Method for finding voltage and wavelength modulation curves of a transmission center wavelength

Abstract

This invention discloses a method for finding the voltage and wavelength modulation curve of the transmission center wavelength, wherein the transmission center wavelength is selected as λ1, the interval step size of the wavelength curve is set, the half-width at half-maximum (H1) of the wavelength curve is set, and the effective voltage range [v] is determined. s v e First interval step size v t 1. Maximum voltage accuracy D'; 2. Voltage v0 corresponding to the maximum light intensity data value of λ1, confirming voltage v i The precision is d0; with v t v0 is used as the second interval step size v it and voltage v i Confirm v i Precision is d i Within the voltage range, the system cycles between the start and end values ​​with a third interval step size, ultimately obtaining a voltage v with an accuracy of D'. D With voltage v D The wavelength modulation curve is obtained by detecting and scanning within the wavelength range (λ1-h1, λ1+h1) and a set wavelength curve interval step size. This invention provides a more accurate and rapid method for finding high-precision voltage and its wavelength modulation curve, applicable to a wider range of applications.

Description

Technical Field

[0001] This invention relates to the field of MEMS Fabry-Perot cavity chip calibration technology, specifically, a method for finding the voltage and wavelength modulation curve of the transmission center wavelength. Background Technology

[0002] The research and application of near-infrared spectrometers are increasing, making it a hot topic in the field of spectroscopy, and its application is becoming increasingly mature abroad. Currently, miniaturized near-infrared spectrometers based on Fabry-Perot (MEMS) interferometric tunable filter chips are the most widely used. MEMS MEMS MEMS chips are spectroscopic chips fabricated using semiconductor integrated circuit technology based on the Fabry-Perot interferometry principle. Different voltages drive the chip to obtain different narrowband spectra. MEMS MEMS MEMS chips exhibit different wavelength characteristics due to various external factors such as temperature, humidity, and pressure. Therefore, understanding the differentiated bias voltage and voltage-wavelength modulation curves of the transmission center wavelength of MEMS MEMS chips, as well as their calibration using lookup table parameters, is a crucial aspect for the widespread application of MEMS MEMS MEMS chips. Therefore, developing a method to find the voltage and wavelength modulation curves of the transmission center wavelength has become an urgent problem to be solved. Summary of the Invention

[0003] The purpose of this invention is to provide a method for finding the voltage and wavelength modulation curve of the transmission center wavelength, which solves the problem in the prior art that uses the voltage corresponding to the maximum light intensity at a wavelength point as the center wavelength voltage of that wavelength point. This provides users with lookup table parameters, but is only applicable to applications with low requirements for the resolution and accuracy of MEMS Fabry-Perot cavity chips.

[0004] The present invention solves the above problems through the following technical solution:

[0005] A method for finding the voltage and wavelength modulation curve of the transmission center wavelength includes:

[0006] Step A: Select the transmission center wavelength to be searched as λ1 and the wavelength interval step size to be detected and scanned according to the wavelength range of the MEMS Fabry-Perot cavity chip. The smaller the step size, the longer the search time and the higher the accuracy of the final result. Conversely, the larger the step size, the shorter the search time and the lower the accuracy. The size will affect the search time and the accuracy of the final wavelength. It is suitable for use when the user has no application requirements.

[0007] Step B: Determine the full width at half maximum (FWHM) h1 of the set wavelength curve;

[0008] Step C: Set the effective voltage range for the transmission center wavelength [v] s v e First interval step size v tAnd the maximum accuracy D' of the required voltage;

[0009] Step D, by obtaining voltage v s With the first interval step size as v t The wavelength λ1 is scanned in an incremental manner until the voltage v is reached. e End, obtain the voltage v0 corresponding to the maximum light intensity data value of λ1, and confirm the voltage v. i The precision is d0;

[0010] Step E, with the first interval step size v t The voltage v corresponding to the maximum light intensity data value of λ1 obtained in step D. o These are respectively used as the second interval step size v it and voltage v i ;

[0011] Step F, with voltage v i Second interval step size v it Based on the basic parameters, confirm v i Precision is d i Within the effective voltage range, in the range of v i -v it +(1 / 10)^(d i +1) is the starting value, v i +v it -(1 / 10)^(d i +1) is the ending value, with the third interval step size (1 / 10)^(d) i +1) Perform a loop, scanning the two wavelength points λ1-h1 and λ1+h1 under the same voltage, and obtain the voltage accuracy d when the absolute value of the light intensity difference between the two wavelength points λ1-h1 and λ1+h1 is the smallest. i +1 voltage v o ′;

[0012] The confirmation of v in step F i Precision is d i If d i If the voltage accuracy is greater than the maximum required accuracy D' set in step C, then v i As v D Proceed directly to step H; conversely, performing light intensity data scanning and calculation on two wavelength points at opposite ends of the wavelength range under the same voltage to minimize the absolute value of the light intensity difference is to make the final wavelength curve more closely resemble a symmetrical curve, improving the accuracy and stability of the voltage and wavelength modulation curves at the transmission center wavelength. When calculating the absolute value of the light intensity difference, considering the characteristics of the wavelength curve, the subsequent scan can be terminated when the light intensity difference between two wavelength points changes from positive to negative or from negative to positive. This yields the voltage accuracy d corresponding to the minimum absolute value of the light intensity difference between the two wavelength points.i +1 voltage v o ′;

[0013] Step G, with a third interval step size (1 / 10)^(d) i +1) and voltage v o ′ are respectively used as the second interval step size v in step F it and voltage v i Repeat step F D'-(d0+1) times to finally obtain the voltage v with precision D' when the absolute value of the light intensity difference between the two wavelengths λ1-h1 and λ1+h1 is minimized. D ;

[0014] In step G, the interval step size v of step F is changed cyclically. it and voltage v i Step F is executed to continuously improve the voltage accuracy of the transmission center wavelength, ultimately obtaining a high-precision voltage for the transmission center wavelength.

[0015] Step H, with voltage v D The wavelength range (λ1-h1, λ1+h1) and the set wavelength curve interval step size are detected and scanned to obtain a high-precision voltage v with the light wavelength λ1 as the transmission center wavelength. D and at voltage v D Wavelength modulation curves in the lower wavelength range (λ1-h1, λ1+h1).

[0016] Step H ultimately obtains a high-precision voltage and wavelength modulation curve for the transmission center wavelength. Then, the curve is fitted with a low-width section to calculate the centroid. The resulting centroid is a value close to the transmission center wavelength. This centroid can provide a reference for MEMS Fabry-Perot cavity chips when light intensity data is unstable.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] This invention solves the problem of existing technologies that use the voltage corresponding to the maximum light intensity at a wavelength point as the center wavelength voltage for that wavelength point, thus providing users with lookup table parameters. Conventional methods for calibrating lookup table parameters are only suitable for applications with low requirements for the resolution and accuracy of MEMS Fabry-Perot cavity chips. Furthermore, they suffer from problems such as low voltage accuracy leading to large voltage deviations and significant shifts in the wavelength modulation curve, difficulty in finding the correct parameters, and low speed. Inaccurate lookup table parameters also result in low resolution and accuracy of the MEMS Fabry-Perot cavity chip during application. This invention provides a more accurate and valuable method for quickly finding the high-precision voltage of the transmission center wavelength and its wavelength modulation curve using lookup table parameters, making it suitable for a wider range of applications. Attached Figure Description

[0019] Figure 1 This is a flowchart of the present invention;

[0020] Figure 2 This is a schematic diagram of a spectral image scanned at a wavelength of 2150nm with an applied voltage range of 8V to 17V and a step size of 1V.

[0021] Figure 3 This is a schematic diagram of the applied voltage scan spectrum when the voltage accuracy is 1.

[0022] Figure 4 This is a schematic diagram of the applied voltage scan spectrum when the voltage accuracy is 2.

[0023] Figure 5 This is a schematic diagram of the applied voltage scan spectrum when the voltage accuracy is 3.

[0024] Figure 6 This is a schematic diagram of a spectral image with a voltage of 14.461V and a scanning wavelength of 2140nm to 2160nm, with an interval of 0.5nm. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0026] Example:

[0027] Combined with appendix Figure 1 As shown, a method for finding the voltage and wavelength modulation curve of the transmission center wavelength includes:

[0028] 101. Select the transmission center wavelength to be searched as λ1 and the wavelength interval step size to be detected and scanned from the wavelength range of the MEMS Fabry-Perot cavity chip.

[0029] 102. Determine the half-peak width h1 of the set wavelength curve by combining the MEMS Fabry-Perot cavity chip design theory.

[0030] In this embodiment, based on the theoretical design of the MEMS Fabry-Perot cavity chip, its half-width is between 10nm and 17nm; its wavelength range is between 1750nm and 2150nm, and its working state is relatively suitable. Therefore, within this range, a center wavelength of 2150nm, a half-width of 10nm, and a wavelength interval step of 0.5nm are selected for specific implementation.

[0031] 103. Set the effective voltage range (V) for the transmission center wavelength. s v e ) and interval step size v t And the maximum accuracy D of the required voltage.

[0032] In this implementation example, the operating voltage of the MEMS Fabry-Perot cavity chip is between 8V and 36V. The center wavelength of the example parameter, 2150nm, is at the lower voltage end. Therefore, to improve the search efficiency, the voltage range is set to 8V to 17V (in the absence of experience, it can also be directly set to the operating voltage range). The interval step size and voltage accuracy need to be set reasonably according to the technical specifications of the power supply equipment. The highest accuracy of the power supply equipment in this example is millivolts, so an accuracy setting of 0 to 3 is reasonable. To improve the voltage efficiency of searching the center wavelength, the interval step size is optimally set between 0.1V and 1V. Parameter customization settings are then performed in conjunction with the previous descriptions.

[0033] 104. By means of voltage v s With an interval step size of v t The wavelength λ1 is scanned in an incremental manner until v e End, obtain the voltage v0 corresponding to the maximum light intensity data value of λ1, and confirm the voltage v. i The precision (precision: the number of decimal places) is d0.

[0034] In this implementation example, a detection scan of the wavelength 2150nm was performed at 10 different voltages, ranging from 8V to 17V with an interval of 1V. Figure 2 A schematic diagram of a spectral image scanned at a wavelength of 2150nm with an applied voltage range of 8V to 17V and a step size of 1V. The voltage corresponding to the maximum light intensity data value at 2150nm is 14V.

[0035] 105. With an interval step size of v t The voltage v0 corresponding to the maximum light intensity data value of λ1 obtained in step d and step f are respectively used as the interval step size v in step f. it and voltage v i .

[0036] In this implementation example, the voltage is set to 14V, corresponding to the maximum light intensity data value at a wavelength of 2150nm, with an interval step size of 1V. Figure 1 The next step interval v is 106. it =1 and voltage v i =14.

[0037] 106. With voltage v i and interval step size v it Based on the basic parameters, confirm v i Precision (precision: refers to the number of decimal places accurate) is d i Within the voltage range of v i -v it +(1 / 10)^(d i +1) is the starting point, v i +vit -(1 / 10)^(d i +1) is the end, proceed with intervals of (1 / 10)^(d) i +1) Perform a loop, scanning the two wavelength points λ1-h1 and λ1+h1 under the same voltage, and obtain the voltage accuracy d when the absolute value of the light intensity difference between the two wavelength points λ1-h1 and λ1+h1 is the smallest. i +1 voltage v o .

[0038] In this implementation example, the voltage v i 14v and interval step size v it The voltage is set to 1V, confirming that the accuracy of a 14V voltage is 0. Within the voltage range, starting with 14-1+(1 / 10)^(0+1)=13.1 and ending with 14+1-(1 / 10)^(0+1)=14.9, a loop is performed with an interval of (1 / 10)^(0+1)=0.1. Under the same voltage, detection and scanning are performed at two wavelength points: 2150-10=2140 and 2150+10=2160, obtaining the following data: Figure 3 A schematic diagram of the applied voltage scanning spectrum when the voltage accuracy is 1. The figure shows that the voltage with a voltage accuracy of 1 corresponds to 14.4V when the absolute value of the light intensity difference between the two wavelengths of 2140nm and 2160nm is the smallest.

[0039] 107. The step size of the above step interval is (1 / 10)^(d) i +1) and voltage v o As respectively Figure 1 The interval step size v in step 106 it and voltage v i Repeat step f D-(d0+1) times to finally obtain the voltage v with precision D corresponding to the minimum absolute value of the light intensity difference between the two wavelengths λ1-h1 and λ1+h1. D .

[0040] In this implementation example, the previous step interval (1 / 10)^(0+1) and the voltage 14.4V are respectively used as the step interval v in step 106. it and voltage v i Repeat step 106 3-(0+1)=2 times, and finally obtain the voltage v with an accuracy of 3 when the absolute value of the light intensity difference between the two wavelengths 2150-10=2140 and 2150+10=2160 is the smallest. D The details are as follows:

[0041] (1) Repeat step 106 for the first time: with an interval step size of 0.1V and a voltage of 14.4V, and therefore with a voltage of V i 14.4v and interval step size vit The voltage is 0.1V, confirming that the accuracy of the 14.1V voltage is 1. Within the voltage range, starting at 14.4 - 0.1 + (1 / 10)^(1+1) = 14.31 and ending at 14.4 + 0.1 - (1 / 10)^(1+1) = 14.49, a cycle is performed with an interval of (1 / 10)^(1+1) = 0.01. Under the same voltage, detection and scanning are performed at two wavelength points: 2150 - 10 = 2140 and 2150 + 10 = 2160, obtaining the following data: Figure 4 A schematic diagram of the applied voltage scanning spectrum when the voltage accuracy is 2. The figure shows that the voltage with a voltage accuracy of 2 corresponds to 14.45V when the absolute value of the light intensity difference between the two wavelengths of 2140nm and 2160nm is the smallest.

[0042] (2) Repeat step 106 for the second time: with an interval step size of 0.01V and a voltage of 14.45V, and therefore with a voltage of V i The values ​​are 14.45v and the interval step size v. it The accuracy is 0.01V, confirming that the voltage of 14.1V has an accuracy of 1. Within the voltage range, starting at 14.4-0.1+(1 / 10)^(1+1)=14.31 and ending at 14.4+0.1-(1 / 10)^(1+1)=14.49, a cycle is performed with an interval of (1 / 10)^(1+1)=0.01. Under the same voltage, detection and scanning are performed at two wavelength points: 2150-10=2140 and 2150+10=2160, obtaining the following data: Figure 5 A schematic diagram of the applied voltage scanning spectrum when the voltage accuracy is 3. The figure shows that the voltage with a voltage accuracy of 3 is 14.461V when the absolute value of the light intensity difference between the two wavelengths of 2140nm and 2160nm is the smallest.

[0043] The voltage of 14.461V with a precision of 3 corresponds to the minimum absolute value of the light intensity difference between the two wavelengths of 2140nm and 2160nm.

[0044] 108. With voltage v D The wavelength range (λ1-h1, λ1+h1) and the set wavelength curve interval step size are detected and scanned to obtain a high-precision voltage v with the light wavelength λ1 as the transmission center wavelength. D and at voltage v D Wavelength modulation curves for the wavelength range (λ1-h1, λ1+h1).

[0045] In this embodiment, a detection scan is performed at a voltage of 14.461V, with a wavelength range of 2140nm to 2160nm and a set wavelength curve interval step of 0.5nm. This yields a high-precision wavelength modulation curve with a transmission center wavelength of 2150nm at 14.461V and a wavelength range of 2140nm to 2160nm, as shown below. Figure 6 A schematic diagram of the spectral image with a voltage of 14.461V and a scanning wavelength of 2140nm to 2160nm with an interval of 0.5nm.

[0046] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can devise many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A method for finding the voltage and wavelength modulation curve of the transmission center wavelength, characterized in that, include: Step A: Select the transmission center wavelength to be found from the wavelength range of the MEMS Fabry-Perot cavity chip. and the wavelength interval step size required for detection scanning; Step B: Determine the full width at half maximum (FWHM) of the set wavelength curve ; Step C: Set the effective voltage range for the transmission center wavelength. First interval step size And the maximum accuracy of the required voltage, D'; accuracy refers to the number of decimal places to which it is accurate; Step D, by means of voltage With the first interval step size as The incrementing method affects the wavelength Perform a scan until the voltage is reached. End, obtain Voltage corresponding to the maximum light intensity data value Confirm voltage The accuracy is ; Step E: Using the first interval step size and the information obtained in step D Voltage corresponding to the maximum light intensity data value These are respectively used as the second interval step size and voltage ; Step F, with voltage Second interval step size Based on the parameters, confirm Precision is Within the effective voltage range - +(1 / 10)^( +1) is the starting value. + -(1 / 10)^( +1) is the ending value, with the third interval step size (1 / 10)^( +1) Perform a cycle, under the same voltage, for... - and + Two wavelength points are used for detection and scanning to obtain the wavelength. - and + The voltage accuracy is when the absolute value of the light intensity difference between two wavelength points is the minimum. +1 voltage ; Step G, with a third interval step size (1 / 10)^( +1) and voltage These are respectively used as the second interval step size in step F. and voltage Repeat step F D'-( +1) times, finally obtaining the wavelength - and + The voltage with precision D' corresponds to the minimum absolute value of the light intensity difference between two wavelength points. ; Step H, with voltage For wavelength range ( , The detection scan is performed at intervals between the set wavelength curves to obtain the wavelength of light. High-precision voltage for transmission center wavelength and in voltage Lower wavelength range ( , The wavelength modulation curve of ).

2. The method for finding the voltage and wavelength modulation curve of the transmission center wavelength according to claim 1, characterized in that, If in step F If the voltage accuracy is greater than the maximum accuracy D', then the voltage... As voltage Proceed directly to step H.

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