Vector vortex light stimulated Brillouin scattering device and method

Abstract

The invention discloses a vector vortex light stimulated Brillouin scattering device and method, and relates to the technical field of nonlinear light. The method is characterized by comprising the following steps of: adjusting a polarization included angle between laser in a linear polarization state and a vortex wave plate main shaft through a half-wave plate, and then entering the vortex wave plate to generate a radial or angular vector vortex light beam; the vector vortex light beam is separated into vertical polarized light and horizontal polarized light through a first polarization beam splitter; one-way transmission, energy amplification and reflection are successively carried out on the vertical polarized light and the horizontal polarized light respectively, the vertical polarized light and the horizontal polarized light are coupled to a stimulated Brillouin scattering medium to carry out a stimulated Brillouin scattering nonlinear effect, and left-handed and right-handed circularly polarized reverse Stokes light is generated and converted into horizontal and vertical reverse Stokes light respectively; and then beam combination is carried out through the second polarization beam splitter, so that stimulated Brillouin scattering output of the vector vortex light is realized. The Brillouin conversion device is compact in structure, small in size, high in stability and practicability and capable of achieving high Brillouin conversion efficiency.

Description

Technical Field

[0001] The present invention relates to the field of nonlinear optical technology, and in particular to a vector vortex light stimulated Brillouin scattering device and method. Background Art

[0002] Compared with scalar vortex beams, vector vortex beams, as spin-orbital angular momentum coupled beams, not only have anisotropic spatial polarization distribution, but also have spiral phase distribution, and carry orbital angular momentum related to the phase distribution. With their unique physical properties, vector vortex beams have attracted much attention in the field of optical technology, and have shown great application potential in many cutting-edge fields such as optical communications, optical micromanipulation, quantum information coding and classical entanglement.

[0003] However, due to its incompatibility with existing laser technology based on a single linear polarization state, as well as the technical bottlenecks faced in the beam splitting, transmission and combining processes, the practical application of vector vortex beams is limited, and related research is relatively scarce. Existing solutions still have obvious shortcomings in some aspects. Summary of the invention

[0004] In view of the above problems, the present invention proposes a vector vortex light stimulated Brillouin scattering device and method to achieve stimulated Brillouin scattering output of vector vortex light.

[0005] According to one aspect of the present invention, a vector vortex light stimulated Brillouin scattering device is proposed, the device comprising: a laser 1, a first half-wave plate 2, a vortex wave plate 3, a first polarization beam splitter 4, a first nonlinear effect module 5, a second nonlinear effect module 6, a fourth half-wave plate 7, and a second polarization beam splitter 8; wherein the first nonlinear effect module 5 comprises a first stimulated Brillouin scattering medium 5-9, and the second nonlinear effect module 6 comprises a second stimulated Brillouin scattering medium 6-9;

[0006] The laser 1 emits a laser with a linear polarization state; the first half-wave plate 2 is used to adjust the polarization angle between the laser with a linear polarization state and the main axis of the vortex wave plate 3; the vortex wave plate 3 is used to generate a radial or angular vector vortex beam based on the incident laser with a linear polarization state; the first polarization beam splitter 4 is used to separate the vector vortex beam into two orthogonal linear polarization state lights, namely horizontally polarized light and vertically polarized light;

[0007] The first nonlinear effect module 5 is used to successively perform unidirectional transmission, energy amplification, and reflection on a single vertically polarized light, and then couple it to the first stimulated Brillouin scattering medium 5-9 to perform stimulated Brillouin scattering nonlinear effect, generate left-handed circularly polarized reverse Stokes light, and convert the left-handed circularly polarized reverse Stokes light into horizontal reverse Stokes light;

[0008] The second non-linear effect module 6 is used to successively perform unidirectional transmission, energy amplification, and reflection on a single horizontally polarized light, and then couple it into the second stimulated Brillouin scattering medium 6-9 to perform the non-linear effect of stimulated Brillouin scattering, generating a right-handed circularly polarized backward Stokes light, and converting the right-handed circularly polarized backward Stokes light into a vertically polarized backward Stokes light;

[0009] The fourth quarter-wave plate 7 is used to rotate the polarization state of the horizontally polarized backward Stokes light returned by the first non-linear effect module 5 by 90 degrees;

[0010] The second polarization beam splitter 8 is used to combine the vertically polarized backward Stokes light output by the fourth quarter-wave plate 7 and the vertically polarized backward Stokes light returned by the second non-linear effect module 6.

[0011] Furthermore, the first non-linear effect module 5 further includes a first optical isolation system, a first quarter-wave plate 5-5, a first amplifier 5-6, a first 45-degree mirror 5-7, and a first convex lens 5-8; the first optical isolation system is used to achieve unidirectional transmission of vertically polarized light; the first quarter-wave plate 5-5 is used to convert the vertically polarized light after unidirectional transmission into left-handed circularly polarized light, and convert the left-handed circularly polarized backward Stokes light into horizontally polarized backward Stokes light; the first amplifier 5-6 is used to amplify the energy of the left-handed circularly polarized light; the first 45-degree mirror 5-7 is used to reflect the left-handed circularly polarized light after energy amplification, and reflect the reflected left-handed circularly polarized backward Stokes light to the first amplifier 5-6; the first convex lens 5-8 is used to couple the reflected left-handed circularly polarized light into the first stimulated Brillouin scattering medium 5-9.

[0012] Furthermore, the second non-linear effect module 6 further includes a second optical isolation system, a second quarter-wave plate 6-5, a second amplifier 6-6, a second 45-degree mirror 6-7, and a second convex lens 6-8; the second optical isolation system is used to achieve unidirectional transmission of horizontally polarized light; the second quarter-wave plate 6-5 is used to convert the horizontally polarized light after unidirectional transmission into right-handed circularly polarized light, and convert the right-handed circularly polarized backward Stokes light into vertically polarized backward Stokes light; the second amplifier 6-6 is used to amplify the energy of the right-handed circularly polarized light; the second 45-degree mirror 6-7 is used to reflect the right-handed circularly polarized light after energy amplification, and reflect the reflected right-handed circularly polarized backward Stokes light to the second amplifier 6-6; the second convex lens 6-8 is used to couple the reflected right-handed circularly polarized light into the second stimulated Brillouin scattering medium 6-9.

[0013] Further, the first optical isolation system includes a first polarizer 5-1, a first Faraday rotator 5-2, a second half-wave plate 5-3, and a second polarizer 5-4; wherein the first Faraday rotator 5-2 is used to irreversibly rotate the polarization plane of the light beam by using the magneto-optical effect, and the second half-wave plate 5-3 is used to adjust the polarization state.

[0014] Further, the second optical isolation system includes a third polarizer 6-1, a second Faraday rotator 6-2, a third half-wave plate 6-3, and a fourth polarizer 6-4; wherein the second Faraday rotator 6-2 is used to irreversibly rotate the polarization plane of the light beam by using the magneto-optical effect, and the third half-wave plate 6-3 is used to adjust the polarization state.

[0015] Further, the distances of the respective devices satisfy the following relational expression:

[0016] L1 + L2 + L3 = L6 + L7 + L8;

[0017] L2 + L3 + L4 + L5 = L7 + L8 + L9 + L10;

[0018] Wherein, L1 represents the distance between the reflection surface of the first polarization beam splitter 4 and the first 45-degree mirror 5-7; L2 represents the distance between the first 45-degree mirror 5-7 and the first convex lens 5-8; L3 represents the distance between the first convex lens 5-8 and the first stimulated Brillouin scattering medium 5-9; L4 represents the distance between the first 45-degree mirror 5-7 and the second polarizer 5-4; L5 represents the distance between the second polarizer 5-4 and the reflection surface of the second polarization beam splitter 8; L6 represents the distance between the reflection surface of the first polarization beam splitter 4 and the second 45-degree mirror 6-7; L7 represents the distance between the second 45-degree mirror 6-7 and the second convex lens 6-8; L8 represents the distance between the second convex lens 6-8 and the second stimulated Brillouin scattering medium 6-9; L9 represents the distance between the second 45-degree mirror 6-7 and the fourth polarizer 6-4; L10 represents the distance between the fourth polarizer 6-4 and the reflection surface of the second polarization beam splitter 8.

[0019] Further, the first stimulated Brillouin scattering medium 5-9 and the second stimulated Brillouin scattering medium 6-9 are carbon disulfide media.

[0020] Further, the fast axis directions of the first quarter-wave plate 5-5 and the second quarter-wave plate 6-5 are both at 45° to the polarization direction.

[0021] According to another aspect of the present invention, a method for stimulated Brillouin scattering of vector vortex light is proposed, and the method is implemented based on the above-mentioned device for stimulated Brillouin scattering of vector vortex light; the method includes:

[0022] The laser with a linearly polarized state is incident on the vortex wave plate 3 after adjusting the polarization angle with the main axis of the vortex wave plate 3 through the first half-wave plate 2, generating a radial or angular vector vortex beam; the vector vortex beam is separated into two orthogonally linearly polarized light by the first polarization beam splitter 4, namely horizontally polarized light and vertically polarized light;

[0023] After the single vertically polarized light and horizontally polarized light are successively subjected to unidirectional transmission, energy amplification, and reflection, they are respectively coupled into the first stimulated Brillouin scattering medium 5-9 and the second stimulated Brillouin scattering medium 6-9 to utilize the pump light to stimulate Brillouin scattering to perform the stimulated Brillouin scattering nonlinear effect, generating left-handed circularly polarized backward Stokes light and right-handed circularly polarized backward Stokes light; and the left-handed circularly polarized backward Stokes light is converted into horizontally backward Stokes light by the first quarter-wave plate 5-5, and the right-handed circularly polarized backward Stokes light is converted into vertically backward Stokes light by the second quarter-wave plate 6-5;

[0024] Then, the polarization state of the horizontally backward Stokes light is rotated by 90 degrees through the fourth half-wave plate 7; subsequently, the vertically backward Stokes light with the rotated polarization state output by the fourth half-wave plate 7 and the vertically backward Stokes light output by the second quarter-wave plate 6-5 are combined by the second polarization beam splitter 8.

[0025] Furthermore, the process of generating the left-handed circularly polarized backward Stokes light and the right-handed circularly polarized backward Stokes light includes: the vertically polarized light realizes unidirectional transmission through the first optical isolation system, and then the vertically polarized light after unidirectional transmission is converted into left-handed circularly polarized light by the first quarter-wave plate 5-5, and then the left-handed circularly polarized light is amplified in energy by the first amplifier 5-6, and then the left-handed circularly polarized light after energy amplification is reflected by the first 45-degree mirror 5-7, and then the reflected left-handed circularly polarized light is coupled into the first stimulated Brillouin scattering medium 5-9 by the first convex lens 5-8; the left-handed circularly polarized backward Stokes light generated in the first stimulated Brillouin scattering medium 5-9 successively passes through the first convex lens 5-8, the first 45-degree mirror 5-7, the first amplifier 5-6, and the first quarter-wave plate 5-5, converting the left-handed circularly polarized backward Stokes light into horizontally backward Stokes light, and then being reflected by the second polarizer 5-4 in the first optical isolation system to the fourth half-wave plate 7;

[0026] The horizontally polarized light undergoes unidirectional transmission through the second optical isolation system, and then passes through the second quarter-wave plate 6-5 to convert the horizontally polarized light that has undergone unidirectional transmission into right-handed circularly polarized light. Subsequently, the right-handed circularly polarized light is amplified in energy by the second amplifier 6-6. Then, the energy-amplified right-handed circularly polarized light is reflected by the second 45-degree mirror 6-7. Subsequently, the reflected right-handed circularly polarized light is coupled into the second stimulated Brillouin scattering medium 6-9 through the second convex lens 6-8; the right-handed circularly polarized backward Stokes light generated in the second stimulated Brillouin scattering medium 6-9 successively passes through the second convex lens 6-8, the second 45-degree mirror 6-7, the second amplifier 6-6, and the second quarter-wave plate 6-5 to convert the right-handed circularly polarized backward Stokes light into vertically polarized backward Stokes light, and then is reflected by the fourth polarizer 6-4 in the second optical isolation system to the second polarization beam splitter 8.

[0027] The beneficial technical effects of the present invention are:

[0028] The present invention provides a vector vortex light stimulated Brillouin scattering device and method. By optimizing the layout parameters, a high Brillouin conversion efficiency can be achieved, and the stimulated Brillouin scattering output of the vector vortex light is realized by adopting a unique structure; the structure of the present invention is compact, has a small volume, strong stability, and high practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understood. In the drawings, several embodiments of the present invention are shown in an exemplary rather than restrictive manner, wherein:

[0030] Figure 1 is a schematic structural diagram of a vector vortex light stimulated Brillouin scattering device proposed by the present invention;

[0031] Figure 2 is a schematic diagram of the distances between various components of a vector vortex light stimulated Brillouin scattering device proposed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The principles and spirit of the present invention will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are provided only to enable those skilled in the art to better understand and then implement the present invention, and do not limit the scope of the present invention in any way. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to be able to fully convey the scope of the present disclosure to those skilled in the art.

[0033] The present invention provides a vector vortex light stimulated Brillouin scattering device, which realizes the stimulated Brillouin scattering of vector vortex light through dual-channel polarization selectivity. As Figure 1As shown in the figure, the device includes: a laser 1, a first half-wave plate 2, a vortex wave plate 3, a first polarization beam splitter 4, a first nonlinear effect module 5, a second nonlinear effect module 6, a fourth half-wave plate 7, and a second polarization beam splitter 8; among them, the first nonlinear effect module 5 includes a first stimulated Brillouin scattering medium 5-9, and the second nonlinear effect module 6 includes a second stimulated Brillouin scattering medium 6-9;

[0034] The laser 1 emits laser light with a linearly polarized state; the first half-wave plate 2 is used to adjust the polarization angle between the laser light with a linearly polarized state and the main axis of the vortex wave plate 3; the vortex wave plate 3 is used to generate a radial or angular vector vortex beam based on the incident laser light with a linearly polarized state; the first polarization beam splitter 4 is used to separate the vector vortex beam into two orthogonally linearly polarized lights, namely horizontally polarized light and vertically polarized light;

[0035] The first nonlinear effect module 5 is used to successively perform unidirectional transmission, energy amplification, and reflection on a single vertically polarized light, and then couple it into the first stimulated Brillouin scattering medium 5-9 to utilize the pump light to stimulate Brillouin scattering for the stimulated Brillouin scattering nonlinear effect, generate a left-handed circularly polarized backward Stokes light, and convert the left-handed circularly polarized backward Stokes light into a horizontally backward Stokes light;

[0036] The second nonlinear effect module 6 is used to successively perform unidirectional transmission, energy amplification, and reflection on a single horizontally polarized light, and then couple it into the second stimulated Brillouin scattering medium 6-9 to utilize the pump light to stimulate Brillouin scattering for the stimulated Brillouin scattering nonlinear effect, generate a right-handed circularly polarized backward Stokes light, and convert the right-handed circularly polarized backward Stokes light into a vertically backward Stokes light;

[0037] The fourth half-wave plate 7 is used to rotate the polarization state of the horizontally backward Stokes light returned by the first nonlinear effect module 5 by 90 degrees;

[0038] The second polarization beam splitter 8 is used to combine the vertically backward Stokes light output by the fourth half-wave plate 7 and the vertically backward Stokes light returned by the second nonlinear effect module 6.

[0039] The working principle of the above device is as follows: The laser 1 outputs laser light with a linear polarization state. Subsequently, the first half-wave plate 2 is used to adjust the direction of the laser polarization state, and a specific angle is set with the main axis of the vortex wave plate 3. Specifically, when the polarization direction of the incident linearly polarized light is parallel to the main axis of the vortex wave plate 3, radial polarization is output, and when it is perpendicular to the main axis, azimuthal polarization is output; after passing through the vortex wave plate 3, a radial or azimuthal vector vortex beam is generated; after the vector vortex beam enters the first polarization beam splitter 4, it is decomposed into two orthogonally polarized light beams: horizontally polarized light and vertically polarized light. These polarization states correspond to the spatial components of the vector beam, and each beam enters an independent optical path.

[0040] Subsequently, in order to achieve unidirectional transmission, the vertically polarized light passes through the first optical isolation system composed of a series connection of the first polarizer 5-1, the first Faraday rotator 5-2, the second half-wave plate 5-3, and the second polarizer 5-4; the horizontally polarized light passes through the second optical isolation system composed of a series connection of the third polarizer 6-1, the second Faraday rotator 6-2, the third half-wave plate 6-3, and the fourth polarizer 6-4; where the first Faraday rotator 5-2 and the second Faraday rotator 6-2 irreversibly rotate the polarization plane of the light beam using the magneto-optical effect, and the second half-wave plate 5-3 and the third half-wave plate 6-3 further precisely adjust the polarization state to ensure that the light beam has a definite polarization direction.

[0041] Subsequently, the light output from the first optical isolation system passes through the first quarter-wave plate 5-5, whose fast axis direction forms a 45° angle with the polarization direction, converting the input light into left-handed circularly polarized light; the light output from the second optical isolation system passes through the second quarter-wave plate 6-5, whose fast axis direction forms a 45° angle with the polarization direction, converting the input light into right-handed circularly polarized light; this step plays a key role in the subsequent stimulated Brillouin scattering process.

[0042] Subsequently, the left-handed circularly polarized light successively passes through the first amplifier 5-6 for energy amplification, is reflected by the first 45-degree mirror 5-7, and is focused by the first convex lens 5-8 onto the first stimulated Brillouin scattering medium 5-9 to generate left-handed circularly polarized backward Stokes light; the right-handed circularly polarized light successively passes through the second amplifier 6-6 for energy amplification, is reflected by the second 45-degree mirror 6-7, and is focused by the second convex lens 6-8 onto the second stimulated Brillouin scattering medium 6-9 to generate right-handed circularly polarized backward Stokes light. Among them, the first convex lens 5-8 and the second convex lens 6-8 are a pair of symmetrically distributed focusing lenses, used to ensure the gain consistency of the dual-channel optical path. The two lenses satisfy the following conditions: the curvature radii of the two lenses are the same and the axial distances of each lens from the corresponding stimulated Brillouin scattering medium cell are the same.

[0043] The return path of the left-handed or right-handed circularly polarized backward Stokes light is as follows: passing through the original first quarter-wave plate 5-5 or the second quarter-wave plate 6-5, the circular polarization state is re-converted into a linear polarization state. The second polarization beam splitter 8 recombines the two beams of light into a single beam of vector vortex light, and at the same time dynamically adjusts the optical path difference between the two beams of light to satisfy the interference condition, finally reproducing the input vector vortex beam, realizing the improvement of the output energy, using the characteristics of Brillouin scattering to achieve pulse width compression. Brillouin scattering has a phase conjugation effect, and the Stokes light will compensate for the wavefront distortion of the pump light during transmission, optimize the output light spot, and improve the polarization purity. Finally, the stimulated Brillouin scattering output of the vector vortex beam is realized. Specifically, the reflected vertically polarized light is focused onto the first stimulated Brillouin scattering medium 5-9 through the first convex lens 5-8, and the transmitted horizontally polarized light is focused onto the second stimulated Brillouin scattering medium 6-9 through the second convex lens 6-8 to increase the optical power density to trigger stimulated Brillouin scattering, and the backward Stokes light is generated through the interaction between the pump light and the acoustic wave field to achieve phase conjugation and energy transfer; the left-handed circularly polarized backward Stokes light generated in the first stimulated Brillouin scattering medium 5-9 passes through the first convex lens 5-8 and is reflected by the first 45-degree mirror 5-7 to the first quarter-wave plate 5-5, converting the left-handed circularly polarized light into horizontally backward Stokes light, being reflected when reaching the second polarizer 5-4, and then passing through the fourth half-wave plate 7 with the principal axis and the polarization direction of 45 degrees to rotate the polarization state by 90 degrees and enter the second polarization beam splitter 8 for beam combination; the right-handed circularly polarized backward Stokes light generated in the second stimulated Brillouin scattering medium 5-9 passes through the second convex lens 6-8 and is reflected by the second 45-degree mirror 6-7 to the second quarter-wave plate 6-5, converting the right-handed circularly polarized light into vertically backward Stokes light, being reflected when reaching the fourth polarizer 6-4, and entering the second polarization beam splitter 8 for beam combination.

[0044] Among them, the electric field of the vector vortex beam generated by the vortex wave plate 3 in the radial or angular direction can be expressed as:

[0045]

[0046] In the formula, E0 is the electric field amplitude; is the azimuth angle; e x and e y are the unit vectors in the x-direction and y-direction respectively. After passing through the first polarization beam splitter 4, the light beam is decomposed into two orthogonal linearly polarized components, where the reflected vertically polarized light is The transmitted horizontally polarized light is The reflected vertically polarized light is converted into left-handed circular polarization through the first quarter-wave plate 5-5 with the fast axis direction at 45° to the polarization direction, expressed as The transmitted horizontally polarized light is converted into right-handed circular polarization through the second quarter-wave plate 6-5 with the fast axis direction at 45° to the polarization direction, expressed as where \(i\) is the imaginary unit.

[0047] Coupled into the stimulated Brillouin scattering medium through a lens to generate backward Stokes light. The Stokes light is a phase conjugate wave propagating backward, with the polarization state remaining unchanged, and returns to the quarter-wave plate along the original optical path. Among them, the Stokes light generated by reflecting the vertically polarized light is polarized and converted after passing through the first quarter-wave plate 5-5 to be reflected when reaching the second polarizer 5-4; the Stokes light generated by transmitting the horizontally polarized light is polarized and converted after passing through the second quarter-wave plate 6-5 to be reflected when reaching the fourth polarizer 6-4; the two-way Stokes lights return to the second polarization beam splitter 8 to be recombined, satisfying the phase matching condition, and the final output is to fully restore the polarization characteristics of the original vector vortex beam.

[0048] During the stimulated Brillouin scattering process, the forward pump light (left-handed or right-handed circularly polarized light) with frequency \(\omega\) p enters the stimulated Brillouin scattering medium and interacts with the backward-propagating Stokes wave with frequency \(\omega\) s . During the stimulated Brillouin scattering process, the gain is determined by the spatial overlap integral of the pump light field \(E\) p and the Stokes light field \(E\) S . The gain coefficient \(g\) is expressed as:

[0049] \(g\propto\iint|E\) p (r,z)|\) 2 |E\) s (r,z)|\) 2 dS

[0050] where \(r\) is the radial coordinate in the transverse plane and \(z\) is the longitudinal coordinate along the light propagation direction.

[0051] Furthermore, in order to ensure the optical path consistency of the double-channel optical path to meet the phase matching condition, first ensure that the optical paths of the double-channel optical path reaching the stimulated Brillouin scattering medium are the same, that is, \(L1 + L2+L3 = L6 + L7+L8\), where \(L1\) represents the distance between the reflection surface of the first polarization beam splitter 4 and the first 45-degree mirror 5-7; \(L2\) represents the distance between the first 45-degree mirror 5-7 and the first convex lens 5-8; \(L3\) represents the distance between the first convex lens 5-8 and the first stimulated Brillouin scattering medium 5-9; \(L6\) represents the distance between the reflection surface of the first polarization beam splitter 4 and the second 45-degree mirror 6-7; \(L7\) represents the distance between the second 45-degree mirror 6-7 and the second convex lens 6-8; \(L8\) represents the distance between the second convex lens 6-8 and the second stimulated Brillouin scattering medium 6-9.

[0052] Secondly, to ensure the gain consistency of the dual-channel optical path L3 = L8, and to ensure that the two Stokes lights are coherently combined after being transmitted through the same optical path to achieve optical path synchronization. In the transmission paths of the two Stokes lights, by adjusting the second polarization beam splitter 8, it is ensured that the physical lengths and layouts of the optical elements (including lenses, mirrors, and wave plates) all meet the symmetry conditions, and the condition L2 + L3 + L4 + L5 = L7 + L8 + L9 + L10 is achieved; where L4 represents the distance between the first 45-degree mirror 5-7 and the second polarizer 5-4; L5 represents the distance between the second polarizer 5-4 and the reflecting surface of the second polarization beam splitter 8; L9 represents the distance between the second 45-degree mirror 6-7 and the fourth polarizer 6-4; L10 represents the distance between the fourth polarizer 6-4 and the reflecting surface of the second polarization beam splitter 8; to ensure that the two Stokes lights meet the interference conditions and completely reproduce the original vector vortex light.

[0053] In summary, according to the dual-channel polarization-selective stimulated Brillouin scattering, the present invention designs a group of polarization beam splitters, which completely cover the interference combination of Stokes lights and achieve the stimulated Brillouin scattering output of vector vortex light. In the embodiments of the present invention, except for the special descriptions of the models of each device, the models of other devices are not limited, and any device that can complete the above functions can be used.

[0054] The following gives an embodiment with specific parameter values.

[0055] The laser 1 emits linearly polarized laser light with a wavelength of 1064 nm and an output energy of 100 mJ (pulse mode, pulse width 10 ns, repetition frequency 1 Hz). Subsequently, the polarization angle is adjusted by the first half-wave plate 2. The incident linearly polarized light has its polarization direction parallel to the main axis of the vortex wave plate 3, and the output radial polarization vector vortex light is decomposed into two orthogonally linearly polarized components by the first polarization beam splitter 4. The reflected vertically polarized light passing through the first polarization beam splitter 4 passes through the first optical isolation system to achieve unidirectional transmission isolation for the single linearly polarized light after beam splitting; the reflected vertically polarized light passes through the first quarter-wave plate 5-5 after passing through the first optical isolation system, with the fast axis direction at 45° to the polarization direction, and is converted into left-handed circular polarization. After passing through the first amplifier 5-6, the energy is amplified from 50 mJ to 300 mJ, and then reflected by the first 45-degree mirror 5-7 and focused by the first convex lens 5-8 with a focal length f = 100 mm onto the first carbon disulfide medium cell with a length of 10 cm (i.e., the first stimulated Brillouin scattering medium 5-9); the transmitted parallel polarized light passes through the second optical isolation system and then through the second quarter-wave plate 6-5, with the fast axis direction at 45° to the polarization direction, and is converted into right-handed circular polarization. After passing through the second amplifier 6-6, the energy is amplified from 50 mJ to 300 mJ, and then reflected by the second 45-degree mirror 6-7 and focused by the second convex lens 6-8 with a focal length f = 100 mm onto the second carbon disulfide medium cell with a length of 10 cm (i.e., the second stimulated Brillouin scattering medium 6-9). The Brillouin gain coefficient g of carbon disulfide B = 5×10 -11 m / W, and the frequency shift is Δν B = 7.5 GHz.

[0056] The anti-Stokes light generated in the first carbon disulfide medium cell is reflected by the first convex lens 5-8 and the first 45-degree mirror 5-7 to the first quarter-wave plate 5-5. The stimulated Brillouin scattering efficiency is 75%, and the energy is 225 mJ. It converts the left-handed circularly polarized light into vertically polarized light and is reflected when reaching the second polarizer 5-4. The stimulated Brillouin scattering efficiency is 75%, and the energy is 225 mJ. Then it passes through the fourth half-wave plate 7 with the main axis and the polarization direction of 45 degrees, rotates the polarization state by 90 degrees, and enters the second polarization beam splitter 8 for beam combination. The anti-Stokes light generated in the second carbon disulfide medium cell is reflected by the second convex lens 6-8 and the second 45-degree mirror 6-7 to the second quarter-wave plate 6-5, converts the right-handed circularly polarized light into horizontally polarized light, is reflected when reaching the fourth polarizer 6-4, and enters the second polarization beam splitter 8 for beam combination. Among them, L1 = L6 = 20 cm, L2 = L7 = 10 cm, L4 = L9 = 5 cm, L5 = L10 = 20 cm. To ensure the gain consistency of the double-channel optical path, L3 = L8 = 5 cm, ensuring that the two Stokes lights are coherently combined after being transmitted through the same optical path, realizing optical path synchronization, ensuring that the physical lengths and layouts of the optical elements (including lenses, mirrors, and wave plates) all meet the symmetry conditions, realizing micron-level optical path regulation, and realizing the condition L2 + L3 + L4 + L5 = L7 + L8 + L9 + L10 = 60 cm, ensuring that the two Stokes lights meet the interference conditions, completely reproducing the original vector vortex light. Finally, the output energy is 450 mJ, the energy amplification efficiency is 9 times, the pulse width is compressed from 10 ns to 2.6 ns, and the polarization purity is increased to 99.5%, forming a synergistic improvement in the four-dimensional performance of energy-time-domain-space-polarization.

[0057] In summary, the present invention proposes a vector vortex beam stimulated Brillouin scattering device and method, which realizes the spatial high-fidelity vector beam fusion through the following technical solutions. The incident laser has a linear polarization state. By adjusting the angle between the linear polarization state and the main axis of the vortex wave plate with a half-wave plate, the generation of a radial or angular vector vortex beam is achieved. The incident vector vortex beam is separated by a polarization beam splitter into a first orthogonal linear polarization state (horizontal polarization) and a second orthogonal linear polarization state (vertical polarization). Each polarization state channel is connected in series with a Faraday rotator, a polarizer, and a half-wave plate to achieve the unidirectional transmission of the vector vortex beam. Subsequently, the two paths convert the linear polarization components into right-handed circular polarization and left-handed circular polarization respectively through a quarter-wave plate, amplify the energy through an amplifier, couple it to the stimulated Brillouin scattering medium through a lens, and utilize the pump light to stimulate Brillouin scattering to generate a backward-propagating Stokes light that satisfies the frequency shift matching condition. Its phase conjugation characteristic automatically compensates for the wavefront distortion in the transmission path. After the Stokes light returns along the original path and is converted into the opposite linear polarization state through a quarter-wave plate, it is recombined through a polarization beam splitter, thereby completely reproducing the polarization-phase coupling characteristic of the incident vector vortex beam. Through the nonlinear effect of stimulated Brillouin scattering, a significant enhancement of the output energy and an active compression of the pulse width are achieved. Based on its phase conjugation characteristic, the Stokes light can dynamically compensate for the wavefront distortion in the transmission of the pump light, synchronously optimize the output spot quality and polarization purity, and form a synergistic improvement in the four-dimensional performance of energy-time-space-polarization.

[0058] Although the spirit and principles of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the disclosed specific embodiments, and the division of each aspect does not mean that the features in these aspects cannot be combined for benefits. This division is only for the convenience of expression. The present invention aims to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A vector vortex light stimulated Brillouin scattering device, characterized in that Comprising: A laser (1), a first half-wave plate (2), a vortex wave plate (3), a first polarization beam splitter (4), a first nonlinear effect module (5), a second nonlinear effect module (6), a fourth half-wave plate (7), and a second polarization beam splitter (8); wherein, the first nonlinear effect module (5) includes a first stimulated Brillouin scattering medium (5-9), and the second nonlinear effect module (6) includes a second stimulated Brillouin scattering medium (6-9); The laser (1) emits laser light with a linearly polarized state; the first half-wave plate (2) is used to adjust the polarization angle between the laser light with a linearly polarized state and the main axis of the vortex wave plate (3); the vortex wave plate (3) is used to generate a radial or angular vector vortex beam based on the incident laser light with a linearly polarized state; the first polarization beam splitter (4) is used to separate the vector vortex beam into two orthogonally linearly polarized lights, namely horizontally polarized light and vertically polarized light; The first nonlinear effect module (5) is used to successively perform unidirectional transmission, energy amplification, and reflection on a single vertically polarized light, and then couple it into the first stimulated Brillouin scattering medium (5-9) to perform the stimulated Brillouin scattering nonlinear effect, generating a left-handed circularly polarized backward Stokes light, and converting the left-handed circularly polarized backward Stokes light into a horizontally backward Stokes light; The second nonlinear effect module (6) is used to successively perform unidirectional transmission, energy amplification, and reflection on a single horizontally polarized light, and then couple it into the second stimulated Brillouin scattering medium (6-9) to perform the stimulated Brillouin scattering nonlinear effect, generating a right-handed circularly polarized backward Stokes light, and converting the right-handed circularly polarized backward Stokes light into a vertically backward Stokes light; The fourth half-wave plate (7) is used to rotate the polarization state of the horizontally backward Stokes light returned by the first nonlinear effect module (5) by 90 degrees; The second polarization beam splitter (8) is used to combine the vertically backward Stokes light output by the fourth half-wave plate (7) and the vertically backward Stokes light returned by the second nonlinear effect module (6).

2. The vector vortex light stimulated Brillouin scattering device according to claim 1, characterized in that The first nonlinear effect module (5) further includes a first optical isolation system, a first quarter-wave plate (5-5), a first amplifier (5-6), a first 45-degree mirror (5-7), and a first convex lens (5-8); the first optical isolation system is used to achieve unidirectional transmission of vertically polarized light; the first quarter-wave plate (5-5) is used to convert the vertically polarized light after unidirectional transmission into left-handed circularly polarized light, and convert the left-handed circularly polarized backward Stokes light into horizontally backward Stokes light; the first amplifier (5-6) is used to amplify the energy of the left-handed circularly polarized light; the first 45-degree mirror (5-7) is used to reflect the left-handed circularly polarized light after energy amplification, and reflect the reflected left-handed circularly polarized backward Stokes light to the first amplifier (5-6); the first convex lens (5-8) is used to couple the reflected left-handed circularly polarized light into the first stimulated Brillouin scattering medium (5-9).

3. The vector vortex beam stimulated Brillouin scattering device according to claim 2, characterized in that The second nonlinear effect module (6) further includes a second optical isolation system, a second quarter-wave plate (6-5), a second amplifier (6-6), a second 45-degree mirror (6-7), and a second convex lens (6-8); the second optical isolation system is used to achieve unidirectional transmission of horizontally polarized light; the second quarter-wave plate (6-5) is used to convert the horizontally polarized light after unidirectional transmission into right-handed circularly polarized light, and convert the right-handed circularly polarized anti-Stokes light into vertically polarized anti-Stokes light; the second amplifier (6-6) is used to amplify the energy of the right-handed circularly polarized light; the second 45-degree mirror (6-7) is used to reflect the right-handed circularly polarized light after energy amplification, and reflect the reflected right-handed circularly polarized anti-Stokes light to the second amplifier (6-6); the second convex lens (6-8) is used to couple the reflected right-handed circularly polarized light into the second stimulated Brillouin scattering medium (6-9).

4. A vector vortex light stimulated Brillouin scattering device according to claim 3, characterized in that The first optical isolation system includes a first polarizer (5-1), a first Faraday rotator (5-2), a second half-wave plate (5-3), and a second polarizer (5-4); wherein the first Faraday rotator (5-2) is used to irreversibly rotate the polarization plane of the light beam by using the magneto-optical effect, and the second half-wave plate (5-3) is used to adjust the polarization state.

5. The stimulated Brillouin scattering device for vector vortex light according to claim 4, wherein The second optical isolation system includes a third polarizer (6-1), a second Faraday rotator (6-2), a third half-wave plate (6-3), and a fourth polarizer (6-4); wherein the second Faraday rotator (6-2) is used to irreversibly rotate the polarization plane of the light beam by using the magneto-optical effect, and the third half-wave plate (6-3) is used to adjust the polarization state.

6. The vector vortex beam stimulated Brillouin scattering device according to claim 5, characterized in that, The distances of each device satisfy the following relational expressions: L1 + L2 + L3 = L6 + L7 + L8; L2 + L3 + L4 + L5 = L7 + L8 + L9 + L10; Wherein, L1 represents the distance between the reflecting surface of the first polarization beam splitter (4) and the first 45-degree mirror (5-7); L2 represents the distance between the first 45-degree mirror (5-7) and the first convex lens (5-8); L3 represents the distance between the first convex lens (5-8) and the first stimulated Brillouin scattering medium (5-9); L4 represents the distance between the first 45-degree mirror (5-7) and the second polarizer (5-4); L5 represents the distance between the second polarizer (5-4) and the reflecting surface of the second polarization beam splitter (8); L6 represents the distance between the reflecting surface of the first polarization beam splitter (4) and the second 45-degree mirror (6-7); L7 represents the distance between the second 45-degree mirror (6-7) and the second convex lens (6-8); L8 represents the distance between the second convex lens (6-8) and the second stimulated Brillouin scattering medium (6-9); L9 represents the distance between the second 45-degree mirror (6-7) and the fourth polarizer (6-4); L10 represents the distance between the fourth polarizer (6-4) and the reflecting surface of the second polarization beam splitter (8).

7. A vector vortex light stimulated Brillouin scattering device according to any one of claims 1-6, characterized in that The first stimulated Brillouin scattering medium (5-9) and the second stimulated Brillouin scattering medium (6-9) are carbon disulfide media.

8. A vector vortex light stimulated Brillouin scattering device according to any one of claims 3-6, characterized in that The fast axis directions of the first quarter-wave plate (5-5) and the second quarter-wave plate (6-5) are both at 45° to the polarization direction.

9. A method for stimulated Brillouin scattering of vector vortex light, characterized in that, The method is implemented based on a vector vortex beam stimulated Brillouin scattering device according to any one of claims 1-8; the method includes: Adjusting the polarization angle between the laser with a linearly polarized state and the main axis of the vortex wave plate through a first half-wave plate (2) and then injecting the laser into the vortex wave plate (3) to generate a radial or angular vector vortex beam; separating the vector vortex beam into two orthogonally linearly polarized lights, namely horizontally polarized light and vertically polarized light, through a first polarization beam splitter (4); Successively performing unidirectional transmission, energy amplification, and reflection on the single vertically polarized light and horizontally polarized light respectively, and then coupling them into a first stimulated Brillouin scattering medium (5-9) and a second stimulated Brillouin scattering medium (6-9) respectively to utilize the pump light to stimulate Brillouin scattering to perform the stimulated Brillouin scattering nonlinear effect and generate left-handed circularly polarized backward Stokes light and right-handed circularly polarized backward Stokes light; Converting the left-handed circularly polarized backward Stokes light into horizontally backward Stokes light by using the first quarter-wave plate (5-5), and converting the right-handed circularly polarized backward Stokes light into vertically backward Stokes light by using the second quarter-wave plate (6-5); Then rotating the polarization state of the horizontally backward Stokes light by 90 degrees through a fourth half-wave plate (7); subsequently, combining the vertically backward Stokes light with the rotated polarization state output by the fourth half-wave plate (7) and the vertically backward Stokes light output by the second quarter-wave plate (6-5) through a second polarization beam splitter (8).

10. A vector vortex beam stimulated Brillouin scattering method according to claim 9, characterized in that The process of generating the left-handed circularly polarized backward Stokes light and the right-handed circularly polarized backward Stokes light includes: The vertically polarized light is unidirectionally transmitted through a first optical isolation system, and then the vertically polarized light after unidirectional transmission is converted into left-handed circularly polarized light by a first quarter-wave plate (5-5), then the left-handed circularly polarized light is energy-amplified by a first amplifier (5-6), then the energy-amplified left-handed circularly polarized light is reflected by a first 45-degree mirror (5-7), and then the reflected left-handed circularly polarized light is coupled into a first stimulated Brillouin scattering medium (5-9) by a first convex lens (5-8); the left-handed circularly polarized backward Stokes light generated in the first stimulated Brillouin scattering medium (5-9) successively passes through the first convex lens (5-8), the first 45-degree mirror (5-7), the first amplifier (5-6), and the first quarter-wave plate (5-5) to convert the left-handed circularly polarized backward Stokes light into horizontally backward Stokes light, and then is reflected by a second polarizer (5-4) in the first optical isolation system to the fourth half-wave plate (7); The horizontally polarized light undergoes unidirectional transmission through the second optical isolation system, and then passes through the second quarter-wave plate (6-5) to convert the unidirectionally transmitted horizontally polarized light into right-handed circularly polarized light. Subsequently, the right-handed circularly polarized light is amplified in energy by the second amplifier (6-6). Then, the energy-amplified right-handed circularly polarized light is reflected by the second 45-degree mirror (6-7). Subsequently, the reflected right-handed circularly polarized light is coupled into the second stimulated Brillouin scattering medium (6-9) through the second convex lens (6-8); the right-handed circularly polarized backward Stokes light generated in the second stimulated Brillouin scattering medium (6-9) successively passes through the second convex lens (6-8), the second 45-degree mirror (6-7), the second amplifier (6-6), and the second quarter-wave plate (6-5) to convert the right-handed circularly polarized backward Stokes light into vertically polarized backward Stokes light, and then is reflected by the fourth polarizer (6-4) in the second optical isolation system to the second polarization beam splitter (8).

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