Detection system

Abstract

The embodiment of the invention discloses a detection system which is used for eliminating the influence of pump light noise and accurately detecting a sample. According to the embodiment of the invention, the device comprises a light source assembly used for emitting probe light and pump light; the first light splitting assembly is used for receiving the pump light and splitting the pump light into pump signal light and pump reference light, and the pump signal light is used for inducing the optical characteristic change of the sample; the signal processing module is used for receiving detection signal light formed by the pumping reference light and the probe light entering a sample, the signal processing module comprises a first denoising assembly, and the first denoising assembly is used for eliminating pumping light noise in the detection signal light according to a pumping noise frequency domain of the pumping reference light; and the signal processing module is also used for determining the detection result of the sample according to the detection signal light after the pump light noise is removed.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optics, and in particular to a detection system. Background Art

[0002] With the continuous development of the chip industry, the design of chips is becoming more and more complex, and the manufacturing steps are becoming more and more complicated. Any failure in the production and processing steps will lead to the failure of the entire chip. Therefore, it is particularly important to introduce a chip detection process after the key processing steps. By detecting information such as the film thickness of the chip, unqualified chips can be eliminated in time to improve the pass rate of chip products. At the same time, due to the continuous reduction in chip size, non-destructive film thickness detection of nano-level or even sub-nanometer film layers has become particularly important. In the detection system based on femtosecond photoacoustic detection technology, pump light noise is an important factor affecting the accuracy of chip film thickness detection.

[0003] Therefore, there is an urgent need for a detection system that can eliminate the influence of pump light noise in the system. Summary of the invention

[0004] The embodiments of the present application provide a detection system for eliminating the influence of pump light noise and accurately detecting samples.

[0005] A first aspect of an embodiment of the present application provides a detection system, including: A light source assembly, used for emitting detection light and pump light; a first light splitting component, used for receiving the pump light and splitting the pump light into a pump signal light and a pump reference light, wherein the pump signal light is used for inducing a change in the optical properties of the sample; A signal processing module, used for receiving the pump reference light and the detection signal light formed by the detection light incident on the sample, the detection signal light is used to obtain a detection signal, the signal processing module includes a first noise removal component, the first noise removal component is used for removing the pump light noise in the detection signal according to the pump noise frequency domain of the pump reference light; The signal processing module is further used to determine the detection result of the sample according to the detection signal after the pump light noise is eliminated.

[0006] In a specific implementation, the first noise removal component is specifically used to perform Fourier transform on the time domain signal of the pump reference light to obtain a pump frequency domain signal, determine the noise frequency domain of the pump reference light from the pump frequency domain signal, perform Fourier transform on the time domain signal of the detection signal to obtain a detection frequency domain signal, and remove the signal belonging to the pump noise frequency domain from the detection frequency domain signal to remove the pump light noise in the detection signal.

[0007] In a specific implementation, the detection system further includes: A second light splitting component is used to receive the detection light and split the detection light into a detection signal light and a detection reference light, wherein the detection signal light is used to irradiate the sample to form the detection signal light; The signal processing module is further used to receive the detection reference light, and the signal processing module further includes: a second noise removal component, used to remove the detection light noise in the detection signal; The signal processing module is further used to determine the detection result of the sample according to the detection signal after eliminating the detection light noise.

[0008] In a specific implementation, the second noise removal component is further used to remove the influence of the common mode noise of the detection system in the detection signal light, and the signal processing module is further used to determine the detection result of the sample according to the detection signal after removing the common mode noise. Alternatively, the first noise removal component is further used to eliminate the influence of common mode noise of the detection system in the detection signal light, and the signal processing module is further used to determine the detection result of the sample based on the detection signal after eliminating the common mode noise.

[0009] In a specific implementation, if the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal, the second noise removal component is specifically used to determine the difference between the time domain signal of the detection signal light and the time domain signal of the detection reference light as the detection signal from which the detection light noise and the common mode noise are eliminated.

[0010] In a specific implementation, if the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal, the second noise removal component is specifically used to remove the detection light noise and the common mode noise in the detection signal to obtain a first detection signal, and transmit the first detection signal to the first noise removal component; The first noise removal component is specifically used to remove the pump light noise in the first detection signal to obtain a second detection signal; The signal processing module is specifically used to determine the detection result of the sample according to the second detection signal.

[0011] In a specific implementation, the first noise removal component is specifically used to remove the pump light noise in the detection signal light to obtain a third detection signal, and transmit the third detection signal to the second noise removal component; The second noise removal component is specifically used to remove the detection light noise and the common mode noise in the third detection signal to obtain a fourth detection signal; The signal processing module is specifically used to determine the detection result of the sample according to the fourth detection signal.

[0012] In a specific implementation, the detection system further includes: a modulation component disposed between the light source component and the first light splitting component on the optical path of the pump light; The modulation component is used to adjust the pump light emitted from the light source component according to the modulation signal, and the modulation component is communicatively connected with the first detection unit; If the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal light, then the first noise removal component is also used to eliminate the modulation noise in the detection signal light that does not conform to the modulation frequency of the modulation signal and does not conform to the preset filtering bandwidth, and the signal processing module is also used to determine the detection result of the sample based on the detection signal light after eliminating the modulation noise.

[0013] In a specific implementation, the detection system further includes: A delay component is arranged in the detection light path and / or the pump light path; The delay component includes a retroreflective mirror and a position adjustment component, and the position adjustment component is used to adjust the position of the retroreflective mirror to adjust the optical path difference between the detection light path and the pump light path when incident on the sample.

[0014] In a specific implementation, the light source assembly includes a laser and a third light splitting assembly; The laser is used to emit an initial light beam; The third light splitting component is used to split the initial light beam emitted by the laser into the detection light and the pump light.

[0015] It can be seen from the above technical scheme that the embodiment of the present application has the following advantages: the pump light emitted by the light source assembly is divided into two beams of light, namely, the pump signal light and the pump reference light, by the first spectroscopic assembly. At the same time, the pump reference light and the detection light emitted by the light source assembly will be incident on the sample to form a detection signal light. Then, since the pump signal light and the pump reference light are obtained by spectroscopic analysis of the pump light, similarly, the pump noise frequency domain of the pump reference light is the same as the frequency domain of the pump signal light. Therefore, the pump light noise in the detection signal light can be eliminated according to the pump noise frequency domain of the pump reference light. Finally, the detection result of the sample is determined according to the detection signal light after the pump light noise is eliminated. This is equivalent to eliminating the influence of the pump light noise in the system on the detection result, which can effectively improve the accuracy of optical detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 A schematic diagram of the structure of the detection system disclosed in the embodiment of the present application; Figure 2 A schematic diagram of a structure in which a second noise removal component is introduced into the detection system disclosed in an embodiment of the present application to remove detection light noise; Figure 3 A schematic diagram of a structure in which a second noise removal component is introduced into the detection system disclosed in an embodiment of the present application to remove detection light noise and common mode noise; Figure 4 A schematic diagram of the structure of the detection system disclosed in the embodiment of the present application after the delay component is introduced; Figure 5 A structural diagram of a specific implementation of a light source component in a detection system disclosed in an embodiment of the present application; Figure 6 A schematic diagram of a structure of a first light splitting component and a second light splitting component in a detection system disclosed in an embodiment of the present application; Wherein, the accompanying drawings are marked as follows: 10. Light source assembly; 11. Laser; 12. Third spectroscopic assembly; 20. First spectroscopic assembly; 30. Signal processing module; 31. First noise reduction assembly; 32. Second noise reduction assembly; 40. Sample; 50. Second spectroscopic assembly; 60. Modulation assembly; 70. Delay assembly; 71. Retroreflector; 72. Position adjustment assembly; 80. Steering element; 90. Collimation assembly; 100. Attenuation plate. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0021] See also Figure 1 , the present application discloses a detection system, comprising: A light source assembly 10, for emitting a detection light and a pump light; A first light splitting component 20, for receiving pump light and splitting the pump light into pump signal light and pump reference light, wherein the pump signal light is used to induce a change in the optical characteristics of the sample 40; A signal processing module, used for receiving the detection signal light formed by the pump reference light and the detection light incident on the sample 40, the detection signal light is used to obtain the detection signal, the signal processing module includes a first noise removal component 31, the first noise removal component 31 is used to remove the pump light noise in the detection signal light according to the pump noise frequency domain of the pump reference light; The signal processing module is also used to determine the detection result of the sample 40 according to the detection signal after the pump light noise is eliminated.

[0022] Specifically, the light source assembly 10 is used to emit detection light and pump light. Then, in order to eliminate the influence of pump light noise, it is also necessary to receive the pump light through the first beam splitter assembly 20 and split the pump light into two beams, namely, pump signal light and pump reference light. Among them, the pump signal light is used to induce changes in the optical properties of the sample 40, while the pump reference light does not need to pass through the sample 40.

[0023] Then, since the pump signal light and the pump reference light are obtained by splitting the pump light, the noise of the pump signal light is related to the noise of the pump reference light, and the pump light noise in the detection signal light is the noise of the pump signal light; in other words, the noise frequency domain of the pump signal light (i.e., the pump noise frequency domain) is the same as the noise frequency domain of the pump reference light, and the noise frequency domain of the pump light in the detection signal light is the noise frequency domain of the pump signal light. Then, by eliminating the signal in the detection signal light in the aforementioned pump noise frequency domain, the detection signal after eliminating the pump light noise can be obtained.

[0024] Finally, the signal processing module can detect some characteristics of the sample 40 based on the detection signal after removing the pump light noise, and obtain corresponding detection results, such as film thickness, sound velocity, and whether there are defects on the surface of the sample 40, which are not limited here.

[0025] In the embodiment of the present application, the pump light emitted by the light source assembly 10 is divided into two beams of light, namely, the pump signal light and the pump reference light, by the first spectroscopic assembly 20. At the same time, the pump reference light and the detection light emitted by the light source assembly 10 are incident on the sample 40 to form a detection signal light. Then, since the pump signal light and the pump reference light are obtained by spectroscopic analysis of the pump light, similarly, the pump noise frequency domain of the pump reference light is the same as the frequency domain of the pump signal light. Therefore, the pump light noise in the detection signal light can be eliminated according to the pump noise frequency domain of the pump reference light. Finally, the detection result of the sample 40 is determined according to the detection signal after eliminating the pump light noise. This is equivalent to eliminating the influence of the pump light noise in the system on the detection result, which can effectively improve the accuracy of optical detection.

[0026] In some specific implementations, the aforementioned first noise removal component 31 is specifically used to perform Fourier transform on the time domain signal of the pump reference light to obtain a pump frequency domain signal, determine the noise frequency domain of the pump reference light from the pump frequency domain signal, perform Fourier transform on the time domain signal of the detection signal light to obtain a detection frequency domain signal, and remove the signal belonging to the pump noise frequency domain from the detection frequency domain signal to remove the pump light noise in the detection signal light, such as by performing noise filtering through filtering processing.

[0027] It can be understood that the detection signal light obtained by the signal processing module is a time domain signal, and to obtain the detection signal light after removing the pump light noise, it is first necessary to obtain the noise frequency domain of the pump signal light. Specifically, the time domain signal of the pump reference light is first Fourier transformed, and the pump reference light can be converted from a time domain signal to a frequency domain signal, that is, a pump frequency domain signal is obtained. In addition, since the noise usually appears as a broadband distribution, that is, it has a high amplitude at multiple frequencies, and the useful signal is usually concentrated in a specific frequency range, the pump noise frequency domain and the useful signal frequency domain in the pump frequency domain signal are quite different. Therefore, it is easy to identify the pump noise frequency domain where the pump light noise is located based on the frequency domain signal of the pump reference light.

[0028] Similarly, it is also necessary to perform Fourier transform on the time domain signal of the detection signal light to obtain the frequency domain signal of the detection signal light, that is, the detection frequency domain signal, and remove all signals belonging to the pump noise frequency domain in the frequency domain signal of the detection signal light through denoising means such as filtering processing, so as to obtain the detection frequency domain signal after the pump noise frequency domain is removed.

[0029] It should be noted that based on the detection frequency domain signal after the pump noise frequency domain is eliminated, the detection signal light after the pump light noise is eliminated can be obtained, or the detection result of sample 40 can be directly determined by the detection frequency domain signal after the pump noise frequency domain is eliminated, which is not limited here.

[0030] Furthermore, considering that in addition to the pump light noise affecting the detection results of the detection system, the detection light noise will also affect the detection results of the detection system. Therefore, referring to the method of eliminating the pump light noise in the above embodiment, the detection light noise is eliminated. Figure 2 , the detection system provided in the embodiment of the present application and Figure 1 The embodiment shown is similar, except that the detection system of this embodiment also includes: a second spectroscopic component 50, used to receive the detection light and divide the detection light into detection signal light and detection reference light, the detection signal light is used to irradiate the sample 40 to form the detection signal light; a signal processing module, also used to receive the detection reference light, the signal processing module also includes: a second noise removal component 32, used to eliminate the detection light noise in the detection signal according to the detection noise frequency domain of the detection reference light; the signal processing module is also used to determine the detection result of the sample 40 according to the detection signal after eliminating the detection light noise.

[0031] In order to eliminate the influence of the detection light noise, it is also necessary to receive the detection light through the second light splitting component 50 and divide the detection light into two beams, namely, the detection signal light and the detection reference light. Among them, the detection reference light does not need to pass through the sample 40, and the detection reference light is used to irradiate the sample 40 together with the pump signal light to form the detection signal light.

[0032] Then, since the detection signal light and the detection reference light are obtained by spectroscopic analysis of the detection light, the noise of the detection signal light is related to the noise of the detection reference light, and the detection light noise in the detection signal light is the noise of the detection signal light; in other words, the noise frequency domain of the detection signal light (i.e., the detection noise frequency domain) is the same as the noise frequency domain of the detection reference light, and the noise frequency domain of the detection light in the detection signal light is the noise frequency domain of the detection signal light. Then, by eliminating the signal in the detection signal light in the aforementioned detection noise frequency domain, the detection signal after eliminating the detection light noise can be obtained. It can be understood that the second noise removal component 32 can remove the detection light noise in a manner similar to the manner in which the first noise removal component 31 eliminates the pump light noise, which will not be repeated here.

[0033] On the basis of the foregoing embodiments, in some specific implementations, the second noise removal component 32 or the first noise removal component 31 is also used to eliminate the influence of common mode noise of the detection system in the detection signal light, and the signal processing module is also used to determine the detection result of the sample 40 based on the detection signal after the common mode noise is eliminated.

[0034] It is understandable that in the embodiment of the present application, it is necessary to remove the common mode noise, pump light noise and detection light noise in the detection signal, and the means for removing the noise include but are not limited to differential signal processing or filtering processing as mentioned in the above embodiments. Among them, the pump light noise and detection light noise in the embodiment of the present application can be removed by differential signal processing or filtering processing, and the common mode noise can be removed by differential signal processing. In the noise suppression scenario of the present application, the second noise removal component 32 can be selected to remove the detection light noise, and the first noise removal component 31 can be used to remove the pump light noise. As for the common mode noise, it can be removed by the second noise removal component 32 or the first noise removal component 31, which is not limited here.

[0035] The denoising method of differential signal processing is described below by taking the second denoising component 32 used to remove common mode noise and detection light noise in the detection signal light, and the first denoising component 31 used to remove pump light noise in the detection signal light as an example.

[0036] Since the detection signal light and the detection reference light are obtained by spectroscopic analysis of the same detection light, and the difference between the detection signal light and the detection signal light is that the detection signal light is formed after the detection signal light is incident on the surface of the sample 40, in other words, the difference between the two is that the detection signal light contains a signal that can reflect the characteristics of the sample 40, such as the thickness of the sample 40 and the sound velocity of the sample 40 and other characteristics of the sample 40. In this way, by subtracting the time domain signal of the detection signal light and the time domain signal of the detection reference light, a signal that does not contain the detection light noise and the pump light noise and can reflect the characteristics of the sample 40 is obtained, that is, a detection signal that eliminates the detection light noise and the common mode noise. Through the above-mentioned differential signal processing method, the suppression ratio of the common mode noise in the detection system can be made greater than or equal to thirty decibels.

[0037] In practical applications, if it is necessary to remove multiple noises in the detection signal, the detection result of sample 40 is usually determined based on the detection signal after removing the aforementioned multiple noises, rather than determining the detection result of sample 40 based on the detection signal light from which only some different noises are removed. For example, the signal processing module determines the detection result of sample 40 based on the detection signal after different noises are removed. In essence, the signal processing module determines the detection result of sample 40 based on the detection signal after all noises are removed, and the noise includes one or more of the detection light noise, the pump light noise, and the common mode noise. Generally, different noises in the detection signal can be removed in sequence according to the needs, or all noises in the detection signal can be removed at once.

[0038] On this basis, if different noises in the detection signal are removed in turn according to the requirements, the second noise removal component 32 can actually be selected to first remove the common mode noise and the detection light noise in the detection signal, and the first noise removal component 31 can further process the first detection signal output by the second noise removal component 32 to remove the pump light noise therein. Finally, the signal processing module can determine the detection result of the sample 40 according to the second detection signal.

[0039] In practical applications, during the noise removal process, the second noise removal component 32 and the first noise removal component 31 usually need to perform a photoelectric conversion operation first, and convert the received light (including but not limited to detection reference light, detection signal light, pump reference light, pump signal light and detection signal light) into electrical signals before processing.

[0040] The following uses the second noise removal component 32 for removing common-mode noise and detection light noise in the detection signal as an example to illustrate the scheme of using photoelectric conversion to achieve noise removal in the process of differential signal processing. The second noise removal component 32 of the embodiment of the present application uses differential signal processing to simultaneously remove common-mode noise and detection light noise, that is, the second noise removal component 32 of the embodiment of the present application is equivalent to a differential balanced detector, and the differential balanced detector obtains the detection light signal and the detection reference light respectively through two photodiodes arranged on its body, and converts the received light into electrical signals for output respectively. Finally, the differential balanced detector performs differential subtraction processing on the two electrical signals output by the two photodiodes respectively, and the signal finally obtained is the signal after the detection light noise and common-mode noise are removed.

[0041] It can be understood that if it is chosen to eliminate different noises in the detection signal light in sequence according to needs, then in addition to the aforementioned elimination order, the first noise elimination component 31 can first eliminate the pump light noise in the detection signal to obtain a third detection signal, and transmit the third detection signal to the second noise elimination component 32; then, the second noise elimination component 32 eliminates the detection light noise and common mode noise in the third detection signal to obtain a fourth detection signal; finally, the signal processing module determines the detection result of the sample 40 according to the fourth detection signal.

[0042] It should also be noted that, in the scenario where different noises in the detection signal need to be removed in sequence, there is a communication connection between the second noise removal component 32 in the signal processing module of the present application and the first noise removal component 31. Generally, the communication connection can be achieved through a wired connection via an optical cable such as a BNC cable or a wireless connection via a wireless communication module, which is not limited here.

[0043] See also Figure 3 , the detection system provided in the embodiment of the present application and Figure 1 , Figure 2 The embodiment shown is similar, except that the detection system of this embodiment also includes: a modulation component 60 arranged between the light source component 10 and the first splitter component 20 on the pump light path, the modulation component 60 modulates one or more of the intensity, phase or frequency of the pump light, and is used to adjust the pump light emitted from the light source component 10 according to the modulation signal, and the modulation component 60 is communicatively connected to the first detection unit; if the second noise removal component 32 is also used to remove the influence of the common mode noise of the detection system in the detection signal light, then the first noise removal component 31 is also used to eliminate the modulation frequency that does not conform to the modulation signal and the modulation noise that does not conform to the preset filter bandwidth in the detection signal light, and the signal processing module is also used to determine the detection result of the sample 40 according to the detection signal after the modulation noise is eliminated.

[0044] It is understandable that the pump light or the detection light is generally modulated in the detection system to distinguish the detection signal light from the pump signal light.

[0045] The following embodiment of the present application takes pump light modulation as an example to describe how to introduce modulation and remove modulation noise in the detection system of the present application. Specifically, the modulation component 60 needs to modulate the pump light emitted by the light source component 10 according to the modulation signal before the pump light is split into two beams by the first beam splitting component 20. Then, the pump signal light and the pump reference light of the embodiment of the present application are both formed by splitting the modulated pump light.

[0046] Then, since the modulation noise in the detection signal is caused by the power fluctuation of the pump light. The embodiment of the present application can consider that the signal in the detection signal that does not match the modulation frequency of the modulation signal belongs to the modulation noise that should be removed. In addition, the embodiment of the present application can also configure a preset filter bandwidth to accurately eliminate the modulation noise in the detection signal. After that, the signal processing module can determine the detection result of the sample 40 based on the detection signal after eliminating the modulation noise. In some specific implementations, if you choose to eliminate different noises in the detection signal light in turn according to needs, the embodiment of the present application can choose to eliminate the modulation noise first among all the noises.

[0047] The modulation signal that triggers the modulation component 60 to modulate can be triggered by the modulation component 60 itself, or sent by a signal generator connected to it in communication. Therefore, the second noise removal component 32 or the first noise removal component 31 that removes the modulation noise can receive the modulation frequency sent by the modulation component 60, or communicate with the signal generator to obtain the corresponding modulation frequency, which is not limited here.

[0048] In practical applications, the light intensity modulator component modulation component 60 in the embodiment of the present application includes one or more of a laser modulator, a light intensity modulator, a phase modulator, and a frequency modulator, and may also include other devices that can realize laser modulation, which are not limited here. The second noise removal component 32 or the first noise removal component 31 that removes the modulation noise may include any device such as a filter or a phase-locked amplifier that can realize signal extraction of a specific bandwidth and a specific frequency, which are not limited here. In addition, if the second noise removal component 32 or the first noise removal component 31 includes a phase-locked amplifier, it is also necessary to configure a photodetector to obtain the corresponding light beam, and then perform a photoelectric conversion operation on it to obtain a corresponding electrical signal that can be processed by the phase-locked amplifier.

[0049] See also Figure 4 , the detection system provided in the embodiment of the present application and Figure 1-Figure 3The embodiment shown is similar, except that the detection system of this embodiment further includes: a delay component 70, which is arranged in the detection light path and / or the pump light path; the delay component 70 includes a retroreflector 71 and a position adjustment component 72, and the position adjustment component 72 is used to adjust the position of the retroreflector 71 to adjust the optical path difference of the detection light path and the pump light path when incident on the sample 40. The delay component can also be any device that can provide an optical path extension for the detection light path and / or the pump light path.

[0050] Specifically, the function of the delay component 70 is to adjust the optical path difference of the detection light path and the pump light path when the detection signal light and the pump signal light are respectively incident on the surface of the sample 40. The detection light path in the detection system refers to the light path through which the detection light (including the detection reference light and the detection signal light) flows, and similarly, the pump light path in the detection system refers to the light path through which the pump light (including the pump reference light and the pump signal light) flows, which is the pump light path.

[0051] Among them, the retroreflective mirror 71 can specifically be a broadband hollow retroreflective mirror, and the position adjustment component 72 can be an electric linear displacement platform or a conventional displacement platform. Any device that can detect the optical path difference between the light path and the pump light path by moving and adjusting the position of the retroreflective mirror 71 is not limited here.

[0052] In the embodiment of the present application, the delay component 70 is provided to adjust the optical path difference between the detection light path and the pump light path, thereby achieving precise control of the time when the detection signal light and the pump signal light reach the sample 40.

[0053] See also Figure 5 , the detection system provided in the embodiment of the present application and Figure 1-Figure 4 The embodiment shown is similar, except that the light source assembly 10 of this embodiment includes a laser 11 and a third beam splitter assembly 12; the laser 11 is used to emit an initial light beam; the third beam splitter assembly 12 is used to split the initial light beam emitted by the laser 11 into a detection light and a pump light.

[0054] Specifically, the third light splitting component 12 is used to split the laser light (i.e.) emitted by the laser 11 into two laser beams according to a preset light splitting ratio, that is, to split the initial light beam into a detection light and a pump light according to a preset light splitting ratio. The laser 11 may be a pulsed laser 11, and the initial light beam emitted by it may be an ultrashort pulsed laser; the preset light splitting ratio may be fixed by a preset configuration, or may be adjusted in real time by adjusting the third light splitting component 12; the preset light splitting ratio may be the ratio of the intensity of the detection light emitted from the third light splitting component 12 to the intensity of the initial light beam, or the ratio of the intensity of the pump light and the intensity of the detection light emitted from the third light splitting component 12 to the intensity of the initial light beam, respectively, which is not limited here.

[0055] In some specific implementations, the third beam splitting component 12, the second beam splitting component 50 and the first beam splitting component 20 of the present application can be beam splitters or semi-transparent and semi-reflective mirrors with preset beam splitting ratios. The third beam splitting component 12, the second beam splitting component 50 and the first beam splitting component 20 correspond to the same or different preset beam splitting ratios, which are not limited here.

[0056] On the basis of the above-mentioned embodiment, in practical application, in order to realize the continuous adjustment of the detection light power and the pump light power respectively, the detection system further includes: Figure 6 The two attenuation plates 100 shown in the figure are used to adjust the detection light power and the pump light power respectively; in order to control the detection signal light and the pump signal light incident on the sample 40 to accurately be incident on the same position of the sample 40, and control the detection signal light to be accurately received by the first noise removal component 31, the detection system also includes Figure 6 The multiple collimating components 90 shown in FIG. Each collimating component 90 may be composed of at least one collimating lens, which is not limited here.

[0057] It should be noted that in order to ensure that the pump signal light, pump reference light, detection reference light and detection signal light accurately reach the sample 40, the corresponding components or units respectively, in a complex detection system, the present application also needs to adapt to the configuration of at least one steering element 80 according to the setting method of the second spectroscopic component 50 and the first spectroscopic component 20, as shown in the specific embodiments described below.

[0058] In a specific implementation, if Figure 1-Figure 5 The second light splitting component 50 and the first light splitting component 20 are arranged in the manner shown in FIG. 1 , and the detection system further includes the following Figure 5 As shown in the figure, the seven steering elements 80 are arranged in sequence on the detection light path from the light source component 10 to the sample 40, namely, the attenuation plate 100, the steering element, the delay component 70, the steering element 80, the modulation component 60, the steering element 80, the second spectroscopic component 50 and the collimation component 90; on the pump light path from the light source component 10 to the sample 40, namely, the attenuation plate 100, the delay component 70, the steering element 80, the first spectroscopic component 20, the steering element 80 and the collimation component 90; wherein the steering element 80 arranged between the second spectroscopic component 50 and the second noise reduction component 32 on the detection light path is used to enable the detection reference light to accurately reach the second noise reduction component 32, and the steering element 80 arranged on the detection light path is used to enable the detection signal light to accurately reach the first noise reduction component 31.

[0059] If adopted Figure 6 The second light splitting component 50 is arranged in the manner shown in FIG. 1 , and the detection system further includes the following Figure 6As shown in the figure, the seven steering elements 80 are arranged in sequence on the detection light path from the light source component 10 to the sample 40, including the attenuation plate 100, the steering element 80, the delay component 70, the steering element 80, the modulation component 60, the second spectroscopic component 50, the steering element 80 and the collimation component 90; and the attenuation plate 100, the delay component 70, the first spectroscopic component 20, the steering element 80, the steering element 80 and the collimation component 90 are arranged in sequence on the pump light path from the light source component 10 to the sample 40; wherein the steering element 80 arranged on the detection light path is used to enable the detection signal light to accurately reach the first noise reduction component 31; wherein the steering element 80 arranged between the first spectroscopic component 20 and the first noise reduction component 31 on the detection light path is used to enable the pump reference light to accurately reach the first noise reduction component 31.

[0060] It can be understood that the setting of the steering element 80 in the above-mentioned embodiments is an implementation method of the present application. In fact, different steering elements 80 can be set on different optical paths in the entire detection system according to the setting requirements to meet the needs of steering the corresponding light beams, which is not limited here.

[0061] The above contents are explanations of the present application in combination with specific embodiments, and the specific implementation of the present application cannot be considered to be limited to these embodiments. For ordinary technicians in the technical field to which the present application belongs, several changes and substitutions can be made without departing from the concept of the present application, which should be considered to belong to the protection scope of the present application.

Claims

1. A detection system, It is characterized in that include: A light source assembly, used for emitting detection light and pump light; a first light splitting component, used for receiving the pump light and splitting the pump light into a pump signal light and a pump reference light, wherein the pump signal light is used for inducing a change in the optical properties of the sample; A signal processing module, used for receiving the pump reference light and the detection signal light formed by the detection light incident on the sample, the detection signal light is used to obtain a detection signal, the signal processing module includes a first noise removal component, the first noise removal component is used for removing the pump light noise in the detection signal according to the pump noise frequency domain of the pump reference light; The signal processing module is further used to determine the detection result of the sample according to the detection signal after the pump light noise is eliminated.

2. The detection system according to claim 1, It is characterized in that The first noise removal component is specifically used to perform Fourier transform on the time domain signal of the pump reference light to obtain a pump frequency domain signal, determine the noise frequency domain of the pump reference light from the pump frequency domain signal, perform Fourier transform on the time domain signal of the detection signal to obtain a detection frequency domain signal, and remove the signal belonging to the pump noise frequency domain from the detection frequency domain signal to remove the pump light noise in the detection signal.

3. The detection system according to any one of claims 1 to 2, It is characterized in that The detection system also includes: A second light splitting component is used to receive the detection light and split the detection light into a detection signal light and a detection reference light, wherein the detection signal light is used to irradiate the sample to form the detection signal light; The signal processing module is further used to receive the detection reference light, and the signal processing module further includes: a second noise removal component, used to remove the detection light noise in the detection signal; The signal processing module is further used to determine the detection result of the sample according to the detection signal after eliminating the detection light noise.

4. The detection system according to claim 3, It is characterized in that The second noise removal component is further used to remove the influence of the common mode noise of the detection system in the detection signal light, and the signal processing module is further used to determine the detection result of the sample according to the detection signal after removing the common mode noise. Alternatively, the first noise removal component is further used to eliminate the influence of common mode noise of the detection system in the detection signal light, and the signal processing module is further used to determine the detection result of the sample based on the detection signal after eliminating the common mode noise.

5. The detection system according to claim 4, It is characterized in that If the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal, the second noise removal component is specifically used to determine the difference between the time domain signal of the detection signal light and the time domain signal of the detection reference light as the detection signal from which the detection light noise and the common mode noise are eliminated.

6. The detection system according to claim 4, It is characterized in that If the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal, the second noise removal component is specifically used to remove the detection light noise and the common mode noise in the detection signal to obtain a first detection signal, and transmit the first detection signal to the first noise removal component; The first noise removal component is specifically used to remove the pump light noise in the first detection signal to obtain a second detection signal; The signal processing module is specifically used to determine the detection result of the sample according to the second detection signal.

7. The detection system according to claim 4, It is characterized in that The first noise removal component is specifically used to remove the pump light noise in the detection signal light to obtain a third detection signal, and transmit the third detection signal to the second noise removal component; The second noise removal component is specifically used to remove the detection light noise and the common mode noise in the third detection signal to obtain a fourth detection signal; The signal processing module is specifically used to determine the detection result of the sample according to the fourth detection signal.

8. The detection system according to claim 4, It is characterized in that The detection system further comprises: a modulation component disposed between the light source component and the first light splitting component on the optical path of the pump light; The modulation component is used to adjust the pump light emitted from the light source component according to the modulation signal, and the modulation component is communicatively connected with the first detection unit; If the second noise removal component is also used to remove the influence of the common mode noise of the detection system in the detection signal light, then the first noise removal component is also used to eliminate the modulation noise in the detection signal light that does not conform to the modulation frequency of the modulation signal and does not conform to the preset filtering bandwidth, and the signal processing module is also used to determine the detection result of the sample based on the detection signal light after eliminating the modulation noise.

9. The detection system according to claim 1, It is characterized in that The detection system also includes: A delay component is arranged in the detection light path and / or the pump light path; The delay component includes a retroreflective mirror and a position adjustment component, and the position adjustment component is used to adjust the position of the retroreflective mirror to adjust the optical path difference between the detection light path and the pump light path when incident on the sample.

10. The detection system according to claim 1, It is characterized in that The light source assembly includes a laser and a third light splitting assembly; The laser is used to emit an initial light beam; The third light splitting component is used to split the initial light beam emitted by the laser into the detection light and the pump light.

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