Dynamic light field regulation and control system and design method thereof

Abstract

According to the dynamic light field regulation and control system and the design method thereof, a multi-wavelength light source and a modulation assembly (light and thin modulation surface) designed in advance are utilized, a dynamic interference field can be flexibly designed, a dynamic light field conforming to expectation is obtained, generation of various complex space-time light fields is achieved, and the dynamic interference field can be flexibly designed. The method comprises line scanning, dot matrix scanning and the like suitable for the field of laser radars, so that a designable dynamic light field is realized only by using a passive modulator, the problem that a traditional dynamic light field modulation method depends on an active modulator is solved, the energy consumption is reduced, the complexity of a scanning system is reduced, and the system reliability is improved. And efficient and diversified dynamic light field generation is realized.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technologies, and more particularly, to a control system for a dynamic light field and a design method thereof. Background Art

[0002] The rapid development of sensor technology, especially in Light Detection and Ranging (LiDAR) systems, depends on the ability to manipulate light with extremely high precision and speed. Traditional mechanical scanning methods are increasingly unable to meet the performance requirements of modern applications such as autonomous vehicles and environmental sensing.

[0003] To address the problem that traditional mechanical scanning methods cannot meet the performance requirements of current LiDAR systems, current traditional dynamic light field modulation methods generally use active modulation devices to achieve the modulation of dynamic light fields. Active modulation devices are devices widely used in fields such as communication and optics. They utilize the physical properties of active media to achieve the modulation of signals such as light and electricity. For example, electro-optic modulators, acousto-optic modulators, semiconductor laser modulators, etc. However, active modulation devices have the drawbacks of complex scanning systems and high energy consumption. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a control system for a dynamic light field and a design method thereof, so as to solve the problems of complex scanning systems and high energy consumption existing in the current dynamic light field modulation using active modulation devices.

[0005] In a first aspect, this application provides a control system for a dynamic light field. The system includes a light source, a modulation component, and a receiving surface; the light source is used to emit at least two incident light beams with different wavelengths and a preset incident angle towards the modulation surface; the modulation component is used to modulate the incident light beams emitted by the light source; wherein, at least two incident light beams with different wavelengths form a dynamic interference light field after being modulated by the modulation component and overlapping on the receiving surface.

[0006] The control system for a dynamic light field provided by this solution can flexibly design the dynamic interference field by using a multi-wavelength light source and a pre-designed modulation component (a thin and light modulation surface), obtain a dynamic light field that meets expectations, and achieve the generation of various complex spatio-temporal light fields, including line scanning, dot matrix scanning, etc. applicable to the field of LiDAR. Thus, this solution realizes a designable dynamic light field only using passive modulation devices, solves the problem of dependence on active modulation devices in traditional dynamic light field modulation methods, reduces energy consumption, reduces the complexity of the scanning system, and realizes the efficient and diverse generation of dynamic light fields.

[0007] In an optional implementation manner of the first aspect, the light source includes at least two laser emission components; each laser emission component includes a laser light source and a corresponding collimator.

[0008] In the above embodiment, in this solution, the light is collimated by a collimator, so that the light is concentrated and propagated in a specific direction, reducing the scattering and divergence of the light, thereby improving the utilization rate of light energy.

[0009] In an alternative embodiment of the first aspect, the modulation component includes a stripe mask or a double-hole mask perpendicular to the interference fringes of the target dynamic light field, a combined modulator of the modulation phase surface, or a combined modulator of multiple metasurfaces with regional modulation.

[0010] In the above embodiment, the modulation component designed in this solution can adopt various different modulation combination forms, so that this solution can be applied to the regulation of various different target dynamic light fields, thereby improving the applicability of this solution.

[0011] In a second aspect, the present application provides a method for designing a regulation system of a dynamic light field. The regulation system includes a light source, a modulation component, and a receiving surface. The incident light beam emitted by the light source is modulated by the modulation component and overlaps on the receiving surface to form a dynamic interference light field. The method includes: obtaining the light field characteristic parameters of the target dynamic light field; wherein, the light field characteristic parameters include spatio-temporal transformation characteristics and light field morphology; according to the spatio-temporal transformation characteristics of the target dynamic light field, determining the incident light beam parameters emitted by the light source; wherein, the incident light wave parameters include the number of light waves and the light wave characteristic parameters; according to the incident light beam parameters and the light field characteristic parameters, determining the modulation parameters of the modulation component.

[0012] The method for designing a regulation system of a dynamic light field provided by this solution determines the incident light beam parameters emitted by the light source through the spatio-temporal transformation characteristics of the required target dynamic light field, and then determines the modulation parameters of the modulation component according to the incident light beam parameters and the light field characteristic parameters, so that this solution can design simple amplitude modulation and phase modulation according to the required light field to achieve partial dot scanning and various stripe transformations, and can also design complex complex amplitude modulation to achieve any dynamic light field, such as any form of dot scanning. Furthermore, by using the designed modulation component and the composite light source, a dynamic light field that meets the expectations can be obtained, realizing the generation of various complex spatio-temporal light fields, making the designed modulation component have the characteristics of high speed, low power consumption, and simple structure. Thus, the problem of dependence on active modulation devices in traditional dynamic light field modulation methods is solved, the energy consumption is reduced, the complexity of the scanning system is reduced, and the efficient and diverse generation of dynamic light fields is realized.

[0013] In an alternative embodiment of the second aspect, determining the incident light beam parameters emitted by the light source in the regulation system according to the transformation characteristics of the target dynamic light field includes: obtaining the magnitude of the electric field strength of each light point in the target dynamic light field at each moment according to the spatio-temporal transformation characteristics of the target dynamic light field; determining the light wave characteristic parameters of the incident light beam emitted by the light source according to the magnitude of the electric field strength of each light point in the target dynamic light field at each moment.

[0014] In an alternative embodiment of the second aspect, determining the wavelength of the incident light beam emitted by the light source according to the magnitude of the electric field strength of each light point in the target dynamic light field at each moment includes:

[0015] In the case where the target dynamic light field is in the form of a plane wave superposition, calculating the optical wave characteristic parameters of the incident light beam emitted by the light source through the first calculation formula E1 of the magnitude of the electric field strength of each light point at each moment:

[0016]

[0017] where E1 is the electric field strength vector at an arbitrary point in space at time t, the subscript i is the physical quantity corresponding to the i-th optical wave, k i is the wave vector corresponding to the i-th optical wave, ω i is the angular frequency corresponding to the i-th optical wave, r i is the position vector, and Ψ is the amplitude vector function corresponding to the i-th optical wave;

[0018] In the case where the target dynamic light field is in the form of a spherical wave superposition, calculating the optical wave characteristic parameters of the incident light beam emitted by the light source through the second calculation formula E2 of the magnitude of the electric field strength of each light point at each moment:

[0019]

[0020] where E2 is the electric field strength vector at an arbitrary point in space at time t, the subscript i is the physical quantity corresponding to the i-th optical wave, k i is the wave number corresponding to the i-th optical wave, ω i is the angular frequency corresponding to the i-th optical wave, r i is the position vector of the position where the light point is located relative to the light source of the i-th optical wave, and Ψ is the amplitude vector function corresponding to the i-th optical wave.

[0021] In the above embodiment, the present solution considers the differences in the optical wave characteristic parameters in the case of different wave superpositions forming different dynamic light fields, and thus realizes the accurate calculation of the optical wave characteristic parameters of the incident light beam emitted by the light source in different dynamic light field cases.

[0022] In an alternative embodiment of the second aspect, determining the modulation parameter of the modulation component according to the incident light beam parameter and the light field characteristic parameter includes: when the number of incident light beams emitted by the light source of the target dynamic light field is 2, and the light field form of the target dynamic light field is a dot matrix dynamic light field, determining that the modulation parameter of the modulation component is stripe amplitude modulation.

[0023] In an alternative embodiment of the second aspect, the modulation parameters of the modulation component are determined according to the incident beam parameters and the optical field characteristic parameters, including: when the number of incident beams emitted by the light source of the target dynamic optical field is 2, and the optical field pattern of the target dynamic optical field is a dynamically changing fringe optical field, it is determined that the modulation component is a combined modulation component of a double-hole mask and a modulation phase surface, wherein the shape of the dynamically changing fringe optical field is related to the pattern shape of the modulation phase surface, and the movement direction of the dynamically changing fringe optical field is related to the pattern change direction on the modulation phase surface.

[0024] In an alternative embodiment of the second aspect, the modulation parameters of the modulation component are determined according to the incident beam parameters and the optical field characteristic parameters, including: when the number of incident beams emitted by the light source of the target dynamic optical field is multiple, and the optical field pattern of the target dynamic optical field is a dot scanning optical field, it is determined that the modulation component is a combined modulation component of multiple metasurfaces with regional modulation, wherein the number of multiple beams is greater than or equal to 2, and the spatio-temporal change characteristics of each light point of the dot scanning optical field are determined according to the light source combination and the complex amplitude distribution after the light passes through the metasurfaces in each region.

[0025] In an alternative embodiment of the second aspect, the complex amplitude distribution E of the metasurface in each region of the combined modulation component of multiple metasurfaces with regional modulation n is obtained by calculation through the formula:

[0026]

[0027] where x and y are the positions corresponding to each point on the metasurface, x m , y m are the corresponding coordinates of the lattice points, k n and ω n are the wave number and angular frequency of the beam incident on the corresponding region, M is the number of lattice points of the target dynamic optical field, f is the focal length corresponding to the metasurface to achieve focusing, that is, the distance between the receiving surface and the metasurface, and T is the transformation period of the target dynamic optical field.

[0028] In the above-mentioned various embodiments, according to the required optical field, the present solution can design simple amplitude modulation and phase modulation to achieve partial lattice scanning and various fringe transformations, or can design complex complex amplitude modulation to achieve any dynamic optical field, such as any form of lattice scanning, thereby significantly improving the applicability of the modulation component designed by the present solution.

[0029] In a third aspect, the present invention provides an electronic device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, it executes the method described in the second aspect or any alternative embodiment of the second aspect.

[0030] Fourthly, the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it executes the method described in any optional implementation manner of the second aspect.

[0031] Fifthly, the present invention provides a computer program product, including a computer program / instructions, and when the computer program / instructions are executed by a processor, it executes the method described in any optional implementation manner of the second aspect.

[0032] The above description is only an overview of the technical solutions of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific implementation manners of the present application are specifically given below. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained according to these drawings.

[0034] Figure 1 It is a schematic structural diagram of a dynamic light field regulation system provided by an embodiment of the present application;

[0035] Figure 2 It is a first flowchart of a design method of a dynamic light field regulation system provided by an embodiment of the present application;

[0036] Figure 3 It is a second flowchart of a design method of a dynamic light field regulation system provided by an embodiment of the present application;

[0037] Figure 4 It is a first example diagram of a dynamic light field regulation system provided by an embodiment of the present application;

[0038] Figure 5 It is a second example diagram of a dynamic light field regulation system provided by an embodiment of the present application;

[0039] Figure 6 It is a third example diagram of a dynamic light field regulation system provided by an embodiment of the present application;

[0040] Figure 7 It is an effect diagram of the third example of a dynamic light field regulation system provided by an embodiment of the present application;

[0041] Figure 8 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

[0042] Icons: 10 - light source; 20 - modulation component; 30 - receiving surface; 8 - electronic device; 801 - processor; 802 - memory; 803 - communication bus. Specific Embodiments

[0043] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0045] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0046] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0047] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0048] In the description of the embodiments of this application, the term "a plurality" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0049] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of the present application.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication between two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0051] The rapid development of sensor technology, especially in lidar systems, depends on the ability to manipulate light with extremely high precision and speed. Traditional mechanical scanning methods are increasingly unable to meet the performance requirements of modern applications such as autonomous vehicles and environmental sensing.

[0052] To solve the problem that traditional mechanical scanning methods cannot meet the performance requirements of current lidar systems, currently, traditional dynamic light field modulation methods generally implement the modulation of the dynamic light field through active modulation devices. Active modulation devices are devices widely used in fields such as communication and optics. They utilize the physical properties of active media to achieve the modulation of optical, electrical, and other signals. For example, electro-optic modulators, acousto-optic modulators, semiconductor laser modulators, etc. However, active modulation devices have the defects of complex scanning systems and high energy consumption.

[0053] Based on the above problems, the present application designs a dynamic light field control system and its design method. By using a multi-wavelength light source and a pre-designed modulation component (a thin and light modulation surface), the dynamic interference field can be flexibly designed to obtain a dynamic light field that meets expectations, realizing the generation of various complex spatio-temporal light fields, including line scanning, dot matrix scanning, etc. applicable to the lidar field. Thus, this solution realizes a designable dynamic light field only using passive modulation devices, solves the problem of dependence on active modulation devices in traditional dynamic light field modulation methods, reduces energy consumption, reduces the complexity of the scanning system, and realizes the efficient and diverse generation of dynamic light fields.

[0054] Based on the above idea, the present application first provides a dynamic light field control system. As Figure 1 shown, the dynamic light field control system includes a light source 10, a modulation component 20, and a receiving surface 30. Among them, the light source 10 is a multi-wavelength light source. Specifically, the light source 10 may include at least two laser emission components. Each laser emission component includes a laser light source and a corresponding collimator. The laser wavelengths emitted by at least two laser emission components are different, and the laser beams emitted by at least two laser emission components may have an angle between them or be parallel to each other.

[0055] The modulation component 20 is a passive modulation device selected according to the required light field, which modulates the amplitude, phase, or complex amplitude of the incident beam. The modulated beams will overlap to form a dynamic light field. Specifically, the modulation component 20 designed in this solution may specifically include a fringe mask perpendicular to the interference fringes of the target dynamic light field, a combined modulation component of a double-hole mask and a modulation phase surface, a combined modulation component of multiple metasurfaces with regional modulation, and so on.

[0056] The receiving surface 30 is a dynamic light field action surface selected according to the application requirements. The laser beams with different wavelengths emitted by the light source 10 overlap on the receiving surface 30 after being modulated by the modulation component 20. The dynamic light field on the receiving surface 30 changes over time according to the design. The receiving surface can be an ordinary white screen, a photosensitive surface of a photodetector, a surface to be processed, etc.

[0057] For the above-designed dynamic light field control system, the light source 10 can emit at least two incident beams with different wavelengths that are parallel to each other or have a certain incident angle with each other. Among them, the modulation component 20 designed in this solution can be pre-designed according to the required target dynamic interference light field, so that after the modulation component 20 modulates the incident beams emitted by the light source, a target dynamic interference light field is formed by overlapping on the receiving surface 30.

[0058] For the dynamic light field control system designed in this solution, by using a multi-wavelength light source and a pre-designed modulation component (a thin and light modulation surface), the dynamic interference field can be flexibly designed, and a dynamic light field that meets the expectations can be obtained, realizing the generation of various complex spatio-temporal light fields, including line scanning, dot matrix scanning, etc. applicable to the lidar field. Thus, this solution realizes a designable dynamic light field only by using passive modulation devices, solves the dependence problem of traditional dynamic light field modulation methods on active modulation devices, reduces energy consumption, reduces the complexity of the scanning system, and realizes the generation of efficient and diverse dynamic light fields.

[0059] As described above, this solution can pre-design the modulation component 20 according to the required target dynamic interference light field. In this regard, the present application provides a design method for a dynamic light field control system. This method can be applied to the control system described above. As Figure 2As shown in the figure, the method can be implemented in the following manner, including:

[0060] Step S200: Obtain the optical field characteristic parameters of the target dynamic optical field.

[0061] Step S210: Determine the incident beam parameters emitted by the light source according to the spatio-temporal transformation characteristics of the target dynamic optical field.

[0062] Step S220: Determine the modulation parameters of the modulation component according to the incident beam parameters and the optical field characteristic parameters.

[0063] In the above embodiment, the target dynamic optical field represents the dynamic optical field required in the actual situation. The optical field characteristic parameters include the spatio-temporal transformation characteristics and the optical field form of the target dynamic optical field. Among them, the spatio-temporal transformation characteristics may include the spatial resolution, time resolution, and transformation period of the target dynamic optical field, etc. The optical field form may include dot matrix dynamic optical field and stripe dynamic optical field, etc. Among them, the optical field characteristic parameters of the target dynamic optical field can be obtained by the user manually inputting according to the optical field characteristic parameters of the dynamic optical field required in the actual situation.

[0064] In the case of obtaining the optical field characteristic parameters of the target dynamic optical field in the above manner, this solution can determine the incident beam parameters emitted by the light source according to the spatio-temporal transformation characteristics of the target dynamic optical field. Specifically, as Figure 3 shown in the figure, this solution can obtain the incident beam parameters emitted by the light source in the following manner, including:

[0065] Step S300: Obtain the magnitude of the electric field intensity of each light point in the target dynamic optical field at each moment according to the spatio-temporal transformation characteristics of the target dynamic optical field.

[0066] Step S310: Determine the optical wave characteristic parameters of the incident beam emitted by the light source according to the magnitude of the electric field intensity of each light point in the target dynamic optical field at each moment.

[0067] In the above embodiment, it was previously described that the spatio-temporal transformation characteristics include the spatial resolution, time resolution, and transformation period of the target dynamic optical field. On this basis, this solution can determine the wavelength and number of incident beams participating in the synthesis according to the spatial resolution, time resolution, and transformation period of the target dynamic optical field. Specifically:

[0068] For two-beam synthesis, the fringe density increases with the increase of the angle θ between the two beams, the fringe width decreases with the increase of θ, and the period of fringe change is fixed as λ1 and λ2 are the wavelengths of the two beams of light respectively, and the change of the single-point light intensity is a fixed light intensity superimposed with a cosine function.

[0069] For the case of multiple beams, the spatio-temporal transformation characteristics of the target dynamic light field characterize the magnitude of the electric field strength of each light point in the target dynamic light field at each moment. Therefore, by obtaining the spatio-temporal transformation characteristics of the target dynamic light field, the magnitude of the electric field strength of each light point at each moment can be obtained. In the case of multiple beams, the change in single-point light intensity (the magnitude of the electric field strength of each light point in the target dynamic light field at each moment) conforms to the Fourier transform relationship.

[0070] Specifically, in the case where the target dynamic light field is in the form of a plane wave superposition, the optical wave characteristic parameters of the incident beam emitted by the light source are calculated through the first calculation formula E1 of the magnitude of the electric field strength of each light point at each moment:

[0071]

[0072] where E1 is the electric field strength vector at an arbitrary point in space at time t, the subscript i is the physical quantity corresponding to the i-th optical wave, k i is the wave vector corresponding to the i-th optical wave, ω i is the angular frequency corresponding to the i-th optical wave, r i is the position vector, and Ψ is the amplitude vector function corresponding to the i-th optical wave;

[0073] In the case where the target dynamic light field is in the form of a spherical wave superposition, the optical wave characteristic parameters of the incident beam emitted by the light source are calculated through the second calculation formula E2 of the magnitude of the electric field strength of each light point at each moment:

[0074]

[0075] where E2 is the electric field strength vector at an arbitrary point in space at time t, the subscript i is the physical quantity corresponding to the i-th optical wave, k i is the wave number corresponding to the i-th optical wave, ω i is the angular frequency corresponding to the i-th optical wave, r i is the position vector of the position where the light point is located relative to the light source of the i-th optical wave, and Ψ is the amplitude vector function corresponding to the i-th optical wave.

[0076] In the case of obtaining the incident beam parameters through the above method, this solution can then determine the modulation parameters of the modulation component according to the incident beam parameters and the light field characteristic parameters. Among them, according to the different requirements of the target dynamic light field, the material and structure of the modulation component are different, and the modulation component can be single-layer or multi-layer.

[0077] As a possible implementation manner, when the number of incident beams emitted by the light source of the target dynamic light field is 2, and the light field form of the target dynamic light field is a dot matrix dynamic light field, the modulation parameter of the modulation component is determined to be stripe amplitude modulation.

[0078] Specifically, for the modulation of the superposition of two light beams, when the target dynamic light field is a dot matrix dynamic light field (such as a rectangular dot matrix), this solution can directly set the modulation parameters of the modulation component to stripe-shaped amplitude modulation. Specifically, the modulation component designed in this solution can be implemented by using a series of strip-shaped masks perpendicular to the interference fringes formed by the two incident light beams. Among them, the mask scale of the modulation component is equivalent to the scale of the interference fringes formed by the two incident light beams.

[0079] As a specific example:

[0080] As Figure 4 shown in Figure (b) of Figure 4 , two parallel light beams with different wavelengths (both around 1064 nm) are incident on the modulation plane at different angles and then overlap on the receiving plane. The corresponding experimental optical path is as shown in Figure (a) of Figure 4 . The distance between the light source and the modulation plane is about 1 m, and the distance between the modulation plane and the receiving plane is about 20 mm. To make the observed light intensity distribution clearer, the light beam is expanded by an expander. The receiving plane is the photosensitive surface of a CCD camera, and its size is 6.4 mm × 5.12 mm. The angle between the two light beams is extremely small. When the modulation plane is not applied, there are only about 3 stripes extending horizontally on the receiving plane, as shown in Figure (c) of Figure 4 . The stripes move vertically upward. If the angle between the two light beams is increased, the stripes will become finer and denser, and the number of stripes on the receiving plane will increase. The modulation plane is a mask. The places on the mask where patterns are engraved are opaque, and the rest are transparent. The patterns engraved on the mask are strip-shaped arrays perpendicular to the interference fringes. The strip width is about 1 mm, and the distance between the midlines of each strip is about 1.6 mm. After applying this mask modulation, the dot matrix scanning as shown in Figure (e) of Figure 4 can be obtained. The scanning speed in both dot matrix scanning and stripe scanning is 3.4 mm / s.

[0081] Note that in this example, to achieve visible dynamic stripes to the naked eye, an acousto-optic modulator in series is used for frequency shifting, and two light beams with a frequency difference of only 2 Hz are obtained. In fact, the movement speed of the stripes can be designed arbitrarily, which depends on the frequency difference between the two light beams. When the frequency difference is large, the movement speed of the stripes can be close to the speed of light.

[0082] As another possible implementation manner, when the number of incident light beams emitted by the light source of the target dynamic light field is 2, and the light field form of the target dynamic light field is a dynamically changing stripe light field, this solution can determine that the modulation component is a combined modulator of a double-hole mask and a modulation phase plane, where the shape of the dynamically changing stripe light field is related to the pattern shape of the modulation phase plane, and the movement direction of the dynamically changing stripe light field is related to the pattern change direction on the modulation phase plane.

[0083] Specifically, the modulation component designed above can modulate two mutually parallel beams of different-wavelength light through a double-hole mask with a small scale, making the light wave approximately a spherical wave, and then modulating the superposition of the spherical waves through the designed modulation phase surface. The final obtained fringe shape and dynamic change characteristics are similar to the designed phase distribution. When different phase modulations are applied, the fringe shape will change similarly to the modulation phase surface. For example, the shape of the dynamically changing fringe light field is related to the pattern shape of the modulation phase surface, and the movement direction of the dynamically changing fringe light field is related to the pattern change direction on the modulation phase surface. Further, the simultaneous modulation of light of multiple wavelengths can be achieved through the same modulation phase surface. The modulation depth (i.e., the optical path change amount) will greatly affect the fringe changes, including the number of fringes and the fringe shape; the modulation in a single direction will cause the fringes to move in this direction, generally moving from the position with shallower modulation to the position with deeper modulation. The fringes will not be exactly the same as the modulation image, but will have differences in angle and position. The specific design of the modulation phase surface includes, but is not limited to, modulation that linearly increases or decreases from the middle to both sides, modulation where the modulation depth is proportional or inversely proportional to the distance from the point to the center, modulation of a spiral phase plate, etc. The modulation depth and modulation direction will greatly affect the fringe width, density, and movement direction.

[0084] As a specific example: The arrangement of the specific device is as shown in Figure 5 (a) in the figure. Two parallel light beams with different wavelengths (1062 nm and 1064 nm respectively) are incident on a double-hole screen (the distance between the two holes is 4 μm). The two diffracted light waves are approximately spherical waves. A transparent modulation phase surface is placed closely against the double-hole screen, and the optical path is changed through a transparent material with uneven thickness to apply different phase modulations to different positions in space. The double-hole screen and the modulation phase surface together form a modulation component, and a receiving surface is placed 0.4 mm away from the modulation component.

[0085] When no phase modulation is applied, the fringes are the conventional scanning fringes as shown in Figure 5 (b) in the figure, and the fringe scanning speed is 5.77×10 7 m / s. When different phase modulations are applied, the fringe shape will change similarly to the phase modulation mode. Figure 5 The optical path modulation in (c) and (e) in the figure is modulation that linearly increases or decreases from the middle to both sides. Figure 5 In (g) in the figure, the modulation depth of each point is proportional to the distance from the point to the center. Figure 5 The situation shown in (i) in the figure is the opposite, so the positions of the corresponding circular fringes are different, and the movement directions of the fringes are also opposite. The slower the fringe movement speed at the thinner fringe position. Figure 5 The average speed of the fringe expansion or contraction shown in (h) and (j) in the figure is 3.32×10 7m / s. The modulation ranges of the above four modulation plates are all 0 - 3.6 mm. Increasing the modulation depth will make the fringes denser, and the centers of circular fringes and the like will be closer to the center of the observation surface. When using a spiral phase plate to modulate the interference of these two spherical waves, various interesting phenomena will occur. When the modulation range is only 0 - 0.56 mm, the fringes change to varying degrees at different positions, and the changing trend is to transform them into fringes rotating around the center. For example, when the modulation range is increased to 0 - 22.59 mm, the fringes shown in the (p) figure in Figure 5 will appear, which rotate clockwise. Changing the modulation direction of the spiral phase plate will also change the rotation direction of the fringes. Similarly, the wider the modulation range, the greater the fringe density. However, it should be noted that the rotating fringes achieved by such a spiral phase plate with a linearly varying modulation depth with angle are not uniform. By non-linearly designing the modulation depth, more ideal fringes can be obtained. Naturally, some fringes with interesting shapes that meet the application requirements can also be obtained by designing the modulation depth.

[0086] As another possible implementation, when the number of incident light beams emitted by the light source of the target dynamic light field is multiple, and the light field form of the target dynamic light field is a dot scanning light field, it is determined that the modulation component is a combined modulation component of multiple metasurfaces with regional modulation. Among them, the number of multiple beams is greater than or equal to 2, and the spatio-temporal variation characteristics of each light point of the dot scanning light field are determined according to the light source combination and the complex amplitude distribution after the light passes through the metasurfaces of each region.

[0087] Specifically, consider the superposition of N light waves with equally spaced frequencies. Suppose that at t = 0, the initial phases of all light waves are equal, and the superposed light field can be simply written as The more the number of superposed waves, the smaller the duty cycle of the energy, and the higher the time resolution between points in the formed dot matrix. The superposed wave is also a periodic function, and the period T is related to the frequency structure of the superposed pulses.

[0088] To form a dot matrix with point-by-point changes, with the number of points being M, phase and time encoding need to be performed on each point.

[0089] For spatial encoding, since the area of the metasurface is small, the distance between metasurfaces can be ignored. It is considered that the central positions of N metasurfaces are all at the coordinate origin.

[0090] Let the coordinates of M dot matrices be (x1, y1),...,(x m , y m ),...,(x M , y M ), then the nth metasurface performs complex amplitude regulation on the light field, and the complex amplitude distribution is:

[0091]

[0092] For time encoding: To achieve the effect of different points flashing, it is necessary to make M points at different phases in the period T. Let the m-th point be at [(m - 1)T] / M, then according to the phase of each point, calculate the phase that the n-th wave should load on this point:

[0093]

[0094] Combining spatial encoding and time encoding, the complex amplitude distribution E of the metasurfaces in each region of the combined modulation component of multiple metasurfaces with regional modulation n Obtained by formula calculation:

[0095]

[0096] where x and y are the corresponding positions of each point on the metasurface, x m , y m are the corresponding coordinates of the dot matrix, k n and ω n are the wave number and angular frequency of the light beam incident on the corresponding region, M is the number of dot matrices of the target dynamic light field, f is the focal length corresponding to the metasurface to achieve focusing, that is, the distance between the receiving surface and the metasurface, and T is the transformation period of the target dynamic light field.

[0097] As a specific example: When using the superposition of multiple light beams, more complex dynamic light field designs can be achieved. Here, dot matrix scanning is taken as an example. The specific device settings of the embodiment are as Figure 6 shown. Here, the modulation surface is the metasurface applying complex amplitude modulation. The metasurface modulation region is divided into 10. The metasurface is designed using the method described above. 10 light waves with equally spaced frequencies in the wavelength range of 1063.9 - 1064.1 nm are used for synthesis. The distance between the receiving surface and the modulation surface is 10 mm. In this way, single-column dot matrix scanning and double-column dot matrix scanning as shown in Figure 7 can be obtained. The scanning period is about 170.341 ps, and the number of scanning points can be designed arbitrarily.

[0098] Note that this example only shows the application of the present invention in dot matrix scanning. In fact, any dynamic light field can be designed according to the ideas and methods provided by the present invention.

[0099] The design method of the dynamic light field modulation system provided by this solution determines the parameters of the incident light beam emitted by the light source through the spatio-temporal transformation characteristics of the required target dynamic light field. Then, according to the incident light beam parameters and the light field characteristic parameters, the modulation parameters of the modulation component are determined, so that this solution can design simple amplitude modulation and phase modulation to achieve partial dot matrix scanning and various stripe transformations according to the required light field, and can also design complex complex amplitude modulation to achieve any dynamic light field, such as dot matrix scanning in any form. Furthermore, the desired dynamic light field can be obtained through the designed modulation component and the composite light source, realizing the generation of various complex spatio-temporal light fields, making the designed modulation component have the characteristics of high speed, low power consumption and simple structure. Thus, the problem of dependence on active modulation devices in traditional dynamic light field modulation methods is solved, the energy consumption is reduced, the complexity of the scanning system is reduced, and the efficient and diverse generation of dynamic light fields is achieved.

[0100] According to some embodiments of the present application, as Figure 8 shown, the present application provides an electronic device 8, including: a processor 801 and a memory 802. The processor 801 and the memory 802 are interconnected and communicate with each other through a communication bus 803 and / or other forms of connection mechanisms (not shown). The memory 802 stores a computer program executable by the processor 801. When the computing device runs, the processor 801 executes the computer program to execute the method of any optional implementation manner, for example, steps S200 to S210: obtaining the light field characteristic parameters of the target dynamic light field; determining the parameters of the incident light beam emitted by the light source according to the spatio-temporal transformation characteristics of the target dynamic light field; determining the modulation parameters of the modulation component according to the incident light beam parameters and the light field characteristic parameters.

[0101] The present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, it executes the method in any of the foregoing optional implementation manners.

[0102] Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM for short), electrically erasable programmable read-only memory (EEPROM for short), erasable programmable read-only memory (EPROM for short), programmable read-only memory (PROM for short), read-only memory (ROM for short), magnetic memory, flash memory, magnetic disk or optical disk.

[0103] The present application provides a computer program product, which when running on a computer, causes the computer to execute the method in any of the optional implementation manners.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A control system for a dynamic light field, characterized in that, The system includes a light source, a modulation component, and a receiving surface; The light source is configured to emit at least two incident light beams with different wavelengths and a preset incident angle towards the modulation component; The modulation component is configured to modulate the incident light beams emitted by the light source; wherein, the at least two incident light beams with different wavelengths form a dynamic interference light field after being modulated by the modulation component and overlapping on the receiving surface.

2. The control system for a dynamic light field according to claim 1, wherein The light source includes at least two laser emission components; Each of the laser emission components includes a laser light source and a corresponding collimator.

3. The dynamic light field regulation system according to claim 1, wherein The modulation component includes a combination modulation component of a fringe mask or a double-hole mask perpendicular to the interference fringes of the target dynamic light field and a modulation phase surface, or a combination modulation component of multiple metasurfaces with sub-region modulation.

4. A design method for a dynamic light field regulation system, characterized in that, The control system includes a light source, a modulation component, and a receiving surface. The incident light beams emitted by the light source form a dynamic interference light field after being modulated by the modulation component and overlapping on the receiving surface; The method includes: Obtaining the optical field characteristic parameters of the target dynamic light field; wherein, the optical field characteristic parameters include spatio-temporal transformation characteristics and optical field morphology; Determining the incident light beam parameters emitted by the light source according to the spatio-temporal transformation characteristics of the target dynamic light field; wherein, the incident light beam parameters include the number of light waves and the optical wave characteristic parameters; Determining the modulation parameters of the modulation component according to the incident light beam parameters and the optical field characteristic parameters.

5. The method according to claim 4, wherein The determining the incident light beam parameters emitted by the light source in the control system according to the transformation characteristics of the target dynamic light field includes: Obtaining the magnitude of the electric field intensity of each light point in the target dynamic light field at each moment according to the spatio-temporal transformation characteristics of the target dynamic light field; Determining the optical wave characteristic parameters of the incident light beam emitted by the light source according to the magnitude of the electric field intensity of each light point in the target dynamic light field at each moment.

6. The method according to claim 5, characterized in that The determining the wavelength of the incident light beam emitted by the light source according to the magnitude of the electric field intensity of each light point in the target dynamic light field at each moment includes: In the case where the target dynamic light field is in the form of a plane wave superposition, calculating the optical wave characteristic parameters of the incident light beam emitted by the light source through the first calculation formula E1 of the magnitude of the electric field intensity of each light point at each moment: where, E1 is the electric field strength vector of any point in space at time t, the subscript i represents the physical quantity corresponding to the i-th light wave, k i is the wave vector corresponding to the i-th light wave, ω i is the angular frequency corresponding to the i-th light wave, r i is the position vector, and Ψ is the amplitude vector function corresponding to the i-th light wave; In the case where the target dynamic light field is in the form of a spherical wave superposition, calculating the optical wave characteristic parameters of the incident light beam emitted by the light source through the second calculation formula E2 of the magnitude of the electric field intensity of each light point at each moment: Among them, E2 is the electric field strength vector at any point in space at time t, and the subscript i represents the physical quantity corresponding to the i-th light wave, k i is the wave number corresponding to the i-th light wave, ω i is the angular frequency corresponding to the i-th light wave, r i is the position vector of the position where the light spot is located relative to the light source of the i-th light wave, and Ψ is the amplitude vector function corresponding to the i-th light wave.

7. The method according to claim 5, characterized in that, The determining the modulation parameters of the modulation component according to the incident light beam parameters and the optical field characteristic parameters includes: In the case where the number of incident light beams emitted by the light source of the target dynamic light field is 2 and the optical field morphology of the target dynamic light field is a dot matrix dynamic light field, determining the modulation parameters of the modulation component as stripe-shaped amplitude modulation.

8. The method according to claim 5, wherein The determining the modulation parameters of the modulation component according to the incident light beam parameters and the optical field characteristic parameters includes: When the number of incident light beams emitted by the light source of the target dynamic light field is 2, and the light field form of the target dynamic light field is a dynamically changing fringe light field, the modulation component is determined to be a combined modulator of a double-hole mask and a modulation phase surface, wherein the shape of the dynamically changing fringe light field is related to the pattern shape of the modulation phase surface, and the movement direction of the dynamically changing fringe light field is related to the pattern change direction on the modulation phase surface.

9. The method according to claim 4, wherein determining the modulation parameters of the modulation component according to the incident light beam parameters and the light field characteristic parameters includes: when the number of incident light beams emitted by the light source of the target dynamic light field is multiple, and the light field form of the target dynamic light field is a dot scanning light field, the modulation component is determined to be a combined modulator of multiple meta-surfaces modulated by regions, wherein the number of multiple beams is greater than or equal to 2, and the spatio-temporal change characteristics of each light point of the dot scanning light field are determined according to the light source combination and the complex amplitude distribution after the light passes through the meta-surfaces of each region.

10. The method according to claim 9, wherein The complex amplitude distribution E of the metasurfaces in each region of the combined modulator of the multiple metasurfaces with sub-region modulation n is obtained by calculation through the formula: where x and y are the positions corresponding to each point on the metasurface, x m , y m are the corresponding coordinates of the lattice points, k n and ω n are the wave number and angular frequency of the light beam incident on the corresponding region, M is the number of lattice points of the target dynamic light field, f is the focal length corresponding to the focusing achieved by the metasurface, that is, the distance between the receiving surface and the metasurface, and T is the transformation period of the target dynamic light field.

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