System and method for improving laser wireless energy transmission efficiency

Abstract

The invention provides a system and method for improving laser wireless energy transmission efficiency, and relates to the technical field of laser wireless energy transmission, the system comprises a transmitting end module, a receiving end module and a transmitting end module, the transmitting end module comprises a laser transmitting array formed by a plurality of independent lasers, and the distance between the lasers is adjustable to control a light beam edge overlapping area; the optical processing unit comprises a focus lens, a diaphragm and an off-axis paraboloid collimating lens which are sequentially arranged along a light path, and the off-axis paraboloid collimating lens is anticlockwise inclined by 45 degrees with a horizontal reference; and the receiving end module comprises a power ball receiver and an elliptical reflector arranged at the center of the power ball, two ends of a long axis of the elliptical reflector point to a laser incident port of the power ball, and an intersection point of the long axis and a short axis coincides with the center of the power ball. The output efficiency of the laser wireless energy transmission system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser wireless energy transmission, and specifically to a system and method for synergistically improving the efficiency of laser wireless energy transmission through incoherent multi-beam combining, off-axis collimation and beam expansion, and ellipsoidal reflection and light homogenization. Background Art

[0002] Laser wireless energy transmission is an advanced technology that uses high-energy lasers as a carrier to achieve wireless power transmission to remote devices through the spatial transmission and photoelectric conversion of electromagnetic waves. Compared with traditional wireless energy transmission methods, laser wireless energy transmission has significant advantages such as long transmission distance, strong directionality, and high energy density. Therefore, it has broad application prospects in aerospace, military equipment, deep-sea exploration and other fields. However, the technology still faces many technical bottlenecks in practical applications. For example, the electro-optical conversion efficiency of high-power lasers is low, the photoelectric conversion efficiency of laser cells is not high, there is significant collimation loss in long-distance transmission of lasers, the beam control accuracy is insufficient, and the light distribution at the receiving end is uneven. These problems all limit the further improvement of the system's transmission efficiency and output power.

[0003] To address the efficiency bottleneck in laser wireless energy transmission technology, researchers both domestically and internationally have proposed a series of improvements from various perspectives, including increasing laser power to ensure sufficient laser power at the receiving end; developing multi-junction photovoltaic cells to improve the photoelectric conversion efficiency of laser cells; optimizing system design to improve the matching between the transmitting laser and the receiving laser cell; and employing methods to uniformly distribute light at the receiving end to reduce circuit losses. These improvements, each with its own distinct focus, complement each other, providing diverse technical approaches to improving the efficiency and reliability of laser wireless energy transmission. However, in practical applications, none of these methods, used alone, can achieve the desired results. Summary of the Invention

[0004] In view of this, and to improve the output efficiency of a laser wireless energy transmission system, the present invention aims to provide a system and method for improving the efficiency of laser wireless energy transmission. At the transmitting end of the system, multiple low-power lasers are combined to produce an incoherent beam superposition effect, thereby achieving a high-power, high-conversion-efficiency light source. To reduce the divergence angle of the large-aperture beam formed after combining multiple beams, thereby reducing light losses caused by light transmission, a defocused parabolic beam expander is used to expand the combined laser beam into collimated light, addressing the problem of the small aperture of a transmission-type beam expander. A power sphere receiver is used as the receiving device at the receiving end, and an elliptical reflector is installed at the center of the power sphere to reflect the laser light incident on the power sphere. The ellipsoid's variable curvature reflective surface increases the illumination area of ​​the central light intensity and reduces the illumination area of ​​the edge light spot. This results in a light spot with a high intensity at the center having a lower power density after elliptical reflection, while a light spot with a weaker intensity at the edge having a higher power density after reflection. Ultimately, the entire inner surface of the power sphere is uniformly and directly illuminated. By comprehensively utilizing the above-mentioned technical means, a laser wireless energy transmission system with high transmission efficiency and high output power is achieved.

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

[0006] Based on the above objectives, in a first aspect, the present invention provides a system for improving the efficiency of laser wireless energy transmission, comprising the following components:

[0007] Transmitter module: A laser emission array composed of multiple independent lasers, with adjustable spacing between lasers to control the overlap area of ​​the beam edges;

[0008] Optical processing unit: including a focusing mirror, an aperture, and an off-axis parabolic collimator arranged in sequence along the optical path, wherein the off-axis parabolic collimator is tilted 45° counterclockwise with respect to the horizontal reference;

[0009] Receiving end module: includes a power ball receiver and an elliptical reflector placed at the center of the power ball. The two ends of the long axis of the elliptical reflector point to the laser incident port of the power ball, and the intersection of the long axis and the short axis coincides with the center of the power ball.

[0010] As a further solution of the present invention, the laser emission array includes at least 8 independent lasers, and the distance between adjacent lasers can be adjusted forward and backward to control the spot superposition area and realize the energy superposition of incoherent edge spots.

[0011] As a further solution of the present invention, the curvature of the elliptical reflector gradually decreases from the major axis end point to the minor axis end point, so that the irradiation area of ​​the high-power density light spot incident on the major axis end point increases after reflection, and the irradiation area of ​​the low-power density light spot incident on the minor axis end point decreases after reflection.

[0012] As a further solution of the present invention, the system for improving the efficiency of laser wireless energy transmission includes two sets of symmetrically arranged transmitting end modules, and the laser beams output by the two modules realize edge spot superposition at the central vertical point position on the inner surface of the power sphere.

[0013] As a further solution of the present invention, the optical processing unit further includes a Fresnel lens, which is arranged on the transmission light path of the off-axis parabolic collimator, and the tooth-shaped structure is one of rectangular, trapezoidal or arc-shaped.

[0014] As a further solution of the present invention, the power ball receiver is composed of a plurality of photovoltaic cells assembled into a spherical structure, and the surface of the elliptical reflector is coated with a high-reflection film that matches the laser wavelength.

[0015] As a further solution of the present invention, the reflecting surface of the off-axis parabolic collimating mirror is an off-axis intercepted portion of the parent parabola, and the focal length range is 55 mm to 200 mm.

[0016] In a second aspect, the present invention provides a method for improving the efficiency of laser wireless energy transmission, comprising the following steps:

[0017] Step S1: By adjusting the spatial positions of multiple independent lasers, the edge spots of each laser beam are controlled to be incoherently superimposed in the transmission path to form a uniform light intensity distribution;

[0018] Step S2: using an off-axis parabolic collimator to expand and collimate the superimposed combined light beams, wherein the off-axis parabolic collimator is placed at a 45° counterclockwise tilt relative to a horizontal reference;

[0019] Step S3: using an elliptical reflector to reflect and homogenize the laser light incident into the power sphere, so that the high-power density spot irradiated at the end point of the long axis is reflected to increase the irradiation area, and the low-power density spot irradiated at the end point of the short axis is reflected to reduce the irradiation area;

[0020] Step S4: Using two symmetrically incident laser beams, edge light spot superposition is achieved at the central vertical point on the inner surface of the power sphere to eliminate light intensity differences.

[0021] As a further solution of the present invention, in step S1, the size of the overlapping area of ​​the edge light spots is controlled by dynamically adjusting the front-to-back spacing of adjacent lasers so that the light intensity of the overlapping area reaches more than 90% of the intensity of the central light spot.

[0022] As a further solution of the present invention, in step S2, an aperture is provided at the entrance of the optical path of the off-axis parabolic collimator to filter out the low-intensity edge light spots that are not superimposed in the combined light spots.

[0023] As a further solution of the present invention, in step S3, the major axis / minor axis intersection of the elliptical reflector coincides with the center of the power sphere, and both ends of the major axis point to the laser incident port, and the curvature gradually decreases from the major axis end point to the minor axis end point.

[0024] As a further solution of the present invention, between step S2 and step S3, the method further includes: using a Fresnel lens to compress the large light spot after long-distance transmission into the incident aperture of the power ball, and the tooth structure of the Fresnel lens is one of rectangular, trapezoidal or arc-shaped.

[0025] As a further solution of the present invention, in step S4, the axis angle between the two symmetrical incident lasers is 90°-180°, and the edge spot overlap rate at the vertex of the power sphere is greater than 80%.

[0026] Compared with the existing technology, the system and method for improving the efficiency of laser wireless energy transmission proposed in the present invention have the following beneficial effects:

[0027] 1. The present invention controls the front, back, left, and right positions and combinations of lasers to coordinate the emission of multiple lasers, forming a combined superposition of incoherent multiple light beams, breaking through the output limitations of a single laser. During the transmission process, the edge light spots of each light spot are superimposed on each other through the light superposition method, thereby increasing the light intensity around the beam, ensuring that the beam has a uniform intensity distribution in a specific area, and thus improving the light transmission efficiency.

[0028] 2. The present invention utilizes the large aperture and defocus characteristics of the off-axis parabolic collimator to solve the problem that the traditional transmission-type beam expander has a small incident aperture and cannot collimate the large spot after superimposing and combining multiple lasers. It reduces the divergence angle of the light beam during laser wireless energy transmission and reduces the transmission loss of the laser in the air.

[0029] 3. The present invention uses an aperture at the rear end of the proximal focusing mirror to block the non-overlapping light spots at the edge of the combined light spot, thereby reducing the adverse effects of the non-overlapping light spots on the uniformity of the light field on the receiving surface, and further improving the uniformity and quality of the light beam.

[0030] 4. The present invention uses a Fresnel lens to reduce a large light spot transmitted over a long distance to a small incident hole that can pass through the power ball. At the same time, the large size characteristic of the Fresnel is utilized to increase the area of ​​the receiver and reduce the loss of edge energy.

[0031] 5. This invention places an elliptical reflector at the center of the power sphere to reflect incident laser light, ensuring that each incident laser beam directly illuminates an area larger than half the power sphere. Furthermore, the two laser beams are symmetrically distributed, allowing the low-density beams of the two laser beams to overlap, increasing the intensity of the edge illumination area, thereby achieving uniform illumination and ultimately ensuring uniform direct illumination of the entire inner surface of the power sphere.

[0032] 6. The present invention utilizes the reflective surface of the ellipsoid with variable curvature to increase the illumination area of ​​the central light intensity and reduce the illumination area of ​​the edge light spot, so that the power density of the light spot with central light intensity decreases after elliptical reflection, while the power density of the light spot with weak light intensity increases after reflection, thereby improving the light uniformity of the inner surface of the power ball.

[0033] In summary, the system and method for improving the efficiency of laser wireless energy transmission of the present invention adopts the combined emission of multiple low-power lasers at the transmitting end to form the effect of incoherent combined beam superposition, thereby realizing a high-power and high-conversion-efficiency light source. A defocused parabolic beam expander is used to expand the combined laser beam into collimated light, which can reduce the divergence angle of the large-aperture beam formed after the multiple beams are combined, thereby reducing the light loss caused by light transmission and solving the problem of small aperture of the transmission-type beam expander; the receiving end adopts a power ball receiver as the receiving device, and an elliptical reflector is installed at the center of the power ball to reflect the laser incident on the power ball. The reflective surface with variable curvature of the ellipse is used to form an irradiation area that increases the central light intensity and reduces the irradiation area of ​​the edge light spot, so that the power density of the light spot with strong central light decreases after the elliptical reflection, while the power density of the light spot with weak light intensity increases after reflection, ultimately making the entire inner surface of the power ball obtain uniform direct irradiation. By comprehensively utilizing the above-mentioned technical means, a laser wireless energy transmission system with high transmission efficiency and high output power is obtained.

[0034] These and other aspects of the present application will be more clearly understood in the following description of the embodiments. It should be understood that the above general description and the following detailed description are merely exemplary and explanatory and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for the exemplary embodiments or related technical descriptions. The drawings are used to provide a further understanding of the present invention and constitute part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the drawings:

[0036] Figure 1 This is a diagram of the structure of a system for improving the efficiency of laser wireless energy transmission according to an embodiment of the present invention.

[0037] Figure 2 This is a diagram of laser beam energy distribution in a system for improving laser wireless energy transmission efficiency according to an embodiment of the present invention.

[0038] Figure 3 This is a flow chart of a method for improving the efficiency of laser wireless energy transmission according to an embodiment of the present invention.

[0039] Reference numerals:

[0040] 1-Laser I, 2-Focusing mirror I, 3-Off-axis parabolic collimator I, 4-Fresnel lens I, 5-Power ball receiver, 6-Elliptical reflector, 7-Aperture I, 8-Laser II, 9-Focusing mirror II, 10-Off-axis parabolic collimator II, 11-Fresnel lens II, 12-Aperture II. DETAILED DESCRIPTION

[0041] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0042] To make the purpose, technical solutions and advantages of the present invention more clearly understood, the following is a further detailed description of the embodiments of the present invention in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0043] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are intended to distinguish two non-identical entities or non-identical parameters with the same name. Therefore, "first" and "second" are used for convenience of expression only and should not be understood as limitations on the embodiments of the present invention. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, other steps or units inherent to a process, method, system, product, or device that includes a series of steps or units.

[0044] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0046] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0047] See also Figure 1As shown, an embodiment of the present invention provides a system for improving the efficiency of laser wireless energy transmission, including a transmitter module, an optical processing unit, and a receiver module. The transmitter module comprises a laser emission array composed of multiple independent lasers, with adjustable spacing between the lasers to control the overlap area of ​​the beam edges; the lasers include laser I1 and laser II8.

[0048] The optical processing unit includes a focusing mirror, an aperture, and an off-axis parabolic collimator mirror arranged in sequence along the optical path, and the off-axis parabolic collimator mirror is tilted 45° counterclockwise with respect to a horizontal reference; wherein, the focusing mirror in the optical processing unit includes focusing mirror I2 and focusing mirror II9, the aperture includes aperture I7 and aperture II12, and the off-axis parabolic collimator mirror includes off-axis parabolic collimator mirror I3 and off-axis parabolic collimator mirror II10.

[0049] The receiving end module includes a power ball receiver 5 and an elliptical reflector 6 placed at the center of the power ball. The two ends of the long axis of the elliptical reflector 6 point to the laser entrance of the power ball, and the intersection of the long axis and the short axis coincides with the center of the power ball. The power ball receiver 5 is a spherical closed receiver composed of many small-sized photovoltaic cells. The elliptical reflector 6 is installed at the center. The elliptical reflector 6 is a fully reflective mirror. The material of the elliptical reflector 6 can be metal, glass, or acrylic with a high-reflective film corresponding to the laser on the curved surface. The intersection of the long axis and the short axis of the ellipse coincides with the center of the power ball, and the curved surfaces at both ends of the long axis face the laser entrance of the power ball.

[0050] After the incident laser is irradiated on the ellipsoid, the center of the light spot coincides with the endpoint of the major axis of the ellipse, and the edge light spot is irradiated on the ellipsoid extending to both sides of the end face. The power density is highest at the endpoint, and the energy distribution gradually decreases towards both sides. Since the curvature of the ellipsoid gradually decreases from the major axis endpoint to the minor axis endpoint, the irradiation area of ​​the reflected light of the center light spot increases, and the irradiation area of ​​the reflected light of the edge light spot decreases, that is, the power density of the center light spot is reduced and the power density of the edge light spot is increased, thereby achieving the effect of improving the light uniformity of the inner surface of the power sphere. After reflection from the ellipsoid, the irradiation area of ​​each laser is larger than half of the power sphere, forming the inner surface of the power sphere near the incident port illuminated by the central light spot, gradually extending to the two ends of the perpendicular center until it exceeds the upper and lower areas of the central vertical point. The vertex corresponding to the central vertical point is the edge of the light spot.

[0051] The symmetrical incidence of the two paths causes the edge spots of the two incident lasers to overlap at the vertex corresponding to the vertical point at the center of the power sphere, further increasing the irradiation intensity of the edge spots, reducing the intensity difference with the irradiation area of ​​the central spot, and improving the light uniformity in the cavity.

[0052] The curvature of the elliptical reflector 6 gradually decreases from the major axis end point to the minor axis end point, so that the irradiation area of ​​the high power density light spot incident on the major axis end point increases after reflection, and the irradiation area of ​​the low power density light spot incident on the minor axis end point decreases after reflection.

[0053] In this embodiment, the system for improving the efficiency of laser wireless energy transmission includes two sets of symmetrically arranged transmitting end modules, and the laser beams output by the two modules achieve edge spot superposition at the central vertical point position on the inner surface of the power sphere.

[0054] In some embodiments, the optical processing unit further includes a Fresnel lens, which is arranged on the transmission light path of the off-axis parabolic collimator, and the tooth-shaped structure is one of rectangular, trapezoidal or arc-shaped, wherein the Fresnel lens includes Fresnel lens I4 and Fresnel lens II11.

[0055] In this embodiment, the power ball receiver 5 is composed of a plurality of photovoltaic cells assembled into a spherical structure, and the surface of the elliptical reflector 6 is coated with a high-reflection film that matches the laser wavelength.

[0056] In this embodiment, the reflective surface of the off-axis parabolic collimator is an off-axis intercept of the parent parabola, with a focal length range of 55mm to 200mm. This invention utilizes the large aperture and defocus characteristics of the off-axis parabolic collimator to address the problem of traditional transmissive beam expanders with a small input aperture, making it incapable of collimating the large spot size resulting from the superposition and combination of multiple laser beams. This reduces the divergence angle of the beam during wireless laser energy transmission and minimizes transmission losses in air.

[0057] In this embodiment, the laser emission array includes at least 8 independent lasers. The spacing between adjacent lasers can be adjusted forward and backward to control the spot superposition area and realize the energy superposition of incoherent edge spots. The laser can be a semiconductor laser, a fiber laser, a solid laser, etc. The laser wavelength can be 808nm, 1064nm, or 532nm. The vertical and horizontal spacing between two adjacent lasers is consistent, but the front and back positions can be adjusted, so that the beam size of different lasers can be controlled, and then the spot overlap position can be controlled. Since the laser is not collimated light, there is always an emission angle. After transmitting for a certain distance, the edges of the spots will be superimposed, and the central spot will still be distributed independently, such as Figure 2 As shown in the figure, the superposition of multiple edge light spots enhances the light intensity at the superposition point, even reaching the same intensity as the center light spot. This results in independent transmission of each laser beam, maintaining the characteristic of low laser transmission loss. The incoherent superposition of edge light spots on the imaging surface increases the light intensity of the edge light spots, thereby improving the uniformity of the transmitted light.

[0058] By controlling the distance between the focusing lens and the laser, the size of the overlapping spot can be controlled, thereby controlling the effect of the light superposition. The superimposed laser light continues to transmit forward and reaches the focusing lens. The lens material can be quartz, glass, K9 glass, etc., with an available focal length of 55mm to 200mm and an available wavelength of 248nm to 1064nm. After the laser is focused by the focusing lens, the focal position coincides with the off-axis parabolic collimator.

[0059] The present invention controls the front, back, left, and right positions and combinations of the lasers to coordinate the emission of multiple lasers, forming a combined superposition of incoherent multiple light beams, breaking through the output limitations of a single laser. During the transmission process, the edge light spots of each light spot are superimposed on each other through the light superposition method, thereby increasing the light intensity around the beam, ensuring that the beam has a uniform intensity distribution in a specific area, and thus improving the light transmission efficiency.

[0060] Since the edges of the combined beam spots cannot be superimposed and still exist in the form of low light intensity, in order to further improve the uniformity and quality of the beam, an aperture is used to block the transmission of the beam edge to reduce the problem of poor light uniformity on the receiving surface caused by this part of light, which leads to a decrease in the system output power.

[0061] Since the reflecting surface of the off-axis parabolic collimator is a portion intercepted from the parent parabola, this design allows the focus to be separated from the optical path, thus avoiding the problem of the focus of the traditional parabolic reflector coinciding with the optical axis. The collimator can be made of gold-plated film, aluminum-plated film, silver-plated film, and laser spectrum coating, etc. The collimator is placed with the horizontal direction as the reference and tilted 45 degrees in the counterclockwise direction. Based on the geometric shape and optical properties of the off-focus parabola, the light beam focused by the lens is collimated into parallel light by the collimator, which plays the role of beam expansion and collimation, forming a large-aperture and high-power multi-beam combining and collimating effect.

[0062] The expanded laser is transmitted over a long distance and reaches the Fresnel lens. The tooth shape of the Fresnel lens can be rectangular, trapezoidal, sawtooth, arc, etc. The light beam is refracted through the equidistant teeth on its surface and focused onto a very small focal point, so that the large light spot transmitted over a long distance can be reduced to a small incident hole that can pass through the power ball. At the same time, the large size characteristics of the Fresnel are utilized to increase the area of ​​the receiver and reduce the loss of edge energy.

[0063] The system and method for improving the efficiency of laser wireless energy transmission of the present invention adopts the combined emission of multiple low-power lasers at the transmitting end to form the effect of incoherent combined beam superposition, thereby realizing a high-power and high-conversion-efficiency light source. A defocused parabolic beam expander is used to expand the combined laser beam into collimated light, which can reduce the divergence angle of the large-aperture beam formed after the multiple beams are combined, thereby reducing the light loss caused by light transmission and solving the problem of small aperture of the transmission-type beam expander. The receiving end adopts a power ball receiver 5 as the receiving device, and an elliptical reflector 6 is installed at the center of the power ball to reflect the laser incident on the power ball. The reflective surface of the elliptical body with variable curvature is used to form an irradiation area that increases the central light intensity and reduces the irradiation area of ​​the edge light spot, so that the power density of the light spot with strong central light decreases after the elliptical reflection, while the power density of the light spot with weak light intensity increases after reflection, ultimately making the entire inner surface of the power ball obtain uniform direct irradiation. By comprehensively utilizing the above-mentioned technical means, a laser wireless energy transmission system with high transmission efficiency and high output power is obtained.

[0064] See also Figure 3 As shown, an embodiment of the present invention also provides a method for improving the efficiency of laser wireless energy transmission, comprising the following steps:

[0065] Step S1: By adjusting the spatial positions of multiple independent lasers, the edge spots of each laser beam are controlled to be incoherently superimposed in the transmission path to form a uniform light intensity distribution;

[0066] Step S2: using an off-axis parabolic collimator to expand and collimate the superimposed combined light beams, wherein the off-axis parabolic collimator is placed at a 45° counterclockwise tilt relative to a horizontal reference;

[0067] Step S3: using the elliptical reflector 6 to reflect and homogenize the laser light incident into the power sphere, so that the high-power density spot irradiated to the end point of the long axis is reflected and the irradiation area is increased, while the low-power density spot irradiated to the end point of the short axis is reflected and the irradiation area is reduced;

[0068] Step S4: Using two symmetrically incident laser beams, edge light spot superposition is achieved at the central vertical point on the inner surface of the power sphere to eliminate light intensity differences.

[0069] Among them, in step S1, by dynamically adjusting the front and back spacing of adjacent lasers, the size of the overlapping area of ​​the edge light spots is controlled so that the light intensity of the overlapping area reaches more than 90% of the intensity of the central light spot. In step S2, an aperture is set at the entrance of the light path of the off-axis parabolic collimator to filter out the low-intensity edge light spots that are not overlapped in the combined light spot. In step S3, the intersection of the major axis / minor axis of the elliptical reflector 6 coincides with the center of the power sphere, and the two ends of the major axis point to the laser incident port, and the curvature gradually decreases from the end point of the major axis to the end point of the minor axis. In step S4, the angle between the axes of the two symmetrical incident lasers is 90°-180°, and the overlap rate of the edge light spots at the vertex of the power sphere is greater than 80%.

[0070] The present invention uses an aperture at the rear end of the proximal focusing mirror to block the non-overlapping light spots at the edge of the combined light spot, thereby reducing the adverse effects of the non-overlapping light spots on the uniformity of the light field of the receiving surface, and further improving the uniformity and quality of the light beam.

[0071] The present invention places an elliptical reflector 6 at the center of the power sphere to reflect incident laser light, ensuring that each incident laser beam directly illuminates an area larger than half the power sphere. Furthermore, the two laser beams are symmetrically distributed, allowing the low-density beam areas of the two laser beams to overlap, increasing the light intensity in the edge illumination area, thereby achieving uniform light distribution and ultimately ensuring uniform direct illumination of the entire inner surface of the power sphere.

[0072] In this embodiment, between step S2 and step S3, the method further includes: using a Fresnel lens to compress the large light spot after long-distance transmission into the incident aperture of the power ball, and the tooth-shaped structure of the Fresnel lens is one of rectangular, trapezoidal or arc-shaped.

[0073] The present invention uses a Fresnel lens to reduce a large light spot transmitted over long distances to a small entrance aperture that can pass through the power sphere. The large size of the Fresnel lens also increases the receiver area and reduces edge energy loss. The present invention utilizes an ellipsoidal reflective surface with variable curvature to create an illuminated area that increases the central light intensity while reducing the illuminated area of ​​the edge light spots. This results in a decrease in the power density of the central light spot after elliptical reflection, while an increase in the power density of the weaker edge light spots after reflection, improving the light uniformity on the inner surface of the power sphere.

[0074] It should be understood that, as used herein, the singular form "a" or "an" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the items listed in association. The serial numbers of the embodiments disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0075] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples. Within the spirit of the embodiments of the present invention, the technical features of the above embodiments or different embodiments may be combined, and there are many other variations of different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the scope of protection of the embodiments of the present invention.

Claims

1. A system for improving the efficiency of laser wireless energy transmission, characterized in that: Includes the following components: Transmitter module: A laser emission array composed of multiple independent lasers, with adjustable spacing between lasers to control the overlap area of ​​the beam edges; Optical processing unit: including a focusing mirror, an aperture, and an off-axis parabolic collimator arranged in sequence along the optical path, wherein the off-axis parabolic collimator is tilted 45° counterclockwise with respect to the horizontal reference; Receiving end module: includes a power ball receiver and an elliptical reflector placed at the center of the power ball. The two ends of the long axis of the elliptical reflector point to the laser incident port of the power ball, and the intersection of the long axis and the short axis coincides with the center of the power ball.

2. The system for improving laser wireless energy transmission efficiency according to claim 1, wherein: The laser emission array includes at least 8 independent lasers, and the distance between adjacent lasers can be adjusted forward and backward to control the overlapping area of ​​the light spots.

3. The system for improving laser wireless energy transmission efficiency according to claim 2, wherein: The curvature of the elliptical reflector gradually decreases from the major axis end point to the minor axis end point, so that the irradiation area of ​​the high power density light spot incident on the major axis end point is increased after reflection, and the irradiation area of ​​the low power density light spot incident on the minor axis end point is reduced after reflection.

4. The system for improving laser wireless energy transmission efficiency according to claim 3, wherein: The system for improving the efficiency of laser wireless energy transmission includes two sets of symmetrically arranged transmitting end modules, and the laser beams output by the two modules achieve edge spot superposition at the central vertical point position on the inner surface of the power sphere.

5. The system for improving laser wireless energy transmission efficiency according to claim 1, wherein: The optical processing unit further comprises a Fresnel lens, which is arranged on the transmission light path of the off-axis parabolic collimator, and the tooth-shaped structure is one of rectangular, trapezoidal or arc-shaped.

6. The system for improving laser wireless energy transmission efficiency according to claim 1, wherein: The power ball receiver is composed of a plurality of photovoltaic cells assembled into a spherical structure, and the surface of the elliptical reflector is coated with a high-reflection film that matches the laser wavelength.

7. The system for improving laser wireless energy transmission efficiency according to claim 1, wherein: The reflecting surface of the off-axis parabolic collimating mirror is an off-axis intercepted portion of the parent parabola, and the focal length range is 55mm to 200mm.

8. A method for improving the efficiency of laser wireless energy transmission, characterized in that: The method is performed based on the system for improving laser wireless energy transmission efficiency according to any one of claims 1 to 7, and the method comprises the following steps: By adjusting the spatial positions of multiple independent lasers, the edge spots of each laser beam are controlled to incoherently superimpose in the transmission path to form a uniform light intensity distribution; The combined light beams are expanded and collimated using an off-axis parabolic collimator, wherein the off-axis parabolic collimator is tilted 45° counterclockwise relative to a horizontal reference; An elliptical reflector is used to reflect and homogenize the laser light incident into the power sphere, so that the high-power density spot irradiated to the end point of the long axis is reflected to increase the irradiation area, while the low-power density spot irradiated to the end point of the short axis is reflected to reduce the irradiation area; Through the dual-path symmetrical incident laser beam, the edge light spot superposition is achieved at the central vertical point position on the inner surface of the power sphere to eliminate the difference in light intensity.

9. The method for improving laser wireless energy transmission efficiency according to claim 8, wherein: By dynamically adjusting the front-to-back spacing between adjacent lasers, the size of the overlapping area of ​​the edge light spots is controlled so that the light intensity in the overlapping area reaches more than 90% of the intensity of the central light spot.

10. The method for improving laser wireless energy transmission efficiency according to claim 9, wherein: An aperture is set at the entrance of the light path of the off-axis parabolic collimator to filter out the low-intensity edge light spots that are not superimposed in the combined light spot.

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