A long-time wavelength stability test system and method for a built-in light source of a spectrometer

Abstract

The application provides a long-time wavelength stability test method and system for a built-in light source of a spectrometer, relates to the technical field of light source testing, and comprises the following steps: starting a mercury lamp light source and a spectrum analyzer, selecting a reference mercury lamp reference wavelength, and adjusting a bandpass optical fiber filter; observing and monitoring the spectrometer to determine whether the reference reference can be observed; if not, the bandpass optical fiber filter is continuously adjusted, so that the reference reference wavelength appears in the specified wavelength observation range; if the reference reference wavelength can be observed, the built-in light source and a wavemeter are started to measure; long-time acquisition is performed on the peak wavelength value and the reference wavelength value to be measured, a screening standard value is set, the variance of long-time measurement data is calculated, it is determined whether the variance of the measurement data is less than the screening standard value, and if yes, the stability is determined to be qualified. The application uses the peak wavelength to calculate the variance to evaluate the stability, can simultaneously perform stability measurement on multiple peak wavelengths, and is suitable for wavelength stability measurement of different types of built-in light sources.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light source testing, in particular to a long-time wavelength stability testing system and method for a built-in light source of a spectrometer. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] Due to the quality of the built-in light source laser itself in the spectrometer and the change of the environment where the spectrometer is located, and other factors, the peak wavelength of the built-in light source may drift during long-time use, thereby affecting the wavelength calibration. Therefore, it is necessary to test the wavelength stability of the built-in light source of the spectrometer, so as to screen out the built-in light source meeting the stability requirement, thereby ensuring the accuracy of the wavelength value of the external incident light measured by the spectrometer.

[0004] The invention patent "light source stability testing system and method" (201310528352.X) discloses a light source stability testing system applied to an image measurement device, which comprises a shooting module, a calculation module, a drawing module, and an output module, and uses the invention to test the stability of the light source.

[0005] The invention patent "high-power laser light source continuous stability testing system and method" (CN201811420106.1) discloses a high-power laser light source continuous stability testing system and method, which comprises a laser generating device, a focusing mirror, a light attenuation device, and a detection device.

[0006] The paper "Establishment and application of wavelength calibration device for 633 nm frequency stabilized laser" (Laser and Optoelectronics Progress, No. 52, 2015) introduces a 633 nm wavelength standard device, uses the beat frequency principle of frequency stabilized laser wavelength calibration, and performs wavelength calibration and stability measurement.

[0007] However, the inventors found that the prior art still has the following problems:

[0008] (1) The current testing method for the wavelength stability of the built-in light source is greatly affected by the external environment (temperature, humidity, air pressure, and vibration), and the test result is not ideal in the case of long-time testing.

[0009] (2) The current stability testing of the built-in light source is mostly based on the light source itself, which is easy to produce different results due to the different quality of the light source itself, resulting in low testing accuracy and poor traceability.

[0010] (3) The current built-in light source stability testing is mostly applicable to DFB type built-in light source, and cannot simultaneously measure multiple peaks for FP type built-in light source.

[0011] (4) Current built-in light source stability test needs frequent manual operation, more troublesome, not conducive to long time measurement. SUMMARY

[0012] The present application proposes a kind of spectrometer built-in light source long time wavelength stability test system and method to solve the above problems, uses mercury lamp as reference light source, adopts difference input measurement, uses peak wavelength variance to judge stability, can simultaneously carry out the stability measurement of multiple peak wavelengths, suitable for different types of built-in light source wavelength stability measurement.

[0013] According to some embodiments, the present application adopts the following technical solutions:

[0014] A kind of spectrometer built-in light source long time wavelength stability test method, comprising:

[0015] Turn on mercury lamp light source and spectrometer, select reference mercury lamp reference wavelength, adjust bandpass fiber filter;

[0016] Observation monitored spectrometer, determine whether reference reference wavelength can be observed in specified wavelength range, if not, continue to adjust bandpass fiber filter, so that reference reference wavelength appears in specified wavelength observation range, if reference reference wavelength can be observed, then turn on built-in light source and wavelength meter to measure;

[0017] Long time acquisition of to-be-measured peak wavelength value and reference wavelength value, set screening standard value, calculate long time measurement data variance, confirm whether measurement data variance is less than screening standard value, if yes, then judge stability qualified.

[0018] According to some embodiments, the present application adopts the following technical solutions:

[0019] A kind of spectrometer built-in light source long time wavelength stability test system, comprising:

[0020] Preprocessing module is used to turn on mercury lamp light source and spectrometer, select reference mercury lamp reference wavelength, adjust bandpass fiber filter;

[0021] Test module is used to observe monitored spectrum, determine whether reference reference wavelength can be observed in specified wavelength range, if not, continue to adjust bandpass fiber filter, so that reference reference wavelength appears in specified wavelength observation range, if reference reference wavelength can be observed, then turn on built-in light source and wavelength meter to measure;

[0022] Long time acquisition of to-be-measured peak wavelength value and reference wavelength value, set screening standard value, calculate long time measurement data variance, confirm whether measurement data variance is less than screening standard value, if yes, then judge stability qualified.

[0023] According to some embodiments, the present application adopts the technical solutions as follows:

[0024] A non-transitory computer readable storage medium for storing computer instructions, which, when executed by a processor, implement the long-term wavelength stability test method for built-in light source of a spectrometer.

[0025] According to some embodiments, the present application adopts the technical solutions as follows:

[0026] An electronic device, comprising a processor, a memory and a computer program; wherein the processor is connected with the memory, and the computer program is stored in the memory; when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes the long-term wavelength stability test method for built-in light source of a spectrometer.

[0027] Compared with the prior art, the present application has the beneficial effects that:

[0028] (1) The present application uses a mercury lamp as a reference light source, the characteristic wavelength spectrum line is extremely narrow, and the wavelength value is accurate and stable, which provides good traceability for long-term wavelength stability test.

[0029] (2) The present application adopts differential input measurement, and the influence of environmental changes on each other is offset, which has good environmental adaptability.

[0030] (3) The present application uses peak wavelength to calculate variance to evaluate stability, which can simultaneously measure the stability of multiple peak wavelengths, and is suitable for wavelength stability measurement of different types of built-in light sources.

[0031] (4) The data acquisition and analysis evaluation of the present application are highly automated, and only need to set the initial standard to automatically perform long-term automatic test.

[0032] (5) The present application contains a monitoring light path, which can be monitored in real time to ensure that the reference wavelength of the mercury lamp light source is always within the specified observation wavelength range. BRIEF DESCRIPTION OF DRAWINGS

[0033] The drawings constituting a part of the specification of the present application are used to provide further understanding of the present application, and the schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitation on the present application.

[0034] Figure 1 The structure principle diagram of the long-term stability test system for built-in light source of the embodiment of the present application;

[0035] Figure 2 The flowchart of the stability test for built-in light source of the embodiment of the present application;

[0036] Figure 3 Waveform diagram of the embodiment of the application for the DFB built-in light source;

[0037] Figure 4 Waveform diagram of the embodiment of the application for the FB built-in light source;

[0038] Figure 5 Stability curve of the 1310 nm light source to be measured according to the embodiment of the application;

[0039] Figure 6 Stability curve of the 1357.018 nm standard light source. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as would be understood by one of ordinary skill in the art to which the application pertains.

[0042] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation, device, component, and / or combination thereof.

[0043] Embodiment 1

[0044] In one embodiment of the application, a long-term wavelength stability test method for a spectrometer built-in light source is provided, comprising:

[0045] Step one: turn on the mercury lamp light source and the spectrometer, select the reference mercury lamp reference wavelength, and adjust the bandpass fiber filter;

[0046] Step two: observe the monitored spectrometer to determine whether the reference reference wavelength can be observed, if not, continue to adjust the bandpass fiber filter so that the reference reference wavelength appears in the specified wavelength observation range, if the reference reference wavelength can be observed, turn on the built-in light source and the wavelength meter to measure;

[0047] Step three: collect the peak wavelength value to be measured and the reference wavelength value for a long time, set the screening standard value, calculate the long-term measurement data variance, and confirm whether the measurement data variance is less than the screening standard value, if yes, determine that the stability is qualified.

[0048] As an embodiment, a long-term wavelength stability test procedure of a built-in light source of a spectrometer includes:

[0049] Step 1: At the beginning of the measurement, first turn on the mercury lamp light source and the spectrometer, and select a reference mercury lamp reference wavelength, which can be selected from Table 3, but note that the selected reference wavelength should satisfy the characteristic wavelength in the wavelength range of 600-1700 nm.

[0050] Considering that the characteristic wavelength spectrum of the mercury lamp has multiple peaks in a certain wavelength range, the selected reference wavelength should follow the characteristics of obvious peak power and easy judgment, and the determination formula is as follows:

[0051] P i =max{P k ,P k+1 ,P k+2 ……} (1)

[0052] Where P k , P k+1 , P k+2 …… are the powers of the corresponding peaks in the specified wavelength range. The selection of the specified wavelength range should ensure that the difference between the to-be-measured wavelength and the reference wavelength is not too large, so as to reduce the error caused by the difference in resolution of different wavelength ranges of the test instrument. Therefore, the value should consider the distribution of the calibrated value λ of the to-be-measured wavelength. For a DFB type built-in light source, it has only a single peak wavelength, and its waveform diagram is shown in Figure 3 At this time, the selection of the reference wavelength range is generally:

[0053] λ1∈[λ-50nm,λ+50nm](2)

[0054] For an FP type built-in light source, since it contains multiple wavelength peaks, the selection of the wavelength range should consider the maximum value λ max and the minimum value λ min of the calibrated value of the to-be-measured wavelength, and its waveform diagram is shown in Figure 4 At this time, the selection of the wavelength range is generally:

[0055] λ1∈[λ min -50nm,λ max +50nm](3)

[0056] At the same time, the selection of the reference wavelength should also consider the adjacent wavelength interval to ensure that the wavelength interval meets the requirements of resolution identification. The adjacent wavelength interval should meet the following condition:

[0057] Δλ=min{λ k -λ k-1 ,λ k+1 -λ k}≥2×FWHM (4)

[0058] where λ k is the selected reference wavelength, λ k-1 and λ k+1 are the adjacent peak wavelengths of the selected reference wavelength, and FWHM is the 3dB spectral width of the selected reference wavelength.

[0059] Step 2: Observing the monitoring spectrometer to observe whether the selected reference wavelength λ k appears in the monitoring range [λ L , λ H ], λ L is the set starting wavelength, and λ H is the set ending wavelength. If not, adjust the bandpass fiber filter so that the reference wavelength appears in the monitoring range. If yes, proceed to the next step.

[0060] λ L ≤ λ k ≤ λ H (5)

[0061] Step 3: Turn on the built-in light source and wavelength meter, set the collection time interval Δ t , the total number of samples N, and perform long-time measurement on the measured wavelength and the reference wavelength, and upload the measurement data to the PC end for data processing.

[0062] Use data processing software to program and process the collected data to obtain the variance Δ2, and give the wavelength stability curve.

[0063]

[0064] where N is the number of measurements within a specified time, λ 2i and λ 1i are the measured wavelength and the reference wavelength of a single measurement, respectively, λ2 is the calibrated value of the measured wavelength, and λ1 is the calibrated value of the reference wavelength.

[0065] If Δ2 is less than or equal to Δ1 (here Δ1 is a pre-set screening standard value), the measured built-in light source meets the wavelength stability requirements of the light source, otherwise it does not meet the requirements, and the conclusion is drawn, and the entire measurement process is ended.

[0066] where the selection of the screening standard value Δ1 is determined according to the actual application, and the smaller the value of Δ1, the higher the requirement for wavelength stability.

[0067] Next, select the measured light source of 1310nm and the reference wavelength of 1357.018nm to test this method, select the value of Δ1 as 0.02nm, and set the measurement time interval Δ tThe total measurement number N is 40, and the measured record data are shown in Table 1 and Table 2.

[0068] Table 1 1310 nm wavelength of the to-be-measured light source (unit: nm)

[0069] 1310.012 1310.011 1310.016 1310.006 1310.006 1310.011 1310.013 1310.014 1310.008 1310.008 1310.015 1310.008 1310.017 1310.012 1310.012 1310.017 1310.015 1310.011 1310.011 1310.011 1310.009 1310.012 1310.013 1310.014 1310.011 1310.010 1310.016 1310.017 1310.012 1310.015 1310.014 1310.009 1310.015 1310.005 1310.013 1310.012 1310.018 1310.013 1310.009 1310.013

[0070] Table 2 1357.018 nm wavelength of the standard light source (unit: nm)

[0071] 1357.014 1357.015 1357.019 1357.018 1357.019 1357.012 1357.017 1357.016 1357.017 1357.013 1357.015 1357.019 1357.014 1357.014 1357.014 1357.016 1357.014 1357.018 1357.021 1357.016 1357.017 1357.017 1357.017 1357.014 1357.018 1357.013 1357.015 1357.015 1357.018 1357.019 1357.018 1357.013 1357.017 1357.017 1357.014 1357.015 1357.018 1357.016 1357.017 1357.018

[0072] The obtained value of Δ2 is 0.014 nm, which satisfies Δ2≦Δ1, indicating that the wavelength stability of the to-be-measured light source meets the requirements.

[0073] Figure 3 The waveform schematic diagram of the DFB type built-in light source only contains one wavelength characteristic peak value in the specified range. Figure 4 The waveform schematic diagram of the FP type built-in light source contains multiple wavelength characteristic peak values in the specified range. Figure 5 The wavelength stability curve generated under the condition that the to-be-measured wavelength calibration value is 1310 nm is actually a polyline representation form of the measurement data of the to-be-measured light source. Figure 6 The wavelength stability curve generated under the condition that the wavelength of the selected mercury lamp standard light source is 1357.018 nm is actually a polyline representation form of the measurement data of the reference wavelength.

[0074] Example 2

[0075] In an embodiment of the present application, a long-time wavelength stability test system of a built-in light source of a spectrometer is provided, comprising:

[0076] The preprocessing module is used for turning on the mercury lamp light source and the spectrometer, selecting a reference mercury lamp reference wavelength, and adjusting a bandpass fiber filter.

[0077] The test module is used for observing the monitored spectrum, determining whether the reference reference wavelength can be observed, if not, continuously adjusting the bandpass fiber filter so that the reference reference wavelength appears in the specified wavelength observation range, and if the reference reference wavelength can be observed, turning on the built-in light source and the wavelength meter to measure.

[0078] The long-time to-be-measured peak wavelength value and the reference wavelength value are collected, a screening standard value is set, the long-time measurement data variance is calculated, and it is determined whether the measurement data variance is less than the screening standard value, if yes, the stability is determined to be qualified.

[0079] Specifically, the internal structure of the system module is as shown in Figure 1As shown, the pre-processing module includes a spectrum analyzer, a standard mercury lamp, a fiber coupler and a fiber filter. The test module includes a wavemeter and a PC processor.

[0080] The built-in light source is a reference light source in the spectrum analyzer, which is generally of a DFB type or an FP type. The reference wavelength is selected from a standard mercury lamp, which generates atomic emission lines based on energy level transitions and can be used as a natural reference. The characteristic wavelengths of the mercury lamp do not change with time and environmental factors such as temperature and humidity, and can be used as a test reference. The specific selection is shown in Table 3. The emitted light of the mercury lamp is transmitted by the fiber coupler, and then passes through the bandpass fiber filter to eliminate the interference of useless spectral lines, so as to limit the passable wavelength to the near-infrared range of 600-1700 nm. The filtered mercury lamp beam is split into two equal paths by a 50:50 beam splitter, one of which is coupled into the wavemeter through a "Y" type fiber to measure the wavelength, and the other of which is input into the spectrum analyzer for waveform monitoring of the mercury lamp. The peak wavelength of the built-in light source in the wavemeter and the selected characteristic peak wavelength of the mercury lamp are recorded, and the obtained data is uploaded to the PC end at a fixed time interval. The PC end processes the long-time collected data to obtain the wavelength stability index variance and the wavelength stability curve, so as to evaluate the wavelength stability of the built-in light source under long-time work.

[0081] The selected reference mercury lamp reference wavelength is selected from a standard reference table, as shown in Table 3. The selected reference wavelength value needs to meet the conditions described above.

[0082] Table 3 Characteristic spectral line wavelength peak of standard mercury lamp (unit: nm)

[0083] 253.625 407.783 714.704 800.616 922.450 296.728 435.833 727.294 811.531 1013.976 302.150 546.074 738.398 826.452 1128.642 313.155 576.960 750.387 842.465 1357.018 334.148 579.066 763.511 852.144 1367.353 365.015 696.543 772.376 866.794 1395.057 404.656 706.722 794.818 912.297 1529.578

[0084] The present application has a standard light source as a test reference, high measurement accuracy, and traceability. It has strong resistance to environmental changes and strong adaptability to the environment. It can be applied to different types of built-in light sources, has high applicability, high automation degree in the test process, and simple operation. It has a monitoring light path and can monitor the working state of the standard light source in real time.

[0085] The system described in Embodiment 2 specifically implements the method flow steps in Embodiment 1.

[0086] Embodiment 3

[0087] In one embodiment of the present application, a non-transitory computer readable storage medium is provided for storing computer instructions, which, when executed by a processor, implement the steps of the long-time wavelength stability test method of the built-in light source of the spectrum analyzer.

[0088] Embodiment 4

[0089] In one embodiment of the present application, an electronic device is provided, comprising: a processor, a memory and a computer program; wherein the processor is connected with the memory, and the computer program is stored in the memory; when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes the steps of the method for testing long-time wavelength stability of a built-in light source of a spectrometer.

[0090] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus for implementing the functions specified in one or more flows and / or blocks.

[0091] These computer program instructions can also be loaded onto a computer or other programmable data processing devices to cause a series of operational steps to be executed on the computer or other programmable data processing devices to produce a computer-implemented process, so that the instructions executed by the computer or other programmable data processing devices provide a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 one or more flows and / or blocks

[0092] The above describes the specific embodiments of the present application in conjunction with the accompanying drawings, but is not a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the scope of protection of the present application.

Claims

1. A method for testing long-term wavelength stability of a built-in light source in a spectrometer, characterized in that, The method comprises the following steps: Turning on the mercury lamp light source and the spectrum analyzer, selecting a reference mercury lamp reference wavelength, and adjusting the bandpass fiber filter; The selected reference mercury lamp reference wavelength considers that the mercury lamp characteristic spectrum has multiple peaks in a certain wavelength range, and the selected reference wavelength is determined according to the peak power and the determined characteristics. The selected reference wavelength is the corresponding mercury lamp characteristic wavelength in the specified wavelength range. The selection of the specified wavelength range should ensure that the difference between the to-be-measured wavelength and the reference wavelength is not too large, and the value should consider the distribution of the calibration value of the to-be-measured wavelength; Observing the monitored spectrum to determine whether the reference reference wavelength can be observed. If not, continue to adjust the bandpass fiber filter so that the reference reference wavelength appears in the specified wavelength observation range. If the reference reference wavelength can be observed, turn on the built-in light source and the wavelength meter to measure. Long-time collection of to-be-measured peak wavelength values and reference wavelength values, setting a screening standard value, calculating the variance of long-time measurement data, and confirming whether the measurement data variance is less than the screening standard value. If yes, it is determined that the stability is qualified.

2. The method for testing long-term wavelength stability of a built-in light source of a spectrometer according to claim 1, wherein, The selected reference mercury lamp reference wavelength is selected from a standard reference table, and the selected reference wavelength satisfies the characteristic wavelength in a specific wavelength range.

3. The method for testing long-term wavelength stability of a built-in light source of a spectrometer according to claim 1, wherein, For the DFB type built-in light source, it has only a single peak wavelength. At this time, the selection of the wavelength range is generally [λ-50nm, λ+50nm].

4. The method for testing long-term wavelength stability of a built-in light source of a spectrometer according to claim 1, wherein, For the built-in light source of FP type, it contains multiple wavelength peaks, at this time the selection of wavelength range should consider the maximum value λ max and the minimum value λ min of the wavelength calibration value to be measured, at this time the selection of wavelength range is generally [λ min -50nm, λ max +50nm].

5. The method for testing long-term wavelength stability of a built-in light source of a spectrometer according to claim 1, wherein, The spectrum analyzer is used to observe whether the selected wavelength peak reference appears in the monitoring range. If not, adjust the bandpass fiber filter so that the reference wavelength appears in the monitoring range.

6. A system for testing long-term wavelength stability of a built-in light source of a spectrometer, characterized in that, The method comprises the following steps: A preprocessing module is used to turn on the mercury lamp light source and the spectrum analyzer, select a reference mercury lamp reference wavelength, and adjust the bandpass fiber filter; A test module is used to observe the monitored spectrum to determine whether the reference reference wavelength can be observed. If not, continue to adjust the bandpass fiber filter so that the reference reference wavelength appears in the specified wavelength observation range. If the reference reference wavelength can be observed, turn on the built-in light source and the wavelength meter to measure. Long-time collection of to-be-measured peak wavelength values and reference wavelength values, setting a screening standard value, calculating the variance of long-time measurement data, and confirming whether the measurement data variance is less than the screening standard value. If yes, it is determined that the stability is qualified.

7. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium is used to store computer instructions, which are executed by the processor to implement the method for testing the long-time wavelength stability of the built-in light source of the spectrometer according to any one of claims 1-5.

8. An electronic device, comprising: The method comprises the following steps: A processor, a memory, and a computer program are provided. The processor is connected with the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the method for testing the long-time wavelength stability of the built-in light source of the spectrometer according to any one of claims 1-5.

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