A calculation method for the effective tunable spectral range of dual-wavelength LCTF

Abstract

The present invention relates to the technical field of liquid crystal electronic devices, and in particular to a method for calculating the effective tuning spectrum range of a dual-wavelength LCTF, which comprises the following steps: determining initial structural parameters; limiting the tuning spectrum range of a gain wavelength to a free spectrum range; limiting the condition that only one gain wavelength is transmitted within the free spectrum range, and calculating the tuning spectrum range of a center wavelength; limiting the tuning spectrum range of the center wavelength to be contained within the free spectrum range, and obtaining the effective tuning spectrum range of the final center wavelength; accurately calculating the effective tuning spectrum range of the gain wavelength; and determining a transmission factor Q that satisfies the conditions based on theoretical design results. p , calculate the delay amount of each cascade liquid crystal; simulate the spectral transmission of the dual-wavelength LCTF system in the free spectrum range; the present invention solves the problem of the complicated design process of the transmission factor of the dual-wavelength LCTF system and simplifies the selection process of the transmission factor of the multiple tuning center wavelength.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal electronic devices, and in particular to a method for calculating the effective tuning spectrum range of a dual-wavelength LCTF. Background Art

[0002] Currently, most research on LCTFs (liquid crystal tunable filters) focuses on improving spectral resolution, increasing switching speed, and suppressing sidelobe transmission. However, these studies all focus on a single transmission wavelength and are not suitable for detecting targets with dual-wavelength response characteristics. Dual-wavelength detection involves designing a dual-channel filter based on the response characteristics of two or more characteristic peaks of a target, ultimately achieving transmission of two characteristic wavelengths. Traditional dual-wavelength narrowband filters are primarily based on optical film theory, Fabry-Preot cavity structure design, and guided mode resonance principles, but none of these methods can achieve wide-band real-time tunable filtering. Therefore, a corresponding dual-wavelength filter must be designed for each characteristic target. The design and implementation methods of dual-wavelength filters can be found in Chinese patent application number CN202311639657.8. However, these methods require calculations and analysis for each central tuning wavelength. Therefore, to reduce the computational complexity of this process, a method is urgently needed to further determine the tuning spectral range of the dual-wavelength LCTF. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a calculation method for the effective tuning spectral range of a dual-wavelength LCTF.

[0004] A method for calculating the effective tuning spectral range of a dual-wavelength LCTF comprises the following steps:

[0005] S1: Determine the initial structural parameters;

[0006] S2: Preliminarily limit the tuning spectrum range of the gain wavelength to the free spectrum range;

[0007] S3: further restricting the condition that only one gain wavelength is transmitted within the free spectrum;

[0008] S4: Calculate the tuning spectrum range of the center wavelength based on the relationship between the center wavelength and the gain wavelength;

[0009] S5: limiting the tuning spectrum range of the central wavelength to be contained in the free spectrum range, and obtaining the effective tuning spectrum range of the final central wavelength;

[0010] S6: According to the gain wavelength calculation formula, further accurately calculate the effective tuning spectrum range of the gain wavelength;

[0011] S7: calculating the retardation of each cascade liquid crystal according to the transmission factor under the condition that the effective tuning spectrum ranges of the central wavelength and the gain wavelength are both within the free spectrum range;

[0012] S8: Calculate the spectral transmittance of the dual-wavelength LCTF system within the free spectrum range using the retardation of each cascaded liquid crystal.

[0013] Through the above steps, dual-wavelength transmission of the LCTF system within the free spectral range is finally achieved.

[0014] Furthermore, the initial structural parameters in step S1 include: free spectral range λ min ~λ max , transmission factor Q p Variation range and number of cascade layers N.

[0015] Furthermore, in step S2, the gain wavelength tuning spectrum range is preliminarily limited to the free spectrum range, and the gain wavelength must meet the following conditions:

[0016]

[0017] where λ c is the center wavelength, λ g is the gain wavelength, Q p is the transmission factor.

[0018] Furthermore, the step S4 includes two cases: c <λ g When Q p -2 and Q p The +1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is:

[0019]

[0020] When λ c >λ g When Q p +2 and Q p The -1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is:

[0021]

[0022] Furthermore, the calculation formula for the delay amount of each cascade liquid crystal in step S7 is:

[0023] Δ n =Q p 2 n-1 λ c (n=1,2,K,N)(4);

[0024] where Δ n is the delay of each cascade liquid crystal.

[0025] Furthermore, in step S8, the calculation formula of the spectral transmittance is:

[0026]

[0027] Where T is the spectral transmittance.

[0028] The present invention also includes an electronic device, including a memory and a processor, wherein the memory stores a computer program, and is characterized in that the processor implements the steps of any of the above methods when executing the computer program.

[0029] The present invention also includes a computer-readable storage medium for storing computer instructions, wherein the computer instructions implement the steps of any of the above methods when executed by a processor.

[0030] The technical solution of the present invention has the following advantages:

[0031] The present invention discloses a method for calculating the effective tuning spectral range of a dual-wavelength LCTF, addressing the complex transmission factor design process for a dual-wavelength LCTF system and simplifying the selection of transmission factors for multiple tuning center wavelengths. The method can calculate the effective tuning spectral range for the center wavelength and gain wavelength for each transmission factor value, and this range is completely within the free spectrum. Therefore, each wavelength within the effective tuning spectral range of the center wavelength can achieve dual-wavelength transmission for its corresponding transmission factor value. This greatly simplifies the process of individually designing transmission factors when tuning multiple or continuous center wavelengths, reducing the computational complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 is a flow chart of the method of the present invention;

[0034] Figure 2 Schematic diagram of the effective spectral tuning range of the center wavelength and gain wavelength;

[0035] Figure 3 It is the dual-wavelength transmittance curve. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0039] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] See also Figure 1 A calculation method for the effective tuning spectral range of a dual-wavelength LCTF is provided, comprising the following steps:

[0041] S1: Determine the initial structural parameters, including: free spectral range λ min ~λ max , the transmission factor Q of the dual-wavelength LCTF system p The range of variation and the number of system cascade layers N; in this embodiment, the free spectrum range is 450 to 750 nm, and the transmission factor Q of the dual-wavelength LCTF system is p The range of variation is 2 to 5, and the number of system cascade layers is N=3.

[0042] S2: The tuning spectrum range of the gain wavelength is initially limited to the free spectrum range, i.e. 450-750 nm. The gain wavelength must meet the following conditions:

[0043]

[0044] where λ c is the center wavelength, λ g is the gain wavelength, Q p is the transmission factor.

[0045] S3: further restricting the condition that only one gain wavelength is transmitted within the free spectrum;

[0046] S4: Calculate the tuning spectrum range of the center wavelength based on the relationship between the center wavelength and the gain wavelength; specifically, there are two cases;

[0047] When λ c <λ g When Q p -2 and Q p The +1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is:

[0048]

[0049] When λ c >λ g When Q p +2 and Q p The -1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is:

[0050]

[0051] Then Q p The spectral tuning range of the central wavelength when taking different values ​​is shown in Table 1;

[0052] Table 1 Q p Central wavelength tuning spectral range

[0053]

[0054] S5: The tuning spectrum range of the central wavelength is limited to be included in the free spectrum range, and the effective tuning spectrum range of the final central wavelength is obtained, as shown in Table 2.

[0055] S6: According to the gain wavelength calculation formula, the effective tuning spectral range of the gain wavelength is further accurately calculated. The gain wavelength calculation formula has been disclosed by the patent in the background technology and belongs to the prior art, so it will not be repeated here. The effective tuning spectral range of the gain wavelength is shown in Table 2.

[0056] Table 2 Q p The effective tuning spectral range of the center wavelength and gain wavelength

[0057]

[0058] Figure 2 Schematic diagram of the spectral tuning range and effective spectral tuning range of the center wavelength and gain wavelength, which is an intuitive representation of the data in Table 1 and Table 2, where (a) and (b) are divided into λ c <λ g and λ c >λ g Two position relationships. In the figure, the pink area is the free spectrum range, the yellow bar area is the tuning spectrum range of the center wavelength, the purple line segment area is the effective tuning spectrum range of the center wavelength, and the green line segment area is the effective tuning spectrum range of the gain wavelength. Figure 2 It can be seen that (1) when Q p = 2, the effective tuning spectrum range of the center wavelength is 675~750nm, and the effective tuning spectrum range of the corresponding gain wavelength is 450~500nm. (2) When Q p =3, the effective tuning spectrum range of the center wavelength is 450~500nm and 600~750nm respectively, and the effective tuning spectrum range of the corresponding gain wavelength is 675~750nm and 450~562.5nm respectively. (3) When Q p =4, the effective tuning spectrum range of the center wavelength is 450~675nm, the effective tuning spectrum range of the gain wavelength is 600~750nm and 450~540nm respectively, and the corresponding position relationships are λ c <λ g and λ c >λ g (4) When Q p = 5, the effective tuning spectrum ranges of the center wavelength are 450~540nm and 600~630nm respectively, and the corresponding effective tuning spectrum ranges of the gain wavelength are 562.5~675nm and 500~525nm respectively. Excluding the overlap of the center wavelength, the specific Q of the dual-wavelength LCTF system is p The design values ​​are shown in Table 3.

[0059] Table 3 Q of dual-wavelength LCTF p Design value

[0060]

[0061] S7: Based on the theoretical design results in Table 3, the delay amount of each cascade liquid crystal is calculated. That is, the delay amount of each cascade liquid crystal is calculated based on the transmission factor under the condition that the effective tuning spectrum range of the center wavelength and the gain wavelength are both within the free spectrum range. The calculation formula is:

[0062] Δ n =Q p 2 n-1 λ c(n=1,2,K,N) (4);

[0063] where Δ n is the delay of each cascade liquid crystal.

[0064] S8: Using the delay of each cascaded liquid crystal, calculate the spectral transmittance of the dual-wavelength LCTF system within the free spectrum range and perform simulation verification; the calculation formula for the spectral transmittance is:

[0065]

[0066] Where T is the spectral transmittance.

[0067] Through the above process, a dual spectrum is finally output to achieve dual wavelength transmission of the LCTF system in the range of 450-750nm. The transmittance curve is as follows: Figure 3 shown.

[0068] Figure 3 The following is a simulated transmittance curve obtained by sampling the center wavelength at 25nm intervals within the range of 450-750nm. The red area represents the center wavelength, and the blue area represents the gain wavelength. It can be seen that the gain wavelengths are all within the free spectrum range, and each center wavelength has only one gain wavelength. Furthermore, the simulated gain center wavelength values ​​are completely consistent with the theoretically calculated gain wavelength values, verifying the validity of the theoretical method. Therefore, the method proposed in this invention can calculate the effective tuning spectral range of the center and gain wavelengths, thereby simplifying the design of a dual-wavelength LCTF.

[0069] The present invention also includes an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0070] The present invention also includes a computer-readable storage medium for storing computer instructions, which implement the steps of the above method when executed by a processor.

[0071] The memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0072] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0073] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0074] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0075] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for calculating the effective tuning spectrum range of a dual-wavelength LCTF, characterized in that: The following steps are involved: S1: Determine the initial structural parameters; S2: Preliminarily limit the tuning spectrum range of the gain wavelength to the free spectrum range; S3: further restricting the condition that only one gain wavelength is transmitted within the free spectrum; S4: Calculate the tuning spectrum range of the center wavelength based on the relationship between the center wavelength and the gain wavelength; S5: limiting the tuning spectrum range of the central wavelength to be contained in the free spectrum range, and obtaining the effective tuning spectrum range of the final central wavelength; S6: According to the gain wavelength calculation formula, further accurately calculate the effective tuning spectrum range of the gain wavelength; S7: calculating the retardation of each cascade liquid crystal according to the transmission factor under the condition that the effective tuning spectrum ranges of the central wavelength and the gain wavelength are both within the free spectrum range; S8: Calculate the spectral transmittance of the dual-wavelength LCTF system within the free spectrum range using the retardation of each cascaded liquid crystal. Through the above steps, dual-wavelength transmission of the LCTF system within the free spectral range is finally achieved.

2. The method according to claim 1, characterized in that The initial structural parameters in step S1 include: free spectral range λ min ~λ max , transmission factor Q p Variation range and number of cascade layers N.

3. The method according to claim 2, characterized in that In step S2, the gain wavelength tuning spectrum range is initially limited to the free spectrum range, and the gain wavelength must meet the following conditions: where λ c is the center wavelength, λ g is the gain wavelength, Q p is the transmission factor.

4. The method according to claim 3, characterized in that The step S4 includes two cases: c <λ g When Q p -2 and Q p The +1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is: When λ c >λ g When Q p +2 and Q p The -1 level transmission wavelengths are all outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is:

5. The method according to claim 4, characterized in that The calculation formula of the delay amount of each cascade liquid crystal in step S7 is: D n =Q p ·2 n-1 l c (n=1,2,K,N)(4); where Δ n is the delay of each cascade liquid crystal.

6. The method according to claim 5, characterized in that In step S8, the calculation formula of spectral transmittance is: Where T is the spectral transmittance.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

8. A computer-readable storage medium for storing computer instructions, characterized in that: When the computer instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images