitter. Each branch includes a chirped pulse amplifier and a time-domain compressor. The laser emitted by the seed source is amplified by the picosecond optical parametric amplifier and then incident on the time-domain stretcher. After being stretched by the time-domain stretcher, it is incident on the nanosecond optical parametric chirped pulse amplifier. After being amplified by the nanosecond optical parametric chirped pulse amplifier, it is incident on the beam splitter. After being split by the beam splitter, multiple beam lines are obtained. Each beam line is respectively incident on the corresponding branch of the beam line. After being amplified by the chirped pulse amplifier, the beam line is incident on the time-domain compressor and then exits after being compressed by the time-domain compressor. Among them, the coarse delay component is located between the beam splitter and the chirped pulse amplifier, and the fine delay component is located between the chirped pulse amplifier and the time-domain compressor.

9. The beam - to - beam time - delay control device for a multi - beam high - energy petawatt laser system according to claim 8, characterized in that, The inter-beam time delay control device for the multi-beam high-energy petawatt laser system further includes: a leakage pulse suppression component, which is located between the coarse delay component and the chirped pulse amplifier, and is used to suppress the leakage pulse of the coarse delay component. The leakage pulse suppression component includes a plurality of suppression units arranged in sequence along the optical path direction. Each suppression unit includes a first Glan prism, a second Pockels cell electro-optic switch, a second Glan prism, and a second half-wave plate arranged in sequence along the optical path direction. The second Pockels cell electro-optic switch is loaded with a half-wavelength voltage.

10. A method for regulating the inter-beam time delay of a multi-beam high-energy petawatt laser system, which is applied to the inter-beam time delay regulating device for a multi-beam high-energy petawatt laser system according to any one of claims 1-9, characterized in that, The inter-beam time delay control method for the multi-beam high-energy petawatt laser system includes: Judging whether the required delay time between the first beam line and the second beam line is greater than the maximum delay time that the fine delay control component can bring. If not, determining the required delay time between the first beam line and the second beam line as the first fine delay time, and issuing a first control command based on the first fine delay time. The first control command is used to control the fine delay control component to work so that the delay time between the first beam line and the second beam line reaches the required delay time. If so, determining the coarse delay time and the fine delay time respectively based on the required delay time between the first beam line and the second beam line. The coarse delay time is N times the maximum delay time that the fine delay control component can bring, and the fine delay time is the difference between the required delay time and the coarse delay time, and the fine delay time is less than the maximum delay time that the fine delay control component can bring. N is a positive integer. Issuing a second control command based on the coarse delay time and the fine delay time. The second control command is used to control the coarse delay control component to work so that the delay time between the first beam line and the second beam line is equal to the coarse delay time, and then control the fine delay control component to work so that the delay time between the first beam line and the second beam line reaches the required delay time.

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