A detection method and a detection system

Abstract

The application provides a detection method and a detection system, wherein the detection method comprises: obtaining first signal light through first detection light, the first detection light comprising a first wavelength range and a second wavelength range; obtaining second signal light through second detection light, the second detection light comprising the second wavelength range and not comprising the first wavelength range; performing first difference processing on the first detection information and the second detection information after first compensation processing, obtaining the first difference between the optical characteristics of the first signal light and the second signal light at each wavelength in the first wavelength range and the corresponding relationship between the wavelength, and obtaining first difference detection information of the first wavelength range; obtaining combined detection information according to the first difference detection information; and obtaining to-be-detected information of a to-be-detected object according to the combined detection information. The application can eliminate the crosstalk of the detection light in the second wavelength range on the detection light in the first wavelength range, and further obtain the detection information in the second wavelength range without crosstalk, thereby improving the detection precision.

Description

Technical Field

[0001] This invention relates to the field of detection, and in particular to a detection method and system for detecting a test object using broadband detection light. Background Technology

[0002] In wafer inspection, using broadband light sources to detect the film layers on the wafer surface can yield a wealth of information, making it a commonly used technique. Ellipsometry, spectrophotometer, and spectral angle profilometer are all devices that utilize broadband light sources to detect the analyte, acquiring spectra that carry information about the analyte to determine its properties.

[0003] However, in the process of using broadband detection, theoretically, the wider the spectrum, the more information can be obtained and the higher the accuracy. However, in reality, there may be interference, which may lead to lower detection accuracy when the spectral width is larger. Summary of the Invention

[0004] To address the above problems, this invention proposes a detection method and system that can reduce spectral crosstalk in signal light, thereby improving detection accuracy.

[0005] The present invention provides a detection method, comprising: performing a first detection on a test object using a first detection light to obtain a first signal light formed by the first detection light passing through the test object, the first detection light including a first wavelength range and a second wavelength range; performing a second detection on the test object using a second detection light to obtain a second signal light formed by the second detection light passing through the test object, the second detection light including the second wavelength range and not including the first wavelength range; obtaining first detection information based on the first signal light, the first detection information including at least the optical characteristics of the first signal light in the first wavelength range, the optical characteristics being positively correlated with light intensity; obtaining second detection information based on the second signal light, the second detection information including at least the optical characteristics of the second signal light in the first wavelength range, wherein the first detection light in the second wavelength range and the second detection light in the second wavelength range are in phase... The light intensity at the same wavelength has a first preset ratio, and the first preset ratio is the same at each wavelength within the second wavelength range; the first detection information and the second detection information are subjected to a first compensation process, such that the first detection information is multiplied by a first compensation coefficient, and the second detection information is multiplied by a second compensation coefficient, and the ratio of the second compensation coefficient to the first compensation coefficient is equal to the first preset ratio; the first detection information and the second detection information after the first compensation process are subjected to a first difference process, and the correspondence between the first difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range is obtained, thus obtaining the first difference detection information within the first wavelength range; combined detection information is obtained based on the first difference detection information, wherein the combined detection information includes at least the first difference detection information; and the test information of the test object is obtained based on the combined detection information.

[0006] Optionally, obtaining combined detection information based on the first difference detection information includes: using a combination of the first difference detection information and the second detection information in the second wavelength range as combined detection information, or using a combination of the first difference detection information and the first detection information in the second wavelength range as combined detection information, or using the first difference detection information as the combined detection information.

[0007] Optionally, obtaining the test information of the test object based on the combined detection information includes: converting each optical feature in the combined detection information into feature parameters of the test object to obtain a feature relationship, wherein the feature parameters are parameter values ​​characterizing the optical properties of the test object, and the feature relationship is the correspondence between the feature parameters and the wavelength; fitting the feature relationship using a theoretical optical model to obtain the test information, wherein the theoretical optical model is a theoretical relationship model between the test information of the test object and the feature parameters.

[0008] Optionally, the first detection information includes: multiple first sub-detection information of a first signal light with different polarization states; the second detection information includes multiple second sub-detection information of a second signal light with different polarization states; performing a first difference processing on the first detection information and the second detection information includes: subtracting the first sub-detection information and the second sub-detection information with the same polarization state respectively to obtain first sub-difference information of multiple polarization states; converting the optical feature into feature parameters of the test object and obtaining feature relationships based on feature parameters of multiple wavelengths includes: converting the optical feature into feature parameters of the test object based on the first sub-difference information of multiple polarization states, and obtaining feature relationships based on feature parameters of multiple wavelengths.

[0009] Optionally, performing a first detection on the object under test using a first detection light to obtain a first signal light formed after the first detection light passes through the object under test includes: polarizing the first detection light beam to give it a first preset polarization state; allowing the polarized first detection light to reach the object under test, whereby the first detection light is reflected, scattered, or transmitted by the object under test to form the first signal light; obtaining first detection information based on the first signal light includes: polarizing the first signal light to obtain first sub-detection information of the first signal light having multiple second preset polarization states; performing a second detection on the object under test using a second detection light to obtain a second signal light formed after the second detection light passes through the object under test includes: polarizing the second detection light beam to give it a first preset polarization state; allowing the second detection light to reach the object under test, whereby the second detection light is reflected, scattered, or transmitted by the object under test to form the second signal light; obtaining second detection information based on the second signal light includes: polarizing the second signal light to obtain second sub-detection information of the second signal light having multiple second preset polarization states.

[0010] Optionally, the characteristic parameters include the surface reflectance of the object under test or the Fourier coefficients.

[0011] Optionally, the optical feature is light intensity, pixel grayscale, or charge value.

[0012] Optionally, converting each optical feature in the combined detection information into feature parameters of the analyte to obtain a feature relationship includes: acquiring standard detection information of a standard sample, wherein the standard detection information includes the correspondence between optical features and wavelengths within at least a first wavelength range, and the feature parameters characterizing the optical features of the standard sample are known preset parameter values; obtaining the feature parameters of the analyte based on the product of the ratio of optical features of the same wavelength in the combined detection information and the standard detection information and the preset parameter value, thereby obtaining the feature relationship.

[0013] Optionally, the characteristic parameter is reflectivity or Fourier coefficient; the information to be measured includes the thickness or height of the film layer on the surface of the object to be measured.

[0014] Optionally, obtaining the test information of the test object based on the combined detection information includes: obtaining the wavelength with the largest optical feature in the combined detection information to obtain the extreme wavelength; obtaining a distance model, wherein the distance model is the correspondence between the wavelength and the height of the test point; obtaining the test information of the test point corresponding to the extreme wavelength based on the distance model and the extreme wavelength, wherein the test information is the height of the test point.

[0015] Optionally, the first wavelength range includes ultraviolet light wavelengths; the second wavelength range includes visible light wavelengths; and the optical power density of the first detection light in the first wavelength range is less than the optical power density of the first detection light in the second wavelength range.

[0016] Optionally, the second wavelength range of the second detection light is a wavelength greater than or equal to a threshold wavelength, wherein the threshold wavelength is any wavelength value from 150nm to 500nm; the first wavelength range includes bands with wavelengths less than or equal to the threshold wavelength.

[0017] Optionally, performing a second detection on the object to be tested using the second detection light includes: filtering light having a first wavelength range and a second wavelength range using a filter to filter out light in the first wavelength range to obtain a second detection light; guiding the second detection light to the object to be tested; and collecting the second signal light using a detector to obtain second detection information.

[0018] Optionally, filtering light having a first wavelength range and a second wavelength range by means of a filter includes: filtering the first detection light by means of the filter to obtain the second detection light by filtering light in the first wavelength range; the first compensation coefficient is 1; and the second compensation coefficient is the transmittance of the filter.

[0019] Optionally, the first detection information further includes: the optical characteristics of the first signal light in the second wavelength range; the detection method further includes: performing a third detection on the test object using a third detection light to obtain a third signal light formed after the third detection light passes through the test object, wherein the third detection light includes the first wavelength range and does not include the second wavelength range;

[0020] The third detection information is obtained based on the third signal light. The third detection information includes at least the optical characteristics of the third signal light in the second wavelength range. The light intensity of the first detection light in the first wavelength range and the third detection light in the first wavelength range at the same wavelength has a second preset ratio.

[0021] The third detected information is subjected to a second compensation process, which multiplies the third detected information by a third compensation coefficient. The ratio of the third compensation coefficient to the first compensation coefficient is equal to the second preset ratio.

[0022] A second difference processing is performed on the first detection information after the second compensation processing and the third detection information after the second compensation processing to obtain the correspondence between the second difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the third signal light at each wavelength within the second wavelength range, thereby obtaining the second difference detection information within the second wavelength range.

[0023] Obtaining combined detection information based on the first difference detection information includes: combining the first difference detection information and the second difference detection information to obtain the combined detection information.

[0024] Optionally, the first preset ratio is greater than or equal to 1; at least one of the first compensation coefficient and the second compensation coefficient is 1.

[0025] Accordingly, a detection system based on the above detection method is also provided, comprising:

[0026] The detection device is used to perform a first detection on a test object using a first detection light to obtain a first signal light formed after the first detection light passes through the test object, wherein the first detection light includes a first wavelength range and a second wavelength range; and to perform a second detection on the test object using a second detection light to obtain a second signal light formed after the second detection light passes through the test object, wherein the second detection light includes the second wavelength range and does not include the first wavelength range.

[0027] The processor is configured to: acquire first detection information based on the first signal light, the first detection information including at least optical characteristics of the first signal light within a first wavelength range, the optical characteristics being positively correlated with light intensity; acquire second detection information based on the second signal light, the second detection information including at least optical characteristics of the second signal light within a first wavelength range; and perform a first difference processing on the first detection information and the second detection information to acquire a first difference between the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, thereby obtaining first difference detection information for the first wavelength range; acquire combined detection information based on the first difference detection information, the combined detection information including at least the first difference detection information; and acquire test information for the analyte based on the combined detection information.

[0028] Optionally, the detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the first detection light passing through the test object and acquiring the second signal light formed by the second detection light passing through the test object.

[0029] Optionally, the light-emitting component includes: a first light source for generating the first detection light; and a second light source for generating the second detection light; or,

[0030] The light-emitting component includes: a light source for generating initial light having a first wavelength range and a second wavelength range; and a filter component for entering and exiting the optical path. If the filter component enters the optical path to filter the initial light, it filters out light in the first wavelength range from the initial light to form a second detection light. If the filter component exits the optical path, the initial light forms a first detection light.

[0031] Optionally, the detection device further includes: a polarizer for polarizing the detection light to give it a first preset polarization state; and an analyzer for polarizing the signal light to give it a second preset polarization state; or

[0032] The detection device includes a dispersive objective lens for converging detection light of different wavelengths to different heights along the optical axis of the detection light.

[0033] The technical solution provided by this invention has the following advantages compared with the prior art:

[0034] In the detection method provided by the present invention, the first detection light includes a first wavelength range and a second wavelength range, and the second detection light includes the second wavelength range but does not include the first wavelength range. The optical characteristics of the first wavelength range in the second detection information obtained from the second detection light are caused by crosstalk from the second detection light in the second wavelength range. By performing a first difference processing on the first and second detection information, first difference detection information of the first wavelength range is obtained, which can eliminate crosstalk from the second wavelength range detection light to the first wavelength range detection light, thereby obtaining detection information of the second wavelength range without crosstalk, and thus improving detection accuracy.

[0035] Furthermore, if the optical power density of the first detection light in the first wavelength range is less than the optical power density of the first detection light in the second wavelength range, then when the second detection light does not include the detection light in the first wavelength range, the optical crosstalk in the combined detection information of the first wavelength range can be eliminated through the first difference processing; and since the optical power density of the first detection light in the first wavelength range is small, its crosstalk to the combined detection information of the second wavelength range is small, which can further improve the detection accuracy.

[0036] Furthermore, the detection method also includes a third detection and a second difference processing, which combines the first difference detection information and the second difference detection information to obtain the combined detection information. This can also eliminate the crosstalk between the first detected light in the first wavelength range and the optical characteristics of the second wavelength in the combined detection information, thereby further improving the detection accuracy. Attached Figure Description

[0037] The present invention will be specifically described below with reference to the accompanying drawings and embodiments. The advantages and implementation methods of the present invention will become more apparent from this description. The content shown in the drawings is for illustrative purposes only and does not constitute any limitation on the present invention. The drawings are schematic only and are not strictly drawn to scale. In the drawings:

[0038] Figure 1 This is a flowchart of each step in the first embodiment of the detection method provided by the technical solution of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the first embodiment of the detection equipment provided by the technical solution of the present invention;

[0040] Figure 3 This is a graph of the detection information obtained in the first embodiment of the detection method provided by the technical solution of the present invention;

[0041] Figure 4 This is a schematic diagram of the structure of the second embodiment of the detection equipment provided by the technical solution of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of each step in the second embodiment of the detection method provided by the technical solution of the present invention. Detailed Implementation

[0043] The detection method provided by the present invention can perform a first difference processing on the first detection information and the second detection information to eliminate the interference of the detection light in the second wavelength range on the detection light in the first wavelength range, thereby improving the detection accuracy.

[0044] In the prior art, in order to increase the amount of information detected by the detection equipment, broadband optical detection is often used. However, due to the limitation of the detector's wavelength sensitivity, crosstalk between different wavelength beams can easily lead to a decrease in detection accuracy.

[0045] To address the aforementioned technical problems, the present invention proposes a detection method that obtains first difference detection information within a first wavelength range by performing a first difference processing on the first detection information and the second detection information, thereby reducing crosstalk between signal lights of different wavelengths and improving detection accuracy.

[0046] The technical solution of the present invention will be described in detail below with reference to the embodiments.

[0047] Figure 1 This is a flowchart of each step in an embodiment of the detection method provided by the technical solution of the present invention.

[0048] refer to Figure 1 The present invention provides a detection method, comprising:

[0049] SP11 performs a first detection on the test object using a first detection light, and obtains a first signal light formed after the first detection light passes through the test object. The first detection light includes a first wavelength range and a second wavelength range.

[0050] SP12 performs a second detection on the test object using a second detection light, and obtains a second signal light formed after the second detection light passes through the test object. The second detection light includes the second wavelength range but does not include the first wavelength range.

[0051] SP13, based on the first signal light, obtain first detection information, the first detection information including at least the optical characteristics of the first signal light in a first wavelength range, the optical characteristics being positively correlated with the light intensity;

[0052] SP14, based on the second signal light, obtain second detection information, the second detection information includes at least the optical characteristics of the second signal light in the first wavelength range, the light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range at the same wavelength has a preset value, and the first preset ratio value is the same at each wavelength in the second wavelength range.

[0053] SP15 performs a first compensation process on the first detected information and the second detected information, so that the first detected information is multiplied by a first compensation coefficient and the second detected information is multiplied by a second compensation coefficient, and the ratio of the second compensation coefficient to the first compensation coefficient is equal to the first preset ratio.

[0054] SP16 performs a first difference processing on the first detection information and the second detection information after the first compensation processing, obtains the correspondence between the first difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, and obtains the first difference detection information within the first wavelength range.

[0055] SP17, obtain combined detection information based on the first difference detection information, wherein the combined detection information includes at least the first difference detection information;

[0056] SP18, obtain the test information of the analyte based on the combined detection information.

[0057] Figure 2 This is a schematic diagram of the structure of a detection device that performs an embodiment of the detection method of the present invention; Figure 3 This is a graph of the detection information obtained in the first embodiment of the detection method provided by the technical solution of the present invention.

[0058] The following combination Figure 2 and Figure 3 The technical solution of the present invention will be described in detail below.

[0059] refer to Figure 1 and Figure 2 Execute step SP11, perform a first detection on the test object 100 using the first detection light, and obtain the first signal light formed after the first detection light passes through the test object 100. The first detection light includes a first wavelength range and a second wavelength range.

[0060] In this embodiment, through Figure 2 The detection equipment performs the detection method.

[0061] The detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the first detection light passing through the test object 100 and the second signal light formed by the second detection light passing through the test object 100.

[0062] In this embodiment, the light-emitting component includes: a light source 110 for generating a first detection light; the detection device further includes: a polarizer 113 for making the detection light polarized, the detection light after passing through the polarizer 113 is incident on the test object 100 and reflected by the test object 100 to form an initial signal light; a compensator 117 and an analyzer 118 are used to adjust the polarization of the initial signal light, adjusting the polarization state of the initial signal light to a preset polarization state to form signal light; the detector is a spectrometer 120 for receiving signal light with a preset polarization state.

[0063] In this embodiment, a first detection light is generated by the light source 110. The first detection light is reflected by the test object 100 to form an initial signal light. The initial signal light passes through the compensator 117 and the analyzer 118 to form a first signal light. The first signal light formed by the first detection light passing through the test object 100 is obtained by the spectrometer 120.

[0064] In this embodiment, the detection device further includes: an incident collimating lens 111 for collimating the detection light generated by the light source 110; an incident converging lens 115 for converging the initial signal light onto the test object 100; an objective lens 116 for collecting the initial signal light reflected by the test object 100 and directing the initial signal light to the compensator 117 and the analyzer 118; and an exit converging lens 119 for converging the signal light onto the spectrometer 120.

[0065] The detection device further includes: a filter 114 for filtering the detection light and removing some wavelength components from the first detection light; and an incident aperture 112 for reducing the size of the light spot incident on the surface of the object to be tested 100.

[0066] The light with a first wavelength range and a second wavelength range is filtered by a filter to filter out the light with the first wavelength range to obtain the second detection light; the second detection light is guided to the object to be tested 100; and the second signal light is collected by a detector to obtain the second detection information.

[0067] In other embodiments, the first detection light is scattered or diffracted by the test object 100 to form the first signal light.

[0068] In this embodiment, the first wavelength range includes ultraviolet light; the second wavelength range includes visible light. Specifically, the second wavelength range of the second detection light is a wavelength greater than or equal to a threshold wavelength, wherein the threshold wavelength is any wavelength value between 199 nm and 355 nm; the first wavelength range includes bands with wavelengths less than or equal to the threshold wavelength.

[0069] In this embodiment, the optical power density of the first detection light in the first wavelength range is less than the optical power density of the first detection light in the second wavelength range.

[0070] If the optical power density of the first detection light in the first wavelength range is less than the optical power density of the first detection light in the second wavelength range, then when the second detection light does not include the detection light in the first wavelength range, the optical crosstalk in the combined detection information of the first wavelength range can be eliminated through the first difference processing; and since the optical power density of the first detection light in the first wavelength range is small, its crosstalk to the combined detection information of the second wavelength range is small, which can further improve the detection accuracy.

[0071] continue Figure 2 Execute step SP12, perform a second detection on the test object 100 using the second detection light, and obtain the second signal light formed after the second detection light passes through the test object 100. The second detection light includes the second wavelength range but does not include the first wavelength range.

[0072] The method for performing a second detection on the test object 100 using a second detection light includes: generating a second detection light; causing the second detection light to reach the test object 100, wherein the second detection light is reflected, scattered, or projected by the test object 100 to form a second signal light. Specifically, in this embodiment, the second detection light is reflected by the test object 100 to form a second signal light.

[0073] The second detection of the test object 100 using the second detection light includes: filtering light with a first wavelength range and a second wavelength range using a filter 114 to filter out light with the first wavelength range and obtain the second detection light; guiding the second detection light to the test object 100; and collecting the second signal light using a detector to obtain the second detection information.

[0074] In this embodiment, filtering light having a first wavelength range and a second wavelength range by filter 114 includes: filtering the first detection light by filter 114 to obtain the second detection light by filtering light in the first wavelength range; the first compensation coefficient is 1; and the second compensation coefficient is the transmittance of filter 114.

[0075] It should be noted that, in the embodiments of the present invention, when the transmittance of the filter 114 approaches 1, the light intensities of the first detection light and the second detection light are basically equal. For ease of calculation, the difference between the first detection light and the second detection light can be ignored, so that both the first compensation coefficient and the second compensation coefficient are 1.

[0076] In other embodiments, the light-emitting component includes: a first light source 110 for generating the first detection light; a second light source 110 for generating the second detection light; and a method for generating the second detection light includes generating the second detection light through the second light source 110.

[0077] refer to Figure 3 Execute step SP13 to obtain first detection information based on the first signal light. The first detection information includes at least the optical characteristics of the first signal light in a first wavelength range, and the optical characteristics are positively correlated with the light intensity.

[0078] In this embodiment, the first detection information includes: multiple first sub-detection information of first signal light with different polarization states.

[0079] Obtaining the first detection information based on the first signal light includes: adjusting the polarization state of the first signal light by rotating the compensator 117 or the analyzer 118, and obtaining the spectral information of the first signal light with different polarization states.

[0080] The first sub-detection information is spectral information; the optical feature is a light intensity value or the resulting image grayscale value, voltage value, or current value. Specifically, in this embodiment, the first sub-detection information is the relationship between the light intensity and wavelength of the first signal light at different wavelengths.

[0081] In this embodiment, the first detection information further includes the optical characteristics of the first signal light in the second wavelength range. In other embodiments, the first detection information may not include the optical characteristics of the first signal light in the second wavelength range.

[0082] Continue to refer to Figure 3 SP14, based on the second signal light, obtain second detection information, the second detection information includes at least the optical characteristics of the second signal light in the first wavelength range, the light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range at the same wavelength has a preset value, and the first preset ratio at each wavelength in the second wavelength range is the same.

[0083] In this embodiment, the second detection information includes multiple second sub-detection information of second signal light with different polarization states.

[0084] Obtaining the first detection information based on the first signal light includes: adjusting the polarization state of the second signal light by rotating the compensator 117 or the analyzer 118, and obtaining the spectral information of the second signal light with different polarization states.

[0085] The second sub-detection information is spectral information; the optical feature is a light intensity value or the resulting image grayscale value, voltage value, or current value. Specifically, in this embodiment, the second sub-detection information is the relationship between the light intensity and wavelength of the second signal light at different wavelengths.

[0086] If the light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range have a preset value at the same wavelength, then...

[0087] I 21 / I 22 =M,I 21 The intensity of the first detection light in the second wavelength range at any wavelength; I 22 M is the light intensity of the second detection light in the second wavelength range at any wavelength; M is the preset value.

[0088] In this embodiment, the preset value is 1, meaning that the light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range are equal at the same wavelength. In other embodiments, the first preset ratio can be 1, 0.5, or other values.

[0089] In this embodiment, the second detection information further includes the optical characteristics of the second signal light in the second wavelength range. In other embodiments, the second detection information may not include the optical characteristics of the second signal light in the second wavelength range.

[0090] Figure 3 A graph showing the detected information in the first embodiment of the detection method of the present invention is shown.

[0091] Please refer to Figure 3SP15 is executed to perform a first compensation process on the first detected information a and the second detected information, so that the first detected information a is multiplied by a first compensation coefficient and the second detected information is multiplied by a second compensation coefficient; the ratio of the second compensation coefficient to the first compensation coefficient is equal to the first preset ratio.

[0092] The first compensation process enables the first detection light that forms the first signal light to have the same power as the second detection light that forms the second signal light, thereby enabling the accurate determination of the optical crosstalk formed by the first detection light in the first wavelength range to the second detection light in the second wavelength range, thereby improving the detection accuracy.

[0093] That is I 21 / I 22 =M,I 21 The intensity of the first detection light in the second wavelength range at any wavelength; I 22 M is the light intensity of the second detection light in the second wavelength range at any wavelength; M is the first preset ratio.

[0094] Then A2 / A1 = M, where A1 is the first compensation coefficient and A2 is the second compensation coefficient.

[0095] In this embodiment, the first preset ratio is 1, so the first compensation coefficient is 1 and the second compensation coefficient is 1, meaning that no compensation is required.

[0096] In other embodiments, if the first preset ratio is 2, then the first compensation processing of the first detected information a and the second detected information includes: multiplying the second detected information by 2.

[0097] Continue to refer to Figure 3 SP16 is executed to perform a first difference processing on the first detection information a after the first compensation processing and the second detection information to obtain the correspondence between the first difference and wavelength of the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, and to obtain the first difference detection information within the first wavelength range.

[0098] The first detection light includes a first wavelength range and a second wavelength range. The second detection light includes the second wavelength range but does not include the first wavelength range. Therefore, the optical characteristics of the first wavelength range in the second detection information obtained from the second detection light are caused by crosstalk of the second detection light in the second wavelength range. By performing a first difference processing on the first detection information a and the second detection information, the first difference detection information of the first wavelength range can be obtained, which can eliminate the crosstalk of the detection light in the second wavelength range to the detection light in the first wavelength range, thereby obtaining the detection information of the second wavelength range without crosstalk, and thus improving the detection accuracy.

[0099] In this embodiment, both the first detected information 'a' and the second detected information are spectral information, and the first difference detected information is spectral information. The first difference processing refers to the correspondence between the first difference obtained by subtracting the optical characteristics of the corresponding wavelength in the second detected information from the first detected information 'a' and the wavelength.

[0100] The first detection information a includes: multiple first sub-detection information of a first signal light with different polarization states; the second detection information includes multiple second sub-detection information of a second signal light with different polarization states;

[0101] The first difference processing of the first detected information a and the second detected information includes: subtracting the first sub-detected information and the second sub-detected information of the same polarization state respectively to obtain the first sub-difference information of multiple polarization states;

[0102] Continue to refer to Figure 3 SP17 is executed, and combined detection information b is obtained based on the first difference detection information. The combined detection information b includes at least the first difference detection information.

[0103] Obtaining combined detection information b based on the first difference detection information includes: using a combination of the first difference detection information and the second detection information in the second wavelength range as combined detection information b, or using a combination of the first difference detection information and the first detection information in the second wavelength range as combined detection information b, or using the first difference detection information as the combined detection information b.

[0104] Specifically, in this embodiment, the combination of the first difference detection information and the second detection information of the second wavelength range is used as the combined detection information b.

[0105] The combination of the first difference detection information and the second detection information in the second wavelength range is used as the combined detection information b. Since the second detection light does not include the first wavelength range, the second detection information in the second wavelength range will not be interfered with by the second detection light in the first wavelength range, thereby improving the detection accuracy.

[0106] Execute SP18 to obtain the test information of the test analyte 100 based on the combined detection information b.

[0107] In this embodiment, obtaining the test information of the test object 100 based on the combined detection information b includes: converting each optical feature in the combined detection information b into feature parameters of the test object 100 to obtain a feature relationship, wherein the feature parameters are parameter values ​​characterizing the optical properties of the test object 100, and the feature relationship is the correspondence between the feature parameters and the wavelength; fitting the feature relationship using a theoretical optical model to obtain the test information, wherein the theoretical optical model is a theoretical relationship model between the test information of the test object 100 and the feature parameters.

[0108] The step of converting the optical features into feature parameters of the object under test 100 and obtaining feature relationships based on feature parameters of multiple wavelengths includes: converting the optical features into feature parameters of the object under test 100 based on the first difference information of multiple polarization states, and obtaining feature relationships based on feature parameters of multiple wavelengths.

[0109] In this embodiment, the step of converting the optical features into feature parameters of the test object 100 and obtaining feature relationships based on feature parameters of multiple wavelengths includes: converting the optical features into feature parameters of the test object 100 based on the first sub-difference information of multiple polarization states, and obtaining feature relationships based on feature parameters of multiple wavelengths.

[0110] Specifically, the number of polarization states is greater than or equal to 8.

[0111] The characteristic parameters are parameter values ​​that characterize the optical properties of the test object 100, that is, parameters of the test object 100 related to the intensity and polarization of the signal light.

[0112] In this embodiment, the characteristic parameters include the surface reflectance or Fourier coefficients of the test object 100, wherein the Fourier coefficients are the non-zero coefficients of one or more Fourier series after the Fourier expansion of the signal light spectrum formed by the detection light reflected by the test object 100.

[0113] In this embodiment, the theoretical optical model is the theoretical relationship between the intensity of the signal light formed by the reflection of the test object 100 after the detection light shines on the test object 100 and the material parameters of the test object 100.

[0114] In this embodiment, the test object 100 is a film layer, and the test information is the film thickness.

[0115] Figure 3 In the diagram, c represents the theoretical detection information curve in the absence of optical crosstalk; from Figure 3 As can be seen, the combined detection information b basically coincides with the theoretical detection information curve c. Therefore, this detection method greatly improves the detection accuracy.

[0116] Figure 4 This is a schematic diagram of the structure of the second embodiment of the detection method of the present invention.

[0117] Please refer to Figure 4 This embodiment and Figures 1 to 3 The similarities between the embodiments shown will not be repeated here, but the differences include:

[0118] In this embodiment, the incident directions of the first detection light and the second detection light are both perpendicular to the surface of the object to be tested.

[0119] In this embodiment, the detection device may not include one or more of the following: a polarizer, a polarizer detector, and a compensator.

[0120] The detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the first detection light passing through the test object and acquiring the second signal light formed by the second detection light passing through the test object.

[0121] In this embodiment, the light-emitting component includes: a light source 121 for generating initial light having a first wavelength range and a second wavelength range; and a filter for entering and exiting the optical path. If entering the optical path, the filter is used to filter out light of the first wavelength range in the initial light to form a second detection light; if exiting the optical path, the filter is used to allow light of the first wavelength range and the second wavelength range to pass through to form a first detection light.

[0122] Beam splitter 124 is used to reflect the initial light to the object under test and to allow the first signal light and the second signal light to pass through to the detector.

[0123] In this embodiment, the filter is located in the optical path between the beam splitter 124 and the object under test; in other embodiments, the beam splitter may also be located in the optical path between the light source 121 and the beam splitter.

[0124] In this embodiment, the detector is a spectrometer 128, which is used to acquire the light intensity of each wavelength in the light beam.

[0125] In this embodiment, the light-emitting device further includes: an incident collimating lens 122 for collimating the initial light generated by the light source 121; an objective lens 126 for converging the initial light after passing through the beam splitter 124 onto the surface of the object under test to form a first detection light or a second detection light, and collecting the first signal light and the second signal light reflected by the object under test; and a converging lens 127 for converging the first signal light and the second signal light after passing through the beam splitter 124 onto the detector.

[0126] The light-emitting device further includes: a filter 125, used to filter the initial light in the first wavelength range and the second wavelength range, filtering out the light in the first wavelength range in the initial light to form the second detection light; and an aperture 123, used to reduce the size of the light spot incident on the surface of the object to be tested.

[0127] It should be noted that in this embodiment, the first detection light and the second detection light are generated at different times by the same light-emitting device, and the processing of the first detection light and the second detection light by the detection device is performed at different times.

[0128] In this embodiment, converting each optical feature in the combined detection information into feature parameters of the analyte to obtain the feature relationship includes: acquiring standard detection information of a standard sample, wherein the standard detection information includes the correspondence between optical features and wavelengths within at least a first wavelength range, and the feature parameters characterizing the optical features of the standard sample are known preset parameter values; obtaining the feature parameters of the analyte based on the product of the ratio of optical features of the same wavelength in the combined detection information and the standard detection information and the preset parameter value, thus obtaining the feature relationship.

[0129] In this embodiment, the analyte in the step of obtaining the combined detection information is replaced by the standard sample. The step of obtaining the standard detection information of the standard sample is the same as the step of obtaining the combined detection information. Therefore, all steps of obtaining the combined detection information, from performing the first detection on the analyte with the first detection light to obtaining the combined detection information based on the first difference detection information, can be incorporated into the step of obtaining the standard detection information of the standard sample.

[0130] Specifically, obtaining standard detection information includes:

[0131] A first detection is performed on a standard sample by a first detection light to obtain a first signal light formed after the first detection light passes through the standard sample. The first detection light includes a first wavelength range and a second wavelength range.

[0132] A second detection is performed on a standard sample using a second detection light to obtain a second signal light formed after the second detection light passes through the standard sample. The second detection light includes the second wavelength range but does not include the first wavelength range.

[0133] First detection information is obtained based on the first signal light, and the first detection information includes at least the optical characteristics of the first signal light in a first wavelength range, wherein the optical characteristics are positively correlated with the light intensity.

[0134] The second detection information is obtained based on the second signal light. The second detection information includes at least the optical characteristics of the second signal light in the first wavelength range. The light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range at the same wavelength has a first preset ratio. The first preset ratio is the same at each wavelength in the second wavelength range.

[0135] The first detection information and the second detection information are subjected to a first compensation process, such that the first detection information is multiplied by a first compensation coefficient, the second detection information is multiplied by a second compensation coefficient, and the ratio of the second compensation coefficient to the first compensation coefficient is equal to the first preset ratio.

[0136] The first detection information and the second detection information after the first compensation processing are subjected to the first difference processing to obtain the correspondence between the first difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, and thus obtain the first difference detection information within the first wavelength range.

[0137] Combined detection information is obtained based on the first difference detection information, wherein the combined detection information includes at least the first difference detection information.

[0138] In other embodiments, the standard detection information of the standard sample can be derived through a theoretical model. Alternatively, obtaining the standard detection information includes:

[0139] The standard sample is subjected to a fifth detection using a fifth detection light to obtain the standard detection information. The optical characteristics of the standard detection information correspond to the wavelengths in the first and second wavelength ranges. The characteristic parameters characterizing the optical characteristics of the standard sample are known values.

[0140] The standard sample is a thin film with known thickness and material.

[0141] The present invention also provides a third embodiment of the detection method.

[0142] The similarities between this embodiment and the second embodiment of the detection method of the present invention will not be repeated here. The differences include:

[0143] The detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the reflection of the first detection light by the object under test, and the second signal light formed by the second detection light by the object under test.

[0144] In this embodiment, the light-emitting component includes: a light source 121 for generating a first detection light and a second detection light; and a beam splitter 124 for reflecting the first and second detection lights to the object under test and allowing the first and second signal lights to pass through to the detector.

[0145] In this embodiment, the detector is a spectrometer 128, which is used to acquire the light intensity of each wavelength in the light beam.

[0146] In this embodiment, the detection device further includes: an incident collimating lens 122 for collimating the detection light generated by the light source 121; a dispersive objective lens 126 for converging different wavelengths of the detection light after passing through the beam splitter 124 to different heights along the optical axis of the dispersive objective lens 126, and collecting the first signal light and the second signal light returned by the object under test; and a converging lens 127 for converging the first signal light and the second signal light after passing through the beam splitter 124 to the detector.

[0147] Obtaining the test information of the test object based on the combined detection information includes: obtaining the wavelength with the largest optical feature in the combined detection information to obtain the extreme wavelength; obtaining a distance model, which is the correspondence between the wavelength and the height of the test point; and obtaining the test information of the test point by obtaining the height of the test point corresponding to the extreme wavelength based on the distance model and the extreme wavelength.

[0148] Figure 5 This is a flowchart of each step in the fourth embodiment of the detection method of the present invention.

[0149] Please refer to Figure 5 This embodiment and Figures 1 to 3 The similarities between the embodiments shown will not be repeated here. The differences include: the first detection information further includes the optical characteristics of the first signal light in the second wavelength range;

[0150] The detection method further includes:

[0151] SP21, the test object 100 is subjected to a third detection by a third detection light to obtain a third signal light formed after the third detection light passes through the test object 100. The third detection light includes the first wavelength range and does not include the second wavelength range.

[0152] SP22, obtain third detection information based on the third signal light, the third detection information includes at least the optical characteristics of the third signal light in the second wavelength range, and the light intensity of the first detection light in the first wavelength range and the third detection light in the first wavelength range at the same wavelength has a second preset ratio.

[0153] SP23, performs a second compensation process on the third detected information, multiplying the third detected information by a third compensation coefficient, wherein the ratio of the third compensation coefficient to the first compensation coefficient is equal to the second preset ratio;

[0154] SP24 performs a second difference processing on the first detection information after the first compensation processing and the third detection information after the second compensation processing to obtain the correspondence between the second difference and wavelength of the optical characteristics of the first signal light and the optical characteristics of the third signal light at each wavelength within the second wavelength range, thereby obtaining the second difference detection information within the second wavelength range.

[0155] The process of obtaining combined detection information based on the second difference detection information includes combining the first difference detection information and the second difference detection information to obtain the combined detection information.

[0156] The detection method further includes a third detection and a second difference processing, which can also eliminate crosstalk between the first signal light in the first wavelength range and the optical features of the second wavelength in the second combined detection information, thereby further improving the detection accuracy.

[0157] The present invention also provides a detection system for performing the detection methods of the first to fourth embodiments of the above-described detection methods. The detection system includes:

[0158] The detection device is used to perform a first detection on a test object using a first detection light to obtain a first signal light formed after the first detection light passes through the test object, wherein the first detection light includes a first wavelength range and a second wavelength range; and to perform a second detection on the test object using a second detection light to obtain a second signal light formed after the second detection light passes through the test object, wherein the second detection light has a second wavelength range and includes the second wavelength range but does not include the first wavelength range.

[0159] The detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the first detection light passing through the test object and acquiring the second signal light formed by the second detection light passing through the test object.

[0160] The light-emitting component includes: a first light source for generating the first detection light; and a second light source for generating the second detection light; or...

[0161] The light-emitting component includes: a light source for generating initial light having a first wavelength range and a second wavelength range; and a filter component for entering and exiting the optical path. If the filter component enters the optical path to filter the initial light, it filters out light in the first wavelength range from the initial light to form a second detection light. If the filter component exits the optical path, the initial light forms a first detection light.

[0162] The detection device further includes: a polarizer for polarizing the detection light to give the detection light a first preset polarization state; an analyzer for polarizing the signal light to give the signal light a second preset polarization state; or the detection device includes: a dispersive objective lens for converging detection light of different wavelengths to different heights along the optical axis of the detection light.

[0163] The detection device in this embodiment is the same as any of the detection devices described in the first to fourth embodiments of the above detection method, and will not be described again here.

[0164] The detection system further includes a processor, the processor being configured to: acquire first detection information based on the first signal light, the first detection information including at least optical characteristics of the first signal light within a first wavelength range, the optical characteristics being positively correlated with light intensity; acquire second detection information based on the second signal light, the second detection information including at least optical characteristics of the second signal light within a first wavelength range; and perform a first difference processing on the first detection information and the second detection information to acquire a first difference between the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, thereby obtaining first difference detection information within the first wavelength range; acquire combined detection information based on the first difference detection information, the combined detection information including at least the first difference detection information; and acquire test information of the analyte based on the combined detection information.

[0165] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A detection method, characterized in that, include: The first detection light is used to perform a first detection on the test object to obtain a first signal light formed after the first detection light passes through the test object. The first detection light includes a first wavelength range and a second wavelength range. The second detection light is used to perform a second detection on the test object to obtain a second signal light formed after the second detection light passes through the test object. The second detection light includes the second wavelength range but does not include the first wavelength range. First detection information is obtained based on the first signal light, and the first detection information includes at least the optical characteristics of the first signal light in a first wavelength range, wherein the optical characteristics are positively correlated with the light intensity. The second detection information is obtained based on the second signal light. The second detection information includes at least the optical characteristics of the second signal light in the first wavelength range. The light intensity of the first detection light in the second wavelength range and the second detection light in the second wavelength range at the same wavelength has a first preset ratio. The first preset ratio is the same at each wavelength in the second wavelength range. The first detection information and the second detection information are subjected to a first compensation process, such that the first detection information is multiplied by a first compensation coefficient, the second detection information is multiplied by a second compensation coefficient, and the ratio of the second compensation coefficient to the first compensation coefficient is equal to the first preset ratio. The first detection information and the second detection information after the first compensation processing are subjected to the first difference processing to obtain the correspondence between the first difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, and thus obtain the first difference detection information within the first wavelength range. Based on the first difference detection information, combined detection information is obtained, wherein the combined detection information includes at least the first difference detection information; The test information of the analyte is obtained based on the combined detection information.

2. The detection method according to claim 1, characterized in that, Obtaining combined detection information based on the first difference detection information includes: using a combination of the first difference detection information and the second detection information in the second wavelength range as combined detection information, or using a combination of the first difference detection information and the first detection information in the second wavelength range as combined detection information, or using the first difference detection information as the combined detection information.

3. The detection method according to claim 1, characterized in that, Obtaining the test information of the test object based on the combined detection information includes: converting each optical feature in the combined detection information into feature parameters of the test object to obtain feature relationships, wherein the feature parameters are parameter values ​​characterizing the optical properties of the test object, and the feature relationships are the correspondence between the feature parameters and the wavelength; fitting the feature relationships using a theoretical optical model to obtain the test information, wherein the theoretical optical model is a theoretical relationship model between the test information of the test object and the feature parameters.

4. The detection method according to claim 3, characterized in that, The first detection information includes: multiple first sub-detection information of a first signal light with different polarization states; the second detection information includes multiple second sub-detection information of a second signal light with different polarization states; The first difference processing of the first detected information and the second detected information includes: subtracting the first sub-detected information and the second sub-detected information of the same polarization state respectively to obtain the first sub-difference information of multiple polarization states; The optical features in the combined detection information are converted into feature parameters of the test object to obtain feature relationships, including: converting the optical features into feature parameters of the test object based on the first sub-difference information of multiple polarization states, and obtaining feature relationships based on feature parameters of multiple wavelengths.

5. The detection method according to claim 4, characterized in that, The first detection of the test object by the first detection light and the acquisition of the first signal light formed by the first detection light after passing through the test object include: polarizing the first detection light beam to give the first detection light beam a first preset polarization state; causing the polarized first detection light to reach the test object, and the first detection light forming the first signal light after being reflected, scattered or transmitted by the test object; Obtaining first detection information based on the first signal light includes: performing polarization analysis on the first signal light to obtain first sub-detection information of the first signal light having multiple second preset polarization states; The second detection light is used to perform a second detection on the test object to obtain a second signal light formed after the second detection light passes through the test object. This includes: polarizing the second detection light beam to give it a first preset polarization state; and allowing the second detection light to reach the test object, whereby the second detection light is reflected, scattered, or transmitted by the test object to form the second signal light. Obtaining second detection information based on the second signal light includes: performing polarization analysis on the second signal light to obtain second sub-detection information of the second signal light having multiple second preset polarization states.

6. The detection method according to claim 3, characterized in that, The characteristic parameters include the surface reflectance or Fourier coefficients of the object under test.

7. The detection method according to claim 3, characterized in that, The optical features are light intensity, pixel grayscale, or charge value.

8. The detection method according to claim 3, characterized in that, The process of converting each optical feature in the combined detection information into feature parameters of the analyte to obtain the feature relationship includes: acquiring standard detection information of a standard sample, wherein the standard detection information includes the correspondence between optical features and wavelengths within at least a first wavelength range, and the feature parameters characterizing the optical features of the standard sample are known preset parameter values; and obtaining the feature parameters of the analyte based on the product of the ratio of optical features of the same wavelength in the combined detection information and the standard detection information and the preset parameter value, thereby obtaining the feature relationship.

9. The detection method according to claim 3 or 8, characterized in that, The characteristic parameter is reflectivity or Fourier coefficient; the information to be measured includes the thickness or height of the film layer on the surface of the object to be measured.

10. The detection method according to claim 1, characterized in that, Obtaining the test information of the test object based on the combined detection information includes: obtaining the wavelength with the largest optical feature in the combined detection information to obtain the extreme wavelength; obtaining a distance model, which is the correspondence between the wavelength and the height of the test point; obtaining the test information of the test point based on the distance model and the extreme wavelength, where the test information is the height of the test point.

11. The detection method according to claim 1, characterized in that, The first wavelength range includes ultraviolet light wavelengths; the second wavelength range includes visible light wavelengths; the optical power density of the first detection light in the first wavelength range is less than the optical power density of the first detection light in the second wavelength range.

12. The detection method according to claim 11, characterized in that, The second wavelength range of the second detection light is a wavelength greater than or equal to a threshold wavelength, wherein the threshold wavelength is any wavelength value between 150nm and 500nm; the first wavelength range includes bands with wavelengths less than or equal to the threshold wavelength.

13. The detection method according to claim 1, characterized in that, The second detection of the test object using the second detection light includes: filtering light having a first wavelength range and a second wavelength range using a filter to filter out light in the first wavelength range to obtain the second detection light; guiding the second detection light to the test object; and collecting the second signal light using a detector to obtain the second detection information.

14. The detection method according to claim 13, characterized in that, Filtering light having a first wavelength range and a second wavelength range by means of a filter includes: filtering the first detection light by means of the filter to obtain the second detection light by filtering the light in the first wavelength range; The first compensation coefficient is 1; the second compensation coefficient is the transmittance of the filter.

15. The detection method according to claim 1, characterized in that, The first detected information also includes: the optical characteristics of the first signal light in the second wavelength range; The detection method further includes: performing a third detection on the test object using a third detection light to obtain a third signal light formed after the third detection light passes through the test object, wherein the third detection light includes the first wavelength range and does not include the second wavelength range; The third detection information is obtained based on the third signal light. The third detection information includes at least the optical characteristics of the third signal light in the second wavelength range. The light intensity of the first detection light in the first wavelength range and the third detection light in the first wavelength range at the same wavelength has a second preset ratio. The third detection information is subjected to a second compensation process, which multiplies the third detection information by a third compensation coefficient. The ratio of the third compensation coefficient to the first compensation coefficient is equal to the second preset ratio. The first detection information after the second compensation process and the third detection information after the second compensation process are subjected to a second difference process to obtain the correspondence between the second difference and the wavelength of the optical characteristics of the first signal light and the optical characteristics of the third signal light at each wavelength within the second wavelength range, thereby obtaining the second difference detection information within the second wavelength range. Obtaining combined detection information based on the first difference detection information includes: combining the first difference detection information and the second difference detection information to obtain the combined detection information.

16. The detection method according to claim 1, characterized in that, The first preset ratio is greater than or equal to 1; at least one of the first compensation coefficient and the second compensation coefficient is 1.

17. A detection system based on the detection method of any one of claims 1 to 16, characterized in that, include: The detection device is used to perform a first detection on a test object using a first detection light to obtain a first signal light formed after the first detection light passes through the test object, wherein the first detection light includes a first wavelength range and a second wavelength range; and to perform a second detection on the test object using a second detection light to obtain a second signal light formed after the second detection light passes through the test object, wherein the second detection light includes the second wavelength range and does not include the first wavelength range. The processor is configured to: acquire first detection information based on the first signal light, the first detection information including at least optical characteristics of the first signal light within a first wavelength range, the optical characteristics being positively correlated with light intensity; acquire second detection information based on the second signal light, the second detection information including at least optical characteristics of the second signal light within a first wavelength range; and perform a first difference processing on the first detection information and the second detection information to acquire a first difference between the optical characteristics of the first signal light and the optical characteristics of the second signal light at each wavelength within the first wavelength range, thereby obtaining first difference detection information for the first wavelength range; acquire combined detection information based on the first difference detection information, the combined detection information including at least the first difference detection information; and acquire test information for the analyte based on the combined detection information.

18. The detection system according to claim 17, characterized in that, The detection device includes: a light-emitting component for generating the first detection light and the second detection light; and a detector for acquiring the first signal light formed by the first detection light passing through the test object and acquiring the second signal light formed by the second detection light passing through the test object.

19. The detection system according to claim 18, characterized in that, The light-emitting component includes: a first light source for generating the first detection light; a second light source for generating the second detection light; or... The light-emitting component includes: a light source for generating initial light having a first wavelength range and a second wavelength range; and a filter component for entering and exiting the optical path. If the filter component enters the optical path to filter the initial light, it filters out light in the first wavelength range from the initial light to form a second detection light. If the filter component exits the optical path, the initial light forms a first detection light.

20. The detection system according to claim 18, characterized in that, The detection device further includes: a polarizer, used to polarize the detection light so that the detection light has a first preset polarization state; A polarizer is used to analyze the polarization of the signal light, giving the signal light a second preset polarization state; or The detection device includes a dispersive objective lens, used to converge detection light of different wavelengths to different heights along the optical axis of the detection light.

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