Transmission-type wavelength conversion device

Abstract

The transmission-type wavelength conversion device comprises a laser scattering layer, a heat sink substrate layer, a wavelength conversion layer and a light homogenizing layer which are sequentially arranged in a stacked mode. Wherein the laser scattering layer is used for scattering laser from a form of Gaussian distribution of energy and strip-shaped light spots into a form of weak Gaussian distribution of energy and round or similar round light spots, the heat sink substrate layer is a light-transmitting substrate with the laser transmittance being 75% or above, and the wavelength conversion layer is used for converting at least part of the laser into fluorescent light. And the light homogenizing layer is used for scattering fluorescent light and residual laser. According to the device, on the premise that no extra lens is added and the size of the white laser light source is not enlarged, through the dual effects of the laser scattering layer and the light beam homogenizing layer, effective shaping of laser spots can be achieved, and the color uniformity and the illumination quality of the white laser light source can be remarkably improved; and a feasible solution is provided for application of a miniaturized and integrated white laser light source in a circular light spot scene.

Description

TECHNICAL FIELD

[0001] The present scheme belongs to the field of laser illumination and display technology, and particularly relates to a transmission type wavelength conversion device. BACKGROUND

[0002] The wavelength conversion device plays a crucial role in the field of laser illumination, especially in the scenario of pursuing a circular light spot of the light source. The traditional laser illumination light source usually utilizes a light path system with a large spatial size to shape the laser light spot, so that the laser light spot incident on the wavelength conversion material becomes circular or quasi-circular, thereby generating a fluorescent light spot close to a circle. These fluorescent light spots are further shaped by subsequent light paths, and finally a circular light spot meeting the illumination requirements is output. However, with the development of the illumination market towards miniaturization, portability and integration, higher requirements are put forward for the laser light source, i.e. while maintaining high brightness, the volume must be miniaturized.

[0003] The white laser light source, as a new type of illumination light source, has attracted much attention due to its small size and high integration. In the white laser light source, the wavelength conversion material is directly arranged inside the laser, and the laser is directly incident on the wavelength conversion material to emit white light. This design does not require additional external structural space, so it can achieve a very small volume and has a significant advantage on the laser illumination platform. However, the white laser light source still faces some technical challenges to realize market application.

[0004] Firstly, due to the very small volume of the white laser light source, the structural space is very limited, usually within 12 millimeters in height. In such a small structural space, it is difficult to shape the strip-shaped laser light spot into a circular light spot by itself. Although a spherical lens can be added to shape the strip-shaped laser light spot into a circular spot, the size, tolerance and sphericity of the spherical lens are extremely high, which is difficult to achieve with existing processing technology, even if it can be achieved, it will greatly increase the cost of the light source.

[0005] Secondly, the original laser emitted by the laser is usually a Gaussian-shaped blue light, and the energy distribution characteristics of the light spot size are high in the center and low in the periphery. When this Gaussian-shaped blue laser excites the wavelength conversion material, the fluorescent light emitted by the wavelength conversion material maintains a Lambertian shape, but the fluorescent light brightness has a difference between the center and the edge. At the same time, the remaining blue light still maintains a Gaussian shape, making the white light circular spot formed by the combined light show a phenomenon of center blue-white and edge yellow, which seriously affects the illumination visual effect.

[0006] Therefore, the application of the wavelength conversion device in the white laser light source needs to solve these technical difficulties to realize the miniaturization, high brightness and good illumination effect of the light source. CONTENT OF THE INVENTION

[0007] The present scheme aims to overcome at least one of the defects in the prior art, and provide a transmissive wavelength conversion device which can realize spot shaping and solve the problem of uneven color of the spot without using additional lenses and increasing the volume of the white laser light source.

[0008] To solve the above technical problems, the following technical solutions are adopted:

[0009] A transmissive wavelength conversion device includes a laser scattering layer, a heat sink substrate layer, a wavelength conversion layer and a light homogenization layer which are sequentially stacked. The laser scattering layer is used to scatter the laser light from a Gaussian energy distribution and a strip-shaped spot shape into a weak Gaussian energy distribution and a circular or similar circular spot shape. The heat sink substrate layer is a light-transmitting substrate with a laser transmittance of more than 75%. The wavelength conversion layer is used to convert at least part of the laser light into fluorescent light. The light homogenization layer is used to scatter the fluorescent light and the remaining laser light.

[0010] Without adding additional lenses and expanding the volume of the white laser light source, the present scheme can effectively shape the laser spot and significantly improve the color uniformity and illumination quality of the white laser light source through the dual effects of the laser scattering layer and the beam homogenization layer, providing a practical solution for the application of small and integrated white laser light sources in circular spot scenarios.

[0011] The weak Gaussian distribution of the present application refers to a Gaussian-like distribution in which the intensity is highest at the center and gradually decays towards both sides, but the difference between the center light intensity and the edge light intensity is smaller than that of a standard Gaussian distribution.

[0012] Specifically, the introduction of the laser scattering layer at the front end of the device enables the device to improve the balance of laser energy distribution while maintaining the blue laser energy density without significant reduction, effectively scattering and reshaping the originally strip-shaped laser spot into a circular shape, thereby solving the problem of difficult laser spot shaping in a compact space. The light beam homogenization layer introduced at the rear end of the device performs in-depth homogenization processing on the fluorescent light and the remaining blue light emitted from the wavelength conversion layer, which not only makes the energy distribution of the fluorescent light and the blue light more balanced, but also significantly improves the color uniformity of the white laser exit spot, effectively solving the common color unevenness phenomenon of "blue and white at the center, yellow at the edge" in the white laser spot, making the color of the entire white light spot consistent and uniform, and greatly improving the illumination effect and the user's visual experience.

[0013] Moreover, the laser scattering layer is arranged on the side of the heat sink substrate layer away from the wavelength conversion layer, rather than between the two, which ensures an unobstructed heat conduction path between the wavelength conversion layer and the heat sink substrate layer, avoids the laser scattering layer becoming an obstacle to heat conduction due to its poor heat conduction performance, effectively guarantees the heat dissipation efficiency of the wavelength conversion layer, enables it to withstand higher laser power, and thus achieves higher white laser limit luminance, and optimizes the overall optical performance and heat management efficiency. The light homogenization layer is independently arranged on the light exit surface of the wavelength conversion layer, rather than fused into the wavelength conversion layer, which ensures that the fluorescence and residual blue light can be effectively scattered and homogenized, while avoiding significant loss of fluorescence, and guarantees the quality and efficiency of light output.

[0014] The laser scattering layer uniformly disperses metal oxide particles that have Rayleigh scattering effect on laser light, which is conducive to scattering the laser light into a form with weak Gaussian distribution of energy and circular or quasi-circular spot shape. The laser scattering layer can be an organic silicone gel layer or an inorganic glass layer. If the laser light is blue light, the median diameter D50 of the metal oxide particles can be controlled to be between 10-40 nm.

[0015] The light homogenization layer uniformly disperses metal oxide particles that have Rayleigh scattering effect and Mie scattering effect on fluorescence and laser light, which is conducive to scattering and homogenizing the fluorescence and residual laser light. The light homogenization layer can be an organic silicone gel layer or an inorganic glass layer. If the laser light is blue light, the median diameter D50 of the metal oxide particles can be controlled to be between 10-100 nm.

[0016] The side of the heat sink substrate layer facing the laser scattering layer is preferably provided with a laser antireflection layer, which is used to increase the transmission of laser light incident on the surface of the heat sink substrate layer, and can reduce the loss of laser light incident on the surface of the heat sink substrate layer after being processed by the laser scattering layer. The laser antireflection layer can be a composite layer formed by laminating two or more of a silicon oxide dielectric film, a titanium oxide dielectric film, and a tantalum oxide dielectric film.

[0017] The side of the heat sink substrate layer facing the wavelength conversion layer is provided with a blue-transmitting and yellow-reflecting layer, which is used to transmit laser light and reflect fluorescence, and can reduce the loss of laser light during emission from the surface of the heat sink substrate layer, and reduce the loss of fluorescence incident on the light homogenization layer after being processed by the wavelength conversion layer. The blue-transmitting and yellow-reflecting layer can be a composite layer formed by laminating two or more of a silicon oxide dielectric film, a titanium oxide dielectric film, and a tantalum oxide dielectric film.

[0018] If the laser is blue light, the heat sink substrate layer is a light-transmitting substrate with a transmittance of 75% or more for the 430-460 nm band of blue light, which can be a glass substrate layer, a sapphire substrate layer, or a diamond substrate layer; the laser anti-reflection layer is an anti-reflection film with a transmittance of 95% or more for the 435-460 nm band of blue light within an incident angle range of 0-30°; and the blue-transmitting yellow-reflecting layer is a blue-transmitting yellow-reflecting film with a transmittance of 95% or more for the 435-460 nm band of blue light within an incident angle range of 0-30°, a reflectance of 99% or more for the 485-700 nm band of fluorescent light within an incident angle range of 0-30°, and a reflectance of 95% or more for the 485-700 nm band of fluorescent light within an incident angle range of 30-60°.

[0019] The wavelength conversion layer can be a ceramic fluorescent layer, a glass fluorescent layer, or an organic silicon fluorescent layer.

[0020] In the above-described transmission type wavelength conversion device, the thickness of the laser scattering layer is preferably 20-40 μm, the thickness of the laser anti-reflection layer is preferably 1-3 μm, the thickness of the heat sink substrate layer is preferably 0.2-1 mm, the thickness of the blue-transmitting yellow-reflecting layer is preferably 5-8 μm, the thickness of the wavelength conversion layer is preferably 25-50 μm, and the thickness of the light homogenization layer is preferably 8-20 μm.

[0021] Compared with the prior art, the present scheme has the following beneficial effects: without increasing additional lenses or expanding the volume of the white laser light source, the dual effects of the laser scattering layer and the light beam homogenization layer not only achieve effective shaping of the laser spot, but also significantly improve the color uniformity and illumination quality of the white laser light source, thereby providing a feasible solution for the application of small and integrated white laser light sources in the circular spot scenario. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings are only used for illustrative purposes and should not be understood as limiting the present scheme; in order to better illustrate the present scheme, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0023] Figure 1 is a structural schematic diagram of a transmission type wavelength conversion device.

[0024] Figure 2 is a structural schematic diagram of a transmission type wavelength conversion device (including a laser anti-reflection layer and a blue-transmitting yellow-reflecting layer).

[0025] Explanation of reference signs: laser scattering layer 100, metal oxide particles 101, laser antireflection layer 200, heat sink substrate layer 300, blue light transmission and yellow light reflection layer 400, wavelength conversion layer 500, light homogenization layer 600, metal oxide particles 601. DETAILED DESCRIPTION

[0026] Please refer to Figure 1 The transmission type wavelength conversion device provided in the present application at least comprises laser scattering layer 100, heat sink substrate layer 300, wavelength conversion layer 500 and light homogenization layer 600 which are sequentially stacked, and can further comprise laser antireflection layer 200 which is stacked between laser scattering layer 100 and heat sink substrate layer 300, and even comprise blue light transmission and yellow light reflection layer 400 which is stacked between heat sink substrate layer 300 and wavelength conversion layer 500, i.e. the transmission type wavelength conversion device can comprise laser scattering layer 100, laser antireflection layer 200, heat sink substrate layer 300, blue light transmission and yellow light reflection layer 400, wavelength conversion layer 500 and light homogenization layer 600 which are sequentially stacked, as shown in Figure 2 Laser is incident from the side of laser scattering layer 100 which is away from heat sink substrate layer 300, and sequentially passes through laser scattering layer 100, laser antireflection layer 200 (if any), heat sink substrate layer 300, blue light transmission and yellow light reflection layer 400 (if any), wavelength conversion layer 500 and light homogenization layer 600, and finally is emitted from the side of light homogenization layer 600 which is away from wavelength conversion layer 500, at least part of the laser is converted into fluorescent light when passing through wavelength conversion layer 500, and the fluorescent light is also emitted from the side of light homogenization layer 600 which is away from wavelength conversion layer 500, and combines with the remaining laser to form white light with uniform color of light spot, which is very suitable for white laser illumination light source and does not cause the volume of white laser illumination light source to increase.

[0027] The laser scattering layer 100 scatters the laser incident to the heat sink substrate layer 300, disperses the energy of the laser from a Gaussian distribution to a weak Gaussian distribution, and after passing through the laser scattering layer 100, the shape of the laser changes from a strip shape to a circular or near-circular shape (referred to as a quasi-circular shape, such as an elliptical shape, etc.). It can meet the demand of circular spot of laser illumination scene, improve the uniformity of laser, and thus improve the problem of "central blue-white and edge yellow" existing in white laser illumination spot, without causing a large loss of energy density at the center of the spot. It ensures that the laser incident to the wavelength conversion layer 500 still maintains a high power density, so as to generate a high-illuminance fluorescence. The laser scattering layer 100 can be an organic silicone glue layer or an inorganic glass layer, and the inorganic glass layer is preferred, and the thickness is preferably 20-40 μm. The inorganic glass layer can be a Zn-B-Si-O glass layer, an Al-Si-B-O glass layer, or a B-Si-O glass layer. The laser scattering layer 100 can be configured with uniformly dispersed metal oxide particles 101. The metal oxide particles 101 have Rayleigh scattering effect on the laser, which is beneficial to disperse the laser into a form with weak Gaussian distribution of energy and circular or quasi-circular shape of spot. The metal oxide particles 101 can be aluminum oxide particles, zinc oxide particles, titanium oxide particles, silicon oxide particles, magnesium oxide particles, or lithium powder particles. If the laser is blue light, the median diameter D50 of the metal oxide particles 101 can be controlled between 10-40 nm.

[0028] The laser scattering layer 100 is ingeniously arranged on the side of the heat sink substrate layer 300 away from the wavelength conversion layer 500, rather than being placed between the two. This layout strategy ensures that the heat conduction path between the wavelength conversion layer 500 and the heat sink substrate layer 300 is unobstructed, and avoids the laser scattering layer 100 becoming an obstacle to heat conduction due to its poor heat conduction performance. If the laser scattering layer 100 is directly adjacent to the wavelength conversion layer 500, the large amount of heat generated by the wavelength conversion layer 500 during high-efficiency operation will be hindered by the laser scattering layer 100, making it difficult to quickly dissipate through the heat sink substrate layer 300, resulting in heat accumulation inside the wavelength conversion layer 500, which may trigger thermal quenching. This not only greatly reduces the laser power tolerance of the wavelength conversion layer 500, but also significantly weakens its limit illuminance. On the contrary, the current design scheme effectively protects the heat dissipation efficiency of the wavelength conversion layer 500 by physically isolating the laser scattering layer 100 from the wavelength conversion layer 500, so that it can tolerate higher laser power, thereby achieving higher white laser limit illuminance and optimizing the overall optical performance and heat management efficiency.

[0029] The heat sink substrate layer 300 serves as a carrier for other layers in the device and functions as a heat conductor and laser transmitter. The laser transmittance of the heat sink substrate layer 300 is greater than 75% to ensure that most of the laser light can pass through the heat sink substrate layer 300 and be incident on the wavelength conversion layer 500. If the laser light is blue light, the transmittance of the heat sink substrate layer 300 for blue light in the 430-460 nm band is greater than 75%, and the heat sink substrate layer 300 can be a glass substrate layer, a sapphire substrate layer, a diamond substrate layer, etc., and is preferably a sapphire substrate layer. The shape of the heat sink substrate layer 300 can be square, strip-shaped, or circular, and is preferably circular, and the thickness is preferably 0.2-1 mm.

[0030] A laser antireflection layer 200 can be arranged on the side of the heat sink substrate layer 300 facing the laser scattering layer 100. The laser antireflection layer 200 functions to reduce the loss of laser light incident on the surface of the heat sink substrate layer 300 after being processed by the laser scattering layer 100. The laser antireflection layer 200 can be a composite layer formed by laminating two or more of a silicon oxide dielectric film, a titanium oxide dielectric film, and a tantalum oxide dielectric film, and the thickness is preferably 1-3 μm. The laser antireflection layer 200 can be attached to the surface of the heat sink substrate layer 300 by evaporation. If the laser light is blue light, the laser antireflection layer 200 is a blue light antireflection layer, and the transmittance of the blue light antireflection layer for blue light in the 435-460 nm band is greater than 95% at an incident angle of 0-30°. The blue light antireflection layer is also referred to as a blue light antireflection film.

[0031] A blue light transmitting and yellow light reflecting layer 400 can be arranged on the side of the heat sink substrate layer 300 facing the wavelength conversion layer 500. The blue light transmitting and yellow light reflecting layer 400 can transmit laser light and reflect fluorescent light in the wavelength conversion layer 500, thereby reducing the loss of laser light during emission from the surface of the heat sink substrate layer 300 and reducing the loss of fluorescent light incident on the light homogenizing layer 600 after being processed by the wavelength conversion layer 500. The blue light transmitting and yellow light reflecting layer 400 can be a composite layer formed by laminating two or more of a silicon oxide dielectric film, a titanium oxide dielectric film, and a tantalum oxide dielectric film, and the thickness is preferably 5-8 μm. The blue light transmitting and yellow light reflecting layer 400 can be attached to the surface of the heat sink substrate layer 300 by evaporation. If the laser light is blue light, the blue light transmitting and yellow light reflecting layer 400 is an optical film layer that transmits blue light and reflects fluorescent light, and is also referred to as a blue light transmitting and yellow light reflecting film. The transmittance of the optical film layer for blue light in the 435-460 nm band is greater than 95% at an incident angle of 0-30°, the reflectance for fluorescent light in the 485-700 nm band is greater than 99% at an incident angle of 0-30°, and the reflectance for fluorescent light in the 485-700 nm band is greater than 95% at an incident angle of 30-60°.

[0032] The wavelength conversion layer 500 receives laser excitation and converts at least part of the laser into fluorescent light (laser-induced light) as a fluorescent emission portion of the device. The wavelength conversion layer 500 can be a ceramic fluorescent layer, a glass fluorescent layer, or an organic silicone fluorescent layer, and is preferably a glass fluorescent layer with a thickness of 25-50 μm. The ceramic fluorescent layer can be a wavelength conversion layer 500 formed by high-temperature sintering of ceramic powder particles such as alumina and magnesium oxide, and fluorescent powder particles such as YAG system yellow powder particles, LuAG system green powder particles, and CaAlSiN3 system red powder particles, and is a prior art that will not be described here. The glass fluorescent layer is a wavelength conversion layer 500 formed by high-temperature sintering of inorganic glass powder and fluorescent powder particles such as YAG system yellow powder particles, LuAG system green powder particles, and CaAlSiN3 system red powder particles, and is also a prior art that will not be described here. The organic silicone fluorescent layer is a wavelength conversion layer 500 formed by high-temperature curing of organic silicone glue and fluorescent powder particles such as YAG system yellow powder particles, LuAG system green powder particles, and CaAlSiN3 system red powder particles, and is also a prior art that will not be described here.

[0033] The light homogenization layer 600 enhances scattering and homogenization of the fluorescent light and residual laser light emitted from the wavelength conversion layer 500, further improves the "central blue-white, edge yellow" problem of the white laser illumination light spot, and makes the color of the white light spot emitted from the light beam homogenization layer uniform. The light homogenization layer 600 can be an organic silicone glue layer or an inorganic glass layer, and is preferably an inorganic glass layer with a thickness of 8-20 μm. The inorganic glass layer can be a Zn-B-Si-O glass layer, an Al-Si-B-O glass layer, or a B-Si-O glass layer. The light homogenization layer 600 can be configured with uniformly dispersed metal oxide particles 601. The metal oxide particles 601 have Rayleigh scattering and Mie scattering effects on the fluorescent light and laser light, which are beneficial to scattering and homogenization of the fluorescent light and residual laser light. The metal oxide particles 601 can be silicon oxide particles, aluminum oxide particles, titanium oxide particles, magnesium oxide particles, etc. If the laser light is blue light, the median diameter D50 of the metal oxide particles 601 can be controlled to 10-100 nm.

[0034] The light homogenization layer 600 is independently positioned on the light-emitting surface of the wavelength conversion layer 500, rather than being fused within it. This design ensures that residual blue light and fluorescence are effectively dispersed and homogenized, while avoiding significant fluorescence loss. If the light homogenization layer 600 were fused with the wavelength conversion layer 500, it would lead to excessive blue light straying, reducing its power density and further dispersing the energy distribution, thus significantly weakening the fluorescence intensity. Furthermore, the refractive index difference between the wavelength conversion material itself and the contained phosphor particles already causes fluorescence scattering. The combined effect of the light homogenization material would greatly intensify the fluorescence scattering, resulting in strong fluorescence scattering within the wavelength conversion layer 500. This would trap a large amount of fluorescence within the wavelength conversion layer 500, preventing effective emission and ultimately drastically reducing the output fluorescence intensity, severely impacting the white light illuminance. Therefore, independently positioning the light homogenization layer 600 effectively solves these problems, ensuring the quality and efficiency of light output.

[0035] To enable those skilled in the art to better understand this solution, the following detailed description is provided in conjunction with specific embodiments. Unless otherwise specified, all structural layers and materials described in the embodiments are commercially available.

[0036] Example 1

[0037] like Figure 2 As shown, the transmissive wavelength conversion device of this embodiment includes a laser scattering layer 100, a laser anti-reflection layer 200, a heat sink substrate layer 300, a blue-transparent and yellow-reflecting layer 400, a wavelength conversion layer 500, and a light homogenization layer 600 stacked sequentially.

[0038] The laser scattering layer 100 is an inorganic glass layer uniformly dispersed with alumina particles, with a thickness of 20-40 μm and a median diameter D50 of the alumina particles of 10-40 nm. The laser anti-reflection layer is a composite layer formed by stacking a silicon oxide dielectric film, a titanium oxide dielectric film and a tantalum oxide dielectric film, with a transmittance of 95% or more for blue light in the 435-460 nm band at an incident angle of 0-30° and a thickness of 1-3 μm. The heat sink substrate layer is a sapphire substrate layer, with a thickness of 0.2-1 mm. The blue-transmitting and yellow-reflecting layer is a composite layer formed by stacking a silicon oxide dielectric film, a titanium oxide dielectric film and a tantalum oxide dielectric film, with a transmittance of 95% or more for blue light in the 435-460 nm band at an incident angle of 0-30°, a reflectance of 99% or more for fluorescent light in the 485-700 nm band at an incident angle of 0-30°, a reflectance of 95% or more for fluorescent light in the 485-700 nm band at an incident angle of 30-60°, and a thickness of 5-8 μm. The wavelength conversion layer is a glass fluorescent layer, with a thickness of 25-50 μm. The light homogenizing layer is an inorganic glass layer uniformly dispersed with alumina particles, with a thickness of 8-20 μm and a median diameter D50 of the alumina particles of 10-100 nm.

[0039] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementation manners are not required or can not be exhausted. Any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A transmissive wavelength conversion device, characterized in that, the device comprises a laser scattering layer, a heat sink substrate layer, a wavelength conversion layer and a light homogenization layer which are sequentially stacked, the laser scattering layer is used for scattering laser from a form of Gaussian energy distribution and strip-shaped spot shape into a form of weak Gaussian energy distribution and circular or similar circular spot shape, the heat sink substrate layer is a light-transmitting substrate with a laser transmittance of 75% or more, the wavelength conversion layer is used for converting at least part of the laser into fluorescent light, and the light homogenization layer is used for scattering the fluorescent light and the remaining laser. 2.The transmissive wavelength conversion device according to claim 1, characterized in that, the laser scattering layer uniformly disperses metal oxide particles which have Rayleigh scattering effect on laser; and / or the light homogenization layer uniformly disperses metal oxide particles which have Rayleigh scattering effect and Mie scattering effect on fluorescent light and laser. 3.The transmissive wavelength conversion device according to claim 2, characterized in that, the laser is blue light, the median diameter D50 of the metal oxide particles in the laser scattering layer is between 10-40nm, and the median diameter D50 of the metal oxide particles in the light homogenization layer is between 10-100nm. 4.The transmissive wavelength conversion device according to claim 2, characterized in that, the laser scattering layer and / or the light homogenization layer is a silicone gel layer or an inorganic glass layer. 5.The transmissive wavelength conversion device according to any one of claims 1-4, characterized in that, one side of the heat sink substrate layer facing the laser scattering layer is provided with a laser anti-reflection layer for anti-reflection of laser incident onto the surface of the heat sink substrate layer; and / or one side of the heat sink substrate layer facing the wavelength conversion layer is provided with a blue light-transmitting and yellow light-reflecting layer for transmitting laser and reflecting fluorescent light. 6.The transmissive wavelength conversion device according to claim 5, characterized in that, the laser is blue light, the heat sink substrate layer is a light-transmitting substrate with a transmittance of 75% or more to 430-460nm waveband blue light, the laser anti-reflection layer is an anti-reflection film with a transmittance of 95% or more to 435-460nm waveband blue light within a 0-30° incident angle range, and the blue light-transmitting and yellow light-reflecting layer is a blue light-transmitting and yellow light-reflecting film with a transmittance of 95% or more to 435-460nm waveband blue light within a 0-30° incident angle range, a reflectance of 99% or more to 485-700nm waveband fluorescent light within a 0-30° incident angle range, and a reflectance of 95% or more to 485-700nm waveband fluorescent light within a 30-60° incident angle range. 7.The transmissive wavelength conversion device according to claim 6, characterized in that, the heat sink substrate layer is a glass substrate layer, a sapphire substrate layer or a diamond substrate layer; and / or the laser anti-reflection layer is a composite layer formed by stacking two or more of a silicon oxide dielectric film, a titanium oxide dielectric film and a tantalum oxide dielectric film; and / or the blue light-transmitting and yellow light-reflecting layer is a composite layer formed by stacking two or more of a silicon oxide dielectric film, a titanium oxide dielectric film and a tantalum oxide dielectric film.

8. The transmissive wavelength conversion device according to claim 5, wherein a thickness of the heat sink substrate layer is 0.2-1 mm; and / or a thickness of the laser anti-reflection layer is 1-3 μm; and / or a thickness of the blue-transmissive and yellow-reflective layer is 5-8 μm.

9. The transmissive wavelength conversion device according to any one of claims 1-4, wherein the wavelength conversion layer is a ceramic fluorescent layer, a glass fluorescent layer, or an organic silicon fluorescent layer.

10. The transmissive wavelength conversion device according to any one of claims 1-4, wherein a thickness of the laser scattering layer is 20-40 μm; and / or a thickness of the wavelength conversion layer is 25-50 μm; and / or a thickness of the light homogenizing layer is 8-20 μm. ​ ​ ​

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