A high-sensitivity conjugate vortex interferometry system and method based on counter-reflection

Abstract

The application provides a high-sensitivity conjugate vortex interference system and method based on counter-reflection. The system belongs to the field of vortex interference and comprises a laser, a vortex phase plate, a first beam splitter prism, a second beam splitter prism, a third beam splitter prism, a fourth beam splitter prism, a first fixed mirror, a second fixed mirror, a third fixed mirror, a double-sided mirror and a camera. The method comprises forming a pair of conjugate vortices through the first beam splitter prism, wherein one beam of vortex light is reflected to the fourth beam splitter prism as an interference arm after passing through the first fixed mirror, the third beam splitter, the double-sided mirror and the third fixed mirror; another beam of vortex light is reflected to the fourth beam splitter prism as a reference arm after passing through the second fixed mirror, the second beam splitter and the double-sided mirror; and the interference light intensity is received by the camera after being combined through the fourth beam splitter. Through the arrangement, a larger rotation angle can be generated under the same displacement, and a small displacement can be more accurately identified.

Description

Technical Field

[0001] This application relates to the field of vortex interferometry, and more specifically, to a highly sensitive conjugate vortex interferometry system and method based on counter-reflection. Background Technology

[0002] The interference method of a vortex interferometer mainly obtains the change in the length of the interferometer arm by observing the rotation direction and angle of the interference pattern: the interferometer arm is the object being measured, and changes in its length, phase, or optical path will cause changes in the interference pattern. The reference arm provides a stable phase reference for comparison with the interferometer arm.

[0003] The existing interference methods mainly include the following two types:

[0004] 1. Interference is performed using vortex light and a spherical reference light, where the vortex light acts as the interference arm and the spherical wave as the reference arm. The change in the interference arm length is obtained by observing the rotation direction and angle of the interference pattern. In other words, when the vortex light, acting as an interference arm, interferes with the spherical reference light, the interference pattern exhibits specific rotational characteristics. These rotational characteristics are related to the orbital angular momentum of the vortex light and the change in the interference arm length. By observing the rotation direction and angle of the interference pattern, the change in the interference arm length can be inferred. For example, if the interference pattern rotates clockwise by a certain angle, it means the length of the interference arm has increased; conversely, if the interference pattern rotates counterclockwise, it means the length of the interference arm has decreased.

[0005] 2. Interference is performed using a pair of conjugate vortex beams, with one vortex beam serving as the interference arm and the other as the reference arm. The change in the length of the interference arm is obtained by observing the rotation direction and angle of the interference image.

[0006] In existing vortex interferometers, only the length of the interference arm changes during the measurement process. Due to the limited change in optical path length, the sensitivity of the rotation angle of the interference pattern as the arm length changes is also limited. The interferometer may not be able to accurately measure very small displacement changes, thus limiting its performance in some high-precision measurement or sensing applications. Summary of the Invention

[0007] The purpose of this application is to provide a highly sensitive conjugate vortex interferometry system and method based on counter-reflection. Under the same displacement, using conjugate vortexes for interference can produce a larger rotation angle, enabling more accurate measurement and identification of minute displacements. This advantage makes conjugate vortex interferometry a potential application in applications requiring high-precision displacement measurement.

[0008] This application is implemented as follows:

[0009] In a first aspect, this application provides a highly sensitive conjugate vortex interferometry system based on counter-reflection, comprising:

[0010] laser, vortex phase plate, first beam splitter prism, second beam splitter prism, third beam splitter prism, fourth beam splitter prism, first fixed mirror, second fixed mirror, third fixed mirror, double-sided mirror and camera;

[0011] The pump light source generated by the laser passes through the vortex phase plate to generate vortex light with a topological charge number of l, and forms a pair of conjugate vortices through the first beam splitter prism, the transmitted light having a topological charge number of l and the reflected light having a topological charge number of -l, which are respectively used as interference light and reference light of an interferometer; wherein

[0012] The vortex light with the topological charge number of l is transmitted by the third beam splitter prism after passing through the first fixed mirror, is reflected by the movable double-sided mirror to the third beam splitter prism, is reflected to the fourth beam splitter prism in turn through the third beam splitter prism and the third fixed mirror, and is used as an interference arm; the double-sided mirror can move along the optical path;

[0013] The vortex light with the topological charge number of -l is reflected by the second fixed mirror, is transmitted by the second beam splitter prism, is reflected by the double-sided mirror, is reflected by the second beam splitter prism to the fourth beam splitter prism in turn, and is used as a reference arm;

[0014] The conjugate vortices are combined by the fourth beam splitter prism, and the interference light intensity is received by the camera.

[0015] Based on the first aspect, the angle between the normal line of the first fixed mirror and the incident light is pi / 8.

[0016] Based on the first aspect, the angle between the normal line of the third fixed mirror and the incident light is pi / 4.

[0017] The second aspect provides a high-sensitivity conjugate vortex interference method based on opposite reflection, which is applied to the above-mentioned interference system, and the method comprises the following steps:

[0018] S1: The pump light source generated by the laser passes through the vortex phase plate to generate vortex light with a topological charge number of l, and forms a pair of conjugate vortices through the first beam splitter prism, the transmitted light having a topological charge number of l and the reflected light having a topological charge number of -l, which are respectively used as interference light and reference light of an interferometer; wherein the vortex light with the topological charge number of l is transmitted by the third beam splitter prism after passing through the first fixed mirror, is reflected by the movable double-sided mirror to the third beam splitter prism, is reflected to the fourth beam splitter prism in turn through the third beam splitter prism and the third fixed mirror, and is used as an interference arm; the double-sided mirror can move along the optical path; the vortex light with the topological charge number of -l is reflected by the second fixed mirror, is transmitted by the second beam splitter prism, is reflected by the double-sided mirror, is reflected by the second beam splitter prism to the fourth beam splitter prism in turn, and is used as a reference arm; the conjugate vortices are combined by the fourth beam splitter prism, and the interference light intensity is received by the camera.

[0019] S2: moving the double-sided mirror along the optical path between the second beam splitting prism and the third beam splitting prism, if the double-sided mirror moves a displacement of Δξ towards the second beam splitting prism, the interference arm length increases by 2Δξ, and the optical field relative to the initial state is represented as: OAM l *exp(i2π / λ*2Δξ)=U(r)exp(ilθ+i4πΔξ / λ);reference arm length decreases by 2Δξ, and the optical field is represented as: OAM -l *exp(-i2π / λ*2Δξ)=U(r)exp(-ilθ-i4πΔξ / λ), if the double-sided mirror moves a displacement of Δξ towards the third beam splitting prism, the interference arm length decreases by 2Δξ, and the optical field relative to the initial state is represented as: OAM -l *exp(-i2π / λ*2Δξ)=U(r)exp(-ilθ-i4πΔξ / λ);reference arm length increases by 2Δξ, and the optical field is represented as: OAM l *exp(i2π / λ*2Δξ)=U(r)exp(ilθ+i4πΔξ / λ),

[0020] Therefore, the double-sided mirror moves a displacement of Δξ along the optical path between the second beam splitting prism and the third beam splitting prism, and the interference light intensity distribution received by the camera after beam combination becomes:

[0021] I tot1 ∝|U(r)exp(ilθ+i4πΔξ / λ)+U(r)exp(-ilθ-i4πΔξ / λ)| 2 =2|U(r)| 2 [1+cos(2lθ+8πΔξ / λ)]

[0022] wherein, I tot1 represents the interference light intensity distribution after beam combination, the symbol ∝ represents a proportional relationship, U(r) represents the amplitude at the propagation cross section, i is the imaginary unit, exp(ilθ) is the angular phase distribution carried, and is related to the topological charge number l, r and θ are the polar radius and azimuth angle of the polar coordinates respectively, and λ is the wavelength; it can be known that the rotation angle of the interference light intensity is Thus, the displacement amount is:

[0023]

[0024] It can be known that the interference pattern of the conjugate vortex produces a larger rotation angle under the same displacement.

[0025] Based on the second aspect, further comprising:

[0026] The normal line of the first fixed mirror and the second fixed mirror forms an angle of pi / 8 with the incident light.

[0027] Based on the second aspect, further comprising:

[0028] The normal line of the third fixed mirror is at an angle of pi / 4 with the incident light.

[0029] In a third aspect, the application provides an electronic device, comprising:

[0030] A memory for storing one or more programs;

[0031] A processor;

[0032] When the one or more programs are executed by the processor, the above-mentioned method is implemented.

[0033] In a fourth aspect, the application provides a computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the above-mentioned method.

[0034] Compared with the prior art, the application has at least the following advantages or beneficial effects:

[0035] 1. Using interference of conjugate vortices, the change of micro displacement can be reflected on the rotation of the interference pattern, which can more accurately measure and identify micro displacement, and realize micro displacement sensing.

[0036] 2. By forming an opposite reflection light path through the second beam splitting prism, the third beam splitting prism and the double-sided mirror, the change of the interference arm optical path is accompanied by an opposite change of the reflection arm optical path, compared with the existing vortex interference system with only a single variable interference arm, the rotation angle is doubled, the sensitivity is higher, and it can be applied to high-precision displacement measurement. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0038] Figure 1 It is a structural schematic diagram of a high-sensitivity conjugate vortex interference system based on opposite reflection according to the application;

[0039] Figure 2 It is a structural schematic diagram of an electronic device according to the application;

[0040] Icon:

[0041] 1, laser; 2, vortex phase plate; 3, first beam splitting prism; 4, second beam splitting prism; 5, third beam splitting prism; 6, fourth beam splitting prism; 7, first fixed mirror; 8, second fixed mirror; 9, third fixed mirror; 10, double-sided mirror; 11, camera; 12, interference pattern; 13, processor; 14, memory; 15, communication interface. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0043] Some embodiments of the present application will be described in detail below in connection with the drawings. Each of the following embodiments and each feature in the embodiments can be combined with each other without conflict.

[0044] EMBODIMENT

[0045] Through long-term research and practice, the inventors have found that in the measurement process of the existing vortex interferometer, only the length of the interference arm changes. Since the amount of change in the optical path is limited, the sensitivity of the rotation angle of the interference pattern 12 to the change in the arm length is also limited, and the interferometer can not accurately measure very small displacement changes, thereby limiting its performance in some high-precision measurement or sensing applications.

[0046] In view of this, the embodiments of the present application provide a high-sensitivity conjugate vortex interferometer system and method based on counter reflection, which can more accurately measure and identify small displacements. This advantage makes the conjugate vortex interferometer have potential application value in applications requiring high-precision displacement measurement.

[0047] To facilitate understanding of the technical solutions, the following names are explained:

[0048] Optical vortex (OV): a scalar beam with an angularly distributed phase gradient at the propagation section, a phase singularity in the center, a spiral wave front, and carrying orbital angular momentum (OAM).

[0049] Topological charge (TC): the ratio of the amount of change in the angular phase to 2pi when the azimuthal angle of the vortex beam propagation section changes by 2pi.

[0050] Conjugate vortex: a pair of vortex beams with opposite topological charges.

[0051] Reference is made to Figure 1 The high-sensitivity conjugate vortex interference system based on counter-reflection includes:

[0052] laser 1, vortex phase plate 2, first beam splitter prism 3, second beam splitter prism 4, third beam splitter prism 5, fourth beam splitter prism 6, first fixed mirror 7, second fixed mirror 8, third fixed mirror 9, double-sided mirror 10 and camera 11;

[0053] The pump light source generated by the laser 1 passes through the vortex phase plate 2 to generate vortex light with a topological charge number of l, and forms a pair of conjugate vortices through the first beam splitter prism 3, the transmission light has a topological charge number of l, and the reflection light has a topological charge number of -l, which are used as the interference light and the reference light of the interferometer, respectively.

[0054] Specifically, the laser 1 outputs pump light, which is a high-intensity light source. The vortex phase plate 2 is a special optical element that can change the phase distribution of light. When light passes through it, its phase will change according to the design of the vortex phase plate 2. The pump light source passes through the vortex phase plate 2 to generate vortex light with l complete phase rotation circles. The first beam splitter prism 3 is used to split the incident light beam into two light beams. These two beams not only have different directions, but also have conjugate vortex characteristics, that is, they have opposite topological charge numbers. The transmission light refers to the light beam that continues to propagate in the original direction (or slightly changes direction but is not reflected) after passing through the first beam splitter prism 3. Here, the topological charge number of the transmission light is l, indicating that its phase wavefront rotates l complete circles around the optical axis. The reflection light refers to the light beam reflected by the beam splitter. Unlike the transmission light, the topological charge number of the reflection light is -l, indicating that the direction of its phase wavefront rotation around the optical axis is opposite to that of the transmission light, that is, it rotates -l complete circles (or, if l is positive, the reflection light phase wavefront rotates clockwise, while the transmission light rotates counterclockwise, and vice versa).

[0055] The vortex light with a topological charge number of l is transmitted by the third beam splitter prism 5 after passing through the first fixed mirror 7, reflected by the third beam splitter prism 5 to the third fixed mirror 9 through the movable double-sided mirror 10, and then reflected by the third fixed mirror 9 to the fourth beam splitter prism 6, serving as an interference arm; the double-sided mirror 10 can move along the optical path;

[0056] The vortex light with a topological charge number of -l is reflected by the second fixed mirror 8, and then transmitted by the second beam splitter prism 4, reflected by the double-sided mirror 10, reflected by the second beam splitter prism 4 to the fourth beam splitter prism 6, serving as a reference arm;

[0057] The conjugate vortices pass through the fourth beam splitter prism 6 to combine and the camera 11 receives the interference light intensity.

[0058] Specifically, the conjugate vortex light is combined at the fourth beam splitter prism 6 to generate an interference pattern. The camera 11 is used to capture the interference pattern and record the interference light intensity. The camera 11 can be a digital camera or any device capable of capturing the light intensity distribution.

[0059] It should be understood that a vortex light field distribution with a topological charge number of l can be expressed as:

[0060] OAM l = U(r)exp(ilθ)

[0061] wherein U(r) represents the amplitude at the propagation section, exp(ilθ) is the carried angular phase distribution, and is related to the topological charge number l, r and θ are the polar radius and azimuth angle of the polar coordinates respectively, and i is the imaginary unit. Similarly, a vortex light field distribution with a topological charge number of -l is:

[0062] OAM -l = U(r)exp(-ilθ)

[0063] Therefore, when a pair of conjugate vortices are combined and interfere, the light intensity distribution of the interference pattern can be expressed as:

[0064] I tot ∝ |OAM l + OAM -l | 2 = exp(-ilθ) = 2|U(r)| 2 [1 + cos(2lθ)]

[0065] wherein I tot1 represents the interference light field intensity distribution after the combination, and the symbol ∝ represents a proportional relationship. It can be seen that the interference light intensity presents a "petal" shape distribution, and the number of "petals" is twice the topological charge number.

[0066] In the present application, when the double-sided mirror 10 moves by a displacement of Δξ towards the beam splitter prism 2, the interference arm length increases by 2Δξ, and the light field relative to the initial state can be expressed as:

[0067] OAM l *exp(i2π / λ*2Δξ) = U(r)exp(ilθ+i4πΔξ / λ),

[0068] The reference arm length decreases by 2Δξ, and thus the light field is expressed as:

[0069] OAM -l *exp(-i2π / λ*2Δξ) = U(r)exp(-ilθ-i4πΔξ / λ),

[0070] At this time, the interference light intensity distribution after the combination received by the camera 11 becomes:

[0071] I tot1 a|U(r)exp(ilθ+i4πΔξ / λ)+U(r)exp(-ilθ-i4πΔξ / λ) 2 =2|U(r)| 2 [1+cos(2lθ+8πΔξ / λ)]

[0072] It can be seen that the rotation angle of the interference light intensity at this time is Thus the displacement amount is obtained:

[0073]

[0074] It can be seen that the opposite reflection light path is formed by the second beam splitting prism 4, the third beam splitting prism 5 and the double-sided mirror 10, so that the optical path of the interference arm changes at the same time, and the opposite change amount of the reflection arm optical path is generated. Compared with the existing vortex interference system with only a single interference arm, the rotation angle is doubled, the sensitivity is higher, and it can be applied to high-precision displacement measurement. Using conjugate vortex for interference can make the change of micro displacement reflected on the rotation of the interference pattern, and the micro displacement can be measured and recognized more accurately, and the micro displacement sensing is realized.

[0075] Preferably, the normal line of the first fixed mirror 7 and the second fixed mirror 8 and the incident light form an angle of pi / 8.

[0076] Specifically, the angle between the normal line of the first fixed mirror 7 and the second fixed mirror 8 and the direction of the incident light is π / 8 radian. Since π radian is equal to 180 degrees, π / 8 radian is equal to 22.5 degrees. That is, the incident light is incident on the surface of the two mirrors at an angle of 22.5 degrees.

[0077] Preferably, the normal line of the third fixed mirror 9 and the incident light form an angle of pi / 4.

[0078] Specifically, the angle between the normal line of the third fixed mirror 9 and the direction of the incident light is π / 4 radian. Similarly, since π radian is equal to 180 degrees, π / 4 radian is equal to 45 degrees. Therefore, the incident light is incident on the surface of the third fixed mirror 9 at an angle of 45 degrees.

[0079] The application also provides a high-sensitivity conjugate vortex interference method based on opposite reflection, which is applied to the above-mentioned interference system, and the method comprises the following steps:

[0080] S1: the pump light generated by the laser 1 passes through the vortex phase plate 2 to generate vortex light with a topological charge of l, and passes through the first beam splitter prism 3 to form a pair of conjugate vortices, the transmitted light has a topological charge of l and the reflected light has a topological charge of -l, which are used as the interference light and the reference light of the interferometer respectively; wherein the vortex light with a topological charge of l is transmitted by the third beam splitter prism 5 after passing through the first fixed mirror 7, is reflected by the movable double-sided mirror 10 to the third beam splitter prism 5, and is reflected by the third beam splitter prism 5 and the third fixed mirror 9 to the fourth beam splitter prism 6 in turn, and is used as the interference arm; the double-sided mirror 10 can move along the optical path; the vortex light with a topological charge of -l is reflected by the second fixed mirror 8, is transmitted by the second beam splitter prism 4, is reflected by the double-sided mirror 10, is reflected by the second beam splitter prism 4 to the fourth beam splitter prism 6, and is used as the reference arm; the conjugate vortices pass through the fourth beam splitter prism 6 to be combined and the interference light intensity is received by the camera 11;

[0081] Specifically, the pump light generated by the laser 1 passes through the vortex phase plate 2 to generate vortex light with a topological charge of l, and the vortex light is divided into two beams after passing through the first beam splitter prism 3: one is transmitted light and the other is reflected light. Due to the phase distribution characteristics of the vortex light, the transmitted light and the reflected light will have opposite topological charges, that is, the topological charge of the transmitted light is l and the topological charge of the reflected light is -l. These two beams of light are called conjugate vortices. The transmitted light and the reflected light (i.e. conjugate vortices with opposite topological charges) are used as the interference light and the reference light of the interferometer. The interference light (transmitted light) and the reference light (reflected light) meet in the interferometer and interfere to form an interference pattern. By analyzing the interference pattern, information about the phase distribution, topological charge, etc. of the vortex light can be obtained.

[0082] S2: the double-sided mirror 10 is moved along the optical path between the second beam splitter prism 4 and the third beam splitter prism 5, if the double-sided mirror 10 is moved by a displacement of Δξ towards the second beam splitter prism 4, the interference arm length increases by 2Δξ, and the optical field relative to the initial state is represented as:

[0083] OAM l *exp(i2π / λ*2Δξ)=U(r)exp(ilθ+i4πΔξ / λ);

[0084] The reference arm length decreases by 2Δξ, so the optical field is represented as:

[0085] OAM -l *exp(-i2π / λ*2Δξ)=U(r)exp(-ilθ-i4πΔξ / λ),

[0086] If the double-sided mirror 10 is moved by a displacement of Δξ towards the third beam splitter prism 5, the interference arm length decreases by 2Δξ, and the optical field relative to the initial state is represented as:

[0087] OAM-l *exp(-i2π / λ*2Δξ)=U(r)exp(-ilθ-i4πΔξ / λ);

[0088] Reference arm length increases 2Δξ, so the light field is represented as:

[0089] OAM l *exp(i2π / λ*2Δξ)=U(r)exp(ilθ+i4πΔξ / λ),

[0090] Therefore, the displacement of the double-sided mirror 10 along the optical path between the second beam-splitting prism 4 and the third beam-splitting prism 5 by Δξ, the interference light intensity distribution received by the camera 11 after the beam combination becomes:

[0091] I tot1 ∝|U(r)exp(ilθ+i4πΔξ / λ)+U(r)exp(-ilθ-i4πΔξ / λ)| 2 =2|U(r)| 2 [1+cos(2lθ+8πΔξ / λ)]

[0092] Where, I tot1 represents the interference light intensity distribution after the beam combination, the symbol ∝ represents the proportional relationship, U(r) represents the amplitude at the propagation cross section, i is the imaginary unit, exp(ilθ) is the angular phase distribution carried, and is related to the topological charge number l, r and θ are the polar radius and azimuth angle of the polar coordinates respectively, and λ is the wavelength; it can be known that the rotation angle of the interference light intensity is Thus, the displacement amount is:

[0093]

[0094] It can be known that, under the same displacement, the interference pattern 12 of the conjugate vortex produces a larger rotation angle.

[0095] The application forms an opposite reflection light path through the second beam-splitting prism 4, the third beam-splitting prism 5 and the double-sided mirror 10, so that the optical path of the interference arm changes while the optical path of the reflection arm produces an opposite change amount. Compared with the existing vortex interference system in which only the single interference arm is variable, the rotation angle is doubled, the sensitivity is higher, and it can be applied to high-precision displacement measurement. The use of conjugate vortex for interference can make the change of the micro displacement reflected on the rotation of the interference pattern, so that the micro displacement can be more accurately measured and recognized, and the micro displacement can be sensed.

[0096] Preferably, the normal line of the first fixed mirror 7 and the second fixed mirror 8 forms an angle of pi / 8 with the incident light.

[0097] Specifically, the angle between the normal line of the first fixed mirror 7 and the direction of the incident light is pi / 8 radian. Since pi radian is equal to 180 degrees, pi / 8 radian is equal to 22.5 degrees. That is, the incident light is incident to the surface of the first fixed mirror 7 at an angle of 22.5 degrees.

[0098] Preferably, the angle between the normal line of the third fixed mirror 9 and the incident light is pi / 4.

[0099] Specifically, the angle between the normal line of the third fixed mirror 9 and the direction of the incident light is pi / 4 radian. Similarly, since pi radian is equal to 180 degrees, pi / 4 radian is equal to 45 degrees. Therefore, the incident light is incident to the surface of the third fixed mirror 9 at an angle of 45 degrees.

[0100] Please refer to Figure 2 The application further provides an electronic device, comprising:

[0101] a memory 14 for storing one or more programs;

[0102] a processor 13; the memory 14 is connected to the processor 13 through a communication interface 15;

[0103] When the one or more programs are executed by the processor 13, all or part of the above method is implemented.

[0104] In the fourth aspect, the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by the processor 13 to implement all or part of the above method.

[0105] It is apparent for those skilled in the art that the application is not limited to the details of the above exemplary embodiments, and the application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the application is defined by the appended claims rather than the above description, and all changes falling within the meaning and range of equivalent elements of the claims are intended to be included in the application. Any reference signs in the claims should not be regarded as limiting the claims.

Claims

1. A high-sensitivity, conjugated vortex interferometry system based on counter- reflection, characterized in that, Comprising: laser, vortex phase plate, first beam splitter prism, second beam splitter prism, third beam splitter prism, fourth beam splitter prism, first fixed mirror, second fixed mirror, third fixed mirror, double-sided mirror and camera; the pump light source generated by the laser passes through the vortex phase plate to generate vortex light with topological charge number l, and passes through the first beam splitter prism to form a pair of conjugate vortices, the transmitted light has topological charge number l and the reflected light has topological charge number -l, which are used as interference light and reference light of an interferometer respectively; wherein the vortex light with topological charge number l is transmitted by the third beam splitter prism after passing through the first fixed mirror, is reflected by the movable double-sided mirror to the third beam splitter prism, is reflected by the third beam splitter prism and the third fixed mirror to the fourth beam splitter prism in turn, and is used as an interference arm; the double-sided mirror can move along the optical path; the vortex light with topological charge number -l is reflected by the second fixed mirror, is transmitted by the second beam splitter prism, is reflected by the double-sided mirror, is reflected by the second beam splitter prism to the fourth beam splitter prism in turn, and is used as a reference arm; the conjugate vortices are combined by the fourth beam splitter prism and the interference light intensity is received by the camera.

2. A high-sensitivity, conjugated vortex interferometry system based on counter- reflection according to claim 1, characterized in that, The normal line of the first fixed mirror and the second fixed mirror forms an angle of pi / 8 with the incident light.

3. A high-sensitivity, conjugated vortex interferometer system based on counter- reflection according to claim 2, characterized in that The normal line of the third fixed mirror forms an angle of pi / 4 with the incident light.

4. A highly sensitive conjugated vortex interferometry method based on counter reflection, characterized in that, The method applied to the interference system of claim 1 comprises the following steps: S1: the pump light source generated by the laser passes through the vortex phase plate to generate vortex light with topological charge number l, and passes through the first beam splitter prism to form a pair of conjugate vortices, the transmitted light has topological charge number l and the reflected light has topological charge number -l, which are used as interference light and reference light of an interferometer respectively; wherein the vortex light with topological charge number l is transmitted by the third beam splitter prism after passing through the first fixed mirror, is reflected by the movable double-sided mirror to the third beam splitter prism, is reflected by the third beam splitter prism and the third fixed mirror to the fourth beam splitter prism in turn, and is used as an interference arm; the double-sided mirror can move along the optical path; the vortex light with topological charge number -l is reflected by the second fixed mirror, is transmitted by the second beam splitter prism, is reflected by the double-sided mirror, is reflected by the second beam splitter prism to the fourth beam splitter prism in turn, and is used as a reference arm; the conjugate vortices are combined by the fourth beam splitter prism and the interference light intensity is received by the camera; S2: moving the double-sided mirror along the optical path between the second beam splitter prism and the third beam splitter prism, if the double-sided mirror moves a displacement of Δξ towards the second beam splitter prism, the interference arm length increases by 2Δξ, the optical field relative to the initial state is represented as: OAM l *exp(i2π / λ*2Δξ) = U(r)exp(ilθ+i4πΔξ / λ); the reference arm length decreases by 2Δξ, the optical field is represented as: OAM -l *exp(-i2π / λ*2Δξ) = U(r)exp(-ilθ-i4πΔξ / λ), if the double-sided mirror moves a displacement of Δξ towards the third beam splitter prism, the interference arm length decreases by 2Δξ, the optical field relative to the initial state is represented as: OAM -l *exp(-i2π / λ*2Δξ) = U(r)exp(-ilθ-i4πΔξ / λ); the reference arm length increases by 2Δξ, the optical field is represented as: OAM l *exp(i2π / λ*2Δξ) = U(r)exp(ilθ+i4πΔξ / λ), Therefore, the displacement of the double-sided mirror along the optical path between the second beam splitter prism and the third beam splitter prism is Δξ, and the interference light intensity distribution received by the camera after the combination becomes: I tot1 a|U(r)exp(ilθ+i4πΔξ / λ)+U(r)exp(-ilθ-i4πΔξ / λ) 2 = 2|U(r)| 2 [1+cos(2lθ+8πΔξ / λ)] where I tot1 represents the intensity distribution of the interference light field after the beam combination, the symbol ∝ represents a proportional relationship, U(r) represents the amplitude at the propagation cross section, i is the imaginary unit, exp(ilθ) is the angular phase distribution carried, and is related to the topological charge number l, r and θ are the polar radius and azimuth angle of the polar coordinates, respectively, and λ is the wavelength; at this time, the rotation angle of the interference light intensity is Thus, the displacement amount is obtained: Under the same displacement, the interference pattern of the conjugate vortices produces a larger rotation angle.

5. A highly sensitive, conjugated vortex interferometry method based on counter reflection according to claim 4, characterized in that, Further comprising: The normal line of the first fixed mirror and the second fixed mirror forms an angle of pi / 8 with the incident light.

6. A highly sensitive, conjugated vortex interferometry method based on counter reflection according to claim 5, characterized in that, Further comprising: The normal line of the third fixed mirror forms an angle of pi / 4 with the incident light.

7. An electronic device, comprising: Comprising: a memory for storing one or more programs; a processor; when the one or more programs are executed by the processor, the method of any one of claims 4-6 is implemented.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method of any one of claims 4-6. The computer program is executed by the processor to implement the method of any one of claims 4-6.

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