Transmission-type wavelength conversion device and preparation method thereof

Abstract

The invention discloses a transmission-type wavelength conversion device and a preparation method thereof. The device comprises a transparent substrate, a fluorescent layer and a functional layer which are sequentially stacked, the fluorescent layer comprises a first packaging body, fluorescent particles and scattering enhancing particles, the mass ratio of the fluorescent particles to the first packaging body is (5-20): 1, and the scattering enhancing particles account for 5-15 wt% of the fluorescent layer; the fluorescent particles comprise first fluorescent particles with a median particle size of 15-22 [mu] m and second fluorescent particles with a median particle size of 3-8 [mu] m, and the mass ratio of the first fluorescent particles to the second fluorescent particles is (2-6): 1; the median particle size or the internal hollow size of the scattering enhanced particles is 200-400 nm; the functional layer comprises a second packaging body and functional phase particles, and the mass ratio of the functional phase particles to the second packaging body is (2-6): 10; and the median particle size or the internal hollow size of the functional phase particles is 10-80 nm. The light spot uniformity is improved, and the light spot effect can be comparable with that of a reflective light spot.

Description

Technical Field

[0001] This solution belongs to the technical field of lighting and display, and specifically relates to a transmissive wavelength conversion device and a preparation method thereof. Background Art

[0002] Based on the advantages of small volume, low cost and simple structure, transmissive laser light sources have great application prospects in some low-power laser lighting occasions where cost control is relatively sensitive, such as laser vehicle lights, laser flashlights, laser endoscopes, etc. For a reflective wavelength conversion device, the stimulated fluorescence and the remaining blue light pass through the reflection layer and then pass through the wavelength conversion layer and exit from the surface of the wavelength conversion layer. In this process, due to the secondary scattering excitation of the wavelength conversion layer, the light has better uniformity, so the light spot on the wall is relatively uniform. In a transmissive wavelength conversion device, after the mixed light is incident on the surface of the wavelength conversion layer and exits from the wavelength conversion layer, the mixed light lacks the secondary scattering excitation of the wavelength conversion layer. Therefore, when the emitted mixed light is projected onto the screen, it is prone to problems such as uneven uniformity, such as local yellow and local blue of the light spot. And as the projection distance of the light becomes farther, the light spot projected onto the screen is enlarged, and the problem of light spot uniformity becomes more prominent, seriously affecting the lighting visual effect. Summary of the Invention

[0003] This solution aims to overcome at least one defect in the prior art and provides a transmissive wavelength conversion device for solving the problem of poor light spot uniformity.

[0004] To solve the above technical problems, the following technical solutions are adopted:

[0005] In a first aspect, a transmissive wavelength conversion device is proposed. The transmissive wavelength conversion device includes a transparent substrate, a fluorescent layer and a functional layer which are sequentially stacked; the fluorescent layer includes a first encapsulant, fluorescent particles and scattering enhancement particles, and the mass ratio of the fluorescent particles to the first encapsulant is (5-20):1, and the scattering enhancement particles account for 5-15 wt% in the fluorescent layer; the fluorescent particles include first fluorescent particles with a median particle size of 15-22 μm and second fluorescent particles with a median particle size of 3-8 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is (2-6):1; the median particle size or the internal hollow size of the scattering enhancement particles is 200-400 nm; the functional layer includes a second encapsulant and functional phase particles, and the mass ratio of the functional phase particles to the second encapsulant is (2-6):10; the median particle size or the internal hollow size of the functional phase particles is 10-80 nm; the thickness of the fluorescent layer is 20-50 μm, and the thickness of the functional layer is 5-20 μm.

[0006] This solution adopts a combination of thick and thin fluorescent particles. The thin second fluorescent particles are filled in the gaps of the framework built by the thick first fluorescent particles, increasing the density of the particle arrangement inside the fluorescent layer. The presence of the second fluorescent particles increases the blue light excitation points and reduces the probability of blue light directly emitting from the surface of the fluorescent layer, thereby weakening the problem of local blue spots in the mixed light spot; while the thick first fluorescent particles mainly provide the luminous efficiency and ensure the blue light power resistance ability of the transmissive wavelength conversion light-emitting device. By controlling the median particle size or the internal hollow size of the scattering enhancement particles, Mie scattering can be applied to the light, enhancing the scattering intensity of blue light and fluorescence inside the fluorescent layer, making the projection of the mixed light in the fluorescent layer more chaotic, and thus improving the problem of local blue or yellowish light in the emitted light. Through specific functional phase particles, Rayleigh scattering is applied to the blue light, enhancing the blue light scattering effect, making the blue light in the emitted mixed light more chaotic, and achieving a light with an almost uniform effect similar to that of the reflective wavelength conversion device. This solution synergistically improves the uniformity of the light spot through the three types of particles: the second fluorescent particles with a smaller particle size, the scattering enhancement particles that cause Mie scattering to the light, and the functional phase particles that cause Rayleigh scattering to the laser. At the same time, by controlling the ratio of the first fluorescent particles to the second fluorescent particles, the proportion of the functional phase particles, and the thicknesses of the fluorescent layer and the functional layer, etc., the luminous efficiency and the blue light power resistance ability of the device are ensured, making the transmitted light spot comparable to the light spot effect of the reflective wavelength conversion device in terms of both uniformity and illuminance.

[0007] The median particle size or the internal hollow size of the functional phase particles is preferably 10 - 40 nm.

[0008] The scattering enhancement particles are preferably one or more of metal oxide particles and organic resin particles, more preferably one or more of alumina, silica, titanium oxide, PS, and PMMA; the functional phase particles are preferably one or more of metal oxide particles and organic resin particles, more preferably one or more of titanium oxide, zirconium oxide, magnesium oxide, alumina, zinc oxide, PS, and PMMA.

[0009] The first encapsulant is preferably silicone rubber, inorganic silicon oxide, or Zn - B - Si - Al - O - based inorganic glass, most preferably Zn - B - Si - Al - O - based inorganic glass; the second encapsulant is preferably silicone rubber, inorganic silicon oxide, or Zn - B - Si - Al - O - based inorganic glass, most preferably Zn - B - Si - Al - O - based inorganic glass.

[0010] The thickness of the transparent substrate is preferably 0.2 - 3 mm.

[0011] The transparent substrate is preferably polished on both sides, and the surface roughness of the polished surface is preferably Ra≤0.01μm. More preferably, a laser antireflection film is coated on the side of the transparent substrate facing away from the fluorescent layer, and an optical film that transmits laser and reflects fluorescence is coated on the side facing the fluorescent layer. The laser antireflection film is a blue light antireflection film, and the average transmittance of the blue light antireflection film for light in the wavelength range of 450 - 465nm is greater than 90% within the incident angle range of 0 - 30°; and / or the optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the average transmittance of the blue-transmitting and yellow-reflecting film for light in the wavelength range of 450 - 465nm is greater than 90% within the incident angle range of 0 - 30°, and the average reflectance for light in the wavelength range of 480 - 700nm is greater than 95%, and the average reflectance for light in the wavelength range of 480 - 700nm is greater than 92% within the incident angle range of 30 - 60°.

[0012] In a second aspect, a method for manufacturing the above-mentioned transmissive wavelength conversion device is proposed. The method includes the following steps:

[0013] Processing the transparent substrate: processing the transparent substrate to a target thickness, and polishing both sides to make the surface roughness Ra≤0.01μm of the polished surface;

[0014] Manufacturing the fluorescent layer: mixing the first encapsulant, fluorescent particles, and scattering enhancement particles to prepare a fluorescent slurry, coating it on the surface of the processed transparent substrate, and sintering at high temperature to form the fluorescent layer;

[0015] Manufacturing the functional layer: mixing the second encapsulant and functional phase particles to prepare a functional slurry, coating it on the surface of the fluorescent layer, and sintering at high temperature to form the functional layer.

[0016] Preferably, the step of processing the transparent substrate further includes: coating a laser antireflection film on one of the polished surfaces, and coating an optical film that transmits laser and reflects fluorescence on the other polished surface; correspondingly, in the step of manufacturing the fluorescent layer: the fluorescent slurry is coated on the optical film that transmits laser and reflects fluorescence.

[0017] The beneficial effects of this solution compared with the prior art are as follows: In this solution, the uniformity of the light spot is improved by the synergistic effect of the second fluorescent particles with a smaller particle size, the scattering enhancement particles that cause Mie scattering to light, and the functional phase particles that cause Rayleigh scattering to laser. At the same time, by controlling the ratio of the first fluorescent particles to the second fluorescent particles, the proportion of the functional phase particles, and the thickness of the fluorescent layer and the functional layer, etc., the luminous efficiency and the ability to withstand blue light power of the device are ensured, so that the transmitted light spot can be comparable to the light spot effect of the reflective wavelength conversion device in terms of both uniformity and illuminance. Description of the Drawings

[0018] The accompanying drawings are only for illustrative purposes and should not be construed as limiting the solution; for a better illustration of the solution, some components in the accompanying drawings may be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0019] Figure 1 is a schematic structural diagram of a transmissive wavelength conversion device.

[0020] Description of reference numerals in the drawings: transparent substrate 100, laser antireflection film 110, optical film for transmitting laser and reflecting fluorescence 120, fluorescent layer 200, first fluorescent particles 210, second fluorescent particles 220, scattering enhancement particles 230, first encapsulation body 240, functional layer 300, functional phase particles 310, second encapsulation body 320. Detailed implementation manners

[0021] This solution proposes a transmissive wavelength conversion device, which includes a transparent substrate, a fluorescent layer and a functional layer stacked in sequence, as Figure 1 shown. Laser is incident from the side of the transparent substrate facing away from the fluorescent layer, and successively passes through the transparent substrate, the fluorescent layer and the functional layer. The fluorescent layer is excited by part of the laser to generate fluorescence, and the mixed light of the fluorescence and the remaining laser exits from the side of the functional layer facing away from the fluorescent layer.

[0022] The transparent substrate can be made of transparent substrates with a thermal conductivity above 30 w / m·k such as sapphire, single crystal silicon, single crystal silicon carbide, single crystal transparent diamond, transparent aluminum nitride, etc. The substrate thickness is preferably 0.2 - 3 mm, and the substrate shape can be circular, square or rectangular. The transparent substrate can be polished on both sides, and the surface roughness of the polished surface is preferably Ra ≤ 0.01 μm. Among them, a laser antireflection film can be plated on the side facing away from the fluorescent layer, and an optical film for transmitting laser and reflecting fluorescence can be plated on the side facing the fluorescent layer.

[0023] The laser antireflection film can be a blue light antireflection film, and the blue light antireflection film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, that is, the average transmittance of light in the 450 - 465 nm band at an incident angle range of 0 - 30° is greater than 90%. The film system materials of the laser antireflection film are mainly composed of titanium oxide, tantalum oxide, silicon oxide, etc., and the laser power damage threshold of the film system > 60 w / mm 2 .

[0024] The optical film for transmitting laser and reflecting fluorescence can be a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg> 95%, that is, the average transmittance of light in the 450 - 465 nm band is greater than 90% within the incident angle range of 0 - 30°, and the average reflectance of light in the 480 - 700 nm band is greater than 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%, that is, the average reflectance of light in the 480 - 700 nm band is greater than 92% within the incident angle range of 30 - 60°. The film system materials of the optical film for transmitting laser and reflecting fluorescence mainly consist of titanium oxide, tantalum oxide, silicon oxide, etc. The laser power damage threshold of the film system > 60 w / mm 2 .

[0025] The fluorescent layer, as the light-emitting part of the transmissive wavelength conversion device, mainly consists of a first encapsulant made of a transparent material and fluorescent particles. The mass ratio of the fluorescent particles to the first encapsulant is (5 - 20):1, and the thickness of the fluorescent layer is 20 - 50 μm. The first encapsulant can be silicone rubber, inorganic silicon oxide, or inorganic glass of the Zn - B - Si - Al - O system. Preferably, it is inorganic glass of the Zn - B - Si - Al - O system, and the transmittance of the first encapsulant in the visible light band of 450 - 750 nm is greater than 90%. The fluorescent particles mainly consist of two or more kinds of particles with different particle sizes; among them, the median particle size D50 of the first fluorescent particles is 15 - 22 μm, ensuring the luminous efficiency and the ability to withstand blue light power of the device; the median particle size D50 of the second fluorescent particles is 3 - 8 μm, increasing the blue light excitation points and reducing the probability of blue light directly emitting from the surface of the fluorescent layer, thereby weakening the problem of local blue spots in the mixed light spot; the mass ratio of the first fluorescent particles to the second fluorescent particles is (2 - 6):1 to avoid poor luminous efficiency and the ability to withstand current points.

[0026] A certain content of scattering - enhancing particles is also added inside the fluorescent layer. Using the Mie scattering principle of light by the scattering - enhancing particles of a specific size itself or the specific - size hollow pores inside the scattering - enhancing particles, the scattering intensity of the laser and fluorescence inside the fluorescent layer is enhanced, making the projection of the mixed light in the fluorescent layer more chaotic and improving the problem of local blue or yellowish light in the emitted light. The scattering - enhancing particles can be metal oxide particles such as aluminum oxide, silicon oxide, titanium oxide, etc., or organic resin - type particles such as PS and PMMA. Structurally, they can be solid particles with a median particle size D50 of 200 - 400 nm, or hollow microsphere particles with an internal hollow size of 200 - 400 nm. The scattering - enhancing particles account for 5 - 15 wt% of the mixed components of the fluorescent layer to avoid excessive scattering causing fluorescence loss.

[0027] The functional layer, which is used to further improve the granularity effect of the light spot on the wall and enhance the light spot uniformity, mainly consists of a second encapsulant made of a transparent material and functional phase particles. The mass ratio of the functional phase particles to the second encapsulant is (2 - 6):10, and the thickness of the functional layer is 5 - 20 μm. The second encapsulant can be silicone rubber, inorganic silicon oxide, or inorganic glass of the Zn - B - Si - Al - O system. Preferably, it is inorganic glass of the Zn - B - Si - Al - O system. The transmittance of the second encapsulant in the visible light band of 450 - 750 nm is greater than 90%. The material of the second encapsulant can be the same as or different from that of the first encapsulant.

[0028] The functional phase particles mainly scatter blue light through Rayleigh scattering (d << λ) using powder microsphere particles of a specific size or pores of a specific size inside the powder microsphere particles. The shorter the wavelength, the stronger the scattering effect. Therefore, the scattering effect on blue light is stronger, and the scattering effect on yellow light is weaker or almost non - existent, making the blue light in the emitted mixed light more disordered, and a light spot with an almost uniform effect similar to that of a reflective wavelength conversion device can be achieved. At the same time, by controlling the particle size of the functional phase particles in this case, the change in the scattering intensity of yellow light is small, and the illuminance of the wavelength conversion device hardly decreases. The functional phase particles can be metal oxide powder microsphere particles such as titanium oxide, zirconium oxide, magnesium oxide, aluminum oxide, zinc oxide, or organic resin powder microsphere particles such as PS and PMMA. Structurally, they can be solid powder microsphere particles with a median particle size D50 of 10 - 80 nm, or hollow powder microsphere particles with an internal hollow size of 10 - 80 nm. The median particle size D50 or the internal hollow size of the powder microsphere particles is preferably 10 - 40 nm.

[0029] This solution also proposes a method for manufacturing the above - mentioned transmissive wavelength conversion device, which includes the following steps:

[0030] (1) Process the transparent substrate. First, process the transparent substrate to the target thickness and perform double - sided polishing so that the surface roughness Ra of the polished surface ≤ 0.01 μm. Then, use methods such as evaporation coating, magnetron sputtering, and chemical vapor deposition to deposit a laser anti - reflection film on one polished surface of the transparent substrate and an optical film that transmits laser and reflects fluorescence on the other polished surface.

[0031] (2) Fabricate the fluorescent layer. First, mix and uniformly disperse the first encapsulant, fluorescent particles, and scattering - enhancing particles through an organic solvent to form a fluorescent slurry. Then, coat the fluorescent slurry on the transparent substrate and sinter it at a high temperature of 600 - 800 °C to obtain a transmissive fluorescent device in which the fluorescent layer is firmly bonded to the transparent substrate.

[0032] (3) Fabricate the functional layer. First, the second encapsulant and the functional phase particles are evenly dispersed by an organic solvent to form a functional slurry. Then, the mixed slurry is coated on the surface of the fluorescent layer and sintered at a high temperature of 600 - 800 °C to obtain a transmissive fluorescent device in which the functional layer is firmly bonded to the fluorescent layer.

[0033] To enable those skilled in the art to better understand this solution, the following further elaborates on this solution in combination with specific embodiments. Unless otherwise specified, the process methods used in the embodiments are all conventional methods; the materials used, unless otherwise specified, can all be obtained through commercial channels.

[0034] Example 1

[0035] The transmissive wavelength conversion device in this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0036] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%.

[0037] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 20 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 20:1, and the scattering enhancement particles account for 5 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 2:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0038] The functional layer is composed of a second encapsulant and functional phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with a median particle size of 10 nm.

[0039] Example 2

[0040] The transmissive wavelength conversion device of this embodiment includes a transparent substrate, a fluorescent layer, and a functional layer that are stacked in sequence.

[0041] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 to 60°, R in the 480 - 700 nm band avg > 92%.

[0042] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 50 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 5:1, and the scattering enhancement particles account for 5 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 6:1. The scattering enhancement particles are alumina particles with a median particle size of 300 nm.

[0043] The functional layer is composed of a second encapsulant and functional phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with a median particle size of 10 nm.

[0044] Example 3

[0045] The transmissive wavelength conversion device of this embodiment includes a transparent substrate, a fluorescent layer, and a functional layer that are stacked in sequence.

[0046] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm bandavg > 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%.

[0047] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn - B - Si - Al - O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0048] The functional layer is composed of a second encapsulant and functional phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn - B - Si - Al - O system. The functional phase particles are titanium oxide particles with a median particle size of 10 nm.

[0049] Example 4

[0050] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0051] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double - polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti - reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti - reflection film for laser is a blue - light anti - reflection film, and the blue - light anti - reflection film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue - transmitting and yellow - reflecting film, and the blue - transmitting and yellow - reflecting film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%.

[0052] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 15 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn - B - Si - Al - O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 400 nm.

[0053] The functional layer is composed of a second encapsulant and functional-phase particles, and has a thickness of 15 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional-phase particles are titanium oxide particles with a median particle size of 10 nm.

[0054] Example 5

[0055] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0056] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, polished on both sides to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue-light anti-reflection film, and the blue-light anti-reflection film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 to 60°, R in the 480 - 700 nm band avg > 92%.

[0057] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering-enhancing particles, and has a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering-enhancing particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering-enhancing particles are alumina particles with a median particle size of 200 nm.

[0058] The functional layer is composed of a second encapsulant and functional-phase particles, and has a thickness of 20 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 2:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional-phase particles are titanium oxide particles with a median particle size of 10 nm.

[0059] Example 6

[0060] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0061] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with a laser antireflection film, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The laser antireflection film is a blue light antireflection film, and the blue light antireflection film satisfies: AOI = 0 - 30°, T in the wavelength band of 450 - 465 nm avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the wavelength band of 450 - 465 nm avg > 90%, R in the wavelength band of 480 - 700 nm avg > 95%; AOI = 30 - 60°, R in the wavelength band of 480 - 700 nm avg > 92%.

[0062] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0063] The functional layer is composed of a second encapsulant and functional phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with a median particle size of 40 nm.

[0064] Example 7

[0065] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked.

[0066] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with a laser antireflection film, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The laser antireflection film is a blue light antireflection film, and the blue light antireflection film satisfies: AOI = 0 - 30°, T in the wavelength band of 450 - 465 nm avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the wavelength band of 450 - 465 nm avg > 90%, R in the wavelength band of 480 - 700 nm avg > 95%; AOI = 30 - 60°, R in the wavelength band of 480 - 700 nm avg > 92%.

[0067] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, and has a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0068] The functional layer is composed of a second encapsulant and functional phase particles, and has a thickness of 5 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 6:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with a median particle size of 40 nm.

[0069] Example 8

[0070] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked.

[0071] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, polished on both sides to a surface roughness Ra ≤ 0.01 μm, with an anti-reflection film for laser plating on one side and an optical film for transmitting laser and reflecting fluorescence on the other side. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%. The optical film for transmitting laser and reflecting fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 to 60°, R in the 480 - 700 nm band avg > 92%.

[0072] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, and has a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0073] The functional layer is composed of a second encapsulant and functional-phase particles, with a thickness of 20 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 2:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional-phase particles are titanium oxide particles with a median particle size of 80 nm.

[0074] Example 9

[0075] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0076] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue-light anti-reflection film, and the blue-light anti-reflection film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%.

[0077] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering-enhancing particles, with a thickness of 40 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering-enhancing particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering-enhancing particles are alumina particles with a median particle size of 200 nm.

[0078] The functional layer is composed of a second encapsulant and functional-phase particles, with a thickness of 10 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional-phase particles are titanium oxide particles with a median particle size of 30 nm.

[0079] Example 10

[0080] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0081] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the wavelength range of 450 to 465 nm avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the wavelength range of 450 to 465 nm avg > 90%, R in the wavelength range of 480 to 700 nm avg > 95%; AOI = 30 to 60°, R in the wavelength range of 480 to 700 nm avg > 92%.

[0082] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, with a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 22 μm and second fluorescent particles with a median particle size of 8 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0083] The functional layer is composed of a second encapsulant and functional phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with a median particle size of 40 nm.

[0084] Example 11

[0085] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0086] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the wavelength range of 450 to 465 nm avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the wavelength range of 450 to 465 nm avg > 90%, R in the wavelength range of 480 to 700 nm avg > 95%; AOI = 30 to 60°, R in the wavelength range of 480 to 700 nm avg > 92%.

[0087] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, and has a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 15 μm and second fluorescent particles with a median particle size of 3 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are alumina particles with a median particle size of 200 nm.

[0088] The functional layer is composed of a second encapsulant and functional phase particles, and has a thickness of 15 μm. Among them, the mass ratio of the functional phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional phase particles are titanium oxide particles with an internal hollow size of 40 nm.

[0089] Example 12

[0090] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0091] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm, with an anti-reflection film for laser plating on one side and an optical film for transmitting laser and reflecting fluorescence on the other side. The anti-reflection film for laser is a blue light anti-reflection film, and the blue light anti-reflection film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%. The optical film for transmitting laser and reflecting fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 to 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 to 60°, R in the 480 - 700 nm band avg > 92%.

[0092] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering enhancement particles, and has a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering enhancement particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic silicon oxide. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering enhancement particles are silica particles with a median particle size of 200 nm.

[0093] The functional layer is composed of a second encapsulant and functional-phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic silicon oxide. The functional-phase particles are PMMA with an internal hollow size of 40 nm.

[0094] Example 13

[0095] The transmissive wavelength conversion device of this example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence.

[0096] The transparent substrate is a circular sapphire substrate with a thickness of 1.6 mm, double-sided polished to a surface roughness Ra ≤ 0.01 μm. One side is coated with an anti-reflection film for laser, and the other side is coated with an optical film that transmits laser and reflects fluorescence. The anti-reflection film for laser is a blue-light anti-reflection film, and the blue-light anti-reflection film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%. The optical film that transmits laser and reflects fluorescence is a blue-transmitting and yellow-reflecting film, and the blue-transmitting and yellow-reflecting film satisfies: AOI = 0 - 30°, T in the 450 - 465 nm band avg > 90%, R in the 480 - 700 nm band avg > 95%; AOI = 30 - 60°, R in the 480 - 700 nm band avg > 92%.

[0097] The fluorescent layer is composed of a first encapsulant, fluorescent particles, and scattering-enhancing particles, with a thickness of 35 μm. Among them, the mass ratio of the fluorescent particles to the first encapsulant is 10:1, and the scattering-enhancing particles account for 10 wt% in the fluorescent layer. The first encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The fluorescent particles include first fluorescent particles with a median particle size of 18 μm and second fluorescent particles with a median particle size of 5 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is 4:1. The scattering-enhancing particles are alumina particles with a median particle size of 200 nm.

[0098] The functional layer is composed of a second encapsulant and functional-phase particles, with a thickness of 15 μm. Among them, the mass ratio of the functional-phase particles to the second encapsulant is 3:10. The second encapsulant is an inorganic glass of the Zn-B-Si-Al-O system. The functional-phase particles are titanium oxide particles and magnesium oxide particles with a median particle size of 40 nm (mass ratio of 13:1).

[0099] Comparative Example 1

[0100] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer stacked in sequence. Except that the mass ratio of the first fluorescent particles to the second fluorescent particles is 1:0 (i.e., there are no second fluorescent particles), the others are the same as in Example 6.

[0101] Comparative Example 2

[0102] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the mass ratio of the first fluorescent particles to the second fluorescent particles is 0:1 (i.e., there are no first fluorescent particles), the others are the same as in Example 6.

[0103] Comparative Example 3

[0104] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the fluorescent layer does not contain scattering enhancement particles, the others are the same as in Example 8.

[0105] Comparative Example 4

[0106] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the mass ratio of the functional phase particles to the second encapsulant is 1:10, the others are the same as in Example 6.

[0107] Comparative Example 5

[0108] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the mass ratio of the functional phase particles to the second encapsulant is 8:10, the others are the same as in Example 6.

[0109] Comparative Example 6

[0110] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the thickness of the functional layer is 30 μm, the others are the same as in Example 6.

[0111] Comparative Example 7

[0112] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the thickness of the fluorescent layer is 55 μm, the others are the same as in Example 6.

[0113] Comparative Example 8

[0114] The transmissive wavelength conversion device of this comparative example includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked. Except that the thickness of the functional layer is 2 μm, the others are the same as in Example 6.

[0115] The transmissive wavelength conversion devices of the above-mentioned examples and comparative examples were respectively assembled on a laser light source system (5m@27mm test lens) for performance testing. The test contents are as follows, and the test results are shown in Table 1.

[0116] (1) Measurement of central illuminance at 2W blue light power: Turn on the light source, align the light output port of the light source with the entrance of the integrating sphere so that the light enters the integrating sphere completely, and measure the central illuminance of the transmissive wavelength conversion device at 2W blue light power.

[0117] (2) Measurement of the tolerance limit blue light power and the limit central illuminance: Adjust the blue light power to a lower range, and then continuously increase the blue light power. Observe the change in luminous flux. When the luminous flux no longer increases or even decreases, record the blue light power and the central illuminance, which are the tolerance limit blue light power and the limit central illuminance of the transmissive wavelength conversion device.

[0118] (3) Wall-mounted light spot effect: Project the light spot onto the wall and observe the uniformity of the light spot.

[0119] Table 1

[0120]

[0121] Remark: A serious blue light leakage spot means that multiple blue light spots appear in the entire test light spot during the wall-mounted light spot effect test.

[0122] Obviously, the above embodiments of this solution are only examples for clearly illustrating this solution, rather than limitations on the implementation manners of this solution. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of this solution shall be included in the protection scope of the claims of this solution.

Claims

1. A transmissive wavelength conversion device, characterized in that, It includes a transparent substrate, a fluorescent layer, and a functional layer that are sequentially stacked; the fluorescent layer includes a first encapsulant, fluorescent particles, and scattering enhancement particles, and the mass ratio of the fluorescent particles to the first encapsulant is (5-20):1, and the scattering enhancement particles account for 5-15 wt% in the fluorescent layer; the fluorescent particles include first fluorescent particles with a median particle size of 15-22 μm and second fluorescent particles with a median particle size of 3-8 μm, and the mass ratio of the first fluorescent particles to the second fluorescent particles is (2-6):1; the median particle size or internal hollow size of the scattering enhancement particles is 200-400 nm; the functional layer includes a second encapsulant and functional phase particles, and the mass ratio of the functional phase particles to the second encapsulant is (2-6):10; the median particle size or internal hollow size of the functional phase particles is 10-80 nm; the thickness of the fluorescent layer is 20-50 μm, and the thickness of the functional layer is 5-20 μm.

2. The transmissive wavelength conversion device according to claim 1, wherein the median particle size or internal hollow size of the functional phase particles is 10-40 nm.

3. The transmissive wavelength conversion device according to claim 1, wherein the scattering enhancement particles are one or more of metal oxide particles and organic resin particles; and / or the functional phase particles are one or more of metal oxide particles and organic resin particles.

4. The transmissive wavelength conversion device according to claim 3, wherein the scattering enhancement particles are one or more of alumina, silica, titanium oxide, PS, and PMMA; and / or the functional phase particles are one or more of titanium oxide, zirconium oxide, magnesium oxide, alumina, zinc oxide, PS, and PMMA.

5. The transmissive wavelength conversion device according to claim 1, wherein the first encapsulant is organosilica, inorganic silicon oxide, or Zn-B-Si-Al-O-based inorganic glass; and / or the second encapsulant is organosilica, inorganic silicon oxide, or Zn-B-Si-Al-O-based inorganic glass.

6. The transmissive wavelength conversion device according to any one of claims 1-5, wherein the thickness of the transparent substrate is 0.2-3 mm.

7. The transmissive wavelength conversion device according to any one of claims 1-5, wherein both sides of the transparent substrate are polished, and the surface roughness of the polished surface is preferably Ra≤0.01 μm; and / or a laser antireflection film is coated on the side of the transparent substrate facing away from the fluorescent layer, and an optical film that transmits laser and reflects fluorescence is coated on the side facing the fluorescent layer.

8. The transmissive wavelength conversion device according to claim 7, wherein The laser anti-reflection film is a blue light anti-reflection film, and the average transmittance of the blue light anti-reflection film for light in the wavelength range of 450 - 465 nm is greater than 90% within the incident angle range of 0 - 30°; and / or the optical film for transmitting laser and reflecting fluorescence is a blue light transmitting and yellow light reflecting film, and the average transmittance of the blue light transmitting and yellow light reflecting film for light in the wavelength range of 450 - 465 nm is greater than 90% within the incident angle range of 0 - 30°, and the average reflectance of the blue light transmitting and yellow light reflecting film for light in the wavelength range of 480 - 700 nm is greater than 95%, and the average reflectance of the blue light transmitting and yellow light reflecting film for light in the wavelength range of 480 - 700 nm is greater than 92% within the incident angle range of 30 - 60°.

9. A method for preparing a transmissive wavelength conversion device according to any one of claims 1 to 8, characterized in that, Comprising the following steps: Processing the transparent substrate: Processing the transparent substrate to a target thickness and performing double-sided polishing so that the surface roughness Ra of the polished surface ≤ 0.01 μm; Fabricating the fluorescent layer: Mixing a first encapsulant, fluorescent particles, and scattering enhancement particles to prepare a fluorescent slurry, coating the fluorescent slurry on the surface of the processed transparent substrate, and performing high-temperature sintering to form the fluorescent layer; Fabricating the functional layer: Mixing a second encapsulant and functional phase particles to prepare a functional slurry, coating the functional slurry on the surface of the fluorescent layer, and performing high-temperature sintering to form the functional layer.

10. The method for preparing a transmissive wavelength conversion device according to claim 9, wherein The step of processing the transparent substrate further includes: Depositing a laser anti-reflection film on one of the polished surfaces and depositing an optical film for transmitting laser and reflecting fluorescence on the other polished surface; In the step of fabricating the fluorescent layer: The fluorescent slurry is coated on the optical film for transmitting laser and reflecting fluorescence.

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