A spectral dynamic programming device and its preparation method and application

Abstract

This invention belongs to the field of photonics, functional optical materials and devices, specifically relating to a spectral dynamic programming device, its fabrication method, and its applications. The spectral dynamic programming device has a three-layer structure, comprising, from bottom to top, a light-emitting thin film, a cholesteric liquid crystal layer, and a circular polarization analyzer. The light-emitting thin film is a fluorescent thin film or an organic room-temperature phosphorescent polymer thin film; the cholesteric liquid crystal layer is a mixture of a photoresponsive chiral molecular switch, a static inverse chiral dopant, and a nematic liquid crystal host. By alternately irradiating the liquid crystal layer with light of different wavelengths, the helical pitch of the liquid crystal layer can be reversibly and continuously adjusted, allowing its photonic bandgap reflection band to sweep across a wide spectral range. This dynamically "tailors" the emission spectrum of the lower light-emitting thin film, achieving continuous and reversible programming of the output color. This device can also generate emission with a high circular polarization asymmetry factor and possesses excellent cycling stability, making it applicable to the optical field.

Description

Technical Field

[0001] This invention belongs to the fields of photonics, functional optical materials and devices, and specifically relates to a spectral dynamic programming device, its preparation method and application. Background Technology

[0002] On-demand programmable control of the fundamental dimensions of light—including its spectrum (color), polarization state, and lifetime (such as phosphorescence afterglow)—is one of the core goals of modern photonics development and the technological foundation for wide color gamut displays, anti-counterfeiting labels with multi-dimensional anti-counterfeiting codes, and smart sensors that enhance signals through time-domain / polarization gating. Light, due to its remote, high-resolution, and wavelength-multi-addressable capabilities, is often considered an ideal stimulus for achieving this type of control. However, realizing this comprehensive programmability still faces significant challenges.

[0003] Current mainstream strategies for utilizing light to modulate luminescence properties are typically based on molecular-level light switching. For example, photochromic units are introduced into luminescent molecules, and their configuration is altered by illumination, thereby affecting luminescence properties. However, this method has an inherent contradiction between performance and functionality: it can usually only restrict color modulation to a few discrete states, far from achieving the continuous spectral control required for high-fidelity applications, and is often accompanied by problems such as decreased luminescence efficiency and material fatigue.

[0004] Therefore, the decoupled photonics engineering method based on optically tunable chiral photonic bandgap (CPBG) filters for finely controlling the emission of static broadband light sources is of great significance for developing a spectral dynamic programming device. Summary of the Invention

[0005] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing a decoupled photonics engineering method for finely controlling the emission of a static broadband light source based on an optically tunable chiral photonic bandgap (CPBG) filter. This method innovatively utilizes the "spectral scissors" properties formed by stacking mature cholesteric liquid crystal (CHS) materials with a circular polarization analyzer to dynamically control fluorescence and afterglow colors. Specifically, the fluorescence color of the CHS-Fluc film can be adjusted from yellow-green to reddish-brown, purple, blue, and green under ultraviolet light irradiation, eventually returning to the initial yellow-green. Furthermore, it exhibits a significant CPF effect at different irradiation times, with a maximum g... lum The value can reach 1.7. The afterglow color based on the CHS-P1 thin film can dynamically adjust to four colors—yellow, orange, red, and green—with prolonged ultraviolet irradiation time, eventually reverting to yellow. lumThe value can be dynamically and reversibly adjusted within 50 cycles in the range of 1.39 to 0.32 without fatigue. Particularly noteworthy is that this method establishes multiple anti-counterfeiting technologies through reversible reflection, fluorescence, or afterglow color modulation, allowing selective extraction of arbitrary patterns. This system, embedding a light-induced soft photonic superstructure, will provide a major breakthrough for the fields of nonlinear dynamics, rewritable displays, and high-density optical security, achieving unprecedented full-spectrum color fidelity.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a spectral dynamic programming device, the spectral dynamic programming device having a three-layer structure, including a light-emitting thin film, a cholesteric liquid crystal layer and a circular polarization analyzer arranged sequentially from bottom to top; wherein, the light-emitting thin film is a fluorescent thin film or an organic room temperature phosphorescent polymer thin film; the cholesteric liquid crystal layer is a mixture of a photoresponsive chiral molecular switch, a static inverse chiral dopant and a nematic liquid crystal host.

[0008] The photoresponsive chiral molecular switch is CHAD-3C-R; the static inverse chiral dopant is S5011; the nematic liquid crystal host is HTW114200-050; and the circular polarization analyzer is a right-handed circular polarizer.

[0009] The components in the cholesteric liquid crystal layer, by mass fraction, are: nematic liquid crystal host 85.1 wt%~89.5 wt%, photoresponsive chiral molecular switch 10 wt%~12.5 wt%, and static trans-chiral dopant 0.5 wt%~2.4 wt%.

[0010] In some embodiments of the present invention, the components in the cholesteric liquid crystal layer are as follows by mass fraction: nematic liquid crystal host 89.5 wt%, photoresponsive chiral molecular switch 10 wt%, and static trans-chiral dopant 0.5 wt%.

[0011] In some embodiments of the present invention, the components in the cholesteric liquid crystal layer are as follows by mass fraction: nematic liquid crystal host 85.1 wt%, photoresponsive chiral molecular switch 12.5 wt%, and static trans-chiral dopant 2.4 wt%.

[0012] In some embodiments of the present invention, when the luminescent film is a fluorescent film, the resulting device, under 365nm ultraviolet light irradiation, exhibits a continuous change in output fluorescence color with increasing irradiation time, in the following order: yellow-green → red-brown → purple → blue → green; its circularly polarized fluorescence has a high asymmetry factor (g) lum The maximum value can reach 1.7.

[0013] In some embodiments of the present invention, when the luminescent film is an organic room-temperature phosphorescent polymer film, the afterglow color of the device obtained after being irradiated with 365 nm ultraviolet light for different times and then having the light source turned off changes continuously in the following order: yellow → orange → red → green; its circularly polarized phosphorescence has a high asymmetry factor (g lum The value can be dynamically adjusted between +1.39 and +0.32.

[0014] A second aspect of the present invention provides a method for fabricating a spectral dynamic programming device, comprising the following steps:

[0015] S1. A luminescent material solution is coated onto a glass substrate and dried to obtain a luminescent thin film;

[0016] S2. Dissolve the photoresponsive chiral molecular switch, the static inverse chiral dopant, and the nematic liquid crystal host in dichloromethane, and heat to completely evaporate the solvent to obtain a chiral liquid crystal mixture;

[0017] S3. The chiral liquid crystal mixture is heated to an isotropic state and injected into a liquid crystal cell through capillary action to obtain the cholesteric liquid crystal layer.

[0018] S4. Place the luminescent film at the bottom, place the cholesteric liquid crystal layer on top of it, and finally cover the circular polarization analyzer. After fixing, the spectral dynamic programming device is obtained.

[0019] In S1, the luminescent material solution is a fluorescent material solution or an organic room-temperature phosphorescent polymer solution; when the luminescent material solution is a fluorescent material solution, the fluorescent material solution is a mixed solution of fluorescent whitening agent 28 and sodium fluorescein; when the luminescent material solution is an organic room-temperature phosphorescent polymer solution, the organic room-temperature phosphorescent polymer solution is a mixed solution of room-temperature phosphorescent polymer P1 and polyvinyl alcohol PVA-1799.

[0020] Specifically, in S1, the fluorescent material solution contains fluorescent whitening agent 28 with a mass-volume concentration of 0.5 mg / mL, sodium fluorescein with a mass-volume concentration of 0.01 mg / mL, and deionized water as the solvent.

[0021] In some embodiments of the present invention, in S1, when the luminescent material solution is a fluorescent material solution, the drying conditions are: drying at room temperature for 2 hours.

[0022] Specifically, in S1, the organic room-temperature phosphorescent polymer solution contains a room-temperature phosphorescent polymer P1 with a mass-volume concentration of 20 mg / mL, a polyvinyl alcohol PVA-1799 with a mass-volume concentration of 80 mg / mL, and deionized water as the solvent.

[0023] In some embodiments of the present invention, in S1, when the luminescent material solution is an organic room temperature phosphorescent polymer solution, the drying conditions are: placed in a vacuum chamber and dried at 50 °C for 24 h.

[0024] In some embodiments of the present invention, in S1, the glass substrate has a size of 2 cm × 2 cm.

[0025] In some embodiments of the present invention, the total mass-volume concentration of the photoresponsive chiral molecular switch, the static inverse chiral dopant, and the nematic liquid crystal host in dichloromethane is 20 mg / mL.

[0026] In S2, the heating conditions are: heating at 70 °C for 2.5 h.

[0027] In S3, the heating condition is 120 ℃; the liquid crystal cell has a cell gap of 20~25 μm.

[0028] In some embodiments of the present invention, in S3, the method for preparing the liquid crystal cell includes the following steps: using a UV adhesive doped with 1 wt% PVA (polyvinyl alcohol) particles as a spacer, coating it on the edge of a cleaned 2 cm × 2 cm quartz glass sheet, and curing the UV adhesive by irradiation with ultraviolet light at a wavelength of 365 nm, thereby precisely forming a cell gap of 20~25 μm.

[0029] In some embodiments of the present invention, the liquid crystal cell has a cell gap of 25 μm.

[0030] A third aspect of the present invention provides an application of a spectral dynamic programming device in any of the following fields: advanced optical anti-counterfeiting, multi-level information encryption, programmable display, and intelligent sensing.

[0031] In some embodiments of the present invention, by alternately irradiating the device with 365 nm ultraviolet light and 530 nm visible light, the helical pitch of the cholesteric liquid crystal layer can be reversibly and continuously adjusted, causing it to continuously sweep the reflection band of circularly polarized light with a specific helical direction within a wavelength range of 450 nm to 900 nm, thereby achieving dynamic programming of the emission spectrum; this light modulation process is reversible and has a cycle stability of more than 50 times. This demonstrates the application prospects of the spectral dynamic programming device provided by the present invention in fields including advanced optical anti-counterfeiting, multi-level information encryption, programmable displays, and intelligent sensing.

[0032] Beneficial effects:

[0033] (1) This invention realizes continuous, reversible, and high-fidelity programming of the emission spectrum: it gets rid of the limitation that molecular switches can only achieve discrete color switching, and can realize smooth and continuous changes of output color in the visible light range, and the process is completely reversible.

[0034] (2) This invention can simultaneously generate high-intensity, tunable circularly polarized light emission, thanks to the selective Bragg reflection effect of the cholesteric liquid crystal helical superstructure. The device can output light emission with high circular polarization. The maximum circular polarization asymmetry factor (g) of the fluorescent device lum The g of phosphorescent devices can reach 1.7. lum The value can also be dynamically adjusted between 1.39 and 0.32, achieving synchronous control of the spectrum and polarization.

[0035] (3) The present invention also has the dimension of phosphorescence lifetime regulation. When room temperature phosphorescent polymer is used as the light-emitting layer, the device can also realize dynamic programming of afterglow color and afterglow circular polarization state, which increases the information carrying capacity of time dimension.

[0036] (4) The present invention has excellent cycle stability and patterning capability: the performance of the device does not significantly decay after at least 50 optical switching cycles. Combined with patterned photomask technology, complex patterns can be dynamically displayed and encrypted on a single device, providing an ideal platform for advanced anti-counterfeiting and secure storage. Attached Figure Description

[0037] The present invention will be further described in detail below with reference to the accompanying drawings, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0038] Figure 1 This is a diagram showing the light emission effect of the CHS-Fluc three-layer device in an embodiment of the present invention.

[0039] Figure 2 This is a diagram showing the light emission effect of the CHS-P1 three-layer device in an embodiment of the present invention.

[0040] Figure 3 This is a diagram showing the physical and optical properties of the CHS liquid crystal layer in an embodiment of the present invention. Figure 3 In the figure, a and b represent the modulation of the reflection band of CHS under ultraviolet and visible light irradiation, respectively. Figure 3 c and d in the text represent CHS in PSS. 365 Status and PSS 530 The reflective band in the state.

[0041] Figure 4 The figures shown are the results of the circularly polarized emission signal intensity and high asymmetry factor of CHS-Fluc and CHS-P1 in the embodiments of the present invention. Figure 4In the figure, a and b represent the circularly polarized fluorescence signal (CPF) of CHS-Fluc under ultraviolet light irradiation for different times, respectively, and g represents the fluorescence signal of CHS-Fluc under ultraviolet light irradiation for different times. lum curve; Figure 4 c and d represent the circularly polarized phosphorescent signal (CPP) of CHS-P1 under ultraviolet light irradiation for different times, respectively, and g represents the phosphorescent signal of CHS-P1. lum Value curve.

[0042] Figure 5 This is a diagram illustrating the application of multidimensional optical encryption in an embodiment of the present invention, wherein... Figure 5 In the image, 'a' represents a dynamic fluorescent "five-petal flower" pattern photolithography, and 'b' represents a dynamic reflective and afterglow-colored "lotus" and "auspicious cloud" pattern photolithography. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0044] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0045] This invention provides a decoupled photonics engineering method for finely controlling the emission of a static broadband light source based on an optically tunable chiral photonic bandgap (CPBG) filter. Specifically, a three-layer structure device is obtained by stacking a light-emitting thin film, a liquid crystal superstructure layer, and a fixed circular polarization analyzer along the light propagation direction. This device utilizes the optically tunable chiral photonic bandgap filter as a "spectral scissors" to achieve continuous, reversible, and high-fidelity programmable control of the emission spectrum of a static broadband light source, demonstrating significant application potential in the field of multidimensional optical encryption. This platform opens new avenues for programmable chiral optical displays, sensors, and high-security anti-counterfeiting technologies.

[0046] In the following examples, fluorescent whitening agent 28 was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., and its specific structural formula is as follows:

[0047] ;

[0048] Sodium fluorescein was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., and its specific structural formula is as follows:

[0049] ;

[0050] CHAD-3C-R was purchased from Jiangsu Hecheng Display Technology Co., Ltd., and its specific structure is as follows:

[0051] ;

[0052] The S5011 was purchased from Jiangsu Hecheng Display Technology Co., Ltd., and its specific structure is as follows:

[0053] .

[0054] In the following examples, HTW114200-050 was purchased from Jiangsu Hecheng Display Technology Co., Ltd.; polyvinyl alcohol PVA-1799 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; and a right-handed circular polarizer with dimensions of 100×100×0.26mm was purchased from Taobao.

[0055] In the following examples, the UV adhesive doped with 1 wt% PVA particles is prepared by adding PVA particles to UV adhesive, wherein the PVA particles account for 1%, and stirring evenly after mixing.

[0056] In the following examples, the room-temperature phosphorescent polymer P1 was prepared according to the preparation method in "Song ZP, Wei J, Liu J, et al.Mechanically‐Tunable and Full‐Color Circularly Polarized Long‐LivedPhosphorescence in Chiral Superstructure Elastomers[J]. Advanced Materials,2025, 37(20): 2419640.", and its specific structural formula is as follows:

[0057] .

[0058] Example 1:

[0059] This embodiment provides a fabrication method for a fluorescence spectroscopy-based dynamically programmable device (CHS-Fluc), and the specific fabrication steps are as follows:

[0060] Step (1): Weigh 28 (5 mg) of fluorescent whitening agent and 0.1 mg of sodium fluorescein, dissolve them in 10 mL of deionized water, and stir magnetically for 2 h at room temperature to obtain a uniform fluorescent solution. Drop the solution (about 15 drops with a dropper) onto a pre-cleaned 2 cm × 2 cm glass substrate and dry it at room temperature for 2 h to form a transparent fluorescent film.

[0061] Step (2): Weigh 89.5 mg of oriented phase liquid crystal HTW114200-050, 10 mg of photoresponsive chiral molecular switch CHAD-3C-R, and 0.5 mg of static chiral dopant S5011, and dissolve them completely in 5 mL of dichloromethane.

[0062] Step (3): The solution obtained in step (2) was heated on a hot plate at 70 °C for 2.5 h to completely evaporate the solvent, resulting in a homogeneous chiral liquid crystal mixture. A UV adhesive doped with 1 wt% PVA (polyvinyl alcohol) particles was used as a spacer and coated onto the edge of a clean quartz glass slide. The UV adhesive was cured by irradiation with 365 nm wavelength ultraviolet light, thus precisely forming a 25 μm cell gap. The liquid crystal mixture was heated to an isotropic state at 120 °C and injected into a liquid crystal cell with a 25 μm cell gap using capillary action to obtain a cholesteric phase liquid crystal layer (CHS liquid crystal layer).

[0063] Step (4): Place the fluorescent film at the bottom, place the CHS liquid crystal layer on top of it, and finally cover it with a right-handed circular polarizer. After aligning the three layers, fix the edges with an optically transparent adhesive to obtain the CHS-Fluc three-layer device.

[0064] Example 2:

[0065] This embodiment provides the fabrication of a room-temperature phosphorescent spectroscopy dynamically programmable device (CHS-P1), and the specific fabrication steps are as follows:

[0066] Step (1): Weigh 50 mg of room temperature phosphorescent polymer P1 and 200 mg of polyvinyl alcohol PVA-1799, add 2.5 mL of deionized water, and stir at 110 °C with high-speed magnetic force for 2 h until a homogeneous P1-PVA mixed solution is formed. Spin-coat 200 μl of the P1-PVA mixed solution onto a pre-cleaned 2 cm × 2 cm glass substrate, and then dry it overnight in a vacuum oven at 50 °C to obtain a P1-PVA phosphorescent film.

[0067] Step (2): Weigh 85.1 mg of oriented phase liquid crystal HTW114200-050, 12.5 mg of photoresponsive chiral molecular switch CHAD-3C-R, and 2.4 mg of static chiral dopant S5011, and dissolve them completely in 5 mL of dichloromethane.

[0068] Step (3): The solution obtained in step (2) was heated on a hot plate at 70 °C for 2.5 h to completely evaporate the solvent, resulting in a homogeneous chiral liquid crystal mixture. A UV adhesive doped with 1 wt% PVA (polyvinyl alcohol) particles was used as a spacer and coated onto the edge of a clean quartz glass slide. The UV adhesive was cured by irradiation with 365 nm wavelength ultraviolet light, thus precisely forming a 25 μm cell gap. The liquid crystal mixture was heated to an isotropic state at 120 °C and injected into a liquid crystal cell with a 25 μm cell gap using capillary action to obtain a cholesteric phase liquid crystal layer (CHS liquid crystal layer).

[0069] Step (4): Stack and fix the phosphorescent film, CHS liquid crystal layer and right-hand circular polarizer in sequence to obtain the CHS-P1 three-layer device.

[0070] Performance verification:

[0071] To verify the luminescence effect of the CHS-Fluc three-layer device prepared in this invention, a power density of 50 mW / cm² was used. 2 The device was irradiated with 365 nm ultraviolet light for different durations, and control groups were set up with no circular polarizer (No-CPF), left-handed circular polarizer (L-CPF), and right-handed circular polarizer (R-CPF).

[0072] Figure 1 This is a diagram showing the light emission effect of a CHS-Fluc three-layer device. Figure 1 It can be seen that during the irradiation period, the fluorescence color emitted by the CHS-Fluc three-layer device (R-CPF) undergoes a continuous change at 1 s, 5 s, 10 s, 15 s, 20 s, 25 s, and 30 s: yellow-green → red-brown → purple → blue → green. In contrast, the control group without a right-handed circular polarizer (No CPF) and with a left-handed circular polarizer (L-CPF) maintains a consistently yellow-green color without any change.

[0073] To verify the light-emitting performance of the CHS-P1 three-layer device prepared in this invention, a power density of 50 mW / cm² was used. 2 The device was irradiated with 365 nm ultraviolet light for different durations, and the light source was immediately turned off to observe the afterglow. Control groups were also set up, one without a right-handed circular polarizer (No CPF) and the other with a left-handed circular polarizer (L-CPF).

[0074] Figure 2 This is a diagram showing the light emission effect of the CHS-P1 three-layer device. Figure 2 It can be seen that after the light source was turned off, at 0 s, 5 s, 10 s, 15 s, 20 s, and 30 s, the CHS-P1 three-layer device emitted long afterglows of different colors. The color changed continuously with the increase of the previous illumination time, specifically: yellow → orange → red → green. In contrast, the control group without a right-handed circular polarizer (No CPF) and with a left-handed circular polarizer (L-CPF) remained yellow throughout, without any change.

[0075] The physical and optical properties of the CHS liquid crystal layer were studied, specifically the performance of CHS under 365 nm ultraviolet light (50 mW / cm²). 2 ) and 530 nm visible light (37 mW / cm) 2The dynamic modulation of photonic bandgap (PBGs) under irradiation was characterized. By controlling the irradiation time of ultraviolet and visible light, the PBGs of CHS can achieve dynamic and reversible modulation over a wide spectral range from ultraviolet (UV) to near-infrared (NIR). Figure 3 The diagram shows the physical and optical properties of the CHS liquid crystal layer. Figure 3 In the figure, a and b represent the modulation of the reflection band of CHS under ultraviolet and visible light irradiation, respectively. Figure 3 c and d in the text represent CHS in PSS. 365 Status and PSS 530 The reflection bands in these states correspond to no CPF, L-CPF, and R-CPF, respectively. Figure 3 It can be seen that by changing the light source of different wavelengths and their illumination time, a regular shift in the peak position of the reflection band can be observed. This indicates that the microstructure of the material undergoes reversible changes under light stimulation, thereby achieving dynamic control of the photonic bandgap (PBGs) and CHS reflection color. (Comparison) Figure 3 c(PSS) 365 (state) and Figure 3 d(PSS) 530 (State), it can be seen that the position and shape of the material's reflection bands are drastically different under different stable states. CHS in PSS 530 Both exhibit right-handed characteristics, indicating that specific lighting conditions can not only adjust the band gap but also lock the chiral configuration of the material.

[0076] The circularly polarized emission signal intensity and high asymmetry factor (g) of CHS-Fluc and CHS-P1 were analyzed by magnetic circularly polarized fluorescence spectroscopy. lum value), Figure 4 The graph shows the results of the circularly polarized emission signal intensity and high asymmetry factor of CHS-Fluc and CHS-P1. Figure 4 In the figure, a and b represent the circularly polarized fluorescence signal (CPF) of CHS-Fluc under ultraviolet light irradiation for different times, respectively, and g represents the fluorescence signal of CHS-Fluc under ultraviolet light irradiation for different times. lum curve; Figure 4 c and d represent the circularly polarized phosphorescent signal (CPP) of CHS-P1 under ultraviolet light irradiation for different times, respectively, and g represents the phosphorescent signal of CHS-P1. lum Value curve. From Figure 4 It can be seen that the circularly polarized fluorescence (CPF) signal of CHS-Fluc can be dynamically and reversibly modulated, and its g lum The values ​​fluctuate between 1.7 and 1.0, which is due to the reversible chiral superstructure change induced by CHAD-3C-R under 365 nm ultraviolet light irradiation. The circularly polarized phosphorescence (CPP) signal of CHS-P1 can be modulated, and its g... lumThe values ​​range from 1.39 to 0.32. The above experiments confirm that the circularly polarized light emission performance (including signal intensity and g) of these two devices... lum The values ​​of both can be dynamically and reversibly modulated by ultraviolet light. The underlying physical mechanism is attributed to the reversible chiral superstructure changes induced by light-triggered CHAD-3C-R in the material.

[0077] Specifically, high asymmetry factor (g) lum The formula for calculating the value is:

[0078] ;

[0079] Among them, I L I R These represent the intensities of left-handed and right-handed circularly polarized light, respectively. .

[0080] g lum The value can be used to measure the degree of polarization and direction of rotation of light. Its range is from -2 to 2, where 2 represents purely left-handed circularly polarized light, -2 represents purely right-handed circularly polarized light, and 0 represents linearly polarized light or unpolarized light. The closer the absolute value of the circular polarization asymmetry factor is to 2, the higher the degree of polarization of the light.

[0081] Example 3:

[0082] This embodiment demonstrates multidimensional optical encryption based on a spectral programming device. The specific fabrication steps are as follows: using the devices fabricated in Examples 1 and 2, combined with a customized pattern mask, an optical information encryption demonstration is performed. Figure 5 This is a demonstration image of multi-dimensional optical encryption applications, including dynamic fluorescence patterns and dynamic phosphorescence / reflection dual-mode patterns. Figure 5 In the diagram, 'a' represents a photolithographic pattern of a five-petaled flower with dynamic fluorescence emission, and 'b' represents photolithographic patterns of a lotus flower and auspicious clouds with dynamic reflective and afterglow colors. The specific experimental steps are as follows:

[0083] Step (1): Place a photomask with a "five-petal flower" pattern above the CHS-Fluc device. Selectively irradiate the five petal regions with 365 nm ultraviolet light for different durations. After removing the mask, a single "five-petal flower" pattern can be observed to simultaneously exhibit five different fluorescent colors: yellow, orange, blue, purple, and red under ultraviolet light, achieving single-pattern multi-color encryption.

[0084] Step (2): A lotus pattern mask is placed above the CHS-P1 device. When the light source is turned off after different periods of UV irradiation on the CHS-P1 film, the lotus pattern sequentially displays blue, green, yellow, and red reflected colors. The image in the intermediate stage remains stable for 24 hours without significant color shift. Simultaneously, in a dark environment, the afterglow emission of CHS-P1 after transmission under the lotus and auspicious cloud patterns is recorded using a circularly polarized filter (R-CPF). Both the reflected and afterglow colors are stably maintained and can be reset by erasing with light of different wavelengths, achieving dual dynamic encryption of the reflection and phosphorescence modes.

[0085] This invention provides a decoupled photonics engineering method for finely controlling the emission of a static broadband light source based on an optically tunable chiral photonic bandgap (CPBG) filter. The filter employs a cholesteric liquid crystal superstructure, the core of which is a stacked structure of a photoresponsive chiral molecular switch and a fixed circular polarization analyzer. By alternating illumination with 365 nm and 530 nm light, the helical pitch can be continuously adjusted, and the circular polarization-selective stopband can be scanned to the visible and near-infrared range (450–900 nm). When coupled with a fluorescent thin film or an organic room-temperature phosphorescent polymer, the device can achieve stable output of five or four reversible continuous colors in the visible light range, and maintain stable operation after at least 50 switching cycles. The device provided by this invention has a simple structure and a mature fabrication method, enabling multidimensional, continuous, and reversible programming of emission color, polarization, and lifetime. It has broad application prospects in advanced optical anti-counterfeiting, multi-level information encryption, programmable displays, and intelligent sensing.

[0086] This invention provides a spectral dynamic programming device, its fabrication method, and its application. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A spectral dynamic programming device, characterized in that, The spectral dynamic programming device has a three-layer structure, including a light-emitting thin film, a cholesteric liquid crystal layer, and a circular polarization analyzer arranged sequentially from bottom to top; wherein, the light-emitting thin film is a fluorescent thin film or an organic room temperature phosphorescent polymer thin film; the cholesteric liquid crystal layer is a mixture of a photoresponsive chiral molecular switch, a static inverse chiral dopant, and a nematic liquid crystal host.

2. The spectral dynamic programming device according to claim 1, characterized in that, The photoresponsive chiral molecular switch is CHAD-3C-R; the static inverse chiral dopant is S5011; the nematic liquid crystal host is HTW114200-050; and the circular polarization analyzer is a right-handed circular polarizer.

3. The spectral dynamic programming device according to claim 2, characterized in that, The components in the cholesteric liquid crystal layer, by mass fraction, are: nematic liquid crystal host 85.1 wt%~89.5 wt%, photoresponsive chiral molecular switch 10 wt%~12.5 wt%, and static trans-chiral dopant 0.5 wt%~2.4 wt%.

4. The method for fabricating the spectral dynamic programming device according to any one of claims 1 to 3, characterized in that, Includes the following steps: S1. A luminescent material solution is coated onto a glass substrate and dried to obtain a luminescent thin film; S2. Dissolve the photoresponsive chiral molecular switch, the static inverse chiral dopant, and the nematic liquid crystal host in dichloromethane, and heat to completely evaporate the solvent to obtain a chiral liquid crystal mixture; S3. The chiral liquid crystal mixture is heated to an isotropic state and injected into a liquid crystal cell through capillary action to obtain the cholesteric liquid crystal layer. S4. Place the luminescent film at the bottom, place the cholesteric liquid crystal layer on top of it, and finally cover it with the circular polarization analyzer. After fixing, the spectral dynamic programming device is obtained.

5. The preparation method according to claim 4, characterized in that, In S1, the luminescent material solution is a fluorescent material solution or an organic room-temperature phosphorescent polymer solution; when the luminescent material solution is a fluorescent material solution, the fluorescent material solution is a mixed solution of fluorescent whitening agent 28 and sodium fluorescein; when the luminescent material solution is an organic room-temperature phosphorescent polymer solution, the organic room-temperature phosphorescent polymer solution is a mixed solution of room-temperature phosphorescent polymer P1 and polyvinyl alcohol PVA-1799.

6. The preparation method according to claim 5, characterized in that, In S1, the fluorescent material solution contains fluorescent whitening agent 28 with a mass-volume concentration of 0.5 mg / mL, sodium fluorescein with a mass-volume concentration of 0.01 mg / mL, and deionized water as the solvent.

7. The preparation method according to claim 5, characterized in that, In S1, the organic room-temperature phosphorescent polymer solution contains a room-temperature phosphorescent polymer P1 with a mass-volume concentration of 20 mg / mL, a polyvinyl alcohol PVA-1799 with a mass-volume concentration of 80 mg / mL, and deionized water as the solvent.

8. The preparation method according to claim 4, characterized in that, In S2, the heating conditions are: heating at 70 °C for 2.5 h.

9. The preparation method according to claim 4, characterized in that, In S3, the heating condition is 120 ℃; the cell gap of the liquid crystal cell is 20~25 μm.

10. The application of the spectral dynamic programming device according to any one of claims 1 to 3 in any of the following fields; said fields include any one of advanced optical anti-counterfeiting, multi-level information encryption, programmable display and intelligent sensing.

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