Laser speckle inhibition element and application thereof

Abstract

Provided in the present application are a laser speckle inhibition element and application thereof. The laser speckle inhibition element comprises a substrate and a micro-nano array disposed on the substrate. The micro-nano array is divided into a plurality of partitions, and a micro-nano array corresponding to at least one of the plurality of partitions is different from micro-nano arrays corresponding to the remaining partitions, so as to reduce laser speckles and improve the definition of a laser image.

Description

Laser speckle suppression elements and their applications

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411977024.2, filed on December 26, 2024, entitled "Laser Speckle Suppression Element and Its Application", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of laser imaging, specifically to a laser speckle suppression element and its application. Background Technology

[0004] Lasers possess characteristics such as narrow linewidth, good polarization, and high brightness. Compared to projection systems using ordinary light sources (such as LEDs), laser projection offers a wider color gamut, higher color saturation, and lower energy consumption, and is currently used in laser cinemas, laser TVs, and micro-projection. Laser projection implementation methods include liquid crystal on silicon (LCOS), digital micromirror devices (DMD), and laser beam scanning (LBS). Different implementation methods have different requirements for the laser. LCOS and DMD use multimode lasers, allowing light incident on their surfaces to have a certain divergence angle, typically within ±10 degrees. LBS, however, requires a single-mode laser to achieve a smaller divergence angle to ensure image resolution. In LBS, due to the small required laser divergence angle and the strong coherence of lasers, when the laser irradiates a rough surface, reflected or transmitted light may randomly exhibit coherent enhancement or cancellation, producing laser speckle and affecting image clarity. Summary of the Invention

[0005] This application provides a laser speckle suppression element and its application to reduce laser speckle and improve the clarity of laser images.

[0006] In a first aspect, this application provides a laser speckle suppression element, which includes a substrate and a micro / nano array disposed on the substrate. The micro / nano array is divided into multiple partitions, and in the multiple partitions, the micro / nano array corresponding to at least one partition is different from the micro / nano arrays corresponding to the other partitions.

[0007] In this system, the micro-nano array in each partition either adjusts the phase or polarization of the incident laser, thereby altering the laser's transmission characteristics. At least one partition has a different micro-nano array than the others; that is, at least some partitions have different micro-nano arrays. These different partitions can produce different phase and polarization effects on lasers of the same frequency, thus changing the laser's phase or polarization.

[0008] Therefore, the laser speckle suppression element of this application, by making different micro-nano arrays between some partitions, can use different partitions to generate different phase adjustments or polarization adjustments on the incident laser light incident on the laser speckle suppression element, thereby reducing the coherence of the light transmitted or reflected from the laser speckle suppression element, thereby reducing speckle caused by the laser coherence characteristics and improving the image clarity of the laser on the imaging surface.

[0009] In one implementation, the partitions are rectangular or regular polygonal. The outer perimeter of the partitions is rectangular or regular polygonal, which facilitates the division of partitions and the fabrication of micro- and nano-arrays within each partition.

[0010] In one implementation, the micro / nano array comprises multiple spaced-apart microstructures, each with a periodic dimension smaller than the wavelength of the incident laser. The micro / nano array is a micro / nano columnar array and may include multiple microstructures. The periodic dimension of a single microstructure is the center-to-center distance between two adjacent microstructures. When the center-to-center distances of a microstructure differ from those of its adjacent microstructures along different directions, the maximum center-to-center distance can be smaller than the wavelength of the incident laser. For example, for a red laser with a wavelength of 639 nm, the periodic dimension of a single microstructure can be less than 700 nm. For a green laser with a wavelength of 520 nm, the periodic dimension of a single microstructure can be less than 520 nm. For a blue laser with a wavelength of 450 nm, the periodic dimension of a single microstructure can be less than 450 nm. When the periodic dimension of each microstructure is smaller than the wavelength of the incident laser, the micro / nano array is guaranteed to be in zero-order light transmission, i.e., the laser transmittance is greater than 80%, reducing the generation of secondary diffracted light.

[0011] In one implementation, the microstructures of the micro-nano array are arranged in a regular pattern, such as rectangular, square, or circular arrays. In another implementation, all microstructures within the micro-nano array are of the same size. During fabrication, the micro-nano arrays within each dimming zone can be fabricated individually. The regular arrangement of the micro-nano arrays and the identical size of each microstructure facilitates fabrication and reduces fabrication difficulty.

[0012] In one implementation, the height of the micro-nano array is the same across different partitions along the thickness direction of the substrate. Since the micro-nano arrays are micro- and nano-scale in size, if their heights differ, each microstructure would require individual etching or deposition during fabrication, increasing the processing darkness. Using the same height for the micro-nano arrays corresponding to different dimming partitions reduces the fabrication difficulty of the micro-nano arrays.

[0013] In one implementation, the micro / nano array is an array structure capable of adjusting the polarization state of light. Using this array structure to adjust the polarization state of laser light, a laser with one polarization state can be converted to another. In one implementation, the micro / nano array can be at least one of a grating, an elliptical cylindrical array, or an irregularly shaped cylindrical array. When the micro / nano array is a grating, an elliptical cylindrical array, or an irregularly shaped cylindrical array, adjustment of the laser polarization state can be achieved.

[0014] In one implementation, the micro / nano array is a grating, and the micro / nano array corresponding to at least one of the partitions differs from the micro / nano arrays corresponding to the other partitions, including: the torsion angle of the grating differs between the different partitions in a plane perpendicular to the substrate thickness direction. The micro / nano array is a grating structure, and by using the grating to adjust the laser, the polarization state of the laser can be changed. When the entire laser speckle suppression element is composed of gratings with different torsion angles arranged in partitions, different polarization states can be formed in the laser incident on the laser speckle suppression element, thereby reducing laser interference and the formation of laser speckle.

[0015] In one implementation, the gratings have the same spacing. Having the same grating spacing across different sections reduces fabrication difficulty.

[0016] In one optional implementation, the micro / nano array is an elliptical cylindrical array or an irregular cylindrical array. The micro / nano array corresponding to at least one of the partitions differs from the micro / nano arrays corresponding to the other partitions, including: in a plane perpendicular to the substrate thickness direction, the torsion angles of the elliptical cylindrical array or irregular cylindrical array differ between the different partitions. The micro / nano array is an elliptical cylindrical array structure or an irregular cylindrical array structure. By using the elliptical cylindrical array or irregular cylindrical array to adjust the laser, the polarization state of the laser can be changed. When the entire laser speckle suppression element is composed of elliptical cylindrical arrays or irregular cylindrical arrays with different torsion angles arranged in partitions, different polarization states can be formed in the laser incident on the laser speckle suppression element, thereby reducing laser interference and reducing the formation of laser speckle. The orthographic projection of the microstructure in the irregular cylindrical array onto the substrate is an asymmetrical irregular shape.

[0017] In one alternative implementation, the elliptical cylinders in the elliptical cylindrical array have the same radial dimension; or, the irregularly shaped cylinders in the irregularly shaped cylinder array have the same radial dimension. Having the same radial dimension for either the elliptical cylinders or the irregularly shaped cylinders reduces the difficulty of manufacturing.

[0018] In one implementation, the micro / nano array is an array structure capable of phase adjustment of light. Using this array structure to achieve phase adjustment of laser light, a laser with a certain phase can be adjusted to a laser with other phases. In one implementation, the micro / nano array is at least one of a cylindrical array or a regular polygonal column array. When the micro / nano array is a cylindrical array or a regular polygonal column array, phase adjustment of the laser light can be achieved.

[0019] In one optional implementation, the micro / nano array is a cylindrical array or a regular polygonal column array. The micro / nano array corresponding to at least one of the partitions differs from the micro / nano arrays corresponding to the other partitions, including: in a plane perpendicular to the substrate thickness direction, the cylindrical arrays differ between different partitions; or, in a plane perpendicular to the substrate thickness direction, the regular polygonal column arrays differ between different partitions. The micro / nano array is a cylindrical array or a regular polygonal column array structure. By using the cylindrical array or the regular polygonal column array to adjust the laser, the phase of the laser can be changed. When the entire laser speckle suppression element is composed of partitioned cylindrical arrays or regular polygonal column arrays with different phases, the laser incident on the laser speckle suppression element can form different phases, thereby reducing laser interference and the formation of laser speckle.

[0020] In one optional implementation, the different cylindrical arrays or the different regular polygonal column arrays between the different partitions include: different densities of cylinders in the cylindrical arrays between different partitions; or, different densities of regular polygonal columns in the regular polygonal column arrays between different partitions. By setting different cylinder densities or regular polygonal column densities, different phases of transmitted or reflected laser light are generated through different partitions, thereby achieving laser phase adjustment.

[0021] In another optional implementation, the density of cylinders in the cylindrical array differs between the different partitions, including: different spacing between cylinders in the cylindrical array between different partitions; and / or different radial dimensions of cylinders in the cylindrical array between different partitions. The cylinder density in the cylindrical array can be adjusted by adjusting the spacing or radial dimension of the cylinders. Furthermore, the radial dimension of the cylinders between different partitions can significantly affect the phase of the laser; therefore, different partitions can be formed using cylindrical arrays of different diameters.

[0022] In another alternative implementation, the density of the regular polygonal columns in the regular polygonal column array differs between the different partitions, including:

[0023] The spacing between the regular polygonal pillars in the regular polygonal pillar array differs between different partitions; and / or, the radial dimensions of the regular polygonal pillars in the regular polygonal pillar array differ between different partitions. The density of the regular polygonal pillars in the regular polygonal pillar array can be adjusted by adjusting the spacing or the radial dimensions of the regular polygonal pillars. Furthermore, the radial dimensions of the regular polygonal pillars between different partitions can significantly affect the phase of the laser; therefore, different partitions can be formed using regular polygonal pillar arrays of different sizes.

[0024] In one implementation, the laser speckle suppression element includes at least two partitions with different micro / nano arrays, wherein at least one partition's micro / nano array is an array structure capable of adjusting the polarization state of light, and at least one partition's micro / nano array is an array structure capable of adjusting the phase of light. Using this combined structure, both polarization state adjustment and phase adjustment of the laser can be achieved simultaneously.

[0025] In one optional implementation, the micro / nano array is divided into at least two partitions with different micro / nano arrays, wherein at least one of the micro / nano arrays in the partition is at least one of a grating, an elliptical cylindrical array, or an irregular cylindrical array; and at least one of the micro / nano arrays in the partition is at least one of a cylindrical array or a regular polygonal cylindrical array. By simultaneously incorporating micro / nano arrays with gratings, elliptical cylindrical arrays, or irregular cylindrical arrays, as well as micro / nano arrays with cylindrical arrays or regular polygonal cylindrical arrays, the polarization and phase of the laser can be simultaneously adjusted, further reducing interference between laser beams and minimizing laser speckle.

[0026] In one alternative implementation, the micro / nano array contains at least two partitions with elliptical cylindrical arrays, the twist angles of the elliptical cylindrical arrays differing between the different partitions. By setting at least two partitions with elliptical cylindrical arrays having different twist angles, at least two polarization states of the incident laser can be adjusted, thereby further weakening the intensity of the laser speckle.

[0027] In one alternative implementation, the micro / nano array contains at least two partitions with elliptical cylindrical arrays, wherein the radial dimensions of the elliptical cylinders in the elliptical cylindrical arrays differ between the different partitions. By setting at least two partitions with elliptical cylindrical arrays of different radial dimensions, at least two polarization states of the incident laser can be adjusted, thereby further weakening the intensity of the laser speckle.

[0028] In one alternative implementation, the micro / nano array contains at least two partitions with cylindrical arrays, wherein the radial dimensions or spacing of the cylinders in the cylindrical array differs between the different partitions. By setting at least two partitions with cylindrical arrays having different radial dimensions or different spacings, at least two phase adjustments can be made to the incident laser, thereby further weakening the intensity of the laser speckle.

[0029] Secondly, this application provides a laser speckle eliminator, which includes a housing and a laser speckle suppression element of this application disposed within the housing.

[0030] The laser speckle eliminator of this application, by incorporating the laser speckle suppression element described herein, can transmit or reflect incident laser light when used in a laser display system. The laser light transmitted or reflected by the laser speckle suppression element has different phases and polarization states, reducing interference and thus decreasing laser correlation. Consequently, the speckle generated at the display screen is weakened or eliminated.

[0031] Thirdly, this application provides a laser projection device, which includes a laser light source and a laser speckle suppression element of this application, wherein the laser light source and the laser speckle suppression element are spaced apart.

[0032] The laser emitted by the laser source can be emitted outward after passing through a laser speckle suppression element to reduce the correlation of the laser.

[0033] Laser projection equipment can include, for example, laser projectors, laser projection pens, and laser projection drones.

[0034] Fourthly, this application provides a laser imaging system, which includes a laser source, a display screen, and a laser speckle suppression element of this application. The laser speckle suppression element is disposed between the laser source and the display screen, and the laser emitted by the laser source is transmitted or reflected by the laser speckle suppression element and then projected onto the display screen.

[0035] The laser imaging system of this application uses a laser source to emit laser light and a display screen to receive it. A laser speckle suppression element is disposed between the laser source and the display screen to transmit or reflect the laser light emitted by the laser source. The laser light transmitted or reflected by the laser speckle suppression element has different phases and polarization states, reducing interference and thus decreasing laser correlation. This weakens or eliminates the speckle generated at the display screen. Attached Figure Description

[0036] Figure 1 is a schematic diagram of a laser imaging system provided in an embodiment of this application;

[0037] Figure 2 is a schematic diagram of the structure of a laser speckle suppression element in transmission mode according to an embodiment of this application;

[0038] Figure 3 is a schematic diagram of the structure of a laser speckle suppression element in reflection mode according to an embodiment;

[0039] Figure 4 is a top view of a micro-nano array structure;

[0040] Figure 5 is a schematic diagram of the laser speckle suppression element with a single grating adjusting the polarization state of the laser.

[0041] Figure 6 is a schematic diagram of the laser speckle suppression element adjusting the polarization state of the laser according to an embodiment of this application;

[0042] Figure 7 is a schematic diagram of the structure of a micro-nano array according to another embodiment of this application;

[0043] Figure 8 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light in one embodiment;

[0044] Figure 9 is a schematic diagram of the structure of a micro-nano array according to another embodiment of this application;

[0045] Figure 10 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light in one embodiment;

[0046] Figure 11 is a schematic diagram of the structure of a micro-nano array according to another embodiment of this application;

[0047] Figure 12 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light in one embodiment.

[0048] Reference numerals: 01-Laser source; 02-Collimating lens; 03-Laser speckle suppression element; 04-Display screen; 10-Substrate; 20-Dimming zone; 20a-First dimming zone; 20b-Second dimming zone; 20c-Third dimming zone; 20d-Fourth dimming zone; 30-Reflective film. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0050] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0051] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0052] In laser imaging systems, especially in LBS imaging systems, due to the strong coherence characteristics of lasers, laser speckle can easily appear on the imaging surface due to the random coherence of the laser, thus affecting the imaging quality.

[0053] Figure 1 illustrates a laser imaging system. As shown in Figure 1, the laser imaging system includes a laser source 01 and a display screen 04. To achieve parallel light transmission, a collimating lens 02 can be disposed between the laser source 01 and the display screen 04. Furthermore, to reduce coherence enhancement or attenuation of the laser light on the display screen 04, the laser imaging system of this embodiment also includes a laser speckle suppression element 03. The laser speckle suppression element 03 can be disposed between the laser source 01 and the display screen 04. When the laser imaging system includes a collimating lens, the laser speckle suppression element 03 can also be disposed between the collimating lens 02 and the display screen 04. The light transmitted or reflected by the laser speckle suppression element 03 converges on the display screen 04 to form the desired display content.

[0054] Figure 2 is a schematic diagram of the structure of a laser speckle suppression element in transmission mode according to an embodiment of this application. As shown in Figure 2, the laser speckle suppression element 03 of this embodiment may include a substrate 10 and a micro / nano array disposed on the substrate 10. The micro / nano array may be divided into multiple partitions. Each partition has a different effect on the laser to adjust the polarization or phase of the laser. For ease of understanding, each partition will be referred to as a dimming partition 20 below.

[0055] In the laser speckle suppression element 03, the number of dimming zones 20 divided by the micro-nano array can be greater than or equal to 2, or greater than or equal to 4, or greater than or equal to 5, or greater than or equal to 10. Exemplarily, the number of dimming zones 20 can be 2-100. Each dimming zone 20 can be a rectangular or square structure. Multiple dimming zones 20 can be arranged in a matrix on the surface of the substrate 10. The dimming zones 20 can be tightly connected to prevent the laser from directly penetrating the substrate 10 between the dimming zones 20 and irradiating the display screen, causing speckle. In one embodiment, multiple dimming zones 20 are tightly connected.

[0056] Referring again to Figure 2, the micro-nano array corresponding to each dimming zone 20 either adjusts the phase or polarization of the incident laser, thereby changing the transmission characteristics of the laser. In the laser speckle suppression element 03 of this application embodiment, among the multiple dimming zones 20, the micro-nano array corresponding to at least one dimming zone 20 is different from the micro-nano arrays corresponding to the remaining dimming zones 20. That is, the micro-nano arrays are different between at least some of the dimming zones 20. In one embodiment, the micro-nano arrays corresponding to each dimming zone 20 in the laser speckle suppression element 03 are all different. Since different dimming zones 20 have different micro-nano arrays, and different dimming zones 20 have different phase and polarization effects on lasers of the same frequency, they can change the phase or polarization of the laser. Therefore, the laser speckle suppression element 03 of this application, by setting dimming zones 20 with different micro-nano arrays, can utilize different dimming zones 20 to generate different phase adjustments or polarization adjustments on the incident laser light incident on the laser speckle suppression element 03, thereby reducing the coherence of the light transmitted from the laser speckle suppression element 03, thus reducing speckle caused by the laser coherence characteristics and improving the image clarity of the laser on the imaging surface. For example, a laser beam with phase 1 can form a phase 1 + phase 2 laser combination after passing through a dimming zone 20 in the laser speckle suppression element 03. And another laser beam with phase 1 can form a phase 1 + phase 3 laser combination after passing through another dimming zone 20 in the laser speckle suppression element 03. Thus, lasers with different phase combinations can be received at the display screen 04.

[0057] In one embodiment of this application, the micro-nano arrays within each dimming zone 20 may have the same structure, while the structures of the micro-nano arrays corresponding to different dimming zones 20 may differ. Since the internal structure of each dimming zone 20 is identical, the effect of the laser on each part within each dimming zone 20 is the same. When the number of dimming zones 20 is large, a laser combination with more discrete polarization states and phases can be obtained. However, too many dimming zones 20 can also affect the laser divergence angle, making it too large. Therefore, in one embodiment of this application, the number of dimming zones 20 can be controlled to be 4-80, 6-70, or 9-60, etc. The specific number can be selected according to the specific application field and imaging requirements of the laser imaging system.

[0058] Figure 3 is a schematic diagram of the structure of a laser speckle suppression element in reflection mode according to an embodiment. As shown in Figure 3, the laser speckle suppression element 03 of this embodiment may include a substrate 10 and a micro / nano array, and may also include a reflective film 30 disposed between the substrate 10 and the micro / nano array. The reflective film 30 may be disposed on the surface of the substrate 10. After the laser irradiates the laser speckle suppression element 03, it is reflected by the reflective film 30 and re-enters the dimming zone 20. Similarly, in the laser speckle suppression element in reflection mode, the micro / nano array corresponding to each dimming zone 20 may generate phase adjustment or polarization adjustment on the incident laser, thereby changing the transmission characteristics of the laser. In the laser speckle suppression element 03 of this embodiment, at least some of the dimming zones 20 correspond to different micro / nano arrays. In one embodiment, the micro / nano arrays corresponding to each dimming zone 20 in the laser speckle suppression element 03 are all different. Since different dimming zones 20 have different micro / nano arrays, and different dimming zones 20 have different phase and polarization effects on lasers of the same frequency, the phase or polarization of the laser can be changed. Therefore, the laser speckle suppression element 03 of this application, by setting up dimming zones 20 with different micro-nano arrays, can use different dimming zones 20 to generate different phase adjustments or polarization adjustments on the incident laser light incident on the laser speckle suppression element 03, thereby reducing the coherence of the light reflected from the laser speckle suppression element 03, thereby reducing speckle caused by the laser coherence characteristics and improving the image clarity of the laser on the imaging surface.

[0059] Similarly, a laser beam with phase 1, after being reflected by a dimming zone 20 in the laser speckle suppression element 03, can form a laser combination of phase 1 and phase 2. Another laser beam with phase 1, after being reflected by another dimming zone 20 in the laser speckle suppression element 03, can form a laser combination of phase 1 and phase 3. Thus, lasers with different phase combinations can be received at the display screen 04.

[0060] In this embodiment, the orthographic projection of the dimming zone 20 onto the substrate 10 can be a rectangle or a regular polygon. The rectangular or regular polygonal shape of the outer periphery of the dimming zone 20 facilitates partitioning and processing.

[0061] As shown in Figures 2 and 3, in one embodiment, the micro-nano array includes multiple spaced microstructures. The microstructures in the micro-nano array corresponding to the same dimming zone 20 can be arranged regularly. For example, the microstructures in the same micro-nano array can be arranged in a rectangular array, a square array, a circular array, a ring array, etc. Here, this application embodiment does not limit the specific arrangement of the microstructures in the micro-nano array. In the thickness direction of the substrate 10, as shown in the z-direction in Figures 2 and 3, the height of the micro-nano array in the same dimming zone 20 is the same. In one embodiment, the height of the micro-nano arrays in different dimming zones 20 is the same. Since the micro-nano array is of micro-nano scale, if the height of the micro-nano array is different, it is necessary to perform etching or deposition processing on each microstructure individually during fabrication, increasing the processing difficulty. Using the same height for the adjustment microstructures corresponding to different dimming zones can reduce the processing difficulty of the micro-nano array.

[0062] In one embodiment, the micro / nano array is an array structure capable of adjusting the polarization state of light. Exemplarily, the array structure capable of adjusting the polarization state of light can be at least one of a grating, an elliptical cylindrical array, or an irregularly shaped cylindrical array. Using this array structure to adjust the polarization state of laser light, laser light with one polarization state can be adjusted to laser light with other polarization states.

[0063] In another embodiment, the micro / nano array is an array structure capable of phase adjustment of light. Exemplarily, the array structure capable of phase adjustment of light can be at least one of a cylindrical array or a regular polygonal column array. The regular polygonal column array can be a regular triangular column array, a square column array, a regular hexagonal column array, etc. Using this array structure to achieve phase adjustment of laser light, a laser with a certain phase can be adjusted to a laser with other phases.

[0064] The following will provide a more detailed description of the specific structure of the micro / nano array in the embodiments of this application and the influence of laser polarization state and phase, with reference to Figures 4 to 12.

[0065] Example 1

[0066] Figure 4 is a top view of a micro / nano array, i.e., a schematic diagram of the structure obtained by observing the micro / nano array along the direction perpendicular to the substrate 10. As shown in Figure 4, the micro / nano array in each dimming zone 20 is a grating. In this embodiment, the grating can be a micro / nano grating array. The gaps between the gratings are perpendicular to the substrate 10. Referring also to Figure 2, for the transmission-type laser speckle suppression element 03, the laser is incident from the other side of the substrate 10, passes through the substrate 10, and exits from the gaps between the gratings. In the plane perpendicular to the thickness direction of the substrate 10, the torsion angles of the gratings corresponding to at least two dimming zones 20 are different. That is, the micro / nano array corresponding to at least one dimming zone 20 is different from the micro / nano arrays corresponding to the other dimming zones 20. When observed from the angle shown in Figure 4, in this embodiment, the torsion angles of the gratings in all different dimming zones 20 are different. The torsion angle of the grating is: taking a straight line as a reference line, the angle between each grating and this straight line is different.

[0067] The following explanation uses four dimming zones as shown in Figure 4 as an example. These four dimming zones 20 are designated as the first dimming zone 20a, the second dimming zone 20b, the third dimming zone 20c, and the fourth dimming zone 20d. Using the x-direction shown in Figure 4 as a reference line, the angle between the grating in the first dimming zone 20a and the x-direction is a1, the angle between the grating in the second dimming zone 20b and the x-direction is a2, the angle between the grating in the third dimming zone 20c and the x-direction is a3, and the angle between the grating in the fourth dimming zone 20d and the x-direction is a4. The values ​​of a1, a2, a3, and a4 are all different. Taking the positive x-direction as an example, the values ​​of a1, a2, a3, and a4 are each independently selected from 0-360°.

[0068] It is understandable that when the laser speckle suppression element 03 includes more dimming zones 20, the twist angle of the grating in each dimming zone 20 is different, thereby obtaining lasers with more polarization states and further reducing speckle formation.

[0069] In this embodiment, the gap width of the gratings in the micro / nano array can be the same or different in different dimming zones 20. For ease of fabrication, in one optional embodiment, the gap width of the gratings is the same across different dimming zones 20. To further obtain lasers with more different polarization states, in another optional embodiment, the gap width of the gratings can be different across different dimming zones 20.

[0070] Within the same dimming zone 20, the gap width of the gratings is the same. Furthermore, along the arrangement direction of the grating gaps, the width of each grating is identical. Using the same structure within the same dimming zone 20 reduces the laser divergence angle, allowing the laser to propagate within a certain range and preventing excessive laser divergence from affecting image clarity.

[0071] To reduce the generation of diffracted light, in each dimming zone 20, the periodic size of a single microstructure in the grating can be smaller than the wavelength of the incident laser. In the grating, the microstructure is a fence. As shown in Figure 4, the periodic size of a single microstructure is the center distance h between adjacent fences. For example, for a red laser with a wavelength of 639 nm, the periodic size of a single microstructure in the grating can be less than 700 nm. For a green laser with a wavelength of 520 nm, the periodic size can be less than 520 nm. For a blue laser with a wavelength of 450 nm, the periodic size can be less than 450 nm. When the periodic size of each microstructure is smaller than the wavelength of the incident laser, the micro / nano array is guaranteed to be in zero-order light transmission, i.e., the laser transmittance is greater than 80%, reducing the generation of secondary diffracted light.

[0072] When the laser speckle suppression element is used in a scenario involving multiple lasers of different wavelengths, the periodic size of a single microstructure in the grating should be smaller than the wavelength of the smallest laser. For example, when the laser speckle suppression element needs to adjust red, blue, and green lasers simultaneously, the periodic size of a single microstructure in the grating should be less than 450 nm.

[0073] In the direction perpendicular to the substrate 10, the grating height (such as the dimension along the z direction in Figure 2) can be close to the wavelength of the laser, such as 0.1-10 times the laser wavelength, or 1-3 times the laser wavelength.

[0074] To illustrate the effectiveness of the laser speckle suppression element of this application, the following comparative experiments are provided.

[0075] Figure 5 is a schematic diagram illustrating the adjustment of the laser polarization state by a single-grating laser speckle suppression element. As shown in Figure 5, the laser speckle suppression element 03 includes a grating with a twisted angle. When a laser beam with a single polarization direction passes through the single-direction micro / nano grating shown in Figure 5, the emitted laser beam remains linearly polarized, but its polarization direction has rotated by 90°. At this point, the micro / nano grating is equivalent to a half-wave plate. The laser beam obtained after passing through this grating still possesses strong coherence characteristics, and the intensity of the laser speckle does not change significantly.

[0076] Figure 6 is a schematic diagram of the laser speckle suppression element adjusting the polarization state of the laser according to an embodiment of this application. As shown in Figure 6, the laser speckle suppression element 03 includes gratings with various twist angles. When a laser with a single polarization direction passes through the multi-directional micro / nano grating array shown in Figure 6, the polarization state distribution of the emitted laser becomes a combination of random polarization states. At this time, the micro / nano gratings are equivalent to a half-wave plate array with the optical axis along different directions. After passing through this micro / nano grating array, the laser becomes a laser with a random combination of polarization states, and its coherence will be significantly reduced. The laser speckle caused by the laser coherence characteristics will also be reduced accordingly.

[0077] Therefore, it can be seen that using dimming zones with different grating arrays to form a laser speckle suppression element will cause random perturbations to the polarization state of the incident laser, resulting in a disordered distribution of the polarization state of the emitted laser. This reduces the coherence of the emitted laser and decreases speckle formation. The laser speckle suppression element of the present application embodiment can achieve static speckle suppression without multi-order diffraction, and the divergence angle of the emitted light can be effectively controlled.

[0078] Example 2

[0079] Figure 7 is a schematic diagram of the structure of a micro / nano array according to another embodiment of this application. As shown in Figure 7, the micro / nano array corresponding to each dimming zone 20 in the laser speckle suppression element 03 has an elliptical cylindrical array. Referring also to Figure 2, in the elliptical cylindrical array, the orthographic projection of each elliptical cylinder onto the substrate 10 is elliptical. The elliptical cylindrical array is formed by arranging elliptical cylinders according to certain rules. For example, multiple elliptical cylinders are arranged in a rectangular array. In addition, multiple elliptical cylinders can also be arranged in a circular array, annular array, or square array, without specific limitations here.

[0080] The elliptical cylinder array is a micro / nano elliptical cylinder array. In this array, the radial dimension of the elliptical cylinders can be at the micro / nano scale. The spacing between the elliptical cylinders can also be at the micro / nano scale. The height of the elliptical cylinders, i.e., the dimension in the direction perpendicular to the substrate (10), can be close to the wavelength of the laser, such as 0.1-10 times the laser wavelength, or 1-3 times the laser wavelength.

[0081] Referring to Figure 7, in the plane perpendicular to the substrate thickness direction, i.e., in the observation plane shown in Figure 7, at least some of the different dimming zones 20 have different torsion angles in their corresponding elliptical cylindrical arrays. That is, the elliptical cylindrical array corresponding to at least one dimming zone 20 is different from the elliptical cylindrical arrays corresponding to the other dimming zones 20. For example, the torsion angles of the elliptical cylindrical arrays are different between different dimming zones 20. The torsion angle of the elliptical cylindrical array can be the angle between the major axis direction of the elliptical cylinder and a specific straight line. Taking the orientation shown in Figure 7 as an example, with the x-direction shown in Figure 7 as the reference straight line, the angle between the major axis direction of the elliptical cylinder in each dimming zone 20 and the x-direction is the torsion angle.

[0082] Laser light is incident on dimming zone 20 and interacts with the elliptical cylindrical array. The polarization state of the emitted laser light is affected by the twist angle of the elliptical cylindrical array, thus changing the polarization state of the emitted light. Because the twist directions of the elliptical cylindrical arrays in the multiple dimming zones 20 are different, the polarization state of the laser light incident on the laser speckle suppression element also changes randomly. This transforms the initially single polarization state of the laser light into a combination of various randomly polarized states through the laser speckle suppression element. After the laser light becomes a combination of randomly polarized states, its coherence is significantly reduced, and the laser speckle caused by the laser coherence characteristics is also reduced accordingly.

[0083] In this system, the radial dimensions of the elliptical cylinders in the elliptical cylindrical array can be the same or different between different dimming zones (20). Elliptical cylinders with different radial dimensions have different effects on the polarization state of the laser. When the radial dimensions of the elliptical cylinders in the elliptical cylindrical array differ between different dimming zones, more random polarization states of laser light can be generated for a single polarization state. When the radial dimensions of the elliptical cylinders in the elliptical cylindrical array corresponding to different dimming zones are the same, the adjustment of the polarization state of the laser is mainly affected by the number of dimming zones, but this arrangement is more convenient for processing different adjustment modules.

[0084] Within the same dimming zone 20, all elliptical cylinders in the elliptical cylindrical array are of the same size and arranged at the same spacing. Using identical structures within the same dimming zone reduces the laser divergence angle, allowing the laser to propagate within a certain range and preventing excessive divergence that could affect image clarity.

[0085] To reduce diffraction, in each dimming zone 20, the periodic dimension of a single microstructure in the elliptical cylindrical array is smaller than the wavelength of the incident laser. In the elliptical cylindrical array, the microstructure is an elliptical cylinder. The periodic dimension of a single microstructure is the center-to-center distance between adjacent elliptical cylinders. In one embodiment, the spacing between the elliptical cylinders in the elliptical cylindrical array is the same in both the x and y directions. Therefore, the periodic dimension of a single microstructure is also the same in all directions. In this case, the periodic dimension of a single microstructure is the center-to-center distance between adjacent elliptical cylinders. When the spacing between the elliptical cylinders in the x and y directions is different, the periodic dimension of a single microstructure is the center-to-center distance between the nearest adjacent elliptical cylinders.

[0086] For example, for red lasers with a wavelength of 639 nm, the periodic size of a single microstructure can be less than 700 nm. For green lasers with a wavelength of 520 nm, the periodic size of a single microstructure can be less than 520 nm. For blue lasers with a wavelength of 450 nm, the periodic size of a single microstructure can be less than 450 nm. When the periodic size of each microstructure is smaller than the wavelength of the incident laser, it can be ensured that the micro / nano array is in zero-order light transmission, that is, the laser transmittance is greater than 80%, reducing the generation of secondary diffracted light.

[0087] Figure 8 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light according to one embodiment. Specifically, Figure 8(a) shows the effect of the micro / nano array on blue light; Figure 8(b) shows the effect of the micro / nano array on green light; and Figure 8(c) shows the effect of the micro / nano array on red light.

[0088] As shown in Figure 8, a micro-nano-scale elliptical cylindrical array structure was designed for 450nm blue laser, 520nm green laser, and 639nm red laser. The laser interacts with the elliptical cylindrical array, and the polarization state of the emitted laser is affected by the twist angle of the elliptical cylindrical array. Specifically, the ratio of the transverse electric polarization (TE) polarization state and the transverse magnetic mode (TM) polarization state of the emitted light changes with the twist angle of the elliptical cylinder, thereby causing the polarization state of the emitted light to change accordingly.

[0089] Taking the green light fluctuations in Figure 8 as an example, as the twist angle of the elliptical cylindrical array changes, the laser in the TE polarization state first decreases and then increases, while the laser in the TM polarization state first increases and then decreases. This demonstrates that changes in the twist angle of the elliptical cylindrical array affect the formation of lasers with different polarization state combinations.

[0090] The test pattern shown in Figure 8 is an exemplary design obtained by applying an elliptical cylindrical array to a dimming zone for 450nm, 520nm, and 639nm lasers. Changing the size of the elliptical cylindrical array can further influence the polarization state of the laser. Similarly, for lasers of other wavelengths, optimization can be achieved by modifying the design of the elliptical cylindrical array structure.

[0091] It is understood that the gratings and elliptical cylindrical arrays involved in the dimming partitions in the embodiments of this application are merely illustrative examples, and other various irregular cylindrical microstructures, such as crescent-shaped arrays, can also influence the laser polarization state. Any array structure that can influence the laser polarization state should be understood as being within the scope of protection of this application.

[0092] Example 3

[0093] Figure 9 is a schematic diagram of the structure of a micro / nano array according to another embodiment of this application. As shown in Figure 9, the micro / nano array corresponding to each dimming zone 20 in the laser speckle suppression element 03 is a cylindrical array. In the cylindrical array, the orthogonal projection of each cylinder on the substrate is circular. The cylindrical array is formed by arranging cylinders according to certain rules. For example, multiple cylinders are arranged in a rectangular array. In addition, multiple cylinders can also be arranged in a circular array, annular array, or square array, without specific limitations.

[0094] The cylindrical array is a micro / nano cylindrical array. In the cylindrical array, the radial dimension of the cylinders can be at the micro / nano scale. The spacing between the cylinders can also be at the micro / nano scale. The height of the cylinders, i.e., the dimension in the direction perpendicular to the substrate, can be close to the wavelength of the laser, such as 0.1-10 times the laser wavelength, or 1-3 times the laser wavelength.

[0095] Referring to Figure 9, in the plane perpendicular to the substrate thickness direction, i.e., in the observation plane shown in Figure 9, at least some of the cylindrical arrays corresponding to different dimming zones 20 are different. That is, the cylindrical array corresponding to at least one dimming zone 20 is different from the cylindrical arrays corresponding to the remaining dimming zones 20. Exemplarily, the cylindrical arrays corresponding to different dimming zones 20 are all different. Exemplarily, the density of the cylinders in the cylindrical arrays corresponding to different dimming zones 20 is different. To obtain cylindrical arrays of different densities, the radial dimensions and spacing of the cylinders in the cylindrical array can be changed. For example, in one embodiment, the spacing between the cylinders in the cylindrical arrays corresponding to different dimming zones 20 is different. In another embodiment, the radial dimensions of the cylinders in the cylindrical arrays corresponding to different dimming zones 20 are different.

[0096] Because the cylinders in a cylindrical array are isotropic in their radial dimensions, the phase of a laser beam is affected when it passes through the isotropic array. However, the polarization state of the laser remains almost unaffected. Therefore, by changing the density of the cylindrical array, combinations of laser beams with random phases can be generated.

[0097] In the same dimming zone 20, all cylinders in the cylindrical array are of the same size and arranged at the same spacing. The identical structure within the same dimming zone 20 reduces the laser divergence angle, allowing the laser to propagate within a certain range and preventing excessive laser divergence from affecting image clarity.

[0098] To reduce diffraction, in each dimming zone 20, the periodic dimension of a single microstructure in the cylindrical array is smaller than the wavelength of the incident laser. In the cylindrical array, the microstructures are cylinders. The periodic dimension of a single microstructure is the center-to-center distance between adjacent cylinders. In one embodiment, the cylindrical array is arranged in a rectangular pattern, where the cylinders are spaced the same in both the x and y directions. Therefore, the periodic dimension of a single microstructure is also the same in all directions. In this case, the periodic dimension of a single microstructure is the center-to-center distance between adjacent cylinders. When the cylindrical array is arranged in a rectangular pattern, the cylinders are spaced differently in the x and y directions, and the periodic dimension of a single microstructure is the center-to-center distance between the nearest adjacent elliptical cylinders.

[0099] For example, for red lasers with a wavelength of 639 nm, the periodic size of a single microstructure can be less than 700 nm. For green lasers with a wavelength of 520 nm, the periodic size of a single microstructure can be less than 520 nm. For blue lasers with a wavelength of 450 nm, the periodic size of a single microstructure can be less than 450 nm. When the periodic size of each microstructure is smaller than the wavelength of the incident laser, it can be ensured that the micro / nano array is in zero-order light transmission, that is, the laser transmittance is greater than 80%, reducing the generation of secondary diffracted light.

[0100] Figure 10 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light according to one embodiment. Specifically, Figure 10(a) shows the effect of the micro / nano array on blue light; Figure 10(b) shows the effect of the micro / nano array on green light; and Figure 10(c) shows the effect of the micro / nano array on red light.

[0101] As shown in Figure 10, a micro-nano-scale cylindrical array structure was designed for 450nm blue laser, 520nm green laser, and 639nm red laser. The laser interacts with the cylindrical array, and the polarization state of the emitted laser is affected by the size of the cylinder in the cylindrical array. Specifically, the phase of the emitted light increases with the increase of the cylinder radius, which in turn causes the phase of the emitted light to change.

[0102] Taking the blue light wave in Figure 10 as an example, the phase of the laser increases with the increase of the cylinder's radius. This demonstrates that changes in the radial dimension of the cylinder affect the laser's phase. By setting up cylinder arrays with different densities, lasers with different phase combinations can be formed.

[0103] The test pattern shown in Figure 10 is an exemplary design obtained by adjusting the cylindrical array in the dimming zone for 450nm, 520nm, and 639nm lasers. Changing the radial dimensions of the cylindrical array can further influence the phase of the laser. Similarly, for lasers of other wavelengths, optimization can be achieved by modifying the design of the cylindrical array structure.

[0104] It is understood that the cylindrical array involved in the dimming partition in the embodiments of this application is only an illustrative example. The cylindrical array in the embodiments of this application may also be other microstructures that can produce different phase delays to affect the laser phase. Other types of microstructures that can produce different phase delays to the laser, such as regular polygonal column arrays, including, but not limited to, regular triangular column arrays, square column arrays, and regular hexagonal column arrays, should be understood to be within the scope of protection of this application.

[0105] When the cylindrical array in Figure 10 is replaced by a regular polygonal column array, the density of the regular polygonal columns in the arrays corresponding to different dimming zones will also differ. For example, the spacing between the regular polygonal columns in the arrays corresponding to different dimming zones will be different; and / or, the radial dimensions of the regular polygonal columns in the arrays corresponding to different dimming zones will be different. The specific design of the regular polygonal column array can be referenced from that of the cylindrical array, and will not be elaborated upon here.

[0106] Example 4

[0107] Figure 11 is a schematic diagram of the structure of a micro / nano array according to another embodiment of this application. As shown in Figure 11, the laser speckle suppression element 03 includes at least two dimming zones 20 with different micro / nano arrays. At least one dimming zone 20 has a micro / nano array capable of adjusting the polarization state of light, and at least one dimming zone 20 has a micro / nano array capable of adjusting the phase of light. Exemplarily, the micro / nano array is divided into at least two dimming zones 20 with different micro / nano arrays, wherein at least one dimming zone 20 has a micro / nano array that is at least one of a grating, an elliptical cylindrical array, or an irregular cylindrical array; and at least one dimming zone has a micro / nano array that is at least one of a cylindrical array or a regular polygonal cylindrical array. By setting dimming zones 20 with micro / nano arrays having different adjustment functions, various combinations of lasers with different polarization states and phases formed by a single laser can be further enabled, thereby further reducing the coherence of the laser and reducing speckle formation.

[0108] In one embodiment of the laser speckle suppression element 03, at least one dimming zone 20 has a micro / nano array with a grating or elliptical cylindrical array, and at least one dimming zone has a micro / nano array with a cylindrical array. The dimming zone with the grating or elliptical cylindrical array is used to adjust the laser polarization state. The dimming zone 20 with the cylindrical array is used to adjust the laser phase. When the laser speckle suppression element 03 includes both types of dimming zones 20, it can simultaneously adjust the polarization state and phase of the laser, obtaining combinations of lasers with various random polarization states and random phases.

[0109] In one embodiment, the laser speckle suppression element 03 includes at least two dimming zones 20 with elliptical cylindrical arrays, wherein the torsion angles of the elliptical cylindrical arrays corresponding to different dimming zones 20 are different. In another embodiment, the laser speckle suppression element 03 includes at least two dimming zones 20 with elliptical cylindrical arrays, wherein the radial dimensions of the elliptical cylinders in the elliptical cylindrical arrays corresponding to different dimming zones 20 are different.

[0110] In another embodiment, the laser speckle suppression element 03 includes at least two dimming zones 20 with cylindrical arrays, wherein the radial dimensions of the cylinders in the cylindrical arrays corresponding to different dimming zones 20 are different or the cylinder spacing is different.

[0111] The combination of different dimming zones in the above embodiments can further improve the diversity of laser polarization state and phase, and further reduce the formation of laser speckle.

[0112] Figure 12 is a schematic diagram illustrating the effect of a micro / nano array on the adjustment of blue, green, and red light according to one embodiment. Specifically, Figure 12(a) shows the effect of the micro / nano array on blue light; Figure 12(b) shows the effect of the micro / nano array on green light; and Figure 12(c) shows the effect of the micro / nano array on red light.

[0113] Figure 12 shows micro- and nano-arrays designed for 450nm blue lasers, 520nm green lasers, and 639nm red lasers. In Figure 12, the vertical axis represents the minor axis of the ellipse, and the horizontal axis represents the major axis. The interaction between the laser and the elliptical cylindrical array alters the laser's polarization state, as shown by the different shapes of TE and TM polarizations in Figure 12. The interaction between the laser and the cylindrical array changes the laser's phase, resulting in different color distributions and varying grayscale levels, as shown in Figure 12. By allowing the laser to interact with both the elliptical and cylindrical arrays, the polarization state of some lasers can be altered, while the phase of others can be changed. This allows for a more diverse range of laser beams, reduces interference, weakens speckle, and improves the imaging quality of the laser imaging system.

[0114] The test pattern shown in Figure 12 is an exemplary design obtained by using cylindrical arrays in dimming zones for 450nm, 520nm, and 639nm lasers. Changing the size design of the elliptical and cylindrical arrays can further influence the phase of the laser. Similarly, for lasers of other wavelengths, optimization can be achieved by modifying the design of the elliptical and cylindrical array structures.

[0115] The laser speckle suppression element of this application embodiment features a partitioned optical microstructure design to form different dimming zones. Each dimming zone has an identical internal structure, but the corresponding micro / nano arrays differ, such as grating twist angles, various sizes of elliptical cylindrical arrays, and various sizes of cylindrical arrays. This allows for adjustment of the incident laser phase, polarization, or a combination of polarization and phase, producing different effects and reducing laser coherence intensity, thus achieving static reduction of laser speckle intensity. In the laser speckle suppression element of this application embodiment, the period of a single microstructure in each dimming zone is smaller than the incident laser wavelength to ensure zero-order light transmission and prevent diffraction of other orders of light, avoiding multi-order diffraction. This allows for effective control of the outgoing light divergence angle, thereby improving the imaging and therapeutic effects of the imaging system.

[0116] In one embodiment, the laser speckle suppression element of this application can be manufactured by a method including the following steps:

[0117] A coating is deposited on the substrate surface to form dimming zones, and different micro / nano array structures are formed by etching the zones, thereby forming dimming zones with different micro / nano arrays.

[0118] For the same technical purpose, this application also provides a laser imaging system. The structure of the laser imaging system can be seen in Figure 1. The laser imaging system may include a laser source 01, a display screen 04, and a laser speckle suppression element 03 according to an embodiment of this application. The laser speckle suppression element 03 is disposed between the laser source 01 and the display screen 04. The laser emitted by the laser source 01 is transmitted or reflected by the laser speckle suppression element 03 and then projected onto the display screen 04. In one embodiment, a collimating lens 02 may also be disposed between the laser source 01 and the laser speckle suppression element 03.

[0119] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A laser speckle suppression element, characterized in that, It includes a substrate and a micro / nano array disposed on the substrate, the micro / nano array being divided into multiple partitions, wherein at least one of the partitions corresponds to a different micro / nano array than the micro / nano arrays corresponding to the other partitions.

2. The laser speckle suppression element according to claim 1, characterized in that, The partition is a rectangular partition or a regular polygonal partition.

3. The laser speckle suppression element according to claim 1 or 2, characterized in that, The height of the micro-nano array is the same along the thickness direction of the substrate.

4. The laser speckle suppression element according to any one of claims 1-3, characterized in that, The micro / nano array is at least one of a grating, an elliptical cylindrical array, or an irregular cylindrical array.

5. The laser speckle suppression element according to claim 4, characterized in that, The micro / nano array is a grating, and the micro / nano array corresponding to at least one of the partitions is different from the micro / nano arrays corresponding to the other partitions, including: In a plane perpendicular to the thickness direction of the substrate, the torsion angle of the grating differs between different partitions.

6. The laser speckle suppression element according to claim 5, characterized in that, The gratings have the same spacing.

7. The laser speckle suppression element according to claim 4, characterized in that, The micro / nano array is an elliptical cylindrical array or an irregular cylindrical array, and the micro / nano array corresponding to at least one of the partitions is different from the micro / nano arrays corresponding to the other partitions, including: Within a plane perpendicular to the thickness direction of the substrate, the torsion angles of the elliptical cylindrical array or the irregular cylindrical array differ between different partitions.

8. The laser speckle suppression element according to claim 7, characterized in that, The elliptical cylinders in the elliptical column array have the same radial dimension; or, the irregularly shaped cylinders in the irregularly shaped column array have the same radial dimension.

9. The laser speckle suppression element according to any one of claims 1-3, characterized in that, The micro / nano array is at least one of a cylindrical array or a regular polygonal cylindrical array.

10. The laser speckle suppression element according to claim 9, characterized in that, The micro / nano array is a cylindrical array or a regular polygonal cylindrical array, and the micro / nano array corresponding to at least one of the partitions is different from the micro / nano arrays corresponding to the other partitions, including: In a plane perpendicular to the thickness direction of the substrate, the cylindrical arrays or the regular polygonal cylindrical arrays are different between different partitions.

11. The laser speckle suppression element according to claim 10, characterized in that, The different cylindrical arrays or the different regular polygonal cylindrical arrays between the different partitions include: The density of cylinders in the cylindrical array differs between different partitions; or, the density of regular polygonal cylinders in the regular polygonal cylinder array differs between different partitions.

12. The laser speckle suppression element according to claim 11, characterized in that, The density of cylinders in the cylindrical array differs between the different partitions, including: The spacing between cylinders in the cylindrical array differs between different partitions; and / or, the radial dimensions of the cylinders in the cylindrical array differ between different partitions.

13. The laser speckle suppression element according to claim 11, characterized in that, The density of regular polygonal pillars in the regular polygonal pillar array differs between the different partitions, including: The spacing between the regular polygon columns in the regular polygon column array is different between different partitions; and / or, the radial dimensions of the regular polygon columns in the regular polygon column array are different between different partitions.

14. The laser speckle suppression element according to any one of claims 1-3, characterized in that, The micro-nano array is divided into at least two partitions with different micro-nano arrays, wherein at least one of the micro-nano arrays of the partition is at least one of a grating, an elliptical cylindrical array, or an irregular cylindrical array; and at least one of the micro-nano arrays of the partition is at least one of a cylindrical array or a regular polygonal cylindrical array.

15. The laser speckle suppression element according to claim 14, characterized in that, The micro / nano array contains at least two partitions with elliptical cylindrical arrays, and the torsion angle of the elliptical cylindrical arrays differs between the different partitions.

16. The laser speckle suppression element according to claim 14 or 15, characterized in that, The micro / nano array contains at least two partitions with elliptical cylindrical arrays, and the radial dimensions of the elliptical cylinders in the elliptical cylindrical arrays are different between different partitions.

17. The laser speckle suppression element according to any one of claims 14-16, characterized in that, The micro / nano array contains at least two partitions with cylindrical arrays, wherein the radial dimensions or the spacing between the cylinders in the cylindrical array differs between different partitions.

18. The laser speckle suppression element according to any one of claims 1-17, characterized in that, The micro-nano array comprises multiple spaced microstructures, each with a periodic dimension smaller than the wavelength of the incident light.

19. A laser speckle eliminator, characterized in that, It includes a housing and a laser speckle suppression element as described in any one of claims 1-18 disposed within the housing.

20. A laser projection device, characterized in that, It includes a laser source and a laser speckle suppression element as described in any one of claims 1-18, wherein the laser source and the laser speckle suppression element are spaced apart.

21. A laser imaging system, characterized in that, The device includes a laser source, a display screen, and a laser speckle suppression element as described in any one of claims 1-18, wherein the laser speckle suppression element is disposed between the laser source and the display screen, and the laser emitted by the laser source is transmitted or reflected by the laser speckle suppression element and then projected onto the display screen.

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