Calculation method applied to effective tuning spectral range of dual-wavelength LCTF

Abstract

The invention relates to the technical field of liquid crystal electronic devices, in particular to a calculation method applied to an effective tuning spectral range of a dual-wavelength LCTF (Liquid Crystal Transistor Fiber), which specifically comprises the following steps: determining initial structure parameters; the tuning spectral range of the gain wavelength is limited to be a free spectral range; the condition that only one gain wavelength transmission exists in the free spectral range is limited, and the tuning spectral range of the center wavelength is calculated; the tuning spectral range of the central wavelength is limited to be contained in the free spectral range, and the effective tuning spectral range of the final central wavelength is obtained; accurately calculating the effective tuning spectral range of the gain wavelength; determining a transmission factor Qp meeting conditions according to a theoretical design result, and calculating the retardation of each cascade liquid crystal; simulating spectral transmission of the dual-wavelength LCTF system in a free spectral range; according to the method, the problem that the design process of the transmission factors of the dual-wavelength LCTF system is complicated is solved, and the selection process of the transmission factors of the tuning center wavelength is simplified.

Description

Technical Field

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

[0002] At present, most of the research on LCTF (liquid crystal tunable filter) focuses on improving spectral resolution, increasing switching speed and suppressing sidelobe transmission. However, these studies are all aimed at a single transmission wavelength and are not suitable for target detection with dual-wavelength response characteristics. Dual-wavelength detection is to design a dual-channel filter based on the two or more characteristic peak response characteristics of the target, and finally realize the transmission of two characteristic wavelengths. Traditional dual-wavelength narrow-band filters are mainly based on optical film theory, Fabry-Preot cavity structure design and guided mode resonance principle preparation, and none of them can achieve wide-band real-time tuning filtering. Therefore, for each characteristic target, a corresponding dual-wavelength filter needs to be designed. The design and implementation method of the dual-wavelength filter can be found in the Chinese patent application number CN202311639657.8. However, the above method needs to be calculated and analyzed for each central tuning wavelength. Therefore, in order to reduce the amount of calculation in the above process, a method is urgently needed to further determine the tuning spectrum 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 according to the size 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 delay 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 cascade 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 initially limited to the free spectrum range, and the gain wavelength needs to meet the following conditions:

[0016]

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

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

[0019]

[0020] When c >λ g When 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 of 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 amount of each cascade liquid crystal.

[0025] Further, in step S8, the calculation formula of 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 calculation method for the effective tuning spectrum range of a dual-wavelength LCTF, which 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 factors of multiple tuning center wavelengths. The method of the present invention can calculate the effective tuning spectrum range of the center wavelength and the gain wavelength for each transmission factor value, and the range is completely within the free spectrum range. Therefore, each wavelength in the effective tuning spectrum range of the center wavelength corresponding to its transmission factor value can achieve dual-wavelength transmission, which greatly simplifies the process of designing the transmission factors one by one when the tuning center wavelength is multiple wavelengths or continuous wavelengths, and simplifies the amount of calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying 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 a dual-wavelength transmittance curve. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are 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", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In addition, the technical features involved in the 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, comprising the following steps:

[0041] S1: Determine the initial structural parameters, which include: free spectral range λ min ~λ max , the transmission factor Q of the dual-wavelength LCTF system p Variation range and number of system cascade layers N; In this embodiment, the free spectrum range is 450-750nm, and the transmission factor Q of the dual-wavelength LCTF system 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. 450-750nm; the gain wavelength must meet the following conditions:

[0043]

[0044] where λ c is the central 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 according to the size relationship between the center wavelength and the gain wavelength; specifically, there are two cases;

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

[0048]

[0049] When c >λ g When 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] 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, which 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 The schematic diagram of the spectral tuning range and effective spectral tuning range of the center wavelength and gain wavelength 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 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 corresponding effective tuning spectrum range of the 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 relationship is λ c <λ g and λ c >λ g (4) When Q p =5, the effective tuning spectrum range of the center wavelength is 450~540nm and 600~630nm, and the corresponding effective tuning spectrum range of the gain wavelength is 562.5~675nm and 500~525nm. Excluding the repeated coverage 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 spectral ranges of the central wavelength and the gain wavelength are both within the free spectral 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 amount of each cascade liquid crystal.

[0064] S8: Calculate the spectral transmittance of the dual-wavelength LCTF system in the free spectrum range using the delay of each cascade liquid crystal, and perform simulation verification; the calculation formula of 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 shown in Figure 3 shown.

[0068] Figure 3 The transmittance curve is a simulated transmittance curve in the range of 450-750nm, where the center wavelength is taken at intervals of 25nm. The red area is the center wavelength and the blue area is 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. In addition, the gain center wavelength value obtained by simulation is completely consistent with the gain wavelength value obtained by theoretical calculation, which verifies the effectiveness of the above theoretical method. Therefore, the method proposed in the present invention can calculate the effective tuning spectral range of the center wavelength and the gain wavelength, thereby simplifying the design of the 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. Among them, 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 SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the method described in the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0072] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part 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, the process or function described in the embodiment of the present application is generated in whole or in part. 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 a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. 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. 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] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. 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 a 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 is not described in detail here.

[0074] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or an instruction 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 devices, discrete gates or transistor logic devices, discrete hardware components. The 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, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined and performed. The software module can be located in a mature storage medium in the field 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 a 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 the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for calculating the effective tuning spectral 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 according to the size 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 delay 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 cascade 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 central 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 p -2 and Q p The +1 level transmission wavelength is outside the free spectrum range. At this time, the tuning spectrum range of the central wavelength is: When c >λ g When 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 amount 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.

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