A tunable laser based on solvent-responsive photonic crystal

Abstract

The present invention discloses a tunable laser based on a solvent-responsive photonic crystal, wherein the resonant cavity of the laser comprises a photonic crystal film, a gain medium and a solvent, wherein the gain medium is fixed between two photonic crystal films with similar photonic band gaps, the gain medium comprises at least two luminescent dyes, and the solvent can change the photonic band gap of the photonic crystal film. Therefore, when the solvent changes the structural parameters of the photonic crystal to move its photonic band gap, and the moved photonic band gap matches the luminescent peaks of different types of luminescent dyes, laser light is formed at the corresponding wavelength after optical pumping, and the laser wavelength of the laser can be tuned under the action of the solvent.

Description

Technical Field

[0001] The present invention relates to the application field of photonic crystal materials, and more specifically, to a tunable laser based on solvent-responsive photonic crystals. Background Art

[0002] Compared with traditional solid-state lasers, tunable lasers have a wide wavelength tuning range, generally as wide as 50 nm or more, and have a wide range of applications. Large-range tunable lasers mainly include semiconductor lasers, perovskite lasers, and vibration level lasers, but the tuning range of these lasers is mostly concentrated in the infrared region. Currently, the most important visible light tunable lasers include various dye lasers and titanium sapphire lasers. Titanium sapphire has very good performance, but it can only be tuned in a very small part of the visible light range. Dye lasers have an extremely wide tuning range and are a strong candidate for large-range tunable lasers. However, the tuning method of dye lasers is relatively complicated to operate, and they are easily affected by energy transfer when multiple dyes are present.

[0003] Tunable lasers based on tunable photonic crystals are easy to operate and can tune the laser band through external stimulation such as applying voltage, stress or changing temperature. Among them, tunable lasers based on solvent-responsive photonic crystals have good application prospects. Summary of the invention

[0004] One object of the present invention is to provide a tunable laser based on solvent-responsive photonic crystals, wherein the solvent can change the photonic bandgap of the photonic crystal film, and the corresponding luminescent dye is used in combination to achieve tunable emission laser wavelength.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A tunable laser based on solvent-responsive photonic crystals, such as Figure 1 As shown, the resonant cavity of the laser includes a photonic crystal film, a gain medium and a solvent. The gain medium is fixed between two photonic crystal films with similar photonic band gaps. The gain medium includes a luminescent dye, and the solvent can change the photonic band gap of the photonic crystal film.

[0007] It should be noted that in the present invention, the solvent changes the photonic bandgap of the photonic crystal film by dropping the solvent on the photonic crystal film and then drying it, or by soaking the photonic crystal film in the solvent and then drying it, which is simple to operate. The emission peak of the luminescent dye included in the gain medium matches the mobile photonic bandgap, and the gain medium can be a film prepared by mixing the luminescent dye and a polymer. The luminescent material in the gain medium can be one or more, as long as the luminescent peak it has matches the photonic bandgap.

[0008] The solvent in the resonant cavity of the laser in the present invention can change the structural parameters of the photonic crystal, causing its photonic bandgap to move. The moved photonic bandgap matches the luminescence peaks of different types of luminescent dyes, and lasers are formed at corresponding wavelengths after optical pumping, thereby achieving tuning of the laser's lasing wavelength under the action of the solvent.

[0009] Preferably, the functional monomers of the photonic crystal film are acrylic acid and its derivatives and acrylamide derivatives. Among them, the functional monomers of acrylic acid and its derivatives include but are not limited to acrylic acid, methacrylic acid, lauric acrylate, methyl acrylate, hydroxyethyl methacrylate, methyl methacrylate, epoxy acrylate, dibutyltin dilaurate, etc.; acrylamide derivatives include but are not limited to N-isopropyl acrylamide, N,N-methylene bisacrylamide, N-hydroxymethyl acrylamide glycol diether, N-hydroxymethyl acrylamide, N-butoxymethyl acrylamide, etc.

[0010] Preferably, the weight proportion of the functional monomer in the photonic crystal film is 50wt%-85wt%.

[0011] Preferably, the photonic crystal film further comprises an acrylate crosslinking agent, and the weight proportion of the acrylate crosslinking agent in the photonic crystal film is 15wt%-50wt%. Further, the acrylate crosslinking agent is preferably isocyanoethyl methacrylate, trimethylolpropane trimethacrylate, hydroxyethyl acrylate, ethylene glycol dimethacrylate, polydipentaerythritol hexaacrylate.

[0012] Preferably, the solvent is an organic solvent containing a hydroxyl group or a carbonyl group, or an alkaline solvent or water. The solvent includes but is not limited to water, methanol, ethanol, propanol, acetone, formaldehyde, acetaldehyde, tetrahydrofuran, chloroform, toluene, and the like.

[0013] Preferably, the weight proportion of the luminescent dye in the gain medium is 0.1 wt%-10 wt%.

[0014] The luminescent dye includes red dye, blue dye and blue dye, etc.

[0015] Red dyes include, but are not limited to, rhodamine B, rhodamine 6G, 4-dicyanomethyl-2-methyl-6-(p-dimethylaminostyrene)H-pyran (DCM), pyrrolidine 597, Illinier Red, Kilton Red S, pyranonitrile, cresol, and the like.

[0016] Green laser dyes include, but are not limited to, pyrrolidine 567, coumarin 153, coumarin 6, fluorescein 7GA, sodium fluorescein, fluorescein 27, para-phenylene vinylene derivative (CNDPASDB), and the like.

[0017] Blue laser dyes include, but are not limited to, coumarin 307, coumarin 440, quinolone 390, stilbene 420, BM-terphenyl, p-terphenyl, and the like.

[0018] The beneficial effects of the present invention are as follows:

[0019] The resonant cavity of the tunable laser provided by the present invention includes a photonic crystal film, a gain medium and a solvent. The solvent can change the structural parameters of the photonic crystal to shift its photonic bandgap. The shifted photonic bandgap matches the luminescence peaks of different types of luminescent dyes. Laser is formed at the corresponding wavelength after optical pumping, thereby achieving tuning of the laser's lasing wavelength under the action of the solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0021] Figure 1 A schematic diagram showing the structure of the resonant cavity in the tunable laser of the present invention is shown.

[0022] Figure 2 A schematic diagram showing the laser wavelength of the tunable laser in Example 1 being tuned from blue to green.

[0023] Figure 3 A schematic diagram showing the laser wavelength of the tunable laser in Example 2 being tuned from green to red. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0025] Example 1

[0026] a) First, prepare a clean 3 mL glass bottle with a lid, and add 0.358 g acrylic acid, 0.358 g N-isopropylacrylamide, 0.0132 g benzyl, 0.0108 g 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone and 0.168 g polydipentaerythritol hexaacrylate in sequence. Then add a clean magnetic bar, wrap the glass bottle with aluminum foil, mark it, place it on a magnetic stirrer, and stir it in the dark for 4 hours until it becomes clear and transparent.

[0027] b) Pour 5wt% KH-570 / toluene solution into the staining jar, take a clean glass piece and insert it into the staining jar, soak for 4 hours, take it out, quickly rinse it with anhydrous ethanol, blow it dry with a hair dryer, and store it in a dust-proof manner for future use.

[0028] c) Overlap the glass sheet with the polystyrene microsphere template with a diameter of 280 nm with the glass sheet soaked in KH-570 and clamp them with a clip. Use a pipette to infiltrate the photoresist prepared in step a into the interlayer of the two glass sheets from bottom to top. After complete penetration, expose it under a UV lamp for 5 minutes and take it out. Break the two glass sheets apart and soak the sample with the photonic crystal in tetrahydrofuran for 8 hours to remove the polystyrene microspheres to obtain a solvent-responsive photonic crystal. 280nm film.

[0029] d) Dissolve 0.1g polyvinyl alcohol in 2g water, add 0.001g sodium fluorescein to the polyvinyl alcohol aqueous solution, stir magnetically for 1 hour, and after it is completely dissolved, spin coat it on a glass slide at a low speed for 8s using a coating machine. Take it out and dry it in the dark.

[0030] e) Dissolve 0.2g polystyrene in 1.33g tetrahydrofuran, then add 0.001g coumarin 307, stir magnetically for about 1 hour until completely dissolved, and spin coat on a glass slide at a low speed for 8s using a gel coater. Take out and dry in the dark, and transfer the obtained film to a polyvinyl alcohol film containing sodium fluorescein to obtain a gain medium.

[0031] f) Two responsive photonic crystal films with similar photonic band gaps are fixed on both sides of a dye-containing polymer film (gain medium) to form a resonant cavity, thereby obtaining a tunable laser based on solvent response.

[0032] like Figure 2 As shown, by exciting the above-mentioned responsive photonic crystal laser with a 355nm laser, a 450nm blue laser can be obtained. When acetaldehyde is added to the photonic crystal in the photonic crystal laser, after the solvent evaporates completely, the photonic bandgap of the photonic crystal is tuned to the green region, and when excited with a 460nm laser, the laser wavelength of the photonic crystal laser becomes 538nm, which is green, and the tuning of the laser wavelength from blue to green is achieved in the range of 450nm to 538nm.

[0033] Example 2

[0034] a) First, prepare a clean 3 mL glass bottle with a lid, and add 0.358 g acrylic acid, 0.358 g N-isopropylacrylamide, 0.0132 g benzyl, 0.0108 g 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone and 0.168 g polydipentaerythritol hexaacrylate in sequence. Add a clean magnetic bar, wrap the glass bottle with aluminum foil, mark it, and place it on a magnetic stirrer in the dark for 4 hours until it becomes clear and transparent.

[0035] b) Pour 5wt% KH-570 / toluene solution into the staining jar, take a clean glass piece and insert it into the staining jar, soak for 4 hours, take it out, quickly rinse it with anhydrous ethanol, blow it dry with a hair dryer, and store it in a dust-proof manner for future use.

[0036] c) Overlap the glass sheet with the polystyrene microsphere template with a diameter of 395 nm with the glass sheet soaked in KH-570 and clamp them with a clip. Use a pipette to infiltrate the photoresist prepared in step a) into the interlayer of the two glass sheets from bottom to top. After complete penetration, expose it under a UV lamp for 5 minutes and take it out. Break the two glass sheets apart and soak the sample with the photonic crystal in tetrahydrofuran for 8 hours to remove the polystyrene microspheres to obtain a solvent-responsive photonic crystal. 395nm film.

[0037] d) Dissolve 0.1g polyvinyl alcohol in 2g water, add 0.001g sodium fluorescein to the polyvinyl alcohol solution, stir magnetically for 1 hour, and after it is completely dissolved, spin coat it on a glass slide at a low speed for 8s using a coating machine. Take it out and dry it in the dark.

[0038] e) Prepare a clean 3ml glass bottle with a lid, add 0.306g acrylic acid, 0.300g N-isopropylacrylamide, 0.0132g benzyl, 0.0108g 2-benzyl-2-(dimethylamino)-4'-morpholinophenyl butanone and 0.370g polydipentaerythritol hexaacrylate in sequence. Add 1 clean magnet, wrap the glass bottle with tin foil, mark it and place it on a magnetic stirrer in the dark and stir for 4 hours until it is clear and transparent. Add 70mg rhodamine B to the above photoresist and stir for 8 hours in the dark until it is clear and transparent. Overlap two pieces of glass and separate them with glass sheets to form a small chamber. Use a pipette to penetrate the photoresist containing rhodamine B into the glass sheet and expose it under ultraviolet light for 5 minutes. Break the glass sheet apart to take out the film, and transfer the film to a polyvinyl alcohol film containing sodium fluorescein to obtain a gain medium.

[0039] f) Two responsive photonic crystal films with similar photonic band gaps are fixed on both sides of a dye-containing polymer film (gain medium) to form a resonant cavity, thereby obtaining a tunable laser based on solvent response.

[0040] like Figure 3 As shown, by exciting the above-mentioned responsive photonic crystal laser with a 460nm laser, a 540nm green laser can be obtained. When acetaldehyde is added to the photonic crystal in the photonic crystal laser, after the solvent evaporates completely, the photonic bandgap of the photonic crystal is tuned to the red region, and when excited with a 532nm laser, the lasing wavelength of the photonic crystal laser becomes 630nm, which is red, and the laser wavelength is tuned from 540nm to 630nm.

[0041] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A tunable laser based on solvent-responsive photonic crystal, characterized in that: The resonant cavity of the laser comprises a photonic crystal film, a gain medium and a solvent, wherein the gain medium is fixed between two photonic crystal films with similar photonic band gaps, the gain medium comprises a luminescent dye and has a luminescent peak that matches the photonic band gap, and the solvent can change the photonic band gap of the photonic crystal film; The functional monomers of the photonic crystal film are acrylic acid and its derivatives and acrylamide derivatives; The weight proportion of the functional monomer in the photonic crystal film is 50wt%-85wt%; The solvent is an organic solvent containing hydroxyl or carbonyl. The method of using the solvent to change the photonic bandgap of the photonic crystal film comprises the steps of dripping the solvent onto the photonic crystal film and then drying it, or soaking the photonic crystal film in the solvent and then drying it. The acrylic acid and its derivative functional monomers include at least one of acrylic acid, methacrylic acid, lauric acrylate, methyl acrylate, hydroxyethyl methacrylate, methyl methacrylate, epoxy acrylate, and dibutyltin dilaurate; The acrylamide derivative includes at least one of N-isopropyl acrylamide, N,N-methylene bisacrylamide, N-hydroxymethyl acrylamide glycol diether, N-hydroxymethyl acrylamide, and N-butoxymethyl acrylamide.

2. The tunable laser according to claim 1, characterized in that: The photonic crystal film also includes an acrylate crosslinking agent, the weight proportion of which in the photonic crystal film is 15wt%-50wt%.

3. The tunable laser according to claim 2, characterized in that: The acrylic ester crosslinking agent includes at least one of isocyanoethyl methacrylate, trimethylolpropane trimethacrylate, hydroxyethyl acrylate, ethylene glycol dimethacrylate, and polydipentaerythritol hexaacrylate.

4. The tunable laser according to claim 1, characterized in that: The weight proportion of the luminescent dye in the gain medium is 0.1 wt%-10 wt%.

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