Reflection-type medium-long wave infrared spectrum measurement system

Abstract

The invention relates to a reflection-type medium-long wave infrared spectrum measurement system, which comprises a light source module, a sample bearing module, a reflection-type medium-long wave infrared spectrum measurement module and a control module, wherein the light source module is used for emitting an initial medium-long wave infrared beam and controlling the initial medium-long wave infrared beam to be incident to a to-be-measured object on the sample bearing module; the collimation and beam splitting module is used for performing collimation and beam splitting on a to-be-measured light beam generated by the initial medium-long wave infrared light beam under the refraction and multiple reflection effects of a to-be-measured object to obtain a first light beam and a second light beam, and the to-be-measured light beam comprises reflection spectrum information and transmission spectrum information of the to-be-measured object; the reference light path module is used for determining a reference light image corresponding to the first light beam; the coding light path module is used for coding the second light beam and determining a signal light image corresponding to the signal light beam; and the data processing module is used for performing spectrum reconstruction according to the reference light image and the signal light image, and determining spectrum information corresponding to the to-be-detected object. The reflection spectrum and the transmission spectrum of the to-be-measured object can be obtained through single measurement, and the accuracy and the resolution ratio of the spectrum information are improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of spectral measurement, and in particular, to a reflection type mid-long wave infrared spectral measurement system. BACKGROUND

[0002] In the prior art, common mid-long wave infrared spectral measurement devices, such as fourier transform infrared spectrometer (FTIR) and dispersive spectrometer, are all transmission type spectral measurement devices, which can achieve high spectral resolution and measurement accuracy, and are mainly suitable for laboratory precision measurement scenarios. However, the transmission type spectral measurement device usually has problems such as single spectral information, large device volume and complex structure, low spectral measurement speed, and difficulty in improving resolution. SUMMARY

[0003] Therefore, the present disclosure provides a reflection type mid-long wave infrared spectral measurement system.

[0004] According to an aspect of the present disclosure, a reflection type mid-long wave infrared spectral measurement system is provided, comprising: a light source module, a sample bearing module, a collimating and splitting module, a reference light path module, an encoded light path module, and a data processing module; the light source module is configured to emit an initial mid-long wave infrared light beam and control the initial mid-long wave infrared light beam to be incident on a to-be-measured object on the sample bearing module; the collimating and splitting module is configured to collimate and split a to-be-measured light beam generated by the initial mid-long wave infrared light beam under the refraction and multiple reflection of the to-be-measured object, to obtain a first light beam and a second light beam, wherein the to-be-measured light beam comprises reflection spectral information and transmission spectral information of the to-be-measured object; the reference light path module is configured to determine a reference light image corresponding to the first light beam; the encoded light path module is configured to encode the second light beam and determine a signal light image corresponding to the encoded signal light beam; and the data processing module is configured to perform spectral reconstruction according to the reference light image and the signal light image, and determine spectral information corresponding to the to-be-measured object.

[0005] In a possible implementation, the light source module comprises: a wide-spectrum mid-long wave infrared light source and a first off-axis focusing sub-module; the first off-axis focusing sub-module is configured to converge the initial mid-long wave infrared light beam emitted by the wide-spectrum mid-long wave infrared light source to the to-be-measured object at a preset deflection angle.

[0006] In a possible implementation, the collimating and splitting module comprises: an off-axis collimating submodule and a wide-spectrum splitting submodule; the off-axis collimating submodule is configured to convert the to-be-tested light beam into a quasi-parallel light beam; and the wide-spectrum splitting submodule is configured to split the quasi-parallel light beam to obtain the first light beam and the second light beam.

[0007] In a possible implementation, the reference light path module comprises: a second off-axis focusing submodule and a first wide-spectrum detection submodule; the second off-axis focusing submodule is configured to focus the first light beam to the first wide-spectrum detection submodule; and the first wide-spectrum detection submodule is configured to receive the first light beam and convert the first light beam into the reference light image.

[0008] In a possible implementation, the encoding light path module comprises: a third off-axis focusing submodule, a spectrum encoding submodule, and a second wide-spectrum detection submodule; the third off-axis focusing submodule is configured to focus the second light beam to the spectrum encoding submodule; the spectrum encoding submodule is configured to perform spectrum encoding on the second light beam by using a plurality of microstructure metasurface units, and output the signal light beam; and the second wide-spectrum detection submodule is configured to receive the signal light beam and convert the signal light beam into the signal light image.

[0009] In a possible implementation, the spectrum encoding submodule is arranged on the surface of the second wide-spectrum detection submodule.

[0010] In a possible implementation, the sample carrying module is made of a substrate material based on the reflectivity satisfying a preset condition.

[0011] In a possible implementation, the data processing module is configured to: perform normalization processing on the signal light image according to the reference light image to determine a normalized image; and determine the spectrum information corresponding to the to-be-tested object according to the normalized image.

[0012] In a possible implementation, the data processing module is configured to: perform inverse solving of an underdetermined equation set by using a compressive sensing algorithm according to the normalized image and a transmission matrix corresponding to the encoding light path module, to determine the spectrum information of the to-be-tested object.

[0013] In a possible implementation, the data processing module is configured to: perform nonlinear mapping analysis on the normalized image by using a preset deep learning algorithm, to determine the spectrum information of the to-be-tested object.

[0014] The reflective mid-long wave infrared spectrum measurement system provided by the embodiment of the present disclosure comprises a light source module, a sample bearing module, a collimating and splitting module, a reference light path module, an encoded light path module, and a data processing module. The initial mid-long wave infrared light beam can be emitted through the light source module, the integrity of the mid-long wave infrared spectrum measurement is ensured, and the initial mid-long wave infrared light beam is controlled to be incident on the object to be measured on the sample bearing module, so that the initial mid-long wave infrared light beam is refracted and multiply reflected in the object to be measured, the obtained measured light beam can contain the reflection spectrum information and the transmission spectrum information of the object to be measured at the same time, the optical characteristics and the structural characteristics of the object to be measured can be more comprehensively reflected, and the adaptability of the system to the object to be measured made of irregular materials and complex application scenarios is improved. The collimating and splitting module can collimate and split the measured light beam to obtain a first light beam and a second light beam, provide spatially distributed light rays for subsequent light path transmission, and realize multi-channel spectrum information measurement. The reference light path module can determine the reference light image corresponding to the first light beam, the encoded light path module can encode the second light beam, and determine the signal light image corresponding to the encoded signal light beam. The data processing module can perform spectrum reconstruction according to the reference light image and the signal light image, and determine the spectrum information corresponding to the object to be measured, so that the reference light image determined by the first light beam without encoding can be used to calibrate the light intensity spatial distribution of the signal light image determined based on the signal light beam, and a reference benchmark is provided for analysis of the signal light beam and reconstruction of the spectrum information. In the case that the spatial light intensity distribution is unknown, the spectrum information reconstruction can be completed only by single image acquisition, the efficiency of spectrum measurement is improved, and the adaptability of the system to dynamic process monitoring and real-time spectrum detection scenarios is enhanced. Further, the system provided by the present disclosure has a simple structure, does not need too many optical elements, has a low manufacturing cost, and has a small overall volume and weight, and has high applicability to complex application scenarios.

[0015] Other features and aspects of the present disclosure will become apparent from the detailed description of exemplary embodiments which follows, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present disclosure and serve to explain the principles of the present disclosure.

[0017] Figure 1 a block diagram of a reflective mid-long wave infrared spectrum measurement system according to an embodiment of the present disclosure is shown;

[0018] Figure 2 a schematic diagram showing refraction and multiple reflections of an initial mid-long wave infrared light beam in an object to be measured according to an embodiment of the present disclosure is shown;

[0019] Figure 3A structural schematic diagram of a reflective mid-long wave infrared spectrum measurement system according to an embodiment of the present disclosure is shown.

[0020] Figure 4 A process schematic diagram of a data processing module using a Tikhonov regularization method for spectrum information reconstruction according to an embodiment of the present disclosure is shown.

[0021] Figure 5 A process schematic diagram of a data processing module using a preset deep learning algorithm for spectrum information reconstruction according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0022] Various exemplary embodiments, features, and aspects of the present disclosure will be explained in detail below with reference to the accompanying drawings. Like reference numerals can be used to refer to like elements throughout the several drawings. It should be noted, that while the following examples are presented with respect to the embodiments, the present disclosure is not limited to these examples. The drawings are not necessarily to scale, and that a particular feature shown with respect to one embodiment can be similar to or incorporated into another embodiment.

[0023] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or the like are open-ended and do not exclude the presence of one or more other features, integers, steps, components, or functions, or groups thereof.

[0024] When an element is referred to as being "connected," "coupled," "responsive," or "related" to another element, it can be directly connected, coupled, responsive, or related to the other element, or intervening elements can be present.

[0025] Although the terms first, second, third, etc. can be used herein to describe various elements / operations, these elements / operations should not be limited by these terms. These terms are only used to distinguish one element / operation from another element / operation. Thus, a first element / operation in some embodiments can be termed a second element / operation in other embodiments without departing from the teachings of the present inventive concept.

[0026] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0027] In addition, for the purpose of convenience and brevity, detailed descriptions of well-known functions and structures incorporated herein can not be described in detail. It should be appreciated that the present disclosure can be practiced with the exact details as other implementations can omit, add, or modify the procedures and / or components described herein.

[0028] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals involved in the present application are authorized by the user or fully authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards in the relevant region.

[0029] In the technical field of material science research and target detection, spectral measurement technology is one of the commonly used technical means for revealing the intrinsic properties of substances. By using spectral measurement technology, the interaction between light in different wavelength ranges and the object to be measured can be analyzed, thereby obtaining information such as the molecular structure, chemical composition, and energy level characteristics of the object to be measured. The mid-to-long-wave infrared spectrum covers the characteristic "fingerprint region" of various molecular vibration and rotation energy levels, and can provide spectral response information with high specificity. Therefore, the mid-to-long-wave infrared spectral measurement technology has high application value in the fields of molecular structure analysis, component analysis, environmental monitoring, life science, and military defense.

[0030] In the prior art, common mid-to-long-wave infrared spectral measurement devices, such as fourier transform infrared spectrometer (FTIR) and dispersive spectrometer, are all transmission type spectral measurement devices, which can achieve high spectral resolution and measurement accuracy, and are mainly suitable for laboratory precision measurement scenarios.

[0031] However, the transmission type spectral measurement device can only obtain the transmission spectrum information of the object to be measured in a specific wavelength range, and cannot simultaneously obtain the reflection spectrum information and other dimensional spectral information of the object to be measured. For objects to be measured with complex structure or special material, only relying on transmission spectrum information cannot fully characterize the optical and structural characteristics of the object to be measured. The transmission type spectral measurement device usually requires the object to be measured to be processed into a specific size or shape before accurate spectral measurement can be performed, which limits the adaptability of the spectral measurement technology to irregularly manufactured objects to be measured and complex application scenarios. Moreover, the transmission type spectral measurement device usually needs to use a point-by-point scanning method to obtain the measurement spectrum, resulting in low efficiency of spectral measurement and lack of applicability to application scenarios requiring rapid measurement.

[0032] On the other hand, the structure of the transmission type spectral measurement device is usually complex, requiring the use of high-precision optical elements or large-volume scanning equipment, resulting in problems such as heavy mechanical structure, large overall size of the device, and high manufacturing and use costs of the transmission type spectral measurement device. For example, the fourier transform infrared spectrometer usually relies on a scanning interferometer with a relatively large volume, and the dispersive spectrometer needs to use high-precision spectral elements such as gratings and prisms.

[0033] Furthermore, the resolution of commonly used spectroscopic measurement devices in existing technologies is easily limited by their own physical properties. For example, the resolution of a Fourier transform infrared spectrometer is constrained by the length of its corresponding interferometer arm, while the resolution of a dispersive spectrometer depends on the density of the grating lines. Therefore, it is difficult to improve the resolution of commonly used spectroscopic measurement devices in existing technologies, making it difficult to meet the high-precision spectroscopic measurement requirements such as fine molecular fingerprint features.

[0034] In view of this, the present disclosure provides a reflective mid-to-long-wave infrared spectroscopy measurement system, which has a simple structure, requires no excessive optical components, has low manufacturing cost, and is small in overall size and weight, making it highly applicable to complex application scenarios. Furthermore, it can complete spectral reconstruction with a single acquisition even when the spatial light intensity distribution is unknown, simultaneously acquiring the reflectance and transmission spectral information of the object under test, improving the comprehensiveness and resolution of spectral information, as well as the efficiency of spectral measurement. The reflective mid-to-long-wave infrared spectroscopy measurement system provided in this disclosure will be described in detail below.

[0035] Figure 1 A block diagram of a reflective mid-to-long-wave infrared spectroscopy measurement system according to an embodiment of the present disclosure is shown. Figure 1 As shown, the system 100 includes: a light source module 101, a sample carrier module 102, a collimation and beam splitting module 103, a reference optical path module 104, an encoding optical path module 105, and a data processing module 106.

[0036] The light source module 101 is used to emit an initial medium- and long-wave infrared beam and control the initial medium- and long-wave infrared beam to be incident on the object to be tested on the sample carrier module 102.

[0037] The collimation and beam splitting module 103 is used to collimate and split the beam to be tested generated by the refraction and multiple reflection of the initial medium- and long-wave infrared beam under the action of the object under test, to obtain a first beam and a second beam. The beam to be tested includes the reflection spectrum information and transmission spectrum information of the object under test.

[0038] The reference optical path module 104 is used to determine the reference optical image corresponding to the first beam.

[0039] The encoding optical path module 105 is used to encode the second beam and determine the signal light image corresponding to the encoded signal beam.

[0040] The data processing module 106 is used to perform spectral reconstruction based on the reference light image and the signal light image to determine the spectral information corresponding to the object under test.

[0041] The specific form of the light source module 101 can be flexibly set according to actual use requirements, for example, can include a wide spectrum medium-long wave infrared light source, etc., and the present disclosure does not make specific limitations thereto. The initial medium-long wave infrared light beam can represent a light beam with a wavelength coverage range of 3 to 14 pm (medium-long wave infrared spectral region), which can ensure the integrity of the medium-long wave infrared spectral measurement.

[0042] The object to be measured can represent any object that needs to be measured by medium-long wave infrared spectroscopy, which can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0043] The sample carrying module 102 is used to place the object to be measured, and the specific form thereof can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0044] In one possible implementation, the sample carrying module 102 is made of a substrate material whose reflectivity satisfies a preset condition.

[0045] The specific content of the preset condition can be flexibly set according to actual use requirements, for example, can include a minimum threshold and a maximum threshold of the reflectivity of the substrate material, etc., and the present disclosure does not make specific limitations thereto.

[0046] By using the sample carrying module 102 whose reflectivity satisfies the preset condition, the reflection efficiency of the initial medium-long wave infrared light after penetrating the sample to be measured can be improved, so as to reduce the influence of the light intensity attenuation of the initial medium-long wave infrared light beam after multiple refraction and reflection in the object to be measured on the information integrity of the measured light beam.

[0047] Figure 2 A schematic diagram of refraction and multiple reflections of an initial medium-long wave infrared light beam in an object to be measured according to an embodiment of the present disclosure is shown. As shown in Figure 2 After the initial medium-long wave infrared light beam irradiates the object to be measured, it is first refracted on the upper surface of the object to be measured, and the refracted light is reflected under the joint action of the lower surface of the object to be measured and the sample carrying module. Part of the refracted light after one reflection will be directly emitted, and the other part will be twice reflected on the upper surface of the object to be measured, back to the inside of the object to be measured, and again reflected under the joint action of the lower surface of the object to be measured and the sample carrying module. In this way, multiple reflections occur, forming the measured light beam.

[0048] By refraction and multiple reflections of the initial medium-long wave infrared light beam in the object to be measured, the obtained measured light beam can contain both the reflection spectral information and the transmission spectral information of the object to be measured, which can more comprehensively reflect the optical characteristics and structural characteristics of the object to be measured compared with the prior art based only on transmission light for spectral measurement, and the adaptability of the system 100 to the object to be measured made of irregular materials and complex application scenarios is improved.

[0049] The to-be-measured light beam generated under the refraction and multiple reflection of the to-be-measured object is generally divergent light, and therefore, the collimating and splitting module 103 is used to collimate and split the to-be-measured light beam to obtain a first light beam and a second light beam in the form of quasi-parallel light, to provide spatially-distributed light for subsequent light path transmission and to realize multi-channel spectral information measurement.

[0050] The structure of the collimating and splitting module 103 will be described in detail below in combination with possible implementations of the present disclosure, and will not be described herein.

[0051] The first light beam and the second light beam obtained by splitting are respectively input into the reference light path module 104 and the encoded light path module 105. The reference light path module 104 can determine a reference light image corresponding to the first light beam; and the encoded light path module 105 can encode the second light beam and determine a signal light image corresponding to the encoded signal light beam. The specific form of the reference light image and the signal light image can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0052] The specific form of the reference light path module 104 and the encoded light path module 105 can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto. The specific method of encoding the second light beam by the encoded light path module 105 can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0053] Since the first light beam and the second light beam are obtained by splitting the to-be-measured light beam, the spatial distribution of the light intensity of the two is actually the same. Therefore, the reference light image determined by using the first light beam without encoding can calibrate the spatial distribution of the light intensity of the signal light image determined based on the signal light beam, thereby providing a reference benchmark for analysis of the signal light beam and reconstruction of spectral information.

[0054] The data processing module 106 can receive the reference light image and the signal light image, and perform spectral reconstruction by using the reference light image and the signal light image to determine the spectral information corresponding to the to-be-measured object. The specific content of the spectral information corresponding to the to-be-measured object can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0055] The specific form of the data processing module 106 can be flexibly set according to actual use requirements. For example, the data processing module 106 can be set as an electronic device such as a terminal device or a server. The terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, and the like. The present disclosure does not make a specific limitation in this regard.

[0056] The process of spectral reconstruction performed by the data processing module 106 according to the reference light image and the signal light image will be described in detail below in combination with possible implementation manners of the present disclosure, and will not be described herein.

[0057] The reflective mid-long wave infrared spectrum measurement system provided in the embodiments of the present disclosure includes a light source module, a sample bearing module, a collimating and splitting module, a reference light path module, an encoded light path module, and a data processing module. The light source module can emit an initial mid-long wave infrared light beam, ensuring the integrity of the mid-long wave infrared spectrum measurement and controlling the initial mid-long wave infrared light beam to be incident on a to-be-measured object on the sample bearing module, so that the initial mid-long wave infrared light beam is refracted and multiply reflected in the to-be-measured object, ensuring that the obtained to-be-measured light beam can contain both the reflection spectrum information and the transmission spectrum information of the to-be-measured object, can more comprehensively reflect the optical characteristics and structural characteristics of the to-be-measured object, and can improve the adaptability of the system to to-be-measured objects made of irregular materials and complex application scenarios. The collimating and splitting module can collimate and split the to-be-measured light beam to obtain a first light beam and a second light beam, providing spatially stable light rays for subsequent light path transmission and realizing multi-channel spectrum information measurement. The reference light path module can determine a reference light image corresponding to the first light beam, and the encoded light path module can encode the second light beam and determine a signal light image corresponding to the encoded signal light beam. The data processing module can perform spectral reconstruction according to the reference light image and the signal light image to determine the spectrum information corresponding to the to-be-measured object. Thus, the reference light image determined by the first light beam without encoding can be used to calibrate the spatial light intensity distribution of the signal light image determined based on the signal light beam, providing a reference benchmark for analysis of the signal light beam and reconstruction of the spectrum information. In the case where the spatial light intensity distribution is unknown, the spectral information reconstruction can be completed by only a single image acquisition, improving the efficiency of the spectrum measurement and enhancing the adaptability of the system to dynamic process monitoring and real-time spectrum detection scenarios. Further, the system provided in the present disclosure has a simple structure, does not require too many optical elements, has a low manufacturing cost, and has a small overall volume and weight, and thus has high applicability to complex application scenarios.

[0058] In a possible implementation, the light source module 101 comprises: a wide-spectrum mid-long-wave infrared light source and a first off-axis focusing sub-module; and the first off-axis focusing sub-module is configured to converge an initial mid-long-wave infrared light beam emitted by the wide-spectrum mid-long-wave infrared light source to a preset deflection angle to the object to be measured.

[0059] For example, as shown in Figure 1 For example, as shown in Figure 1 The light source module 101 comprises: a wide-spectrum mid-long-wave infrared light source 1011 and a first off-axis focusing sub-module 1012.

[0060] The specific form of the wide-spectrum mid-long-wave infrared light source 1011 can refer to the implementation in the related art, for example, a mid-infrared supercontinuum laser source can be used, and the present disclosure does not make a specific limitation thereto.

[0061] The specific form of the first off-axis focusing sub-module 1012 can be flexibly set according to actual use requirements, for example, the first off-axis focusing sub-module 1012 can comprise at least two off-axis parabolic mirrors, and the present disclosure does not make a specific limitation thereto.

[0062] Generally, the initial mid-long-wave infrared light beam emitted by the wide-spectrum mid-long-wave infrared light source 1011 has a certain divergence angle, in order to improve the adaptability of the system 100 to different forms of the object to be measured, the first off-axis focusing sub-module 1012 can be used to converge the initial mid-long-wave infrared light beam to the surface of the object to be measured at a preset deflection angle, thereby reducing the spectral measurement area and improving the spectral measurement accuracy. The specific value of the preset deflection angle can be flexibly set according to actual use requirements, and the present disclosure does not make a specific limitation thereto.

[0063] Figure 3 A structure diagram of a reflective mid-long-wave infrared spectrum measurement system according to an embodiment of the present disclosure is shown. As shown in Figure 3 The system 300 comprises: a wide-spectrum mid-long-wave infrared light source 301, an off-axis parabolic mirror 302, an off-axis parabolic mirror 303, and a sample carrying module 304. The divergent initial mid-long-wave infrared light beam emitted by the wide-spectrum mid-long-wave infrared light source 301 is continuously reflected by the off-axis parabolic mirror 302 and the off-axis parabolic mirror 303, and is focused on the object to be measured placed on the sample carrying module 304. Generally, the sample carrying module 304 is arranged at the focal point position of the off-axis parabolic mirror 303, so that the incident spot size of the initial mid-long-wave infrared light beam when incident to the object to be measured is small, and the measured light beam obtained through refraction and multiple reflections is approximately divergent light.

[0064] On the other hand, by the first off-axis focusing sub-module 1012, the transmissive optical element in the coaxial light path can also be avoided, wavelength selectivity of the initial mid-long wave infrared light beam is generated, and the probability of optical information loss is reduced.

[0065] In a possible implementation, the collimating and splitting module 103 comprises: an off-axis collimating sub-module and a wide-spectrum splitting sub-module; the off-axis collimating sub-module is configured to convert the to-be-measured light beam into a quasi-parallel light beam; and the wide-spectrum splitting sub-module is configured to split the quasi-parallel light beam to obtain the first light beam and the second light beam.

[0066] For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012. Figure 1 For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012. Figure 1 The off-axis collimating sub-module 1011 can convert the divergent to-be-measured light beam into a quasi-parallel light beam, and control the quasi-parallel light beam to be incident on the wide-spectrum splitting sub-module 1012, so as to avoid wavelength selectivity of the to-be-measured light beam in the collimating and splitting process of the to-be-measured light beam, and reduce the probability of optical information loss. The specific form of the off-axis collimating sub-module 1011 can be flexibly set according to actual use requirements, for example, the first off-axis focusing sub-module 1012 can be an off-axis parabolic mirror, and the present disclosure does not make a specific limitation in this regard.

[0067] The wide-spectrum splitting sub-module 1012 can split the quasi-parallel light beam to obtain the first light beam and the second light beam, and control the first light beam to be incident on the reference light path module 104 and control the second light beam to be incident on the coded light path module 105, so as to realize double-channel measurement of spectral information. The specific form of the wide-spectrum splitting sub-module 1012 can refer to the implementation in the related art, for example, a wide-spectrum splitting mirror can be used, and the present disclosure does not make a specific limitation in this regard.

[0068] For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012.

[0069] For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012. Figure 3 For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012. Figure 3 The system 300 comprises: an axial parabolic mirror 305 and a wide-spectrum splitting mirror 306. The divergent to-be-measured light beam is reflected by the off-axis parabolic mirror 305 to be converted into a quasi-parallel light beam, and is incident on the wide-spectrum splitting mirror 306. The wide-spectrum splitting mirror 306 separates the quasi-parallel light beam into the first light beam and the second light beam.

[0070] In a possible implementation, the reference light path module 104 comprises: a second off-axis focusing sub-module and a first wide-spectrum detection sub-module; the second off-axis focusing sub-module is configured to focus the first light beam to the first wide-spectrum detection sub-module; and the first wide-spectrum detection sub-module is configured to receive the first light beam and convert the first light beam into a reference light image.

[0071] For example, as shown in FIG. 10, the collimating and splitting module 103 comprises: an off-axis collimating sub-module 1011 and a wide-spectrum splitting sub-module 1012. Figure 1For example, as shown in Figure 1 The reference light path module 104 includes a second off-axis focusing sub-module 1041 and a first wide-spectrum detection sub-module 1042.

[0072] The second off-axis focusing sub-module 1041 can focus the first light beam on the detection surface of the first wide-spectrum detection sub-module 1042 with a smaller effective area, thereby increasing the optical power density to ensure that the first wide-spectrum detection sub-module 1042 can produce an effective response to the first light beam and reduce the probability of loss of optical information in the first light beam. The specific form of the second off-axis focusing sub-module 1041 can be flexibly set according to actual use requirements, for example, the second off-axis focusing sub-module 1041 can be set as an off-axis parabolic mirror, and the present disclosure does not make specific limitations thereto.

[0073] The first wide-spectrum detection sub-module 1042 can receive the first light beam and convert the first light beam into a reference light image; the specific form of the first wide-spectrum detection sub-module 1042 can refer to the implementation in the related art, for example, the first wide-spectrum detection sub-module 1042 can be set as a wide-spectrum camera, and the present disclosure does not make specific limitations thereto.

[0074] For example, as shown in Figure 3 For example, as shown in Figure 3 The system 300 includes an off-axis parabolic mirror 307 and a wide-spectrum camera 308. After the off-axis parabolic mirror 307 receives the first light beam from the wide-spectrum beam splitter 306, the off-axis parabolic mirror 307 reflects and focuses the first light beam on the detection surface of the wide-spectrum camera 308.

[0075] In one possible implementation, the encoding light path module 105 includes a third off-axis focusing sub-module, a spectral encoding sub-module, and a second wide-spectrum detection sub-module; the third off-axis focusing sub-module is configured to focus the second light beam to the spectral encoding sub-module; the spectral encoding sub-module is configured to perform spectral encoding on the second light beam by using a plurality of microstructure super surface units, and output a signal light beam; and the second wide-spectrum detection sub-module is configured to receive the signal light beam and convert the signal light beam into a signal light image.

[0076] For example, as shown in Figure 1 For example, as shown in Figure 1 The encoding light path module 105 includes a third off-axis focusing sub-module 1051, a spectral encoding sub-module 1052, and a second wide-spectrum detection sub-module 1053.

[0077] The third off-axis focusing submodule 1051 can focus the second light beam to the spectral encoding submodule 1052, improve the optical power density, and reduce the probability of optical information loss in the second light beam. The specific form of the third off-axis focusing submodule 1051 can be flexibly set according to actual use requirements. For example, the third off-axis focusing submodule 1051 can be set as an off-axis parabolic mirror, and the present disclosure does not make specific limitations thereto.

[0078] The spectral encoding submodule 1052 has a plurality of microstructure metasurface units, which can differentially encode the light of different wavelength components in the second light beam, and output the encoded signal light beam. This process can also be referred to as wavelength-dependent intensity modulation. Any one microstructure metasurface unit can modulate the wavelength-dependent transmittance of the light incident to the microstructure metasurface unit.

[0079] The transmittance modulation function corresponding to the spectral encoding submodule can be expressed as formula (1):

[0080]

[0081] Among them, represents the transmittance modulation function of the spectral encoding submodule; represents the surface spatial position of the spectral encoding submodule; represents the wavelength of the second light beam; represents the amplitude modulation factor corresponding to the spectral encoding submodule, represents the phase modulation factor corresponding to the spectral encoding submodule, and the amplitude modulation factor and the phase modulation factor The specific content of the amplitude modulation factor and the phase modulation factor

[0082] is set according to the system parameters such as the spectral resolution of the system 100, and the present disclosure does not make specific limitations thereto. In an example, the relationship between the system parameters such as the spectral resolution of the system 100 and the transmittance modulation function can be designed to optimize the spectral resolution as the target to determine the amplitude modulation factor and the phase modulation factor .

[0083] The specific form of the spectral encoding submodule and any one microstructure metasurface unit can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto. The specific number of microstructure metasurface units included in the spectral encoding submodule can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0084] The second wide-spectrum detection submodule 1053 can receive the signal light beam and convert the signal light beam into a signal light image. The specific form of the second wide-spectrum detection submodule 1053 can refer to the implementation manner in the related art, for example, the second wide-spectrum detection submodule 1053 can be set as a wide-spectrum camera, and the present disclosure does not make a specific limitation thereto. It should be noted that the first wide-spectrum detection submodule and the second wide-spectrum detection submodule are usually of the same type of detection device, so as to ensure the accuracy and reliability when the signal light image is analyzed based on the reference light image.

[0085] In a possible implementation manner, the spectrum encoding submodule is arranged on the surface of the second wide-spectrum detection submodule.

[0086] In order to reduce the influence of the diffraction effect of the spectrum encoding submodule on the spectral measurement resolution of the system 100, and improve the integrated density of the system 100 and reduce the spatial size of the system 100, the spectrum encoding submodule can be attached to the surface of the second wide-spectrum detection submodule.

[0087] For example, as shown in FIG. 3, the system 300 includes an off-axis parabolic mirror 309 and a wide-spectrum camera 310 with a surface integrated with a spectrum encoding submodule. After the off-axis parabolic mirror 309 receives the second light beam from the wide-spectrum beam splitter 306, the second light beam is reflected and focused on the wide-spectrum camera 310 with a surface integrated with a spectrum encoding submodule, for encoding and imaging. Figure 3 Figure 3 As shown in FIG. 3, the system 300 includes an off-axis parabolic mirror 309 and a wide-spectrum camera 310 with a surface integrated with a spectrum encoding submodule. After the off-axis parabolic mirror 309 receives the second light beam from the wide-spectrum beam splitter 306, the second light beam is reflected and focused on the wide-spectrum camera 310 with a surface integrated with a spectrum encoding submodule, for encoding and imaging.

[0088] In a possible implementation manner, the data processing module 106 is configured to: perform normalization processing on the signal light image according to the reference light image to obtain a normalized image; and determine the spectral information corresponding to the to-be-measured object according to the normalized image.

[0089] After being encoded by the spectrum encoding submodule, the light intensity distribution of the signal light beam can be represented by formula (2):

[0090]

[0091] wherein, represents the light intensity distribution of the signal light beam; represents the light intensity distribution of the second light beam.

[0092] The first wide-spectrum detection submodule and the second wide-spectrum detection submodule usually cannot distinguish the information of light rays of different wavelengths, but will integrate and output each wavelength of light rays in a preset response wavelength band. Therefore, the reference light image output by the first wide-spectrum detection submodule can be represented by formula (3):

[0093]

[0094] wherein,​ represents a reference light image; represents a simulated response rate of the first wide-spectrum detection sub-module to the outcoming light ray of the mth microstructure metasurface unit of the spectrum encoding sub-module; represents a light intensity distribution of the first light beam.

[0095] In the case where the second wide-spectrum detection sub-module and the first wide-spectrum detection sub-module adopt the same type of detection device, the signal light image output by the second wide-spectrum detection sub-module can be represented as formula (4):

[0096]

[0097] wherein, represents a signal light image.

[0098] Based on the reference light image, the data processing module 106 can perform normalization processing on the signal light image, reduce or even eliminate the influence of the spatial distribution of the system 100 as an optical system on the spectrum measurement, and obtain a normalized image irrelevant to the system characteristics of the system 100. Specifically, the normalized image can be represented as formula (5):

[0099]

[0100] wherein, represents a normalized image; represents a transmittance modulation function corresponding to the mth microstructure metasurface unit of the spectrum encoding sub-module; represents the spectrum information of the to-be-measured object after normalization.

[0101] Therefore, the data processing module 106 can determine the spectrum information corresponding to the to-be-measured object according to the normalized image and the transmittance modulation function corresponding to each microstructure metasurface unit in the spectrum encoding sub-module.

[0102] Through the above process, the system 100 only needs to perform single acquisition of the reference light image and the signal light image on the to-be-measured object, and can realize the spectrum information reconstruction of the to-be-measured object. Compared with the transmissive spectrum measurement device in the prior art which relies on point-by-point or step-by-step scanning, the system 100 can effectively improve the efficiency and speed of spectrum measurement, and has good adaptability to application scenarios of dynamic process detection and real-time spectrum detection. On the other hand, by using the joint calibration of the reference light image and the signal light image, the influence of the unknown light intensity distribution on the surface of the spectrum encoding sub-module on the accuracy of spectrum measurement can be avoided, and the accuracy and stability of the reconstructed spectrum information can be improved.

[0103] In one possible implementation, the data processing module 106 is used to: use a compressed sensing algorithm to solve the inverse of the underdetermined system of equations based on the normalized image and the transmission matrix corresponding to the coded optical path module, and determine the spectral information of the object to be measured.

[0104] In the actual system 100, the continuous wavelength range needs to be discretized into multiple points for processing, and the obtained spectral information is also composed of multiple discretized spectral points to be measured. Therefore, formula (5) can be discretized into formula (6):

[0105]

[0106] in, This represents the normalized response signal of the second broadband detection submodule to the m-th microstructure metasurface unit of the spectral coding submodule. Represents the n spectral points to be measured in the spectral information of the object to be measured; This represents the transmission matrix corresponding to the coded optical path module, which is composed of the transmittance modulation function corresponding to each microstructure metasurface unit in the spectral coding submodule.

[0107] Typically, the number m of microstructure metasurface units in the spectral encoding submodule is less than the number n of spectral points to be measured in the spectral information of the object under test. Therefore, formula (6) is an underdetermined system of equations. The data processing module 106 can use a compressed sensing algorithm to solve the underdetermined system of equations in reverse to determine the spectral information of the object under test. The specific implementation method of the compressed sensing algorithm can be found in the implementation methods in related technologies, and this disclosure does not limit it in detail.

[0108] In one example, the data processing module 106 can use the Tikhonov regularization method to solve the underdetermined system of equations in reverse to determine the spectral information of the object to be measured.

[0109] Figure 4 This diagram illustrates the process of a data processing module reconstructing spectral information using the Tikhonov regularization method according to an embodiment of the present disclosure. Figure 4 As shown, the response signal after normalization processing by the second broadband detection submodule... The transmission matrix corresponding to the encoding optical path module and preset regularization parameters Construct the regularization equation. The regularization equation can be expressed as formula (7):

[0110]

[0111] Preset regularization parameters The specific value of the regularization parameter can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0112] The objective function corresponding to the regularization equation can be represented as formula (8):

[0113]

[0114] The regularization equation can be solved with the optimization objective function as the goal to obtain a spectral information reconstruction result. The specific method for solving the regularization equation can refer to the implementation in the related art, for example, a direct inverse method, a singular value decomposition (SVD) algorithm, a QR decomposition algorithm, a conjugate gradient algorithm, etc. can be used, and the present disclosure does not make specific limitations thereto.

[0115] The spectral information reconstruction result can be represented as formula (9):

[0116]

[0117] The spectral information reconstruction result is determined as the spectral information of the to-be-detected object when the multi-dimensional evaluation result corresponding to the spectral information reconstruction result indicates that the accuracy and stability of the spectral information reconstruction result meet the preset requirements. When the multi-dimensional evaluation result corresponding to the spectral information reconstruction result indicates that the accuracy and stability of the spectral information reconstruction result do not meet the preset requirements, the value of the preset regularization parameter is adjusted, the regularization equation is re-constructed and solved until the spectral information of the to-be-detected object is determined.

[0118] The specific method for multi-index evaluation of the spectral information reconstruction result can be flexibly set according to actual use requirements, for example, the residual of the spectral information reconstruction result and the L curve can be determined, and the present disclosure does not make specific limitations thereto. The specific content of the preset requirements can be flexibly set according to actual use requirements, and the present disclosure does not make specific limitations thereto.

[0119] Through the above process, the underdetermined equation set formed by sparse sampling can be inversely solved by combining microstructure metasurface coding and compressed sensing algorithm, so as to realize the spectral reconstruction accuracy beyond the limitation of traditional hardware. In the case that the hardware performance of the system 100 is limited, the resolution of the spectral information of the to-be-detected object is improved, and the detection capability of the system 100 is improved.

[0120] ​In a possible implementation, the data processing module 106 is configured to: perform nonlinear mapping analysis on the normalized image by using a preset deep learning algorithm to determine the spectral information of the to-be-detected object.

[0121] Based on formula (6), the data processing module 106 can determine that the response signal of the second wide-spectrum detection sub-module after normalization has a nonlinear mapping relationship with the spectral information of the to-be-detected object , which can be specifically represented as formula (10):

[0122]

[0123] Therefore, the data processing module 106 can construct a sample data set composed of the response signal of the second wide-spectrum detection sub-module after normalization and the sample spectral information of the known object, and pre-train a preset deep learning algorithm capable of analyzing the nonlinear mapping relationship between the response signal of the second wide-spectrum detection sub-module after normalization and the spectral information of the to-be-detected object , which can be specifically represented as formula (10): by using the sample data set and the deep learning algorithm; and then perform nonlinear mapping analysis on the normalized image by using the preset deep learning algorithm to determine the spectral information of the to-be-detected object. The specific form of the preset deep learning algorithm can be flexibly set according to actual needs, which is not limited in the present disclosure.

[0124] Figure 5 FIG. 1 shows a process diagram of reconstructing spectral information by using a preset deep learning algorithm according to a data processing module of an embodiment of the present disclosure. As shown in FIG. 1, after determining the normalized response signal of the second wide-spectrum detection sub-module to the m microstructure metasurface units of the spectral encoding sub-module Figure 5 , the normalized response signal is input into a pre-trained neural network model to directly determine the n to-be-detected spectral points in the spectral information of the to-be-detected object . The specific form of the pre-trained neural network model can be flexibly set according to the implementation in the related art, which is not limited in the present disclosure.

[0125] Through the above process, the spectral information of the to-be-detected object can be reconstructed by combining microstructure metasurface encoding and deep learning algorithm through nonlinear mapping analysis, which can improve the resolution of the spectral information of the to-be-detected object and improve the detection capability of the system 100 without being limited by traditional hardware.

[0126] ​​The reflective mid-to-long-wave infrared spectroscopy measurement system of this disclosure includes a light source module, a sample carrier module, a collimation and beam splitting module, a reference optical path module, an encoding optical path module, and a data processing module. The light source module emits an initial mid-to-long-wave infrared beam, ensuring the integrity of the mid-to-long-wave infrared spectroscopy measurement. It also controls the initial mid-to-long-wave infrared beam to be incident on the object under test on the sample carrier module, causing the initial mid-to-long-wave infrared beam to undergo refraction and multiple reflections within the object under test. This ensures that the resulting beam contains both the reflection and transmission spectral information of the object under test, providing a more comprehensive reflection of the optical and structural characteristics of the object. Furthermore, it improves the system's adaptability to objects made of irregular materials and complex application scenarios. The collimation and beam splitting module collimates and splits the beam under test, obtaining a first beam and a second beam. This provides spatially stable light for subsequent optical path transmission and enables multi-channel spectral information measurement. The reference optical path module determines the reference light image corresponding to the first beam, and the encoding optical path module encodes the second beam and determines the signal light image corresponding to the encoded signal beam. The data processing module can perform spectral reconstruction based on the reference light image and the signal light image to determine the spectral information corresponding to the object under test. This allows the reference light image, determined by the first beam without encoding, to be used to calibrate the spatial distribution of light intensity based on the signal light image determined by the signal beam. This provides a reference benchmark for signal beam analysis and spectral information reconstruction. Even when the spatial light intensity distribution is unknown, spectral information reconstruction can be completed with only a single image acquisition, improving the efficiency of spectral measurement and enhancing the system's adaptability to dynamic process monitoring and real-time spectral detection scenarios. Furthermore, by combining microstructure metasurface encoding with spectral reconstruction algorithms, the underdetermined equations formed by sparse sampling can be solved inversely, achieving spectral reconstruction accuracy that surpasses traditional hardware limitations. This improves the resolution of the spectral information of the object under test and enhances the system's detection capabilities even with limited hardware performance. Moreover, the system provided in this disclosure has a simple structure, requires fewer optical components, has lower manufacturing costs, and is small in overall size and weight, making it highly applicable to complex application scenarios.

[0127] It should be noted that, although... Figure 1 and Figure 3The reflective mid-long wave infrared spectral measurement system is exemplarily introduced as above, but those skilled in the art can understand that the present disclosure should not be limited thereto. In fact, the user can completely flexibly set the specific optical element composition and optical path structure in the reflective mid-long wave infrared spectral measurement system according to personal preferences and / or actual application scenarios, as long as the measured light beams including the reflection spectrum and the transmission spectrum of the object to be measured can be obtained at the same time, and through the coding of the microstructure super surface unit and the double detection channel architecture, the spectral reconstruction is completed through single acquisition in the case of unknown spatial light intensity distribution, and the spectral information of the object to be measured with high resolution is obtained.

[0128] The above has described various embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A reflective mid-to-long-wave infrared spectroscopy measurement system, characterized in that, The system includes: a light source module, a sample carrying module, a collimation and beam splitting module, a reference optical path module, an encoding optical path module, and a data processing module; The light source module is used to emit an initial mid-to-long-wave infrared beam and control the initial mid-to-long-wave infrared beam to be incident on the object to be tested on the sample carrier module. The collimation and beam splitting module is used to collimate and split the initial mid-to-long-wave infrared beam into a test beam generated by the refraction and multiple reflections of the test object, to obtain a first beam and a second beam, wherein the test beam includes the reflection spectrum information and transmission spectrum information of the test object; The reference optical path module is used to determine the reference optical image corresponding to the first beam; The encoding optical path module is used to encode the second beam and determine the signal light image corresponding to the encoded signal beam; The data processing module is used to perform spectral reconstruction based on the reference light image and the signal light image to determine the spectral information corresponding to the object under test.

2. The system according to claim 1, characterized in that, The light source module includes: a broadband mid-to-long-wave infrared light source and a first off-axis focusing submodule; The first off-axis focusing submodule is used to focus the initial mid-to-long-wave infrared beam emitted from the broadband mid-to-long-wave infrared light source onto the object to be measured at a preset deflection angle.

3. The system according to claim 1 or 2, characterized in that, The collimation and beam splitting module includes: an off-axis collimation submodule and a broadband beam splitting module; The off-axis collimation submodule is used to convert the beam under test into a quasi-parallel beam; The broadband beam splitting submodule is used to split the quasi-parallel beam to obtain the first beam and the second beam.

4. The system according to claim 1 or 2, characterized in that, The reference optical path module includes: a second off-axis focusing submodule and a first broadband detection submodule; The second off-axis focusing submodule is used to focus the first beam onto the first broadband detection submodule; The first broadband detector submodule is used to receive the first beam and convert the first beam into the reference light image.

5. The system according to claim 1 or 2, characterized in that, The encoded optical path module includes: a third off-axis focusing submodule, a spectral encoding submodule, and a second broadband detection submodule; The third off-axis focusing submodule is used to focus the second beam onto the spectral encoding submodule; The spectral encoding submodule is used to spectrally encode the second beam using multiple microstructure metasurface units and then output the signal beam. The second broadband detection submodule is used to receive the signal beam and convert the signal beam into the signal light image.

6. The system according to claim 5, characterized in that, The spectral encoding submodule is disposed on the surface of the second broadband detection submodule.

7. The system according to claim 1 or 2, characterized in that, The sample carrier module is made based on a substrate material whose reflectivity meets preset conditions.

8. The system according to claim 1 or 2, characterized in that, The data processing module is used for: Based on the reference light image, the signal light image is normalized to determine the normalized image; Based on the normalized image, the spectral information corresponding to the object under test is determined.

9. The system according to claim 8, characterized in that, The data processing module is used for: Using compressed sensing algorithm, the spectral information of the object under test is determined by inversely solving the underdetermined equations based on the normalized image and the transmission matrix corresponding to the coded optical path module.

10. The system according to claim 8, characterized in that, The data processing module is used for: Using a preset deep learning algorithm, nonlinear mapping analysis is performed on the normalized image to determine the spectral information of the object under test.

Images