Low-stray-light ultraviolet-visible spectrograph and target spectrum radiance detection method

Abstract

The invention discloses a low stray light ultraviolet visible spectrograph and a target spectrum radiance detection method, the spectrograph comprises an optical lens cone module, a stray light elimination module and a light splitting detection module, the stray light elimination module comprises a short-wave pass filter A and a short-wave pass filter B, and the two short-wave pass filters can be sequentially inserted into a light path; a target light beam is received and converged by the optical lens cone module, and enters the light splitting detection module after the stray light influence is eliminated by the stray light eliminating module, so that the target light beam is split and detected, and a low-stray-light target spectral signal is formed. According to the target spectrum radiance detection method, spectrum calibration is carried out on the low-stray-light ultraviolet-visible spectrograph, and after segmented radiation calibration is carried out, the target spectrum radiance detection method is used for high-precision calculation of target spectrum radiance. According to the invention, a plurality of short-wave pass optical filter combinations and segmented radiation calibration are adopted, so that a good stray light eliminating effect can be obtained in an ultraviolet visible detection wavelength range with lower economic cost and time cost.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectric detection, and in particular is a low stray light ultraviolet-visible spectrometer and a target spectrum radiance detection method which can significantly improve the measurement accuracy of ultraviolet radiation. Background Art

[0002] UV-visible spectrometers are widely used in environmental detection, life sciences, biotechnology and other fields. The dispersion element of the spectrometer separates the spatial image of the slit into different wavelengths and places it in different areas of the detection array. Ideally, the image of each wavelength and field of view will fall on the specific area corresponding to the detection array. However, in reality, due to non-ideal factors such as multiple reflections on the surface of the structure and high-order diffraction, in addition to the image of a specific wavelength and a specific field of view, the detection array will also receive stray light of other wavelengths that arrive from abnormal paths, i.e., spectral stray light, and stray light of other fields of view that arrive from abnormal paths, i.e., spatial stray light. Among them, spectral stray light is the main stray light in most applications. Spectral stray light may cause large measurement errors and affect the quantitative analysis of target detection data.

[0003] The methods commonly used to eliminate the influence of spectral stray light include: linear gradient filter method, short-wave pass filter, data post-processing method, etc. The linear gradient filter method is to install a linear gradient filter on the detection array and make the filter transmission wavelength coincide with the corresponding wavelength specific area on the detection array, thereby filtering out all irrelevant spectral stray light in each specific area, thereby greatly filtering out spectral stray light; the short-wave pass filter is a filter that transmits within the working band of the spectrometer and cuts off the response wavelengths of the other detectors, thereby filtering out long-wave stray light; the data post-processing method mainly obtains the stray light distribution matrix of the spectrometer by scanning with a monochromatic light source through special experiments, and solves the ideal signal of each wavelength without stray light through data processing methods, thereby realizing stray light correction, without the need for customized filters, and with low economic cost. The above methods have the following problems when applied to the elimination of stray light in ultraviolet-visible spectrometers:

[0004] 1) The linear gradient filter is technically difficult, the customization cost is very high, and the assembly between the linear gradient filter and the detector is difficult;

[0005] 2) The optional transmission band of short-wave pass filters is usually the visible band, while the coating of filters that ensure transmission of the ultraviolet and visible bands is difficult and the customization cost is very high;

[0006] 3) The data post-processing method has high experimental time and labor costs, large data volume, and relatively complex data processing. Summary of the invention

[0007] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a low-stray light UV-visible spectrometer and a target spectral radiance detection method, so as to obtain a good stray light elimination effect in the UV-visible detection wavelength range with lower economic cost and time cost, thereby overcoming the problems of high technical difficulty and high cost of traditional spectral stray light elimination methods.

[0008] The solution adopted by the present invention to solve the technical problem is:

[0009] The present invention discloses a low stray light ultraviolet-visible spectrometer, comprising: an optical lens barrel module and a spectroscopic detection module, wherein a stray light elimination module is embedded in the optical lens barrel module, and the stray light elimination module comprises: a short-wave pass filter A, a short-wave pass filter B and a channel switching device;

[0010] The short-wave pass filter A and the short-wave pass filter B are installed on the channel switching device, so that the channel switching device can control the short-wave pass filter A or the short-wave pass filter B to cut into the optical path of the optical lens barrel module;

[0011] The optical lens barrel module receives the target light beam and after the stray light is eliminated by the stray light elimination module, enters the light splitting detection module for splitting and detecting the target light beam after the stray light is eliminated to form a target spectrum signal with low stray light.

[0012] The low stray light UV-visible spectrometer described in the present invention is also characterized in that:

[0013] The wavelength range covered by the transmission area of ​​the short-wave filter A is to ,in, and The wavelength range covered by the cut-off region of the short-wave pass filter A is the lower limit wavelength of the response of the detector in the spectroscopic detection module. To upper wavelength ;

[0014] The wavelength range covered by the transmission area of ​​the short-wave filter B is to ,in, and The wavelength range covered by the cut-off region of the short-wave pass filter B is the lower limit wavelength of the response of the detector in the spectroscopic detection module. To upper wavelength ;in, ;

[0015] The maximum detection wavelength range of the low stray light UV-visible spectrometer is to , define the boundary wavelength of short-wave pass filters A and B as .

[0016] The target spectral radiance detection method of the present invention is characterized in that it is applied to the low stray light ultraviolet-visible spectrometer according to claim 1 or 2, and comprises the following steps:

[0017] Step 1) Spectral calibration:

[0018] Step 1.1) placing the low stray light UV-visible spectrometer directly opposite the mercury lamp, and turning on the low stray light UV-visible spectrometer and the mercury lamp to preheat until they are stable;

[0019] Step 1.2) The low stray light UV-visible spectrometer collects mercury lamp spectra multiple times and averages them to obtain an original spectrum, wherein the abscissa of the original spectrum is the wavelength and the ordinate is the spectral response DN value;

[0020] Step 1.3) Select the characteristic wavelength sequence of the mercury lamp from the original spectrum The spectra near the center wavelengths are Gaussian fitted and the fitting center wavelength sequences are obtained as follows: ,in, represents the xth characteristic wavelength of the mercury lamp, represents the xth fitting center wavelength; X represents the total number of characteristic wavelengths of mercury lamp;

[0021] Step 1.4) As the horizontal axis, is the ordinate, the wavelength sequence of the original spectrum After interpolation, the wavelength sequence of the calibrated spectrum is obtained ,in, represents the yth wavelength of the original spectrum, Y represents the total number of wavelengths, Represents the yth wavelength of the spectrum after calibration;

[0022] definition The closest to The two wavelengths are denoted as and ,and , then the effective wavelength sequence corresponding to the short-wave pass filter A is , the effective wavelength sequence corresponding to the short-wave pass filter B is ;

[0023] Step 2: Channel-by-channel radiation calibration:

[0024] Step 2.1) placing the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly opposite the light outlet of the xenon lamp integrating sphere light source, and preheating the low stray light UV-visible spectrometer and the calibrated standard spectrometer to be stable;

[0025] Step 2.2) the channel switching device controls the short-wave pass filter A to be inserted into the optical lens barrel module, so that the short-wave pass filter A is in the optical path of the low stray light UV-visible spectrometer;

[0026] Set the integration time to ;

[0027] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A is in the light path;

[0028] The xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ;in, It represents that when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A is in the light path, the xenon lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in;

[0029] After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the xenon lamp integrating sphere after the short-wave pass filter A is in the light path is obtained. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere after the short-wave pass filter A is in the light path;

[0030] Step 2.3) the channel switching device controls the short-wave pass filter B to be inserted into the optical lens barrel module, so that the short-wave pass filter B is in the optical path of the low stray light UV-visible spectrometer;

[0031] Set the integration time to ;

[0032] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A is in the light path;

[0033] The xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ,in, It represents that when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter B is in the light path, the xenon lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in;

[0034] The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the xenon lamp integrating sphere after the short-wave pass filter B is in the light path. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere after the short-wave pass filter B is in the light path;

[0035] Step 2.4) placing the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly opposite the light outlet of the halogen tungsten lamp integrating sphere light source, and preheating the low stray light UV-visible spectrometer and the calibrated standard spectrometer to be stable;

[0036] Step 2.5) the channel switching device controls the short-wave pass filter A to be inserted into the optical lens barrel module, so that the short-wave pass filter A is in the optical path of the low stray light UV-visible spectrometer;

[0037] Set the integration time to ;

[0038] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A is in the light path;

[0039] The radiance spectrum of the halogen tungsten lamp integrating sphere After interpolation, we get The corresponding spectral radiance sequence ;in, It represents that when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A is in the light path, the halogen tungsten lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in;

[0040] After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter A is in the light path is obtained. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a halogen tungsten lamp integrating sphere after the short-wave pass filter A is in the light path;

[0041] Step 2.6) the channel switching device controls the short-wave pass filter B to be inserted into the optical lens barrel module, so that the short-wave pass filter B is in the optical path of the low stray light UV-visible spectrometer;

[0042] Set the integration time to ;

[0043] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A is in the light path;

[0044] The radiance spectrum of the halogen tungsten lamp integrating sphere After interpolation, we get The corresponding spectral radiance sequence ,in, It represents that when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter B is in the light path, the halogen tungsten lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in;

[0045] The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter B is in the light path. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a halogen tungsten lamp integrating sphere after the short-wave pass filter B is in the light path;

[0046] Step 2.7) Extraction of responsiveness by segment:

[0047] definition is the stray light cutoff wavelength, The closest to The two wavelengths are denoted as and ,and , according to the stray light boundary wavelength The wavelength of the short-pass filter , the final absolute responsivity sequence R of the low stray light UV-visible spectrometer is obtained using formula (1):

[0048] (1)

[0049] In formula (1), , The low stray light UV-visible spectrometer is calibrated by inserting the short-wave pass filter A into the optical path and observing the xenon lamp integrating sphere. , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter A is inserted into the optical path to observe the halogen tungsten lamp integrating sphere for calibration. , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter B is inserted into the optical path to observe the xenon lamp integrating sphere for calibration. , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter B is inserted into the optical path to observe the halogen tungsten lamp integrating sphere for calibration. , The corresponding absolute responsivity respectively;

[0050] Step 3: Target observation and spectral radiance calculation:

[0051] Step 3.1) Target observation:

[0052] The channel switching device controls the short-wave filter A1 to be inserted into the optical path and sets the integration time After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave filter A. ;in, Indicates the target effective signal corresponding to the yth wavelength corresponding to the short-wave pass filter A;

[0053] The channel switching device controls the short-wave filter B to be inserted into the optical path and sets the integration time. After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave filter B. ;in, Indicates the target effective signal corresponding to the yth wavelength corresponding to the short-wave pass filter B;

[0054] Step 3.2) Calculate the target spectral radiance according to formula (2): :

[0055] (2)

[0056] In formula (2), , When the short-wave pass filter A is inserted into the optical path to observe the target, the low stray light UV-visible spectrometer , The corresponding average background-subtracted signals respectively; , When the short-wave pass filter B is inserted into the optical path to observe the target, the low stray light UV-visible spectrometer , The corresponding average background-subtracted signals respectively; When the short-wave pass filter A is inserted into the optical path to observe the target, the low stray light UV-visible spectrometer The corresponding average background-subtracted signal; When the short-wave pass filter B is inserted into the optical path to observe the target, the low stray light UV-visible spectrometer The corresponding average background-subtracted signal.

[0057] Compared with the prior art, the beneficial effects of the present invention are:

[0058] 1. The present invention adopts a combination of multiple short-wave pass filters, each of which covers a target working band, has low production difficulty, and can effectively reduce economic costs; through the detection method of inserting different short-wave pass filters into the optical path in sequence, the time-sharing and segmented detection of the target spectrum of the working band and the elimination of long-wave stray light are realized, which has a good stray light elimination effect;

[0059] 2. The present invention adopts a segmented calibration method, and flexibly selects the calibration light source and absolute response data based on the stray light ratio, realizes high-precision radiation calibration with a relatively small time cost, and effectively ensures the quantitative application level of target detection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The figure is a schematic diagram of the composition of the low stray light UV-visible spectrometer of the present invention;

[0061] Figure 2 Schematic diagram of the working wavelength of the low stray light ultraviolet-visible spectrometer of the present invention;

[0062] Numbers in the figure: 1-optical lens tube module, 2-stray light elimination module, 3-spectroscopy detection module, 2.1-short wave pass filter A, 2.2-short wave pass filter A, 2.3-channel switching device. DETAILED DESCRIPTION

[0063] In this embodiment, Figure 1 As shown, a low stray light ultraviolet visible spectrometer comprises: an optical lens barrel module 1 and a spectroscopic detection module 3, a stray light elimination module 2 is embedded in the optical lens barrel module 1, and the stray light elimination module 2 comprises: a short-wave pass filter A2.1, a short-wave pass filter B2.2 and a channel switching device 2.3; its detection wavelength range is required to be 300 to 650nm;

[0064] The short-wave pass filter A2.1 and the short-wave pass filter B2.2 are installed on the channel switching device 2.3, so that the channel switching device 2.3 can control the short-wave pass filter A2.1 or the short-wave pass filter B2.2 to cut into the optical path of the optical lens barrel module 1, and the channel switching device 2.3 can also control the empty channel or the background channel to cut into the optical path of the optical lens barrel module 1. The empty channel refers to a channel that does not affect the optical path, and the background channel refers to a channel that is completely opaque.

[0065] The optical lens barrel module 1 receives the target light beam and after the stray light is eliminated by the stray light elimination module 2, it enters the spectroscopic detection module 3 for spectroscopically detecting and detecting the target light beam after the stray light is eliminated, so as to form a target spectrum signal with low stray light.

[0066] like Figure 2 As shown, the wavelength range covered by the transmission area of ​​the short-wave filter A2.1 is to ,in, and The wavelength range covered by the cut-off area of ​​the short-wave filter A2.1 is the lower limit wavelength of the response of the detector in the spectroscopic detection module 3. To upper wavelength ; Preferably, the short-wave pass filter A2.1 is a colored glass ZWB;

[0067] The transmission area of ​​the short-wave filter B2.2 covers the wavelength range of to ,in, and The wavelength range covered by the cutoff area of ​​the short-wave pass filter B2.2 is the lower limit wavelength of the response of the detector in the spectroscopic detection module 3. To upper wavelength ;in, ; Preferably, the short-wave pass filter B2.2 is a short-wave pass coated filter;

[0068] The maximum detection wavelength range of the low stray light UV-visible spectrometer is to , define the boundary wavelength of short-wave pass filters A2.1 and B as In this embodiment, the boundary wavelength is 357 nm.

[0069] The target spectral radiance detection method of the low stray light UV-visible spectrometer includes the following steps:

[0070] Step 1 Spectral calibration:

[0071] Step 1.1) Place the low stray light UV-visible spectrometer directly opposite the mercury lamp, and turn on the low stray light UV-visible spectrometer and the mercury lamp to preheat until they are stable;

[0072] Step 1.2) The low stray light UV-visible spectrometer collects mercury lamp spectra multiple times and averages them to obtain the original spectrum, where the abscissa of the original spectrum is the wavelength and the ordinate is the spectral response DN value;

[0073] Step 1.3) Select the characteristic wavelength sequence of the mercury lamp from the original spectrum The spectra near the center wavelengths are Gaussian fitted and the fitting center wavelength sequences are obtained as follows: ,in, represents the xth characteristic wavelength of the mercury lamp, represents the xth fitting center wavelength; X represents the total number of characteristic wavelengths of mercury lamp;

[0074] Step 1.4) As the horizontal axis, is the ordinate, the wavelength sequence of the original spectrum After interpolation, the wavelength sequence of the calibrated spectrum is obtained ,in, represents the yth wavelength of the original spectrum, Y represents the total number of wavelengths, Represents the yth wavelength of the spectrum after calibration;

[0075] definition The closest to The two wavelengths are denoted as and ,and , then the effective wavelength sequence corresponding to the short-wave pass filter A2.1 is , the effective wavelength sequence corresponding to the short-wave pass filter B2.2 is .

[0076] Step 2: Use xenon lamp and tungsten halogen lamp with obvious difference in spectral radiance distribution to perform channel radiation calibration:

[0077] Step 2.1) Place the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly at the light outlet of the xenon lamp integrating sphere light source, and preheat the low stray light UV-visible spectrometer and the calibrated standard spectrometer until they are stable;

[0078] Step 2.2) The channel switching device 2.3 controls the short-wave pass filter A2.1 to be inserted into the optical lens tube module 1, so that the short-wave pass filter A2.1 is in the optical path of the low stray light UV-visible spectrometer;

[0079] Set the integration time to ;

[0080] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectra of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly. The abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, It represents the average background-subtracted signal corresponding to the yth wavelength when observing the xenon lamp integrating sphere with the low stray light UV-visible spectrometer after the short-wave pass filter A2.1 is in the light path;

[0081] Xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ;in, It represents the xenon lamp integrating sphere obtained by the standard spectrometer when the low stray light UV-visible spectrometer is observing the xenon lamp integrating sphere after the short wave pass filter A2.1 is in the light path. The spectral radiance corresponding to the y-th wavelength in;

[0082] After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the xenon lamp integrating sphere after the short-wave pass filter A2.1 is in the light path is obtained. ;in, Represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere with the short-wave pass filter A2.1 in the light path.

[0083] Step 2.3) The channel switching device 2.3 controls the short-wave pass filter B2.2 to be inserted into the optical lens tube module 1, so that the short-wave pass filter B2.2 is in the optical path of the low stray light UV-visible spectrometer;

[0084] Set the integration time to ;

[0085] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectra of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly. The abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, It represents the average background-subtracted signal corresponding to the yth wavelength when observing the xenon lamp integrating sphere with the low stray light UV-visible spectrometer after the short-wave pass filter A2.1 is in the light path;

[0086] Xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ,in, It represents the xenon lamp integrating sphere obtained by the standard spectrometer when the low stray light UV-visible spectrometer is observing the xenon lamp integrating sphere after the short wave pass filter B2.2 is in the light path. The spectral radiance corresponding to the y-th wavelength in;

[0087] The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibration when observing the xenon lamp integrating sphere after the short-wave pass filter B2.2 is placed in the light path. ;in, Represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere with the shortwave pass filter B2.2 in the light path.

[0088] Step 2.4) Align the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly to the light outlet of the halogen tungsten lamp integrating sphere light source, and preheat the low stray light UV-visible spectrometer and the calibrated standard spectrometer to be stable.

[0089] Step 2.5) The channel switching device 2.3 controls the short-wave pass filter A2.1 to be inserted into the optical lens tube module 1, so that the short-wave pass filter A2.1 is in the optical path of the low stray light UV-visible spectrometer;

[0090] Set the integration time to ;

[0091] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectra of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly. Among them, the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, It represents the average background-subtracted signal corresponding to the yth wavelength when observing the halogen tungsten lamp integrating sphere with the short-wave pass filter A2.1 in the light path of the low stray light UV-visible spectrometer;

[0092] Halogen tungsten lamp integrating sphere spectrum radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ;in, It represents the halogen tungsten lamp integrating sphere obtained by the standard spectrometer when the low stray light UV-visible spectrometer is observing the halogen tungsten lamp integrating sphere after the short wave pass filter A2.1 is in the light path. The spectral radiance corresponding to the y-th wavelength in;

[0093] After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter A2.1 is in the light path is obtained. ;in, It represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short wave pass filter A2.1 is placed in the light path.

[0094] Step 2.6) The channel switching device 2.3 controls the short-wave pass filter B2.2 to be inserted into the optical lens tube module 1, so that the short-wave pass filter B2.2 is in the optical path of the low stray light UV-visible spectrometer;

[0095] Set the integration time to ;

[0096] The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectra of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly. Among them, the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, It represents the average background-subtracted signal corresponding to the yth wavelength when observing the halogen tungsten lamp integrating sphere with the short-wave pass filter A2.1 in the light path of the low stray light UV-visible spectrometer;

[0097] Halogen tungsten lamp integrating sphere spectrum radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ,in, The halogen tungsten lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in;

[0098] The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibration when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter B2.2 is placed in the light path. ;in, Represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a halogen tungsten lamp integrating sphere with the shortwave pass filter B2.2 in the light path.

[0099] Step 2.7) Extraction of response segmentation:

[0100] Normally, all types of spectrometers need to evaluate the spectral stray light coefficient to check the distribution of stray light at different wavelengths, and based on this, determine the calibration strategy and the strategy for using the calibration data. Normally, the stray light coefficient increases as the wavelength decreases. In this embodiment, the wavelength range where the stray light coefficient is greater than 1% is considered to have a large stray light, and the wavelength where the stray light coefficient = 1% is taken as the stray light demarcation point. In this embodiment, the stray light demarcation point is 400nm. The wavelength range less than the stray light demarcation point of 400nm uses xenon lamp radiation calibration data, because its energy is mainly concentrated in short waves, it can effectively control the proportion of stray light introduced by long-wave energy, and improve the accuracy of the calibration data. The wavelength range greater than the stray light demarcation point of 400nm uses halogen tungsten lamp radiation calibration data. Definition is the stray light cutoff wavelength, let The closest to The two wavelengths are denoted as and ,and , according to the stray light boundary wavelength The crossover wavelength with the short-wave pass filter , using formula (1) to obtain the final absolute responsivity sequence R of the low stray light UV-visible spectrometer:

[0101] (1)

[0102] In formula (1), , The low stray light UV-visible spectrometer is calibrated by inserting the short-wave filter A2.1 into the optical path to observe the xenon lamp integrating sphere , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is calibrated by inserting the short-wave filter A2.1 into the optical path to observe the halogen tungsten lamp integrating sphere , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is calibrated by inserting the short-wave filter B2.2 into the optical path to observe the xenon lamp integrating sphere , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is calibrated by inserting the short-wave filter B2.2 into the optical path to observe the halogen tungsten lamp integrating sphere , The corresponding absolute responsivity.

[0103] Step 3: Target observation and spectral radiance calculation:

[0104] Step 3.1) Target Observation:

[0105] The wavebands corresponding to the short-wave pass filter A2.1 and the short-wave pass filter B2.2 are observed in time division, and the spectral radiances of the wavebands corresponding to the short-wave pass filter A2.1 and the short-wave pass filter B2.2 are solved in turn.

[0106] The channel switching device 2.3 controls the short-wave filter A2.1 to insert into the optical path and sets the integration time. After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave filter A2.1. ;in, It represents the target effective signal corresponding to the yth wavelength corresponding to the short-wave filter A2.1;

[0107] The channel switching device 2.3 controls the short-wave filter B2.2 to insert into the optical path and sets the integration time. After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave filter B2.2. ;in, Indicates the target effective signal corresponding to the yth wavelength corresponding to the shortwave pass filter B2.2.

[0108] Step 3.2) Calculate the target spectral radiance according to formula (2): :

[0109] (2)

[0110] In formula (2), , When the short-wave filter A2.1 is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, , The corresponding average background-subtracted signals respectively; , When the short-wave filter B2.2 is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, , The corresponding average background-subtracted signals respectively; When the short-wave filter A2.1 is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, The corresponding average background-subtracted signal; When the short-wave filter B2.2 is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, The corresponding average background-subtracted signal.

Claims

1. A low stray light UV-visible spectrometer, comprising: An optical lens barrel module (1) and a spectroscopic detection module (3), characterized in that a stray light elimination module (2) is embedded in the optical lens barrel module (1), and the stray light elimination module (2) comprises: a short-wave pass filter A (2.1), a short-wave pass filter B (2.2) and a channel switching device (2.3); The short-wave pass filter A (2.1) and the short-wave pass filter B (2.2) are mounted on a channel switching device (2.3), so that the channel switching device (2.3) can control the short-wave pass filter A (2.1) or the short-wave pass filter B (2.2) to cut into the optical path of the optical lens barrel module (1); The optical lens barrel module (1) receives the target light beam and, after the stray light is eliminated by the stray light elimination module (2), enters the light splitting detection module (3) for splitting and detecting the target light beam after the stray light is eliminated, thereby forming a target spectrum signal with low stray light.

2. A low stray light UV-visible spectrometer according to claim 1, characterized in that: The wavelength range covered by the transmission area of ​​the short-wave filter A (2.1) is to ,in, and The wavelength range covered by the cut-off region of the short-wave pass filter A (2.1) is the lower limit wavelength of the response of the detector in the spectroscopic detection module (3). To upper wavelength ; The wavelength range covered by the transmission area of ​​the short-wave filter B (2.2) is to ,in, and The wavelength range covered by the cut-off region of the short-wave pass filter B (2.2) is the lower limit wavelength of the response of the detector in the spectroscopic detection module (3). To upper wavelength ;in, ; The maximum detection wavelength range of the low stray light UV-visible spectrometer is to , define the boundary wavelength of short-wave pass filters A(2.1) and B as .

3. A method for detecting target spectral radiance, characterized in that: The method is applied to the low stray light ultraviolet-visible spectrometer according to claim 1 or 2, and comprises the following steps: Step 1) Spectral calibration: Step 1.1) placing the low stray light UV-visible spectrometer directly opposite the mercury lamp, and turning on the low stray light UV-visible spectrometer and the mercury lamp to preheat until they are stable; Step 1.2) The low stray light UV-visible spectrometer collects mercury lamp spectra multiple times and averages them to obtain an original spectrum, wherein the abscissa of the original spectrum is the wavelength and the ordinate is the spectral response DN value; Step 1.3) Select the characteristic wavelength sequence of the mercury lamp from the original spectrum The spectra near the center wavelengths are Gaussian fitted and the fitting center wavelength sequences are obtained as follows: ,in, represents the xth characteristic wavelength of the mercury lamp, represents the xth fitting center wavelength; X represents the total number of characteristic wavelengths of mercury lamp; Step 1.4) As the horizontal axis, The ordinate is the wavelength sequence of the original spectrum After interpolation, the wavelength sequence of the calibrated spectrum is obtained ,in, represents the yth wavelength of the original spectrum, Y represents the total number of wavelengths, Represents the yth wavelength of the spectrum after calibration; definition The closest to The two wavelengths are denoted as and ,and , then the effective wavelength sequence corresponding to the short-wave pass filter A (2.1) is , the effective wavelength sequence corresponding to the short-wave pass filter B (2.2) is ; Step 2: Channel-by-channel radiation calibration: Step 2.1) placing the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly opposite the light outlet of the xenon lamp integrating sphere light source, and preheating the low stray light UV-visible spectrometer and the calibrated standard spectrometer to be stable; Step 2.2) The channel switching device (2.3) controls the short-wave pass filter A (2.1) to be inserted into the optical lens barrel module (1), so that the short-wave pass filter A (2.1) is located in the optical path of the low stray light ultraviolet-visible spectrometer; Set the integration time to ; The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; The xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ;in, It represents that when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path, the xenon lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in; After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the xenon lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path is obtained. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; Step 2.3) The channel switching device (2.3) controls the short-wave pass filter B (2.2) to be inserted into the optical lens barrel module (1), so that the short-wave pass filter B (2.2) is located in the optical path of the low stray light ultraviolet-visible spectrometer; Set the integration time to ; The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the xenon lamp integrating sphere for multiple times, and after preprocessing, the xenon lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the xenon lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the xenon lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; The xenon lamp integrating sphere spectral radiance spectrum After interpolation, we get The corresponding spectral radiance sequence ,in, It represents that when the low stray light UV-visible spectrometer observes the xenon lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path, the xenon lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in; The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the xenon lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a xenon lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path; Step 2.4) placing the low stray light UV-visible spectrometer and the calibrated standard spectrometer directly opposite the light outlet of the halogen tungsten lamp integrating sphere light source, and preheating the low stray light UV-visible spectrometer and the calibrated standard spectrometer to be stable; Step 2.5) The channel switching device (2.3) controls the short-wave pass filter A (2.1) to be inserted into the optical lens barrel module (1), so that the short-wave pass filter A (2.1) is located in the optical path of the low stray light ultraviolet-visible spectrometer; Set the integration time to ; The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ;in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; The radiance spectrum of the halogen tungsten lamp integrating sphere After interpolation, we get The corresponding spectral radiance sequence ;in, It represents that when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path, the halogen tungsten lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in; After dividing the average background-subtracted signal corresponding to the same wavelength by the spectral radiance, the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path is obtained. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a halogen tungsten lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; Step 2.6) The channel switching device (2.3) controls the short-wave pass filter B (2.2) to be inserted into the optical lens barrel module (1), so that the short-wave pass filter B (2.2) is located in the optical path of the low stray light ultraviolet-visible spectrometer; Set the integration time to ; The low stray light UV-visible spectrometer and the calibrated standard spectrometer simultaneously collect the spectrum of the halogen tungsten lamp integrating sphere for multiple times, and after preprocessing, the halogen tungsten lamp integrating sphere observation signal spectrum of the low stray light UV-visible spectrometer and the halogen tungsten lamp integrating sphere spectrum radiance spectrum of the standard spectrometer are obtained accordingly, wherein the abscissa of the halogen tungsten lamp integrating sphere observation signal spectrum is , the vertical axis is the average background-subtracted signal sequence ,in, represents the average background-subtracted signal corresponding to the yth wavelength when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter A (2.1) is in the light path; The radiance spectrum of the halogen tungsten lamp integrating sphere After interpolation, we get The corresponding spectral radiance sequence ,in, It represents that when the low stray light UV-visible spectrometer observes the halogen tungsten lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path, the halogen tungsten lamp integrating sphere obtained by the standard spectrometer is The spectral radiance corresponding to the y-th wavelength in; The average background-subtracted signal corresponding to the same wavelength is divided by the spectral radiance to obtain the absolute responsivity sequence obtained by calibrating the low stray light UV-visible spectrometer when observing the halogen tungsten lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path. ;in, represents the absolute responsivity corresponding to the yth wavelength obtained by calibration of the low stray light UV-visible spectrometer when observing a halogen tungsten lamp integrating sphere after the short-wave pass filter B (2.2) is in the light path; Step 2.7) Extraction of responsiveness by segment: definition is the stray light cutoff wavelength, The closest to The two wavelengths are denoted as and ,and , according to the stray light boundary wavelength The wavelength of the short-pass filter , using formula (1) to obtain the final absolute responsivity sequence R of the low stray light UV-visible spectrometer: (1) In formula (1), , The low stray light UV-visible spectrometer is calibrated by inserting a xenon lamp integrating sphere into the optical path of the short-wave pass filter A (2.1). , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter A (2.1) is inserted into the optical path to observe the halogen tungsten lamp integrating sphere for calibration , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter B (2.2) is inserted into the optical path and the xenon lamp integrating sphere is observed for calibration. , The corresponding absolute responsivity respectively; , The low stray light UV-visible spectrometer is obtained when the short-wave pass filter B (2.2) is inserted into the optical path to observe the halogen tungsten lamp integrating sphere for calibration. , The corresponding absolute responsivity respectively; Step 3: Target observation and spectral radiance calculation: Step 3.1) Target observation: The channel switching device (2.3) controls the short-wave filter A (2.1) to be inserted into the optical path and sets the integration time. After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave filter A (2.1). ;in, Indicates the target effective signal corresponding to the yth wavelength corresponding to the short-wave pass filter A (2.1); The channel switching device (2.3) controls the short-wave filter B (2.2) to be inserted into the optical path and sets the integration time. After that, the target spectrum is collected multiple times and the average is taken and the background signal is subtracted to obtain the target effective signal sequence corresponding to the short-wave pass filter B (2.2). ;in, Indicates the target effective signal corresponding to the yth wavelength corresponding to the short-wave pass filter B (2.2); Step 3.2) Calculate the target spectral radiance according to formula (2): : (2) In formula (2), , When the short-wave pass filter A (2.1) is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, , The corresponding average background-subtracted signals respectively; , When the short-wave pass filter B (2.2) is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, , The corresponding average background-subtracted signals respectively; When the short-wave pass filter A (2.1) is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, The corresponding average background-subtracted signal; When the short-wave pass filter B (2.2) is inserted into the optical path of the low stray light UV-visible spectrometer to observe the target, The corresponding average background-subtracted signal.

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