High-efficiency high-brightness laser illumination waveguide structure composite transparent ceramic and preparation method thereof

Abstract

The invention discloses high-efficiency and high-brightness laser illumination waveguide structure composite transparent ceramic and a preparation method thereof, and belongs to the technical field of transparent ceramic. The composite transparent ceramic is of a three-layer structure, the middle layer is made of Dy-doped YAG transparent ceramic, the chemical composition general formula of the middle layer is (Y1-xDyx) 3Al5O12, x is the molar percentage of Dy < 3 + > doped Y < 3 + > position and is larger than or equal to 0.01 and smaller than or equal to 0.08, the two sides of the middle layer are claddings, the two sides of the middle layer are made of YAG transparent ceramic, and the chemical composition general formula of the middle layer is Y3Al5O12. The preparation method comprises the following steps: preparing an intermediate layer Dy: YAG waveguide layer and a YAG cladding layer by adopting a water-based tape casting technology and a vacuum sintering method, then sequentially carrying out lamination, dry pressing and glue discharging on the cladding layer, the waveguide layer and the cladding layer, and carrying out cold isostatic pressing treatment to obtain a compact and uniform green body. The waveguide ceramic prepared by the invention can obtain mode-controllable directional white light illumination, has the characteristics of high directionality and laser directionality, has the advantages in long-distance illumination, and is mature in process, relatively low in cost and suitable for mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transparent ceramics, in particular to a high-efficiency high-brightness laser illumination waveguide structure composite transparent ceramic and a preparation method thereof. BACKGROUND

[0002] Laser display technique (LDT) has significant advantages such as rich color, high saturation and strong contrast, and is widely considered as the mainstream technology of future high-end display such as large-screen projection, laser television and mobile phone projection. Among them, the light source is the core component of laser display. The current mainstream schemes of laser display light source include laser display light source based on RGB three primary color laser synthesis and fluorescent conversion type laser display light source.

[0003] The former directly uses high-power and color-pure laser devices to realize white laser output through beam combination, and there is no Stokes loss generated by fluorescent powder, the electro-optical conversion efficiency is higher, and high-power and high-brightness white light output can be easily obtained. However, the cost of the three-color synthetic laser display light source is high, and speckle is easy to occur, so the application range is small. The latter has been developed more fully, and many researchers at home and abroad have devoted themselves to improving the efficiency, thermal conductivity, and fluorescence thermal stability of the fluorescent body, and have produced many excellent results, so that the laser lighting and display light source based on the fluorescent converter can be realized. However, the complex preparation process leads to a substantial increase in cost. Moreover, the fluorescent converter type laser display light source covers the high directionality of laser, and the power density saturation threshold is difficult to improve. At present, there is no clear improvement route. ASE light source is a light source based on spontaneous emission amplification, which is generated by stimulated emission of spontaneous emission fluorescence. The output power of the ASE light source is currently in the kW level, and the spectral range is wide, the performance is stable, and other characteristics are consistent with the pursuit of laser lighting, so the ASE effect has important reference significance for laser lighting. The literature (Xu J, Huang L, Leng J, et al. Optics Express, 2015, 23 (5): 5485-5490.) realizes the kilowatt-level power output of the super-fluorescent fiber light source, and the highest power reaches 1.01kW. The ASE light source prepared in the literature (Xu J, Ye J, Xiao H, et al. High Power Laser Science and Engineering, 2018, 6: e46.) generates the highest power of 3.14kW in the single-fiber output of the current broadband super-fluorescent light source, and the light-light conversion efficiency is 80.74%. However, the wavelength of the current high-power ASE light source is in the infrared region, and there are few ASE light sources in the visible light band for lighting. The literature (Liu X, Chen B, Pun E Y B, et al. Optical Materials, 2013, 35 (3): 590-595.) uses ion exchange method to construct Tm 3+ / Ho 3+ / Yb 3+ co-doped NMAG glass waveguide, which is excited by 974nm laser to generate ASE white light. However, the glass has poor thermal conductivity, and the ion exchange method can only be used in glass, and the ion exchange method cannot prepare precise waveguide layers.

[0004] In summary, the properties of the ASE light source can be used for laser lighting, but there are few applications in the visible light range at present, and no waveguide structure suitable for the ASE light source in the visible light band has been found. SUMMARY

[0005] In view of the problems existing in the prior art, the application provides a high-efficiency high-brightness laser illumination waveguide structure composite transparent ceramic and a preparation method thereof, which can meet the application requirements of high-power laser display products.

[0006] To achieve the above-mentioned object, the application adopts the following technical scheme:

[0007] The first aspect of the application provides a high-efficiency high-brightness laser illumination waveguide structure composite transparent ceramic, which has a three-layer structure, the middle layer is a waveguide layer, the material is Dy 3+ doped YAG transparent ceramic, the general chemical formula is (Y 1-x Dy x )3Al5O 12 , wherein x is the mole percentage of Y 3+ site doped with Dy 3+ , 0.01<=x<=0.08, and the thickness of the middle waveguide layer is 50-100 microns; the two sides are cladding layers, the material is YAG transparent ceramic, the general chemical formula is Y3Al5O 12 , and the thickness of the single cladding layer is 1.25-2.5 mm; the middle layer and the cladding layer form a fluorescent transmission waveguide, the fluorescent light is transmitted in the middle layer under the constraint of the interface between the middle layer and the cladding layer, the cladding layer and the air form an excitation light waveguide, the excitation light is transmitted along the cladding layer under the constraint of the interface between the cladding layer and the air, penetrates through the middle layer, excites the fluorescent material in the middle layer to emit light, and amplifies the fluorescent light generated in the middle layer when the fluorescent light is transmitted in the fluorescent transmission waveguide, thereby generating high-efficiency high-brightness white light.

[0008] The composite transparent ceramic provided by the application has a thermal conductivity of greater than or equal to 11 W·m -1 ·K -1 , a light efficiency of greater than or equal to 250 lm / W, and a saturation light power density threshold of greater than or equal to 40 W / mm 2 . The above-mentioned transparent ceramic with a waveguide structure cooperates with the Dy:YAG fluorescent material in the waveguide middle layer to generate ASE output under the excitation of pump light, and the output light has a color rendering index of greater than or equal to 85.

[0009] The second aspect of the application provides a preparation method of the above-mentioned high-efficiency high-brightness laser illumination waveguide structure composite transparent ceramic, which is prepared by a flow casting technology and a vacuum sintering method, and includes the following steps:

[0010] S1, preparing a waveguide layer Dy:YAG, the general chemical formula is (Y 1-x Dy x )3Al5O 12 , wherein x is the mole percentage of Y 3+ site doped with Dy 3+ ; 0.01<=x<=0.08;

[0011] S1-1. Weigh yttrium oxide, aluminum oxide, and dysprosium oxide as raw material powders according to the stoichiometric ratio of each element in the molecular formula, add sintering aids, mix by ball milling, dry and sieve to obtain mixed powder;

[0012] S1-2. First, the mixed powder is ball-milled with water and dispersant. Then, binder, plasticizer and defoamer are added and ball-milling is continued to obtain slurry.

[0013] S1-3. Adjust the height between the scraper and the substrate to 130-260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying, peel it off from the substrate to form a cast film with a thickness of 50-100μm. After cutting, obtain the finished green blank to be sintered.

[0014] S2. Preparation of cladding material YAG

[0015] S2-1. Weigh yttrium oxide and aluminum oxide as raw material powders according to the stoichiometric ratio of each element in the molecular formula, add sintering aids, mix by ball milling, dry and sieve to obtain mixed powder;

[0016] S2-2. First, the mixed powder is ball-milled with water and dispersant. Then, binder, plasticizer and defoamer are added and ball-milling is continued to obtain slurry.

[0017] S2-3. Adjust the height between the scraper and the substrate to 130-260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying, peel it off from the substrate to form a cast film with a thickness of 50-100μm. After cutting, it is made into a green blank to be sintered.

[0018] S3. Preparation of waveguide ceramics

[0019] S3-1. The cladding layer is stacked and dry-pressed in the order of cladding-waveguide layer-cladding layer. After the dry-pressed blank is debonded, it is then subjected to cold isostatic pressing to obtain a dense and uniform blank.

[0020] S3-2. The blank is vacuum sintered. The sintered ceramic is then annealed to eliminate defects such as oxygen vacancies. Finally, it is ground, polished, and finely ground on the sides to prepare transparent waveguide ceramic.

[0021] Preferably, the sintering aids mentioned in steps S1-1 and S2-1 are MgO and TEOS, with the amount of MgO added being 0.05-0.25 wt% of the total mass of the raw material powder, and the amount of TEOS added being 0.4-1.0 wt% of the total mass of the raw material powder.

[0022] Preferably, the dispersant in steps S1-2 and S2-2 is polyacrylic acid, and the amount added is 0.8-1.5 wt% of the mass of the mixed powder; the binder is polyvinyl alcohol, and the amount added is 6.0-10.0 wt% of the mass of the mixed powder; the plasticizer is polyethylene glycol, and the amount added is 4.2-7.0 wt% of the mass of the mixed powder; and the defoamer is polypropylene glycol, and the amount added is 2.0-3.5 wt% of the mass of the mixed powder.

[0023] Preferably, in step S3-1, the adhesive is discharged at 800°C for 10 hours.

[0024] Preferably, in step S3-1, the material is subjected to cold isostatic pressing at 250 MPa for 1 minute.

[0025] Preferably, in step S3-3, the vacuum sintering process is carried out at 1760°C with a firing rate of 10... 3 The pressure sintering process is 30 hours, and the annealing process is annealing in air at 1450℃ for 10 hours.

[0026] This invention presents an ASE-based laser display light source solution that combines the advantages of tri-color synthesis and fluorescence conversion laser illumination devices. It introduces the concept of stimulated emission into the illumination system, amplifying spontaneously emitted fluorescence through stimulated emission. Furthermore, it manages the beam modes within the system using waveguide effects, achieving mode-controllable directional white light illumination. The use of waveguide structures to confine the ASE modes effectively improves beam quality and solves problems such as low pre-fluorescence extraction rate, difficulty in fluorescence shaping, and blue centering of far-field beams in traditional phosphor laser illumination.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The waveguide ceramic prepared in this invention can achieve mode-controllable directional white light illumination, exhibiting high directionality and maintaining the directional characteristics of lasers. This provides advantages in long-distance illumination. It can generate ASE white light under 353nm-365nm ultraviolet laser excitation, with a beam angle ≤2°, and avoids fluorescence saturation caused by excessively long spontaneous emission level lifetimes. The laser excitation power density is 40W / mm². 2 At that time, the maximum luminous efficiency is ≥250lm / W.

[0029] 2. The water-based tape casting method is used to prepare waveguide ceramics. By adjusting the gap height of the scraper and carrier tape, a waveguide layer with a diameter of 50-100μm can be obtained. The optical waveguide structure can be formed in one step. Relying on the high-precision tape casting method, the waveguide accuracy can be achieved at the hundred-micron level. This process is mature, has low cost, and is suitable for mass production.

[0030] 3. The waveguide structure is used to confine the ASE mode, which effectively improves the beam quality and solves the problems of low pre-fluorescence extraction rate, difficulty in fluorescence shaping, and blue center of far-field spot in traditional phosphor laser illumination. Attached Figure Description

[0031] Figure 1 This is a transmittance curve of the waveguide ceramics prepared in Embodiments 1, 2, and 3 of the present invention.

[0032] Figure 2 This is the color coordinate diagram of the waveguide ceramic prepared in Example 1 of the present invention under 353nm ultraviolet laser excitation. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] A method for preparing a high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic includes the following steps:

[0036] S1: Fabrication of waveguide layer Dy:YAG

[0037] S1-1 uses Y2O3, Al2O3, and Dy2O3 as raw material powders, according to the molecular formula (Y 0.99 Dy 0.01 )3Al5O 12 Weigh out 33.7g of yttrium oxide, 25.7g of aluminum oxide, and 0.56g of dysprosium oxide according to the stoichiometric ratio. Add 0.06g of MgO and 330μL TEOS as sintering aids. After ball milling and mixing, dry at 55℃ for 10h and sieve through a 100-mesh sieve three times to obtain a mixed powder.

[0038] S1-2 First, 50g of mixed powder is ball-milled with 50g of deionized water and 0.4g of dispersant polyacrylic acid. Then, 3g of binder polyvinyl alcohol, 2.1g of plasticizer polyethylene glycol and 1g of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0039] S1-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 25℃ for 24h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 3.5mm×2cm to make a finished green blank to be sintered.

[0040] S2: Preparation of cladding material YAG

[0041] S2-1 uses Y2O3 and Al2O3 as raw material powders, according to the molecular formula Y3Al5O 12 Weigh out 34.24g of yttrium oxide and 25.76g of aluminum oxide according to the stoichiometric ratio, add 0.06g of MgO and 330μL of TEOS as sintering aid, ball mill and mix them, dry at 55℃ for 10h, and sieve through a 100-mesh sieve 3 times to obtain mixed powder;

[0042] S2-2 First, 50g of mixed powder is ball-milled with 50g of deionized water and 0.6g of dispersant polyacrylic acid. Then, 3g of binder polyvinyl alcohol, 2.1g of plasticizer polyethylene glycol and 1g of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0043] S2-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 25℃ for 24h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 3.5mm×2cm to make a finished green blank to be sintered.

[0044] S3: Fabrication of waveguide ceramics

[0045] S3-1 is dry-pressed in the order of cladding-waveguide-cladding, with 25 layers of upper and lower cladding and one waveguide layer. After dry pressing, the blank is debonded at 800℃ for 10 hours and then cold isostatically pressed at 250MPa for 1 minute to obtain a dense and uniform blank.

[0046] S3-2 involves sintering the billet in a vacuum sintering furnace at 1760°C with a sintering rate of 10... 3 The ceramic was sintered under pressure for 30 hours, and then annealed in air at 1450℃ for 10 hours to eliminate defects such as oxygen vacancies. Finally, it was ground, polished, and finely ground on the sides to produce a transparent waveguide ceramic.

[0047] The transparent waveguide ceramic prepared in this embodiment has a maximum transmittance of 82.13% in the visible light range. Figure 1 As shown; by excitation with a 353nm ultraviolet laser, white ASE emission can be produced, with color coordinates (0.33, 0.35). Figure 2 As shown; the color rendering index is 89, the quantum efficiency is 50%, and the laser excitation power density is 40 W / mm². 2 At that time, the maximum luminous efficiency was 253 lm / W, and the thermal conductivity was 11.9 W·m. -1 ·K -1 The optical gain coefficient is 33.38 cm. -1 The maximum divergence angle of the beam is 1.5°.

[0048] Example 2

[0049] A method for preparing a high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic includes the following steps:

[0050] S1: Fabrication of waveguide layer Dy:YAG

[0051] S1-1 uses Y2O3, Al2O3, and Dy2O3 as raw material powders, according to the molecular formula (Y 0.97 Dy 0.03 )3Al5O 12 Weigh out 32.9g of yttrium oxide, 25.5g of aluminum oxide, and 1.68g of dysprosium oxide according to the stoichiometric ratio. Add 0.15g of MgO and 350μL TEOS as sintering aids. After ball milling and mixing, dry at 55℃ for 10h and then sieve through a 100-mesh sieve three times to obtain a mixed powder.

[0052] S1-2 First, 50g of mixed powder is ball-milled with 70g of deionized water and 0.75g of dispersant polyacrylic acid. Then, 5g of binder polyvinyl alcohol, 3.5g of plasticizer polyethylene glycol and 1.75g ​​of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0053] S1-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 35℃ for 48h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 1.5cm×5cm to make a green blank to be sintered.

[0054] S2: Preparation of cladding material YAG

[0055] S2-1 uses Y2O3 and Al2O3 as raw material powders, according to the molecular formula Y3Al5O 12 34.24 g of yttrium oxide and 25.76 g of aluminum oxide were weighed according to the stoichiometric ratio. 0.15 g of MgO and 350 μL of TEOS were added as sintering aids. After ball milling and mixing, the mixture was dried at 55 °C for 10 h and then sieved three times through a 100-mesh sieve to obtain a mixed powder.

[0056] S2-2 First, 50g of mixed powder is ball-milled with 70g of deionized water and 0.75g of dispersant polyacrylic acid. Then, 5g of binder polyvinyl alcohol, 3.5g of plasticizer polyethylene glycol and 1.75g ​​of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0057] S2-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 35℃ for 48h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 1.5cm×5cm to make a finished green blank to be sintered.

[0058] S3: Fabrication of waveguide ceramics

[0059] S3-1 is dry-pressed in the order of cladding-waveguide-cladding, with 25 layers of upper and lower cladding and one waveguide layer. After dry pressing, the blank is debonded at 800℃ for 10 hours and then cold isostatically pressed at 250MPa for 1 minute to obtain a dense and uniform blank.

[0060] S3-2 involves sintering the billet in a vacuum sintering furnace at 1760°C with a sintering rate of 10... 3 The ceramic was sintered under pressure for 30 hours, and then annealed in air at 1450℃ for 10 hours to eliminate defects such as oxygen vacancies. Finally, it was ground, polished, and finely ground on the sides to produce a transparent waveguide ceramic.

[0061] The transparent waveguide ceramic prepared in this embodiment has a maximum transmittance of 81.05% in the visible light range. Figure 1 As shown, white ASE emission can be generated by excitation with a 353nm ultraviolet laser, with color coordinates (0.33, 0.35); the color rendering index is 86, the quantum efficiency is 46%, and the laser excitation power density is 40W / mm². 2 At that time, the maximum luminous efficiency was 251 lm / W, and the thermal conductivity was 11.4 Wm. -1 K -1 The optical gain coefficient is 33.02 cm⁻¹. -1 The maximum divergence angle of the beam is 2.0°.

[0062] Example 3

[0063] A method for preparing a high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic includes the following steps:

[0064] S1: Fabrication of waveguide layer Dy:YAG

[0065] S1-1 uses Y2O3, Al2O3, and Dy2O3 as raw material powders, according to the molecular formula (Y 0.92 Dy 0.08 )3Al5O 12 Weigh out 30.8g of yttrium oxide, 25.1g of aluminum oxide, and 4.43g of dysprosium oxide according to the stoichiometric ratio. Add 0.03g of MgO and 300μL of LTEOS as sintering aids. After ball milling and mixing, dry at 55℃ for 10h and then sieve through a 100-mesh sieve three times to obtain a mixed powder.

[0066] S1-2 First, 50g of mixed powder is ball-milled with 60g of deionized water and 0.6g of dispersant polyacrylic acid. Then, 4g of binder polyvinyl alcohol, 2.8g of plasticizer polyethylene glycol and 1.5g of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0067] S1-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 30℃ for 36h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 5mm×3cm to make a finished green blank to be sintered.

[0068] S2: Preparation of cladding material YAG

[0069] S2-1 uses Y2O3 and Al2O3 as raw material powders, according to the molecular formula Y3Al5O 12 Weigh out 34.24g of yttrium oxide and 25.76g of aluminum oxide according to the stoichiometric ratio, add 0.03g of MgO and 300μL of TEOS as sintering aid, ball mill and mix them, dry at 55℃ for 10h, and then sieve through a 100-mesh sieve 3 times to obtain mixed powder.

[0070] S2-2 First, 50g of mixed powder is ball-milled with 60g of deionized water and 0.6g of dispersant polyacrylic acid. Then, 4g of binder polyvinyl alcohol, 2.8g of plasticizer polyethylene glycol and 1.5g of defoamer polypropylene glycol are added and ball-milled again to obtain a slurry.

[0071] S2-3 Adjust the height between the scraper and the substrate to 260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying at 30℃ for 36h, peel it off from the substrate to form a cast film with a thickness of 100μm. Then cut the cast film to a size of 5mm×3cm to make a finished green blank to be sintered.

[0072] S3: Fabrication of waveguide ceramics

[0073] S3-1 is dry-pressed in the order of cladding-waveguide-cladding, with 25 layers of upper and lower cladding and one waveguide layer. After dry pressing, the blank is debonded at 800℃ for 10 hours and then cold isostatically pressed at 250MPa for 1 minute to obtain a dense and uniform blank.

[0074] S3-2 involves sintering the billet in a vacuum sintering furnace at 1760°C with a sintering rate of 10... 3 The ceramic was sintered under pressure for 30 hours, and then annealed in air at 1450℃ for 10 hours to eliminate defects such as oxygen vacancies. Finally, it was ground, polished, and finely ground on the sides to produce a transparent waveguide ceramic.

[0075] The transparent waveguide ceramic prepared in this embodiment has a maximum transmittance of 79.01% in the visible light range. Figure 1 As shown, white ASE emission can be generated by excitation with a 353nm ultraviolet laser, with color coordinates (0.33, 0.35); the color rendering index is 85, the quantum efficiency is 45%, and the laser excitation power density is 40W / mm². 2At that time, the maximum luminous efficiency was 250 lm / W, and the thermal conductivity was 11.3 Wm. -1 K -1 The optical gain coefficient is 33.03 cm. -1 The maximum divergence angle of the beam is 1.8°.

[0076] It should be noted that in the above embodiments, the height between the squeegee and the substrate is set to 260 μm, resulting in a cast film thickness of 100 μm. Alternatively, the height between the squeegee and the substrate can be adjusted to 130 μm, resulting in a cast film thickness of 50 μm.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic, characterized in that, The composite transparent ceramic has a three-layer structure with cladding layers on both sides. The material is YAG transparent ceramic, and its general chemical formula is Y3Al5O. 12 The middle layer is a waveguide layer, and the material is Dy. 3+ Doped YAG transparent ceramics have the general chemical formula (YAG) 1-x Dy x )3Al5O 12 , where x is Dy 3+ Y-doped 3+ The percentage of moles in a given position, 0.01 ≤ x ≤ 0.

08.

2. The high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic according to claim 1, characterized in that, The thickness of the intermediate waveguide layer is 50μm-100μm, and the thickness of the single-sided cladding layer is 1.25mm-2.5mm.

3. A method for preparing a high-efficiency, high-brightness laser illumination waveguide structure composite transparent ceramic as described in claim 1 or 2, characterized in that, The process employs water-based casting technology and vacuum sintering, including the following steps: S1. Prepare the waveguide layer Dy:YAG, whose general chemical formula is (Y 1-x Dy x )3Al5O 12 , where x is Dy 3+ Y-doped 3+ The percentage of moles in a given position; 0.01 ≤ x ≤ 0.08; S1-1. Weigh yttrium oxide, aluminum oxide, and dysprosium oxide as raw material powders according to the stoichiometric ratio of each element in the molecular formula, add sintering aids, mix by ball milling, dry and sieve to obtain mixed powder; S1-2. First, the mixed powder is ball-milled with water and dispersant. Then, binder, plasticizer and defoamer are added and ball-milling is continued to obtain slurry. S1-3. Adjust the height between the scraper and the substrate to 130-260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying, peel it off from the substrate to form a cast film with a thickness of 50μm-100μm. After cutting, it is made into a green blank to be sintered. S2. Preparation of cladding material YAG S2-1. Weigh yttrium oxide and aluminum oxide as raw material powders according to the stoichiometric ratio of each element in the molecular formula, add sintering aids, mix by ball milling, dry and sieve to obtain mixed powder; S2-2. First, the mixed powder is ball-milled with water and dispersant. Then, binder, plasticizer and defoamer are added and ball-milling is continued to obtain slurry. S2-3. Adjust the height between the scraper and the substrate to 130-260μm, pour the slurry into the casting machine for casting, and obtain a wet blank. After drying, peel it off from the substrate to form a cast film with a thickness of 50μm-100μm. After cutting, it is made into a green blank to be sintered. S3. Preparation of waveguide ceramics S3-1. The cladding layer is stacked and dry-pressed in the order of cladding-waveguide layer-cladding layer. After the dry-pressed blank is debonded, it is then subjected to cold isostatic pressing to obtain a dense and uniform blank. S3-2. The blank is vacuum sintered. The sintered ceramic is then annealed to eliminate defects such as oxygen vacancies. Finally, it is ground, polished, and finely ground on the sides to prepare transparent waveguide ceramic.

4. The preparation method according to claim 3, characterized in that, The sintering aids mentioned in steps S1-1 and S2-1 are MgO and TEOS. The amount of MgO added is 0.05-0.25 wt% of the total mass of the raw material powder, and the amount of TEOS added is 0.4-1.0 wt% of the total mass of the raw material powder.

5. The preparation method according to claim 3, characterized in that, The dispersant mentioned in steps S1-2 and S2-2 is polyacrylic acid, and the amount added is 0.8-1.5 wt% of the mass of the mixed powder; the binder is polyvinyl alcohol, and the amount added is 6.0-10.0 wt% of the mass of the mixed powder; the plasticizer is polyethylene glycol, and the amount added is 4.2-7.0 wt% of the mass of the mixed powder; the defoamer is polypropylene glycol, and the amount added is 2.0-3.5 wt% of the mass of the mixed powder.

6. The preparation method according to claim 3, characterized in that, In step S3-1, the adhesive is discharged at 800℃ for 10 hours.

7. The preparation method according to claim 3, characterized in that, In step S3-1, cold isostatic pressing is performed at 250 MPa for 1 min.

8. The preparation method according to claim 3, characterized in that, In step S3-3, the vacuum sintering process is carried out at 1760°C with a firing rate of 10... 3 The pressure sintering process is 30 hours, and the annealing process is annealing in air at 1450℃ for 10 hours.

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