A gain medium laminated structure, a preparation method thereof, and an application thereof

Abstract

This application belongs to the field of organic laser technology, and specifically discloses a gain medium laminated structure, a preparation method and an application thereof. The gain medium laminated structure is formed by sequentially depositing two layers of gain media on the same substrate to form a gain medium laminated structure. The gain medium laminated structure is used in a laminated structure device, and each layer of gain medium exhibits a gain effect, enabling in-situ dual ASE and laser emission.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic lasers, and particularly relates to a gain medium laminated structure and a preparation method thereof, an application of using the gain medium laminated structure as a laminated planar waveguide to realize multi-band amplified spontaneous emission, and an application of using the gain medium laminated structure as a laminated DFB grating device to realize multi-band laser parallel emission. Background Art

[0002] The history of organic lasers is almost as long as that of lasers themselves. Organic materials stand out due to their large optical gain, wide emission coverage, and good material compatibility. As a laser medium, organic polymers have a large stimulated emission cross-section, and population inversion can be achieved under low optical pumping energy. A simple waveguide structure is sufficient to generate low-threshold gain narrowing in a sub-micron thick film. Laser emission can be easily achieved using a grating, and the optical wavelength can be easily tuned. Among all potential gain media, organic materials stand out due to their large optical gain, wide emission coverage, and good material compatibility.

[0003] Organic-inorganic halide perovskites combine advantages such as large optical absorption, long balanced carrier diffusion length, and low-cost low-temperature synthesis methods. Perovskites also exhibit interesting optoelectronic properties in the gain layers of light-emitting diodes (LEDs) and lasers. Perovskite-based LEDs have recently reached a maximum external quantum efficiency (EQE) of over 20%. In the field of lasers, after the initial demonstrations of optically pumped room-temperature ASE and lasers, the potential of perovskites with low cost, emission tunability, and solution processability is also being exploited and applied to laser diodes.

[0004] However, considering the potential competitors for next-generation display technologies, laser displays have also attracted increasing interest due to their high brightness, wide color gamut, and high contrast. Utilizing the unique property of lasers, namely the polarization property of emission, provides great feasibility for directly fabricating three-dimensional images visible to the naked eye. Lasers are expected to be strong candidates for the light source of next-generation display technologies.

[0005] To develop a full-color laser display panel, a large-scale periodic red, green, and blue pixel laser array is required. If gain media with different light properties are arranged periodically as integrated pixels and corresponding feedback structures are formed for laser output, a microfabrication process is needed, which is relatively complex to implement. Therefore, integrated multi-band lasers are more difficult to achieve than single-band lasers. However, multi-band lasers have richer colors and are obviously more applicable in fields such as laser display and scanning detection. Periodic grating structures can be obtained through programmatically controllable electron beam lithography. The advantage of this large-area film formation avoids the micro-operation of the gain medium. The device structure using stacked thin films can support the parallel output of multi-color lasers and can be used as a design scheme for multi-band lasers and a method for realizing large-scale full-color laser displays.

[0006] Organics and perovskites have good compatibility with solution processing. Large-area device fabrication can be easily achieved through a simple solution deposition method, and the good film-forming property provides more choices for substrate materials. Based on this, our research group provided a scheme for fabricating two gain medium structures using the solution deposition method. See the published literature: Sun Huizhi, Research on the Performance of Organic Polymer and Perovskite Material Multilayer Film Laser Devices [D]. Nanjing University of Posts and Telecommunications, 2020. DOI: 10.27251 / d.cnki.gnjdc.2020.000733. However, for the two-layer gain medium structure fabricated by the solution deposition method disclosed in the literature, an interface layer needs to be added to form a distinct boundary between the two gain media. This method of fabricating stacked devices by adding an interface layer is first cumbersome in the preparation process. Second, adding an interface layer in the grating structure is disadvantageous. The upper structure is highly separated from the grating, making it more difficult for the lower layer to receive energy and resulting in a higher threshold. Summary of the Invention

[0007] Based on the current state of the art, the present invention proposes a new device fabrication method, aiming to further simplify the construction of the gain medium stacked structure by the solution deposition method and reduce the interlayer loss and property degradation in the stacked structure of the stacked device. This fabrication method can integrate two or more gain media in the same laser device, obtaining a solution for achieving in-situ simultaneous multi-band amplified spontaneous emission (ASE) and lasing under single-beam optical pumping. This method is of great significance for the fabrication of large-area and flexible laser devices and can be applied to fields such as laser display. Moreover, the idea of this stacked structure expands the structure of laser devices, and the idea of integrating more structures into a single device has a guiding role in the progress of the organic light-emitting diode (OLED) industry and the organic laser field.

[0008] The technical solution of the present invention is as follows: The present invention discloses a preparation method of a gain medium laminated structure. The preparation method forms a gain medium laminated structure by sequentially depositing two layers of gain media on the same substrate, which is used in a laminated structure device. Each layer of gain medium exhibits a gain effect, and in-situ double ASE and laser emission can be achieved.

[0009] In a first aspect, the present invention discloses a preparation method of a gain medium laminated structure. As Figure 1 shown, the method includes the following steps: cleaning and drying the substrate material; dissolving the first gain medium in the first solvent to form a first gain medium solution, and dissolving the second gain medium in the second solvent to form a second gain medium solution; coating the first gain medium solution on the substrate, drying and annealing to form a first gain medium film, coating the second gain medium solution on the first gain medium film, and after drying and annealing, forming a second gain medium film; finally, preparing and forming the gain medium laminated structure, and the laminated structure is composed of the first gain medium and the second gain medium sequentially deposited and formed on the substrate material;

[0010] The first gain medium and the second gain medium include, but are not limited to, laser dyes, perovskites, organic small molecules, quantum dots, oligomers, and organic polymer materials that can be processed into films;

[0011] The first solvent is the solvent of the first gain medium solution; the second solvent is the solvent of the second gain medium solution, and the second solvent cannot dissolve the first gain medium to avoid severe degradation of the properties of the first gain medium film.

[0012] The substrate material is a transparent substrate or a grating substrate, and the production materials of the transparent substrate or the grating substrate are selected from quartz, glass, and flexible plastics;

[0013] Preferably, the first solvent and the second solvent are independently selected from methanol, ethanol, N,N-dimethylformamide (DMF), water, toluene, xylene, chloroform, chlorobenzene, and p-xylene;

[0014] Furthermore, when coating the first gain medium solution on the substrate, drying and annealing, the coating method includes, but is not limited to, drop coating or spin coating. Preferably, spin coating is used for coating. The specific steps are: the spin coating speed is 2000-6000 rpm, the spin coating acceleration is 4000-6000 rpm / s, and annealing is performed on a constant temperature hot stage at 100 °C for 2-5 min;

[0015] Further, a second gain medium solution is coated on the first gain medium film, dried and annealed. The coating method includes but is not limited to drop coating or spin coating. Preferably, spin coating is used for coating. The specific steps are as follows: the spin coating speed is 2000 - 6000 rpm, the spin coating acceleration is 4000 - 6000 rpm / s, and annealing is performed on a constant temperature hot stage at 100°C for 2 - 5 min;

[0016] Further, the preparation method of the gain medium laminate structure further includes spin coating at least one more layer of gain medium solution on the second gain medium. That is, the gain medium laminate structure includes but is not limited to two - layer gain medium laminates, and the laminate structure can be extended to three layers or more. However, it should be noted that the gain medium spin - coated on the second gain medium is denoted as the third gain medium, and its solvent, i.e., the third solvent, cannot dissolve the second gain medium or cause a drastic degradation of the properties of the second gain medium film. By analogy, if a fourth gain medium solution is spin - coated on the third gain medium, the fourth solvent used to dissolve the fourth gain medium cannot dissolve the third gain medium to avoid a drastic degradation of the properties of the third gain medium film; that is, the solvent of the later - coated layer cannot dissolve the gain medium of the adjacent previously - coated layer.

[0017] In a second aspect, the present invention provides a gain medium laminate structure prepared by the above - mentioned preparation method.

[0018] Preferably, the thickness of the first gain medium film is 70 - 150 nm; the thickness of the second gain medium film is 100 - 180 nm.

[0019] Preferably, the second gain medium is a yellow - green light gain medium F8BT or a red - light gain medium F8BT - P3HT. It should be noted that the full name of F8BT is Poly[(9,9 - di - n - octylfluorenyl - 2,7 - diyl)-alt-(benzo[2,1,3]thiadia - zol - 4,8 - diyl)];

[0020] The F8BT - P3HT is formed by mixing F8BT and P3HT. Among them, the mass ratio of F8BT is 70 - 95%, and P3HT is poly(3 - hexylthiophene).

[0021] Preferably, the first gain medium is a blue light gain medium PFN-Br, i.e., poly[(9,9-bis(3′-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]dibromide); More preferably, the PFN-Br is dissolved in the first solvent methanol at a concentration of 12 mg / mL. Correspondingly, the second gain medium is dissolved in the second solvent toluene. Even more preferably, the second gain medium is F8BT dissolved in toluene at a concentration of 25 mg / mL or F8BT-P3HT dissolved in toluene at a concentration of 25 mg / mL;

[0022] Preferably, the first gain medium is a perovskite gain medium: CH3NH3PbBr3 (hereinafter referred to as MAPbBr3), and the MAPbBr3 is a green light gain medium. More preferably, the MAPbBr3 precursor solution is formed by dissolving methylammonium bromide (MABr) and lead acetate (Pb(Ac)2) in N,N-dimethylformamide solution (DMF) at a concentration of 0.5 mmol / mL.

[0023] In a third aspect, the present invention also discloses the application of the gain medium stack structure in a stacked planar waveguide device. Specifically, as Figure 1 shown, when the substrate material is a transparent substrate, the constructed gain medium stack structure is a stacked planar waveguide device; that is, the stacked planar optical waveguide device includes a substrate, a first gain medium, and a second gain medium.

[0024] Preferably, the transparent substrate is a quartz substrate, which has good light transmittance.

[0025] Furthermore, when the first gain medium is PFN-Br and the second gain medium is F8BT or F8BT-P3HT, the stacked planar waveguide device realizes dual ASE parallel output under the pumping of a 390 nm, 10 Hz pulsed laser;

[0026] Furthermore, when the first gain medium is MAPbBr3 and the second gain medium is F8BT-P3HT, dual ASE parallel output is realized under the pumping of a 450 nm, 10 Hz pulsed laser.

[0027] In a fourth aspect, the present invention also discloses the application of the gain medium stack structure in a stacked DFB grating device. Specifically, when the substrate material is a grating, the constructed gain medium stack structure is a stacked DFB grating device; that is, the stacked DFB device includes a grating substrate, a first gain medium, and a second gain medium.

[0028] Furthermore, the first gain medium is PFN-Br, and the second gain medium is F8BT or F8BT-P3HT. Dual-laser parallel output is achieved under the pumping of a 390 nm, 10 Hz pulsed laser.

[0029] Furthermore, the first gain medium is MAPbBr3, and the second gain medium is F8BT-P3HT. Dual-laser parallel output is achieved under the pumping of a 450 nm, 10 Hz pulsed laser.

[0030] In some specific embodiments, the grating is a two-dimensional second-order distributed feedback (DFB) grating made of quartz, which is used to achieve vertical emission of the laser.

[0031] In some specific embodiments, the grating period can be 300 nm, and the filling factor is 50%, which matches the first gain medium, as Figure 7a shown.

[0032] In some specific embodiments, the grating period can be 330 nm, and the filling factor is 50%, which matches the second gain medium, as Figure 7b shown.

[0033] In some specific embodiments, the grating period can be 390 nm, and the filling factor is 50%, which matches the second gain medium, as Figure 7c shown.

[0034] Principle of the invention: The first gain medium and the second gain medium have good film-forming properties and are immiscible between layers, showing a superposition phenomenon of absorption and emission in the stacked structure, as Figure 3a , Figure 3b , Figure 3c . On this basis, a stacked planar optical waveguide device is constructed. Under the pumping of a beam of laser, each active layer can achieve gain, realizing parallel output of dual-band amplified spontaneous emission (ASE). Integrating it onto the grating structure realizes parallel emission of multi-band lasers, as Figure 4 , Figure 5 , Figure 6 .

[0035] Beneficial effects:

[0036] First, in the stacked structure described in this application, compared with the prior art, the gain media of the present invention are directly stacked without adding any other layers similar to the interface layer. On the one hand, the process is streamlined, and on the other hand, the interlayer loss and property degradation are reduced.

[0037] Second, the stacked structure described in this application provides a method for parallel emission of multi-band lasers and also has the characteristics of large-area preparation, providing a solution for applications in fields such as laser display and multi-color laser manufacturing.

[0038] Thirdly, in the prior art, there has been no planar waveguide device or stacked DFB grating device that constructs a direct stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Embodiments of the present disclosure will now be further explained in detail only by way of examples with reference to the accompanying drawings, where:

[0040] Figure 1 is the process of the stacked planar optical waveguide and the stacked DFB structure involved in the example of the gain medium stacked structure of the present invention;

[0041] Figure 2a is a schematic diagram of the preparation process of the stacked planar waveguide device described in the specific embodiment;

[0042] Figure 2b is a schematic diagram of the preparation process of the stacked DFB grating device described in the specific embodiment;

[0043] Figure 3a is the absorption and emission spectra of the single-layer and stacked structures of PFN-Br / F8BT in the specific embodiment;

[0044] Figure 3b is the absorption and emission spectra of the single-layer and stacked structures of PFN-Br / F8BT-P3HT in the specific embodiment;

[0045] Figure 3c is the absorption and emission spectra of the single-layer and stacked structures of MAPbBr3 / F8BT-P3HT in the specific embodiment;

[0046] Figure 4 is the blue-green dual-band ASE and laser of the quartz / PFN-Br / F8BT / air bilayer planar optical waveguide structure involved in the specific embodiment;

[0047] Figure 5 is the blue-red dual-band ASE and laser of the quartz / PFN-Br / F8BT-P3HT / stacked structure involved in the specific embodiment;

[0048] Figure 6 is the blue-red dual-band ASE and laser of the quartz / MAPbBr3 / F8BT-P3HT / stacked structure involved in the specific embodiment;

[0049] Figure 7a 、 Figure 7b 、 Figure 7c respectively show the scanning electron microscope images of the two-dimensional second-order diffraction grating with a grating period of 300 nm involved in the examples of the present application. SPECIFIC EMBODIMENT

[0050] Next, in combination with the accompanying drawings and specific embodiments, the present disclosure will be further described in detail. The following embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the essence of the present invention, modifications and substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention; in the drawings, the same components or components with the same functions are marked with the same symbols, and repeated descriptions thereof are omitted.

[0051] It should be noted that the terms "comprising" and "having" in the present disclosure and any variations thereof, for example, the processes, methods, systems, products or devices of a series of steps or units included or had do not necessarily have to be limited to those steps or units clearly listed, but may include or have other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0052] In addition, the subheadings and the like involved in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, and they only serve as a reading prompt. Such subheadings should neither be construed as used to divide the content of the article, nor should the content under the subheadings be limited only within the scope of the subheadings.

[0053] Example 1

[0054] Cleaning of the substrate: The quartz substrate is cleaned twice each with deionized water, acetone, and ethanol in sequence, and then the quartz substrate is placed in a constant temperature oven at 60 °C for drying treatment for more than 2 hours. After drying, plasma treatment (Plasma treatment) is carried out for 2 min.

[0055] Cleaning of the grating: The grating is cleaned twice each with deionized water, acetone, and ethanol in sequence, and then the grating is placed in a constant temperature oven at 60 °C for drying treatment for more than 2 hours. After drying, plasma treatment (Plasma treatment) is carried out for 2 min.

[0056] Preparation of the solution: PFN-Br is dissolved in methanol at a concentration of 12 mg / mL, and F8BT is dissolved in toluene at a concentration of 25 mg / mL.

[0057] Preparation method of the stacked planar waveguide device: As Figure 2aAs shown, the first gain medium PFN-Br was spin-coated on a quartz substrate at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of approximately 130 nm; the second gain medium F8BT was spin-coated on PFN-Br at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of approximately 130 nm; a stacked planar waveguide device of quartz / PFN-Br / F8BT / air was formed. Under the pumping of a 390 nm, 10 Hz pulsed laser, the blue-green dual ASE parallel output as shown in Figure 4 was achieved.

[0058] Fabrication method of the stacked DFB grating device: As shown in Figure 2b The first gain medium PFN-Br was spin-coated on 300 nm and 330 nm gratings (both with a filling factor of 50%) at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of approximately 130 nm; the second gain medium F8BT was spin-coated on PFN-Br at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of approximately 130 nm; a stacked DFB grating device of PFN-Br / F8BT was formed. Under the pumping of a 390 nm, 10 Hz pulsed laser, the blue-green dual laser parallel output as shown in Figure 4 was achieved.

[0059] As shown in Figure 3a are the absorption and emission spectra of the single-layer film of the first gain medium PFN-Br with a thickness of 130 nm, the single-layer film of the second gain medium F8BT with a thickness of 130 nm, and the stacked structure composed of the two;

[0060] Example 2

[0061] The cleaning steps of the substrate and the grating are exactly the same as those in Example 1.

[0062] Solution preparation: PFN Br was dissolved in methanol at a concentration of 12 mg / mL, and F8BT-P3HT was dissolved in toluene at a concentration of 25 mg / mL (where F8BT is 85 wt% and P3HT is 15 wt%).

[0063] Fabrication method of the stacked planar waveguide device: As shown in Figure 2aAs shown in the figure, the first gain medium PFN-Br was spin-coated on a quartz substrate at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of about 130 nm; the second gain medium F8BT-P3HT was spin-coated on PFN-Br at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of about 130 nm; a planar waveguide structure of quartz / PFN-Br / F8BT-P3HT / air was formed. Under the pumping of a 390 nm, 10 Hz pulsed laser, the blue-red dual ASE parallel output as shown in Figure 5 was achieved.

[0064] Fabrication method of the stacked DFB grating device: As shown in Figure 2b the figure, the first gain medium PFN-Br was spin-coated on 300 nm and 390 nm gratings (both with a filling factor of 50%) at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of about 130 nm; the second gain medium F8BT-P3HT was spin-coated on PFN-Br at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min, with a film thickness of about 130 nm; a stacked DFB grating structure of PFN-Br / F8BT-P3HT was formed. Under the pumping of a 390 nm, 10 Hz pulsed laser, the blue-red dual laser parallel output as shown in Figure 5 was achieved.

[0065] As shown in Figure 3b the figure, are the absorption and emission spectra of the single-layer film of the first gain medium PFN-Br with a thickness of 130 nm, the single-layer film of the second gain medium F8BT-P3HT with a thickness of 130 nm, and the stacked structure composed of the two;

[0066] Example 3

[0067] The cleaning steps of the substrate and the grating are exactly the same as those in Example 1.

[0068] Solution preparation: Methylammonium bromide (MABr) and lead acetate (Pb(Ac)2) were dissolved in N,N-dimethylformamide solution (DMF) at a concentration of 0.5 mmol / mL to form a precursor solution of MAPbBr3, and stirred in a glove box under a N2 atmosphere at room temperature for 8 hours.

[0069] Fabrication method of the stacked planar waveguide device: As shown in Figure 2aAs shown, the first gain medium MAPbBr3 was spin-coated on a quartz substrate at a spin-coating speed of 6000 rpm, a spin-coating acceleration of 6000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 5 min to promote the formation of perovskite crystallization. The film thickness was about 70 nm. The second gain medium F8BT-P3HT was spin-coated on MAPbBr3 at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min. The film thickness was about 130 nm. A planar waveguide structure of quartz / MAPbBr3 / F8BT-P3HT / air was formed. Under 450 nm, 10 Hz pulsed laser pumping, the green-red dual ASE parallel output as shown in Figure 6 was achieved.

[0070] Fabrication method of the stacked DFB grating device: As shown in Figure 2b The first gain medium MAPbBr3 was spin-coated on 330 nm and 390 nm gratings (both with a filling factor of 50%) at a spin-coating speed of 6000 rpm, a spin-coating acceleration of 6000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 5 min. The film thickness was about 70 nm. The second gain medium F8BT-P3HT was spin-coated on MAPbBr3 at a spin-coating speed of 3000 rpm, a spin-coating acceleration of 4000 rpm / s, and annealed on a constant-temperature hot stage at 100 °C for 2 min. The film thickness was about 130 nm. A stacked DFB grating device of MAPbBr3 / F8BT-P3HT was formed. Under 450 nm, 10 Hz pulsed laser pumping, the green-red dual laser parallel output as shown in Figure 6 was achieved.

[0071] As shown in Figure 3c are the absorption and emission spectra of the single-layer film of the first gain medium MAPbBr3 with a thickness of 70 nm, the single-layer film of the second gain medium F8BT-P3HT with a thickness of 130 nm, and the stacked structure composed of the two.

[0072] In summary, through the direct stacking of the gain media, the dual-band parallel emission of amplified spontaneous emission (ASE) was achieved on a flat quartz, and at the same time, the dual-band parallel output of the laser was achieved by stacking on the DFB grating.

[0073] Although the present disclosure has been specifically described above in conjunction with the accompanying drawings and embodiments, it can be understood that the above description does not limit the present disclosure in any form. Those skilled in the art can make deformations and changes to the present disclosure according to needs without departing from the essence and scope of the present disclosure, and these deformations and changes all fall within the scope of the present disclosure.

Claims

1. A method for preparing a laminated structure of a gain medium, characterized in that, The method includes the following steps: cleaning and drying the substrate material; dissolving the first gain medium in the first solvent to form a first gain medium solution, and dissolving the second gain medium in the second solvent to form a second gain medium solution; coating the first gain medium solution on the substrate, drying and annealing to form a first gain medium film, coating the second gain medium solution on the first gain medium film, and after drying and annealing, forming a second gain medium film; finally, preparing the gain medium stacked structure, which is composed of the first gain medium and the second gain medium deposited and formed into films in sequence on the substrate material; the first gain medium and the second gain medium include but are not limited to laser dyes, perovskites, organic small molecules, quantum dots, oligomers, and organic polymer materials that can be processed into films; the second solvent cannot dissolve the first gain medium; the substrate material is a transparent substrate or a grating substrate, and the production materials of the transparent substrate or the grating substrate are selected from quartz, glass, and flexible plastics; When the first gain medium is PFN-Br and the second gain medium is F8BT or F8BT-P3HT; When the first gain medium is MAPbBr3 and the second gain medium is F8BT-P3HT.

2. The preparation method of the gain medium laminated structure according to claim 1, characterized in that: The first solvent and the second solvent are each independently selected from methanol, ethanol, N,N-dimethylformamide (DMF), water, toluene, xylene, chloroform, chlorobenzene, and p-xylene.

3. The preparation method of the gain medium laminate structure according to claim 1, characterized in that: The preparation method further includes spin-coating at least one more layer of gain medium solution on the second gain medium, that is, the gain medium stacked structure includes but is not limited to a two-layer gain medium stack, and the stacked structure can be extended to three layers or more layers, and the solvent of the later-coated layer cannot dissolve the gain medium of the adjacent previously-coated layer.

4. The gain medium stacked structure prepared by the preparation method according to any one of claims 1-3.

5. The gain medium laminate structure according to claim 4, characterized in that, The thickness of the first gain medium film is 70-150 nm; the thickness of the second gain medium film is 100-180 nm.

6. A laminated planar waveguide device, characterized in that, The stacked planar waveguide device includes the gain medium stacked structure according to claim 4.

7. A stacked DFB grating device, characterized in that, The stacked DFB grating device includes the gain medium stacked structure according to claim 4.

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