An optical signal decoding system and encoding system based on structural color sheets

Abstract

The present invention belongs to the field of communications, and specifically relates to an optical signal decoding system and encoding system based on a structural color plate. The optical signal decoding system is used to decode a received drive signal containing several continuous power values ​​into corresponding text information; the optical signal decoding system includes a structural color plate, a fixture, an optical drive assembly, a color light source, an optical receiver, and a decoder. The base film of the structural color plate is made of a material that can be photobend. The optical drive assembly irradiates the structural color plate to cause it to bend and deform. The optical receiver receives a single color light emitted by the color light source and reflected by the structural color grating. The decoder is electrically connected to the light signal receiver. The received optical signal is then converted into text information and output. The optical signal encoding system is used to encode arbitrary text information into a drive signal containing several continuous power values. The present invention solves the defects of traditional optical communication means such as insufficient security and stability, high hardware cost, and easy cracking.

Description

Technical Field

[0001] The present invention belongs to the field of communications, and in particular relates to an optical signal decoding system and encoding system based on structured color sheets. Background Art

[0002] In recent years, optical information encryption technology has played a significant role in the field of information security. Compared to traditional mathematical-based computer cryptography and information security technologies, optical information security technology offers advantages such as a multidimensional key space and the inherent ability to rapidly and parallelly process large amounts of data. Currently, several methods have been developed to achieve optical information encryption. For example, an optical encryption algorithm combining off-axis holography and DRPE technology has been proposed to implement optical image encryption using digital holography; an optical image encryption method has been proposed combining the Grytor transform with chaos theory; a three-dimensional optical image encryption method has been proposed combining the Arnold transform with the gravity model; and a three-dimensional optical information security processing method based on integrated imaging has been proposed.

[0003] However, in pursuit of higher security, optical information requires the use of extremely complex encryption technology. The decryption process of these encrypted signals often relies on additional instruments and equipment, such as thermal devices, multi-wavelength light sources, mechanical stimulation units, magnetic devices, etc. In addition, the practical application of optical information encryption in different scenarios is also subject to other challenges. For example, luminous information can usually only be read out once and is not reproducible, and the recorded information requires pre-designed special information presentation means for display. These defects make the above scheme significantly limited in information transmission, and therefore does not have broad practical value. At the same time, the encryption process of the above optical information communication method still relies on traditional encryption means, which leads to the risk of information being easily cracked and hacked after encryption; the above defects have hindered the practical application of optical information communication. Summary of the Invention

[0004] In order to address the shortcomings of traditional optical communication methods, such as insufficient security and stability, high hardware cost of the system, and easy cracking of communication content, the present invention provides an optical signal decoding system and encoding system based on structured color sheets.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] A structural color sheet-based optical signal decoding system is used to decode a received drive signal containing several continuous power values ​​into corresponding text information; the data types of the text information include letters, characters, and Chinese characters. The structural color sheet-based optical signal decoding system provided by the present invention includes: at least one structural color sheet, a fixture, an optical drive assembly, a color display light source, an optical receiver, and a decoder.

[0007] Each structural color sheet consists of a base film and a structural color grating sheet. The base film is in the form of a long strip; one end of the base film is fixed, and the other end is free. The structural color grating sheet is attached to the surface of the free end of the base film. The base film is made of a photobendable material.

[0008] The clamp is used to clamp the structural color piece along the fixed end of the structural color piece.

[0009] The optical drive assembly includes a signal receiver and an excitation light source. The signal receiver is configured to receive a drive signal containing a series of power values. The excitation light source receives the drive signal and, based on the power values ​​contained in the drive signal, controls the excitation light source to generate excitation light of corresponding power. The excitation light illuminates the middle portion of the base film surface of the structural color sheet, driving the free end of the structural color sheet to bend at a corresponding angle.

[0010] The color-rendering light source is located on a side close to the free end of the structural color sheet; the color-rendering light source adopts a full-color light source, and the color-rendering light source irradiates an area corresponding to the structural color grating sheet part in the structural color sheet.

[0011] The light receiver is located on the side of the color rendering light source. It receives the single-color light emitted by the color rendering light source and reflected by the structured color grating. There are seven types of single-color light: red, orange, yellow, green, blue, indigo, and violet. The light receiver outputs the characteristic value corresponding to each single-color light received. The characteristic value is used to characterize the wavelength, color, or frequency of the single-color light.

[0012] The decoder is electrically connected to the light signal receiver. The decoding process is as follows: First, at least two characteristic values ​​are acquired at a preset sampling frequency. Then, according to a preset "wavelength / frequency / light color-to-number" comparison table, the characteristic value of any single color of light is converted into a corresponding number from 0 to 7. A shift addition is performed to obtain a multi-digit septenary number composed of multiple numbers. Finally, according to a preset "number-to-text" comparison table, any multi-digit septenary number is converted into the corresponding text information and output.

[0013] As a further improvement of the present invention, the base film in the structural color sheet adopts a MXene-IPTS / PE double-layer film.

[0014] The preparation method of MXene-IPTS / PE double-layer membrane is as follows:

[0015] Ti3C2T was obtained by chemical liquid phase etching x solution. Then Ti3C2T xThe solution is then compounded with isocyanatepropyltriethoxysilane (IPTS). A MXene-IPTS film is then obtained by vacuum filtration. Finally, a polyethylene (PE) adhesive film is attached to the surface of the MXene-IPTS film to obtain the desired MXene-IPTS / PE bilayer membrane.

[0016] As a further improvement of the present invention, the preparation process of the structural color grating sheet in the structural color sheet is as follows:

[0017] A nanosecond laser and lens system are used to generate a periodic interference light field. Carbon ink droplets are deposited onto the surface of a polydimethylsiloxane (PDMS) film to form a carbon layer. The carbon-coated PDMS film is then placed on a two-dimensional moving platform and optically processed using the interference light field generated by the nanolaser to create the desired structural color grating.

[0018] In the present invention, the theoretical fringe period of the interference periodic light field is 890 nm.

[0019] As a further improvement of the present invention, the type of the excitation light source in the optical drive assembly is specifically selected according to the material type of the base film.

[0020] When the base film adopts a MXene-IPTS / PE double-layer film, the excitation light source adopts an infrared point laser that can generate near-infrared light with a wavelength range of 808±10nm.

[0021] As a further improvement of the present invention, the color rendering light source is selected to be a white light source that can generate full-color visible light with a wavelength range of 390-760nm.

[0022] As a further improvement of the present invention, the light receiver adopts a color sensor or a spectrometer; the color sensor is used to distinguish the color of the received single color light, and the spectrometer is used to analyze the frequency or wavelength of the received single color light.

[0023] As a further improvement of the present invention, the fixture includes at least one clamping position, each of which is mounted with a structured color flake. In the optical signal decoding system, the number of structured color flakes corresponds to the number of clamping positions in the fixture, the number of near-infrared rays emitted by the excitation light source in the optical drive assembly, and the number of signal channels in the optical receiver. Based on the number of these components, the optical signal decoding system is categorized into single-channel, dual-channel, and multi-channel solutions.

[0024] In a single-channel scheme, an excitation light source generates a single excitation beam that illuminates the structured color sheet. During each sampling period, a decoder continuously receives two eigenvalues ​​generated by the same light receiver, generating a two-digit heptad number and converting it into the corresponding text message. In a single-channel scheme, the maximum information capacity of the sampled signal is 49.

[0025] In a dual-channel approach, the excitation light source generates two parallel excitation beams, which illuminate two structured color flakes. During each sampling period, the decoder synchronously receives the corresponding eigenvalues ​​generated by the two light receivers, generating a two-digit heptad number and converting it into the corresponding text message. In this dual-channel approach, the maximum information capacity of the sampled signal is 49.

[0026] In the multi-channel scheme, assuming the number of channels is n, n ≥ 3, the excitation light source generates n parallel excitation light rays, which are irradiated on n structural color sheets. The decoder synchronously receives the corresponding eigenvalues ​​generated by n light receivers in each sampling period, and then generates an n-bit septenary number; and converts it into the corresponding text information. In the multi-channel scheme, the maximum information capacity of the sampled signal is 7 n .

[0027] As a further improvement of the present invention, in the decoder, when the maximum information capacity of the sampled signal exceeds the total number of letters or characters in the decoding result, the encoding rules of the decoder use the excess signal bits as redundant signals to overcome signal noise in the system.

[0028] The present invention also includes an optical signal encoding system based on structured color flakes, which is used in conjunction with the aforementioned optical signal encoding system based on structured color flakes to encode arbitrary text information into a driving signal containing several continuous power values. The optical signal encoding system provided by the present invention includes: a signal acquisition unit, a rule storage unit, a first conversion unit, a second conversion unit, a third conversion unit, and a driving signal generation unit.

[0029] The information acquisition unit is used to acquire text information to be encoded, and the data types of the text information include letters, characters and Chinese characters.

[0030] The rule storage unit is used to store three comparison tables representing the coding rules, namely the "power-wavelength / frequency / light color" comparison table, the "wavelength / frequency / light color-number" comparison table, and the "number-text" comparison table. The "power-wavelength / frequency / light color" comparison table is generated based on the mapping relationship between the power value of each laser light source in the aforementioned structured color plate-based optical signal coding system and the wavelength / frequency / light color of the single color light received by its corresponding optical receiver. Each power value corresponds one-to-one to the characteristic value of a wavelength / frequency / light color. The "wavelength / frequency / light color-number" comparison table is a mapping relationship table established according to the preset corresponding rules. In the "wavelength / frequency / light color-number" comparison table, the characteristic value of the wavelength / frequency / light color of any single color light corresponds to a unique number from 0 to 6. The "number-text" comparison table is used to establish a one-to-one mapping relationship between any character, letter, or text and an N-digit heptad number; N≥2.

[0031] The first conversion unit is used to convert the text information to be encoded into the corresponding N-digit heptad number by querying the "number-text" comparison table. The N-digit heptad numbers corresponding to each letter / character / Chinese character are arranged in sequence to form a digital queue.

[0032] The second conversion unit is used to convert the heptad number on each bit in the digital queue generated by the first conversion unit into the corresponding wavelength / frequency / light color characteristic value by querying the "wavelength / frequency / light color-number" comparison table; thereby forming a characteristic value queue.

[0033] The third conversion unit is used to convert the characteristic value of each bit in the characteristic value queue generated by the second conversion unit into a corresponding power value by querying the "power-wavelength / frequency / light color" comparison table, thereby obtaining a power value queue.

[0034] The driving signal generating unit is used to obtain the power value queue generated by the third converting unit, and encode the power value queue into a driving signal to be sent containing several consecutive power values.

[0035] The present invention also includes a secure communication system that utilizes a non-encrypted signal transmission channel in any existing communication method to transmit signals and implements real-time secure communication between any two communicating parties. The secure communication system provided by the present invention includes: a channel, a signal encryption module, a signal transmission module, a signal reception module, and a signal decryption module.

[0036] Among them, the channel serves as a channel for signal transmission between communication objects.

[0037] The signal encryption module is installed on the signal transmitter side. The signal encryption module uses the aforementioned optical signal encoding system based on structured color sheets. The signal encryption module converts the text information in the plaintext signal to be sent by the signal transmitter into the corresponding drive signal according to the preset encoding rules.

[0038] The signal sending module is installed on the side of the signal sending end. The signal sending module is used to package the driving signal into a ciphertext signal and transmit the ciphertext signal from the signal sending end to the signal receiving end through the channel.

[0039] The signal receiving module is installed on the signal receiving end side. The signal receiving module is used to receive the encrypted signal sent by the signal sending module and decrypt the received encrypted signal to obtain the corresponding driving signal.

[0040] The signal decryption module is installed on the signal receiving end; it utilizes the aforementioned structured color sheet-based optical signal decoding system. At the signal receiving end, the module modulates the excitation light source in the optical drive assembly based on the driving signal, causing the structured color sheet-based optical signal decoding system to respond accordingly and retrieve the text information output by the decoder.

[0041] As a further improvement of the present invention, in a secure communication system, the "power-wavelength / frequency / light color" comparison table is a fixed comparison table, in which the mapping relationship between parameters is determined by the device hardware parameters of the optical signal decoding system based on the structured color sheet.

[0042] The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table are dynamic comparison tables that can be pre-set or dynamically updated according to the communication confidentiality level. The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table of the signal sending end and the signal receiving end are updated synchronously. The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table together serve as the keys for the signal sending end and the signal receiving end to conduct confidential communication.

[0043] As a further improvement of the present invention, the secure communication system further includes a display module, which is installed on the side of the signal receiving end and is used to display the text information output by the signal decryption module.

[0044] The present invention also provides a secure communication method that uses the aforementioned secure communication system to achieve secure communication between any two communicating parties. The implementation process of the secure communication method includes three different stages: signal encryption, signal transmission, and signal decryption.

[0045] 1. Signal encryption stage:

[0046] (1) Obtain the text content in the plaintext information to be sent.

[0047] (2) According to a preset "number-text" comparison table, the text content is converted word by word into a corresponding N-digit heptad number, and the N-digit heptad numbers corresponding to each letter / character / Chinese character in the text content are arranged in order to form a digital queue.

[0048] (3) According to a preset “wavelength / frequency / light color-number” comparison table, the heptad number on each bit in the digital queue is converted into the corresponding characteristic value of the wavelength / frequency / light color, thereby forming a characteristic value queue.

[0049] (4) According to a preset "power-wavelength / frequency / light color" comparison table, the characteristic value of each bit in the characteristic value queue is converted into a corresponding power value; thus, a power value queue is obtained.

[0050] (5) A driving signal including several consecutive power values ​​is generated according to the power value queue, and the driving signal is packaged to obtain a ciphertext signal to be sent.

[0051] 2. Signal transmission stage

[0052] (6) The encrypted signal is sent from the signal sending end to the signal receiving end through the existing channel.

[0053] (7) Synchronously update the “number-text” comparison table and the “wavelength / frequency / light color-number” comparison table at the signal receiving end.

[0054] 3. Signal Decryption Stage

[0055] (8) Obtain the encrypted signal and unpack it to obtain the corresponding driving signal.

[0056] (9) The driving signal is input to the optical drive assembly, and the optical signal decoding system based on the structured color film, which includes the optical drive assembly and the optical receiver, responds to the driving signal, and then obtains a response signal of a dynamically changing single color light at the optical receiver.

[0057] (10) The decoder decodes the response signal, obtains the corresponding text information and outputs it.

[0058] As a further improvement of the present invention, the decoding process of the decoder is as follows:

[0059] (10.1) The decoder samples the response signal at a preset sampling frequency to obtain sampling signals, each of which contains at least two characteristic values ​​corresponding to the wavelength, frequency or color of a single color light.

[0060] (10.2) The decoder converts the value of each sampled signal obtained according to the "wavelength / frequency / light color-digit" comparison table to obtain the corresponding multi-digit heptad number.

[0061] (10.3) The decoder converts each multi-digit heptad number into the corresponding text content according to the "number-text" comparison table, and outputs the plaintext information corresponding to the text content.

[0062] The technical solution provided by the present invention has the following beneficial effects:

[0063] Based on the material properties of photodeformable materials and diffraction gratings, the present invention designs a set of components that can modulate optical signals, and designs a complete set of signal encoding and decoding systems based on this special optical signal modulation component, forming a communication system that can transmit signals.

[0064] One of the unique features of the communication system designed by this invention is its hardware-level encryption properties. It can convert optical signals into electrical signals at the hardware level, and convert optical signals into text messages at the software level. This enables more efficient and secure communication, making the system more difficult to crack and achieving a higher level of security.

[0065] In the special confidential communication system provided by the present invention, the encoding and decoding of information are completed locally on the device, the data volume of the ciphertext information is small, and information is transmitted using various existing communication methods. Therefore, it has extremely high versatility and can be widely promoted and applied.

[0066] Based on the above advantages, the technical solution provided by the present invention can fully solve the problems in various existing communication solutions, such as the optical information encryption technology needs to rely heavily on external large-scale stimulating decryption equipment, cannot be read repeatedly, and is prone to information leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0068] Figure 1 This is a system principle diagram of an optical signal decoding system based on structured color sheets provided in Example 1 of the present invention.

[0069] Figure 2 This is a flow chart showing the working principle of the decoder in embodiment 1 of the present invention.

[0070] Figure 3 Schematic diagram of the warping deformation of the MXene-IPTS / PE double-layer film under near-infrared light excitation in Example 1 of the present invention.

[0071] Figure 4 Flowchart of the MXene-IPTS film preparation process in Example 1 of the present invention.

[0072] Figure 5 This is a flow chart of the MXene-IPTS / PE double-layer membrane composite process in Example 1 of the present invention.

[0073] Figure 6 This is a system principle diagram of the nanosecond laser and lens system for generating an interference light field in Example 1 of the present invention.

[0074] Figure 7 Schematic diagram of the structure of a portion of the structural color grating sheet in the structural color sheet of Example 1 of the present invention.

[0075] Figure 8This is a simulation diagram of the light intensity distribution in the interference periodic light field when preparing the structural color grating in Example 1 of the present invention.

[0076] Figure 9 for Figure 7 Scanning electron microscope image of the microstructure of the medium-structure color flake.

[0077] Figure 10 For Figure 1 System schematic diagram of the dual-channel solution corresponding to the single-channel solution.

[0078] Figure 11 For Figure 1 System schematic diagram of the three-channel solution corresponding to the single-channel solution.

[0079] Figure 12 This is a system module block diagram of the optical signal coding system based on structured color sheets provided in Example 2 of the present invention.

[0080] Figure 13 This is a system module block diagram of the secure communication system provided in Example 3 of the present invention.

[0081] Figure 14 This is a system module block diagram of a secure communication system with a two-way communication function provided in Example 3 of the present invention.

[0082] Figure 15 This is the system module block diagram of the secure communication system after adding the display module.

[0083] Figure 16 This is a flowchart of the secure communication method provided in Example 4 of the present invention. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0085] Example 1

[0086] This embodiment provides an optical signal decoding system based on structured color sheets, which is used to decode a received drive signal containing a series of power values ​​into corresponding text information. The data types of the text information include letters, characters, and Chinese characters. In short, when the optical signal decoding system provided in this embodiment receives a series of drive signals with power values ​​having certain coding characteristics, the system can output the text information corresponding to the drive signals.

[0087] The structural principle diagram of the optical signal decoding system based on the structured color sheet provided in this embodiment is as follows: Figure 1As shown. Figure 1 As can be seen in the figure, this type of optical signal decoding system includes: at least one structural color plate, a fixture, an optical drive assembly, a color light source, a light receiver, and a decoder.

[0088] Each structural color sheet consists of a base film and a structural color grating sheet. The base film is long and strip-shaped; one end is fixed and the other is free. The structural color grating sheet is attached to the surface of the free end of the base film. The base film is made of a photobendable material. A clamp is used to clamp the structural color sheet along the fixed end.

[0089] The optical drive assembly includes a signal receiver and an excitation light source. The signal receiver is configured to receive a drive signal containing a series of power values. The excitation light source receives the drive signal and, based on the power values ​​contained in the drive signal, controls the excitation light source to generate excitation light of corresponding power. The excitation light illuminates the middle portion of the base film surface of the structural color sheet, driving the free end of the structural color sheet to bend at a corresponding angle.

[0090] The color-rendering light source is located on a side close to the free end of the structural color sheet; the color-rendering light source adopts a full-color light source, and the color-rendering light source irradiates an area corresponding to the structural color grating sheet part in the structural color sheet.

[0091] The light receiver is located on the side of the color rendering light source. It receives the single-color light emitted by the color rendering light source and reflected by the structured color grating. There are seven types of single-color light: red, orange, yellow, green, blue, indigo, and violet. The light receiver outputs the characteristic value corresponding to each single-color light received. The characteristic value is used to characterize the wavelength, color, or frequency of the single-color light.

[0092] The decoder is electrically connected to the optical signal receiver. Figure 2 As shown, the decoding process of the decoder is as follows: first, at least two characteristic values ​​are acquired at a preset sampling frequency. Then, according to a preset "wavelength / frequency / light color-number" comparison table, the characteristic value of any single color light is converted into a corresponding number from 0 to 7. A shift addition is performed to obtain a multi-digit septenary number composed of multiple numbers. Finally, according to a preset "number-text" comparison table, any multi-digit septenary number is converted into the corresponding text information and output.

[0093] In order to more clearly introduce the principles and functions of the optical signal decoding system based on structural color sheets provided in this embodiment, this embodiment first introduces the characteristics of special photodeformable materials. The inventive technicians discovered a special thin film material-MXene-IPTS / PE double-layer film during their research. MXene-IPTS / PE double-layer film is a typical photodeformable material. The characteristics of this material are: the base film itself has a certain hardness and structural strength. When the base film is processed into a long strip sheet, the base film can remain flat in its natural state. However, when the base film is clamped from one side of the base film and then irradiated with near-infrared light in the middle of the base film, it can be observed that the other side of the base film relative to the fixed side (ie, the free end) undergoes obvious warping deformation. The excitation light source used in this embodiment is an infrared point laser that can generate near-infrared light with a wavelength range of 808±10nm. The deformation state is roughly as follows. Figure 3 In particular, after repeated experiments, the present technicians also found that there is a certain correlation between the degree of warping deformation of the free end of the base film and the power of the irradiated near-infrared light.

[0094] In view of this special material and its properties, the present invention technicians have designed the following Figure 1 In the optical signal decoding system based on structural color sheets, if a series of different power values ​​are continuously input to the signal receiver in the optical drive component of the system and the excitation light source is driven to generate excitation light of corresponding power, the free end of the structural color sheet can be dynamically deformed. Figure 1 In this system, the structural color grating sheet and the base film "combination film" in the structured color sheet form a special "diffraction grating" that disperses the full-color light incident from the color-rendering light source and projects the reflected single-color light onto a light receiver on the same side as the color-rendering light source. As the power of the near-infrared light emission changes, the deformation of the structural color sheet dynamically adjusts, causing the composition of the single-color light received by the light receiver to change. Through a series of tests, the inventors determined the power level of the excitation light source that corresponds to the light receiver receiving seven different single-color lights: red, orange, yellow, green, blue, indigo, and violet. Furthermore, the inventors verified the repeatability of the system's response to varying near-infrared light powers. Specifically, each time the technicians adjusted the excitation light source power to the corresponding value, the light receiver captured light of the corresponding frequency and wavelength. This response is reproducible.

[0095] It should be emphasized that: in the solution of the present invention, in order to enable the optical signal decoding system in this embodiment to generate a mapping between data containing a large amount of text information of different data types (such as letters, characters, and Chinese characters, etc.) and a single seven-color light, this embodiment has designed a new encoding method and designed a corresponding decoder in combination with the encoding method.

[0096] The encoding and decoding method provided in this embodiment is as follows: First, each color of light is defined as a corresponding seven-base-hexadecimal number. For example, red, orange, yellow, green, blue, indigo, and violet are represented as 0, 1, 2, 3, 4, 5, and 6, respectively. The mapping relationship between the two can be expressed as a "wavelength / frequency / light color-number" comparison table, where each different color of light is associated with a unique seven-base-hexadecimal number. The "wavelength / frequency / light color-number" comparison table is shown in Table 1 below:

[0097] Table 1: Tabular form of the "wavelength / frequency / light color-number" comparison table Next, if the received signal curve of the optical receiver is sampled to obtain a sampled signal, each basic signal unit of the sampled signal corresponds to a color light type. In the sampled signal, if each two different color light types are used to represent a two-digit septenary number, then this two-digit septenary number can represent a total of 7×7 states, for a total of 49. These 49 states can represent a maximum of 26 English letters (A to Z), as well as a series of 23 special characters such as "space," "!", "%," "&," "?", etc. Accordingly, if more information can be represented using color light, the number of colors in the single sampled signal can be increased to obtain a septenary number with more bits. For example, if three colors of light are used to represent a sampled signal, the colors correspond to a three-digit septenary number, and the state bits can represent a total of 7×7×7 states, for a total of 343, which can be used to represent 36 English letters and 307 special characters. This can basically cover all English text transmission requirements. Accordingly, the Chinese character library has approximately 40,000 to 80,000 characters. If a 6-bit heptad number of six colors of light is used, 117,649 state bits can be generated, which can completely cover all Chinese characters.

[0098] In the encoding and decoding rules of this embodiment, multiple different colored lights are converted into multi-digit heptad numbers, which are then used to represent the corresponding text information expressed in Chinese or English characters. Based on this, this embodiment constructs a "number-to-text" comparison table.

[0099] Taking the use of two hexadecimal digits to represent the 26 English letters AZ as an example, the tabular form of the "number-text" comparison table in this implementation is shown in Table 2:

[0100] Table 2: Number-to-text comparison table containing 26 English letters

[0101]

[0102] Therefore, in the optical signal decoding system based on the structural color sheet provided in this embodiment, the complete signal decoding logic is as follows: first, the system receives a series of power values, and responds to different power values ​​by emitting near-infrared light of different powers. The near-infrared light of different powers illuminates the structural color sheet, causing it to bend to different degrees, and causing the optical receiver to receive colored light of different wavelengths and frequencies.

[0103] The decoder then samples the light receiver's response curve to obtain a series of characteristic combinations of color lights. Each characteristic combination of two color lights is considered a unit, generating a sampling signal. The characteristic values ​​of each color light in each sampling signal are first converted through a "wavelength / frequency / light color-to-number" comparison table to obtain a corresponding two-digit heptad number. This two-digit heptad number is then converted into a corresponding English letter or symbol using a "number-to-text" comparison table.

[0104] Ultimately, when a series of power values ​​are input into the front end of the optical signal decoding system based on structural color sheets, the back end of the system can output a series of text content, such as letters, characters, and Chinese characters.

[0105] In this embodiment, the base film in the structural color sheet is a MXene-IPTS / PE double-layer film. The MXene-IPTS / PE double-layer film is a special composite film structure, and its preparation method is roughly as follows:

[0106] Ti3C2T was obtained by chemical liquid phase etching x solution. Then Ti3C2T x The solution is then compounded with isocyanatepropyltriethoxysilane (IPTS). A MXene-IPTS film is then obtained by vacuum filtration. Finally, a polyethylene (PE) adhesive film is attached to the surface of the MXene-IPTS film to obtain the desired MXene-IPTS / PE bilayer membrane.

[0107] In detail, the preparation process of MXene-IPTS / PE double-layer membrane includes two major steps. The first step is to prepare MXene-IPTS material. This process is relatively complicated; the process flow is roughly as follows: Figure 4 shown.

[0108] First, Ti3C2T xIt is the most representative MXene material and can be manufactured by chemical liquid phase etching method. The aluminum layer in the precursor material Ti3AlC2 is selectively corroded by 40wt% hydrofluoric acid. During the acid etching process, Ti3AlC2 powder is slowly immersed in 40% hydrofluoric acid at a ratio of 1g:10ml and continuously stirred at room temperature for 6 to 18 hours. The resulting mixture is washed with distilled water and centrifuged to a pH value above 6. Then, the precipitate is collected by vacuum filtration and dried in a vacuum freeze dryer to obtain Ti3C2T x Powder.

[0109] Next, Ti3C2T x Add to dimethyl sulfoxide, continue stirring for 18 hours, and centrifuge to remove dimethyl sulfoxide. Subsequently, the resulting precipitate was added to 300 mL of distilled water, ultrasonicated for 20 minutes to 4 hours, and centrifuged at 3500 r / min for 1 hour. Finally, a precipitate containing layered Ti3C2T x The supernatant of Ti3C2T x The solution is further compounded with isocyanatepropyltriethoxysilane (IPTS), and vacuum filtration is used to filter it into a composite thin film material; that is, the desired MXene-IPTS film.

[0110] The second step is to prepare the MXene-IPTS / PE flexible double-layer membrane. This process is relatively simple and the process steps are roughly as follows: Figure 5 First, a commercially available anisotropic polyethylene (PE) adhesive film is selected; the PE film is adhered to the surface of the MXene-IPTS film and then cut to the appropriate angle and size to obtain the desired MXene-IPTS / PE flexible double-layer membrane.

[0111] In the solution of this embodiment, the preparation process of the structural color grating sheet in the structural color sheet is as follows:

[0112] A nanosecond laser and lens system are used to form a periodic interference light field. Figure 6 Schematic diagram of the principle of laser interference light field forming system. Figure 6 In the process, the laser beam emitted by the nanosecond laser first passes through a beam splitter, and the laser beam is divided into two beams with the same energy. The two beams are then converged into a 1×1mm 2 Finally, by precisely adjusting the optical path length, the light beams overlap on the sample, forming an interference periodic light field. The theoretical fringe period of the interference periodic light field generated in this embodiment is 890nm.

[0113] Next, carbon ink is dropped onto the surface of a polydimethylsiloxane (PDMS) film to form a carbon layer. The carbon-coated PDMS film is then placed on a two-dimensional moving platform and optically processed using the interference light field generated by a nanolaser to create the desired structural color grating. This structural color grating is then attached to a base film to create the desired structural color flake.

[0114] In the preparation process of this embodiment, the local structure of the structural color grating in the obtained structural color sheet is as follows: Figure 7 As shown, Figure 8 This is a simulation diagram of the distribution of light intensity in the interference periodic light field when the structural color grating is formed in this area. Figure 9 In the structural color film Figure 7 Scanning electron microscope photograph of a part.

[0115] In the solution of this embodiment, the role of the excitation light source in the optical drive assembly is to illuminate the structural color sheet, so that it responds to the power of the excitation light and produces different degrees of bending deformation. There is more than one type of photobending material that can be selected in the base film under consideration, and the light components of the excitation light that can excite base films of different materials to undergo bending deformation are also different. Therefore, the type of excitation light source needs to be selected according to the material type of the base film. For example, in this embodiment, when the base film adopts a MXene-IPTS / PE double-layer film, the excitation light source adopts an infrared point laser that can generate near-infrared light with a wavelength range of 808±10nm.

[0116] It should be emphasized that the reason the optical receiver in this embodiment can receive light of different colors is mainly because the "diffraction grating" in the optical structure sheet disperses the light emitted by the color rendering light source and reflects the color light of specific components to the sensitive element of the optical receiver. Therefore, the decomposed color rendering light source itself must select a complex light containing all colors of light (or become white light or full-color light). In fact, the color rendering light source here should select a light source with light components as close to natural light as possible. Specifically, in actual applications, the color rendering light source in this embodiment selects a white light LED light source that can generate full-color visible light in the wavelength range of 390-760nm.

[0117] The optical receiver in this embodiment primarily analyzes the composition of received single-color light. The analysis results can be characterized by properties such as color, wavelength, and frequency. Therefore, in practical applications, the optical receiver can employ a color sensor or spectrometer; the color sensor is used to distinguish the color of the received single-color light, while the spectrometer is used to analyze the frequency or wavelength of the received single-color light. In fact, in some alternative implementations of this embodiment, cameras based on CMOS or CCD sensors can also achieve the corresponding color resolution function.

[0118] In this embodiment, the fixture includes at least one clamping position, each of which is mounted with a structured color flake. In the optical signal decoding system, the number of structured color flakes corresponds to the number of clamping positions in the fixture, the number of near-infrared rays emitted by the excitation light source in the optical drive assembly, and the number of signal channels in the optical receiver. Based on the number of these components, optical signal decoding systems are categorized into single-channel, dual-channel, and multi-channel solutions.

[0119] In a single-channel solution, the excitation light source generates a channel of excitation light that illuminates the structural color film. The decoder continuously receives two eigenvalues ​​generated by the same light receiver in each sampling cycle, and then generates a two-digit heptad number; and converts it into the corresponding text information. In a single-channel solution, the maximum information capacity of the sampled signal is 49. Figure 1 This is a typical system structure diagram of a single-channel solution.

[0120] In a dual-channel approach, the excitation light source generates two parallel excitation beams, which illuminate two juxtaposed structured color patches. During each sampling period, the decoder simultaneously receives the corresponding eigenvalues ​​generated by the two light receivers, generating a two-digit heptad number and converting it into the corresponding text message. In this dual-channel approach, the maximum information capacity of the sampled signal is 49. Figure 10 This is a schematic diagram of the system structure of a typical dual-channel solution provided in this embodiment.

[0121] In the multi-channel scheme, assuming the number of channels is n, n ≥ 3, the excitation light source generates n parallel excitation light rays, which are irradiated on n structural color sheets. The decoder synchronously receives the corresponding eigenvalues ​​generated by n light receivers in each sampling period, and then generates an n-bit septenary number; and converts it into the corresponding text information. In the multi-channel scheme, the maximum information capacity of the sampled signal is 7 n . Figure 11 A typical structural diagram of a three-channel system.

[0122] Combine Figure 1 、 Figure 10 and Figure 11 As can be seen, as the number of system channels increases, the information capacity of the sampled signal also increases. In the decoder, when the maximum information capacity of the sampled signal exceeds the total number of letters or characters in the decoded result, the decoder's encoding rules use the excess signal bits as redundancy to overcome signal noise in the system. This improves the system's fault tolerance during signal transmission or decoding.

[0123] Example 2

[0124] This embodiment provides an optical signal encoding system based on structured color sheets, which is used in conjunction with the optical signal encoding system based on structured color sheets in Example 1 to encode arbitrary text information into a driving signal containing several continuous power values. Figure 12 As shown, the optical signal encoding system provided by this embodiment includes: a signal acquisition unit, a rule storage unit, a first conversion unit, a second conversion unit, a third conversion unit, and a driving signal generation unit.

[0125] The information acquisition unit is used to acquire text information to be encoded, and the data types of the text information include letters, characters and Chinese characters.

[0126] The rule storage unit is used to store three comparison tables representing the coding rules, namely the "power-wavelength / frequency / light color" comparison table, the "wavelength / frequency / light color-number" comparison table, and the "number-text" comparison table. The "power-wavelength / frequency / light color" comparison table is generated based on the mapping relationship between the power value of each laser light source in the aforementioned structured color plate-based optical signal coding system and the wavelength / frequency / light color of the single color light received by its corresponding optical receiver. Each power value corresponds one-to-one to the characteristic value of a wavelength / frequency / light color. The "wavelength / frequency / light color-number" comparison table is a mapping relationship table established according to the preset corresponding rules. In the "wavelength / frequency / light color-number" comparison table, the characteristic value of the wavelength / frequency / light color of any single color light corresponds to a unique number from 0 to 6. The "number-text" comparison table is used to establish a one-to-one mapping relationship between any character, letter, or text and an N-digit heptad number; N≥2.

[0127] The first conversion unit is used to convert the text information to be encoded into the corresponding N-digit heptad number by querying the "number-text" comparison table. The N-digit heptad numbers corresponding to each letter / character / Chinese character are arranged in sequence to form a digital queue.

[0128] The second conversion unit is used to convert the heptad number on each bit in the digital queue generated by the first conversion unit into the corresponding wavelength / frequency / light color characteristic value by querying the "wavelength / frequency / light color-number" comparison table; thereby forming a characteristic value queue.

[0129] The third conversion unit is used to convert the characteristic value of each bit in the characteristic value queue generated by the second conversion unit into a corresponding power value by querying the "power-wavelength / frequency / light color" comparison table, thereby obtaining a power value queue.

[0130] The driving signal generating unit is used to obtain the power value queue generated by the third converting unit, and encode the power value queue into a driving signal to be sent containing several consecutive power values.

[0131] Example 3

[0132] Based on the first and second embodiments, this embodiment further provides a secure communication system that utilizes a non-encrypted signal transmission channel in any existing communication means to transmit signals and realizes real-time secure communication between any two communication objects. Figure 13 As shown, the secure communication system provided by this embodiment includes: a channel, a signal encryption module, a signal sending module, a signal receiving module, and a signal decryption module.

[0133] The channel is a passage for signal transmission between communication objects. The communication methods that can be used in the present invention include microwave communication, satellite communication, optical fiber communication, network communication, etc.

[0134] The signal encryption module is installed on the side of the signal transmitter. The signal encryption module adopts the optical signal encoding system based on the structured color sheet as described in Example 2. The signal encryption module converts the text information in the plaintext signal to be sent by the signal transmitter into a corresponding driving signal according to a preset encoding rule.

[0135] The signal sending module is installed on the side of the signal sending end. The signal sending module is used to package the driving signal into a ciphertext signal and transmit the ciphertext signal from the signal sending end to the signal receiving end through the channel.

[0136] The signal receiving module is installed on the signal receiving end side. The signal receiving module is used to receive the encrypted signal sent by the signal sending module and decrypt the received encrypted signal to obtain the corresponding driving signal.

[0137] The signal decryption module is installed on the signal receiving end; it uses the structured color sheet-based optical signal decoding system described in Example 1. At the signal receiving end, the signal decryption module modulates the excitation light source in the optical drive assembly according to the driving signal, causing the structured color sheet-based optical signal decoding system to respond accordingly and obtain the text information output by the decoder.

[0138] The signal sending module and the signal receiving module in this embodiment can adopt communication modules that support any existing communication protocol, for example, functional modules that support cellular mobile communication, HPLC, WLAN, Bluetooth, WIFI, radio, satellite communication and other communication methods.

[0139] In the actual application process of the secure communication system provided by this embodiment, each communication object can actually be configured with a full set of signal encryption modules, signal transmission modules, signal reception modules, and signal decryption modules at the same time. A duplex communication module with both signal transmission and signal reception functions is also used. Thus, the following can be achieved between any two communication objects A and B: Figure 14 Two-way communication shown.

[0140] In the secure communication system of this embodiment, the "power-wavelength / frequency / light color" comparison table is a fixed comparison table, in which the mapping relationship between parameters is determined by the device hardware parameters of the optical signal decoding system based on the structured color sheet.

[0141] The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table are dynamic comparison tables that can be pre-set or dynamically updated according to the communication confidentiality level. The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table of the signal sending end and the signal receiving end are updated synchronously. The "number-text" comparison table and / or the "wavelength / frequency / light color-number" comparison table together serve as the keys for the signal sending end and the signal receiving end to conduct confidential communication.

[0142] In a further improved solution of this embodiment, as Figure 15 As shown, the secure communication system further includes a display module, which is installed on the side of the signal receiving end and is used to display the text information output by the signal decryption module.

[0143] Example 4

[0144] This embodiment provides a secure communication method, which uses the secure communication system of embodiment 3 as the hardware of the communication device and implements secure communication between any two communication objects through the following method. Figure 16 As shown in FIG, the implementation process of the confidential communication method includes three different stages: signal encryption stage, signal transmission stage, and signal decryption stage:

[0145] 1. Signal encryption stage:

[0146] (1) Obtain the text content in the plaintext information to be sent.

[0147] (2) According to a preset "number-text" comparison table, the text content is converted word by word into a corresponding N-digit heptad number, and the N-digit heptad numbers corresponding to each letter / character / Chinese character in the text content are arranged in order to form a digital queue.

[0148] (3) According to a preset “wavelength / frequency / light color-number” comparison table, the heptad number on each bit in the digital queue is converted into the corresponding characteristic value of the wavelength / frequency / light color, thereby forming a characteristic value queue.

[0149] (4) According to a preset "power-wavelength / frequency / light color" comparison table, the characteristic value of each bit in the characteristic value queue is converted into a corresponding power value; thus, a power value queue is obtained.

[0150] (5) A driving signal including several consecutive power values ​​is generated according to the power value queue, and the driving signal is packaged to obtain a ciphertext signal to be sent.

[0151] 2. Signal transmission stage

[0152] (6) The encrypted signal is sent from the signal sending end to the signal receiving end through the existing channel.

[0153] (7) Synchronously update the “number-text” comparison table and the “wavelength / frequency / light color-number” comparison table at the signal receiving end.

[0154] 3. Signal Decryption Stage

[0155] (8) Obtain the encrypted signal and unpack it to obtain the corresponding driving signal.

[0156] (9) The driving signal is input to the optical drive assembly, and the optical signal decoding system based on the structured color film, which includes the optical drive assembly and the optical receiver, responds to the driving signal, and then obtains a response signal of a dynamically changing single color light at the optical receiver.

[0157] (10) The decoder decodes the response signal, obtains the corresponding text information and outputs it. The decoding process of the decoder is as follows:

[0158] (10.1) The decoder samples the response signal at a preset sampling frequency to obtain sampling signals, each of which contains at least two characteristic values ​​corresponding to the wavelength, frequency or color of a single color light.

[0159] (10.2) The decoder converts the value of each sampled signal obtained according to the "wavelength / frequency / light color-digit" comparison table to obtain the corresponding multi-digit heptad number.

[0160] (10.3) The decoder converts each multi-digit heptad number into the corresponding text content according to the "number-text" comparison table, and outputs the plaintext information corresponding to the text content.

[0161] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical signal decoding system based on structural color film, characterized in that: It is used to decode a received driving signal containing several continuous power values ​​into corresponding text information, where the data type of the text information includes letters, characters and Chinese characters; the optical signal decoding system includes: At least one structural color sheet, comprising a base film and a structural color grating sheet; the base film is in the shape of an elongated strip; one end of the base film is a fixed end, and the other end is a free end, and the structural color grating sheet is attached to the surface of the free end of the base film; the base film is made of a photobendable material; a clamp for clamping the structural color sheet along a fixed end of the structural color sheet; An optical drive assembly includes a signal receiver and an excitation light source; the signal receiver is configured to receive a drive signal containing a plurality of continuous power values; the excitation light source receives the drive signal and controls the excitation light source to generate excitation light of corresponding power according to the power values ​​contained in the drive signal; the excitation light is irradiated onto the middle portion of the base film surface of the structural color sheet to drive the free end of the structural color sheet to bend and deform at a corresponding angle; A color-rendering light source is located on a side close to the free end of the structural color sheet; the color-rendering light source is a full-color light source, and the color-rendering light source illuminates the area corresponding to the structural color grating sheet portion of the structural color sheet; a light receiver located on one side of the color-rendering light source; the light receiver is used to receive single-color light emitted by the color-rendering light source and reflected by the structured color grating; the single-color light is divided into seven types, namely red, orange, yellow, green, blue, indigo, and violet; the light receiver outputs a characteristic value corresponding to each received single-color light, and the characteristic value is used to characterize the wavelength, color, or frequency of the single-color light; and A decoder is electrically connected to the optical receiver; the decoding process of the decoder is as follows: at least two characteristic values ​​are obtained each time according to a preset sampling frequency, and then the characteristic value of any single color light is converted into a corresponding number from 0 to 7 according to a preset "wavelength / frequency / light color-number" comparison table, and a multi-digit septenary number composed of multiple numbers is obtained by shifting and adding them; and then any multi-digit septenary number is converted into corresponding text information according to a preset "number-text" comparison table and output.

2. The optical signal decoding system based on structured color sheets according to claim 1, wherein: The base film in the structural color sheet is a MXene-IPTS / PE double-layer film; the preparation method of the MXene-IPTS / PE double-layer film is as follows: Ti3C2T was obtained by chemical liquid phase etching x solution; then Ti3C2T x The solution is compounded with isocyanatepropyltriethoxysilane; a MXene-IPTS film is then obtained by vacuum filtration; finally, a polyethylene adhesive film is attached to the surface of the MXene-IPTS film to obtain the desired MXene-IPTS / PE double-layer film.

3. The optical signal decoding system based on structured color sheets according to claim 2, wherein: The preparation process of the structural color grating sheet in the structural color sheet is as follows: A nanosecond laser and a lens system are used to form a periodic interference light field. Carbon ink droplets are dropped onto the surface of a polydimethylsiloxane film to form a carbon layer. The PDMS film coated with the carbon layer is then placed on a two-dimensional moving platform and optically processed using the interference light field formed by a nanolaser to obtain the desired structural color grating. The theoretical fringe period of the interference light field is 890nm.

4. The optical signal decoding system based on structured color sheets according to claim 2, wherein: The type of the excitation light source in the optical drive assembly is selected according to the material type of the base film; When the base film is a MXene-IPTS / PE double-layer film, the excitation light source is an infrared point laser that can generate near-infrared light with a wavelength range of 808±10nm.

5. The optical signal decoding system based on structured color sheets according to claim 1, wherein: The color rendering light source is a white light source that can generate full-color visible light with a wavelength range of 390-760nm.

6. The optical signal decoding system based on structured color sheets according to claim 1, wherein: The light receiver adopts a color sensor or a spectrometer; the color sensor is used to distinguish the color of the received single color light, and the spectrometer is used to analyze the frequency or wavelength of the received single color light.

7. The optical signal decoding system based on structured color sheets according to claim 1, wherein: The fixture contains at least one clamping position, and each clamping position is installed with a structural color piece; in the optical signal decoding system, the number of structural color pieces, the number of clamping positions in the fixture, the number of near-infrared light emitted by the excitation light source in the optical drive assembly, and the number of signal channels of the optical receiver correspond to each other; according to the difference in the number of components, the optical signal decoding system is divided into single-channel, dual-channel and multi-channel solutions.

8. The optical signal decoding system based on structured color sheets according to claim 7, wherein: In a single-channel scheme, the excitation light source generates a channel of excitation light, which is irradiated on the structured color patch. The decoder continuously receives two eigenvalues ​​generated by the same light receiver in each sampling cycle, and then generates a two-digit heptad number and converts it into the corresponding text information. The maximum information capacity of the sampled signal is 49. In the dual-channel scheme, the excitation light source generates two parallel excitation light beams, which are irradiated on two structural color patches. The decoder synchronously receives the corresponding eigenvalues ​​generated by the two light receivers during each sampling period, and then generates a two-digit heptad number and converts it into the corresponding text information. The maximum information capacity of the sampled signal is 49. In the multi-channel scheme, assuming the number of channels is n, n ≥ 3, the excitation light source generates n parallel excitation light rays, which are irradiated on n structural color pieces; the decoder synchronously receives the corresponding eigenvalues ​​generated by n light receivers in each sampling period, and then generates an n-bit septenary number and converts it into the corresponding text information; the maximum information capacity of the sampling signal is 7 n .

9. The optical signal decoding system based on structured color sheets according to claim 1, wherein: In the decoder, when the maximum information capacity of the sampled signal exceeds the total number of letters or characters in the decoded result, the coding rule of the decoder uses the excess signal bits as redundant signals to overcome signal noise in the system.

10. An optical signal coding system based on structured color film, characterized by: The optical signal encoding system is used in conjunction with the optical signal encoding system based on the structured color sheet according to any one of claims 1 to 9, and is used to encode arbitrary text information into a driving signal containing a plurality of continuous power values; the optical signal encoding system comprises: An information acquisition unit, configured to acquire text information to be encoded, wherein the data types of the text information include letters, characters, and Chinese characters; A rule storage unit, configured to store three comparison tables representing coding rules, namely a "power-wavelength / frequency / light color" comparison table, a "wavelength / frequency / light color-number" comparison table, and a "number-text" comparison table; the "power-wavelength / frequency / light color" comparison table is generated based on a mapping relationship between the power value of each laser light source in the structured color sheet-based optical signal coding system and the wavelength / frequency / light color of a single color light received by its corresponding optical receiver; each power value corresponds one-to-one to a characteristic value of a wavelength / frequency / light color; the "wavelength / frequency / light color-number" comparison table is a mapping relationship table established according to a preset correspondence rule, wherein the characteristic value of the wavelength / frequency / light color of any single color light in the "wavelength / frequency / light color-number" comparison table corresponds to a unique number from 0 to 6; the "number-text" comparison table is configured to establish a one-to-one mapping relationship between any character, letter, or text and an N-digit heptad number; N ≥ 2; a first conversion unit, configured to convert the text information to be encoded into corresponding N-digit heptad numbers word by word by consulting the "digit-text" comparison table; and to arrange the N-digit heptad numbers corresponding to the letters / characters / Chinese characters in sequence to form a digital queue; a second conversion unit configured to convert the heptad number on each digit in the digital queue generated by the first conversion unit into a characteristic value of the corresponding wavelength / frequency / light color by querying the "wavelength / frequency / light color-number" comparison table, thereby forming a characteristic value queue; a third conversion unit configured to convert the characteristic value of each bit in the characteristic value queue generated by the second conversion unit into a corresponding power value by querying the "power-wavelength / frequency / light color" comparison table, thereby obtaining a power value queue; and The driving signal generating unit is configured to obtain the power value queue generated by the third converting unit and encode the power value queue into a driving signal to be sent containing a plurality of consecutive power values.

Images