Sample signal enhancement device and detection system

Abstract

The invention discloses a sample signal enhancement device and a detection system, and relates to the technical field of laser detection, the sample signal enhancement device comprises a first plano-concave lens and a second plano-concave lens which are arranged opposite to each other, the first plano-concave lens and the second plano-concave lens are confocal at the center of a sample bin, the sample bin is arranged between the first plano-concave lens and the second plano-concave lens, the plane of the first plano-concave lens is plated with a first wavelength laser transmitting film, the concave surface of the first plano-concave lens is plated with a second wavelength laser reflecting film, and the concave surface of the second plano-concave lens is plated with a second wavelength laser reflecting film; the frequency doubling crystal is arranged between the first plano-concave lens and the sample bin and is used for converting the laser with the first wavelength penetrating through the first plano-concave lens into laser with the second wavelength; and the laser with the second wavelength is circularly reflected between the first plane-concave lens and the second plane-concave lens and excites a sample in the sample bin to generate a sample signal.

Description

Technical Field

[0001] The present application relates to the field of laser detection technology, and in particular, to a sample signal enhancement device and a detection system. Background Art

[0002] With the continuous development of laser technology, Raman detection technology and its application scope using laser as excitation source are becoming more and more extensive. The detection objects in practical applications are diverse, and solids, liquids and gases can all use laser as excitation source to detect Raman signals.

[0003] The monitoring of the combustion process by detecting the gas components in the flame during the combustion process through Raman spectroscopy is of great significance for the research of engines. However, due to the strong radiation background of the flame during the combustion process, it brings great interference to the detection of weak signals such as Raman. The current common solution is to use the synchronous and instant generation characteristics of Raman signals and excitation light, use pulsed lasers to excite Raman signals, and then use time-gated cameras to control the exposure time to collect only Raman signals within the pulse duration. The radiation intensity of the flame relative to the pulse laser within the pulse duration range is relatively good relative to the Raman signal generated by the laser, which can effectively reduce the interference of background signals. The usual test method uses high-energy pulsed lasers such as actively Q-switched nanosecond 532nm green lasers or picosecond lasers to focus the pulsed laser through the combustion chamber, and then use a spectrometer + ICCD (Intensified Charge-Coupled Device) camera to collect the Raman signals generated by the pulses. A higher signal-to-noise ratio can be obtained by increasing the energy of the laser pulse, but this method cannot be increased infinitely. High-energy laser pulses will ionize the air to produce laser wire drawing, and the generated plasma luminescence will drown out the Raman signal. The laser can also be focused onto the sample to be tested, reflected a limited number of times by a high-reflection mirror to the sample to enhance the signal, and then the Raman signal generated by the laser point on the sample is collected through a collection optical path to the spectral signal measurement device for detection.

[0004] Among them, the gas Raman signal is increased by using a 532nm high-reflection mirror, specifically including: focusing the excitation light on the sample to be tested, then the excitation light penetrates the sample and passes through two 532nm high-reflection mirrors to achieve a second focus on the sample to be tested, the excitation light penetrates the sample again and passes through two 532nm high-reflection mirrors to achieve a third focus on the sample to be tested, and then the excitation light penetrates the sample and enters the laser collection bucket. The signal generated by the excitation passes through an achromatic lens and a 532nm laser cutoff filter and then enters a signal acquisition device. This technical solution is to improve the excitation efficiency by reflecting the excitation light four times through four high-reflection mirrors. In this solution, the excitation light passes through the sample to be tested three times for excitation, the number of excitations is limited, the excitation efficiency is limited, and the sample signal intensity is limited. In addition, the use of a non-collinear laser multiple reflection light path can only focus on one point in the combustion chamber, so the actual excitation of the sample is mainly point excitation, and the excitation efficiency is not high. Due to the limited intensity of the sample excitation signal, in order to obtain better experimental results, the pulse duration is limited. Depending on the length of the optical path, the pulse technical time is usually about several to ten nanoseconds. Therefore, the gating speed requirements of the signal acquisition device are relatively high. The existing system uses an ICCD camera, which increases the system cost.

[0005] This section is intended to provide a background or context to the embodiments of the present application as recited in the claims. No admission is made that the description herein is prior art by inclusion in this section. Summary of the invention

[0006] The purpose of the present application is to provide a sample signal enhancement device and a detection system, which can at least solve one of the above-mentioned technical problems existing in the current sample signal enhancement devices and detection systems.

[0007] The present application embodiment provides a sample signal enhancement device, including: A first plano-concave mirror and a second plano-concave mirror are arranged opposite to each other, the first plano-concave mirror and the second plano-concave mirror are co-focused at the center of the sample chamber, wherein the sample chamber is arranged between the first plano-concave mirror and the second plano-concave mirror, the plane surface of the first plano-concave mirror is coated with a first wavelength laser transmission film, the concave surface is coated with a second wavelength laser reflection film, and the concave surface of the second plano-concave mirror is coated with a second wavelength laser reflection film; A frequency doubling crystal is arranged between the first plano-concave mirror and the sample chamber, and converts the laser light of the first wavelength passing through the first plano-concave mirror into the laser light of the second wavelength, so that the laser light of the second wavelength is cyclically reflected between the first plano-concave mirror and the second plano-concave mirror and excites the sample in the sample chamber to generate a sample signal.

[0008] In some embodiments, the sample comprises at least one of: a gas, a liquid, a solid.

[0009] In some embodiments, the transmittance of the first wavelength laser transmitting film to the first wavelength laser is above 99%; the reflectivity of the second wavelength laser reflecting film to the second wavelength laser is above 99%.

[0010] The present application embodiment provides a detection system, including the sample signal enhancement device described in any of the above embodiments, and further including: A light source, which outputs laser light of the first wavelength; A signal acquisition device collects and analyzes the sample signal.

[0011] In some embodiments, the invention further includes an optical component disposed between the light source and the first plano-concave mirror, wherein the optical component guides the laser light of the first wavelength emitted by the light source into the first plano-concave mirror.

[0012] In some embodiments, the optical component includes a half-wave plate, a reflector, and a convex lens; wherein, The half-wave plate is arranged on the optical path of the laser light of the first wavelength output by the light source, and the half-wave plate adjusts the polarization direction of the laser light of the first wavelength output by the light source to achieve phase matching with the frequency doubling crystal; The reflector is arranged on the optical path of the outgoing light from the half-wave plate, and reflects the laser light adjusted by the half-wave plate to the convex lens, so that the laser light passes through the convex lens vertically; The convex lens converges the laser reflected by the reflector to the first plano-concave mirror / the frequency doubling crystal / between the first plano-concave mirror and the frequency doubling crystal.

[0013] In some embodiments, the optical component also includes a Faraday optical isolator arranged between the light source and the half-wave plate, and the Faraday optical isolator isolates the first wavelength laser reflected by the convex lens, the first plano-concave mirror, the frequency doubling crystal and the second plano-concave mirror, thereby preventing the reflected first wavelength laser from entering the light source.

[0014] In some embodiments, a third plano-concave mirror is further included, which is arranged opposite to the signal acquisition device. The focus of the third plano-concave mirror is located at the center of the sample chamber, and the line connecting the third plano-concave mirror and the signal acquisition device is perpendicular to the line connecting the first plano-concave mirror and the second plano-concave mirror. The third plano-concave mirror collects the sample signal excited in the sample chamber and outputs the collected sample signal to the signal acquisition device.

[0015] In some embodiments, the signal acquisition device includes an Edge Filter, a spectrometer, and a CCD camera (Charge-Coupled Device) arranged along a straight line; wherein, The Edge filter is arranged opposite to the third plano-concave mirror, and the Edge filter collects the sample signal excited in the sample chamber and filters out stray light in the sample signal, so that the effective signal in the sample signal is high-passed; The spectrometer is arranged between the Edge filter and the CCD camera, and the spectrometer collects the effective signal and analyzes the spectral information of the effective signal by means of line integration; The CCD camera converts the spectral information into electrical signals.

[0016] In some embodiments, the signal acquisition device further includes a collimating lens and a focusing lens arranged on the straight line; wherein, The collimating lens is arranged between the sample chamber and the edge filter, and the collimating lens collects the sample signal excited by the center of the sample chamber and converts the sample signal into parallel light; The focusing lens is arranged between the Edge filter and the spectrometer, and the focusing lens converges the effective signal passing through the Edge filter onto the slit of the spectrometer.

[0017] The sample signal enhancement device and detection system provided in the embodiment of the present application, the first plano-concave mirror and the second plano-concave mirror form a resonant cavity of the second wavelength laser, so that the second wavelength laser generated by the first wavelength laser through the frequency doubling crystal can circulate almost infinitely in the resonant cavity and continuously cyclically excite the sample in the sample chamber, thereby doubling the effective laser excitation power and greatly improving the number of excitations, thereby doubling the obtainable sample signal by an order of magnitude, and improving the laser pulse duration from the nS (nanosecond) level to the uS (microsecond) level, which can effectively reduce the requirements for subsequent signal acquisition devices, and can use conventional signal acquisition devices to collect sample signals, which can solve the problems of high requirements for signal acquisition devices and high system costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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 of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the structure of a sample signal enhancement device provided in an embodiment of the present application.

[0020] Figure 2 A schematic diagram of the structure of a detection system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] 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.

[0022] With reference to the following description and accompanying drawings, the specific embodiments of the present application are disclosed in detail, indicating the way in which the principles of the present application can be adopted. It should be understood that the embodiments of the present application are not limited in scope. Within the scope of the spirit and clauses of the appended claims, the embodiments of the present application include many changes, modifications and equivalents.

[0023] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0024] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components.

[0025] In order to solve at least one of the above problems existing in the prior art, the present application provides a sample signal enhancement device, such as Figure 1 As shown, the sample signal enhancement device 01 includes: A first plano-concave mirror 11 and a second plano-concave mirror 12 are arranged opposite to each other, the first plano-concave mirror 11 and the second plano-concave mirror 12 are cofocused at the center of a sample chamber (omitted in the figure), wherein the sample chamber is arranged between the first plano-concave mirror 11 and the second plano-concave mirror 12, the plane surface of the first plano-concave mirror 11 is coated with a first wavelength laser transmission film, the concave surface is coated with a second wavelength laser reflection film, and the concave surface of the second plano-concave mirror 12 is coated with a second wavelength laser reflection film; The frequency doubling crystal 13 is arranged between the first plano-concave mirror 11 and the sample chamber, and converts the laser light of the first wavelength passing through the first plano-concave mirror 11 into the laser light of the second wavelength, so that the laser light of the second wavelength is cyclically reflected between the first plano-concave mirror 11 and the second plano-concave mirror 12 and excites the sample 200 in the sample chamber to generate a sample signal.

[0026] Specifically, the first plano-concave mirror 11 and the second plano-concave mirror 12 are arranged face to face, and their center lines are aligned. The first plano-concave mirror 11 is used to transmit the laser of the first wavelength, and has high reflection to the laser of the second wavelength, and the second plano-concave mirror 12 has high reflection to the laser of the second wavelength, and the first plano-concave mirror 11 and the second plano-concave mirror 12 form a resonant cavity of the laser of the second wavelength, so that the laser of the second wavelength generated by the frequency doubling crystal 13 of the first wavelength circulates almost infinitely in the resonant cavity and continuously excites the sample in the sample chamber, so that the effective excitation power of the laser is multiplied and the number of excitations is greatly increased, so that the sample signal (which can be a Raman signal) that can be obtained is multiplied by an order of magnitude, and the laser pulse duration is increased from the nS (nanosecond) level to the uS (microsecond) level, which can effectively reduce the requirements of the subsequent signal acquisition device, and the sample signal can be collected by using a conventional signal acquisition device, which can solve the problems of high requirements for the signal acquisition device and high system cost.

[0027] In some embodiments, the transmittance of the first wavelength laser transparent film to the first wavelength laser is above 99%, thereby achieving a high transmittance effect of the first wavelength laser by the first plano-concave mirror 11; the reflectivity of the second wavelength laser reflective film to the second wavelength laser is above 99%, thereby achieving a high reflective effect of the second plano-concave mirror 12 to the second wavelength laser.

[0028] In some embodiments, the sample 200 includes at least one of the following: gas, liquid, solid. When the sample 200 includes gas, the gas may include gas in a combustion flame. For example, the sample signal enhancement device 01 is used to detect the gas components in the flame during the combustion process to monitor the combustion process, which is of great significance for the study of engines.

[0029] In some embodiments, the first wavelength is twice the second wavelength. For example, the first wavelength is 1064 nm and the second wavelength is 532 nm.

[0030] Based on the same inventive concept, the present application also provides a detection system, such as Figure 2 As shown, the detection system 100 includes the sample signal enhancement device 01 described in any of the above embodiments, and also includes: a light source 02, which outputs the laser of the first wavelength; and a signal acquisition device 03, which collects and analyzes the sample signal.

[0031] Specifically, the light source 02 is used to generate a laser of a first wavelength, for example, it can be a pulsed laser; the first plano-concave mirror 11 in the sample signal enhancement device 01 transmits the laser of the first wavelength, and highly reflects the laser of the second wavelength, the second plano-concave mirror 12 highly reflects the laser of the second wavelength, the second plano-concave mirror 12 and the first plano-concave mirror 11 form a resonant cavity of the second wavelength laser, so that the second wavelength laser generated by the first wavelength laser through the frequency doubling crystal 13 can circulate almost infinitely in the resonant cavity and continuously cyclically excite the sample, thereby achieving the doubling of the sample signal, and the laser pulse duration is increased from the nS level to the uS level, which can effectively reduce the requirements of the subsequent signal acquisition device 03, and the conventional signal acquisition device 03 can be used to collect the combustion gas sample signal.

[0032] like Figure 2 As shown, in some embodiments, an optical component 04 is further included between the light source 02 and the first plano-concave mirror 11 , and the optical component 04 guides the laser light of the first wavelength emitted by the light source 02 into the first plano-concave mirror 11 .

[0033] like Figure 2 As shown, in some embodiments, the optical component 04 also includes a half-wave plate 41, a reflector 42 and a convex lens 43; wherein the half-wave plate 41 is arranged on the optical path of the light emitted by the light source 02, and the half-wave plate 41 adjusts the polarization direction of the laser of the first wavelength output by the light source 02 to achieve phase matching with the frequency doubling crystal 13; the reflector 42 is arranged on the optical path of the light emitted by the half-wave plate 41, and reflects the laser adjusted by the half-wave plate 41 to the convex lens 43, so that the laser passes through the convex lens 43 vertically; the convex lens 43 converges the laser reflected by the reflector 42 to the first plano-concave mirror 11 / the frequency doubling crystal 13 / between the first plano-concave mirror 11 and the frequency doubling crystal 13.

[0034] Specifically, the half-wave plate (1 / 2λ wave plate) 41 is used to adjust the polarization direction of the laser to achieve phase matching with the frequency doubling crystal 13 to achieve the best frequency doubling efficiency. The reflector 42 is used to change the direction of the laser so that the laser passes vertically through the convex lens 43 and converges into the resonant cavity formed by the first plano-concave mirror 11 and the second plano-concave mirror 12. For example, the laser can be converged to the first plano-concave mirror 11, or can be converged to the frequency doubling crystal 13, or can be converged between the first plano-concave mirror 11 and the frequency doubling crystal 13.

[0035] like Figure 2As shown, in some embodiments, the optical component 04 also includes a Faraday optical isolator 44 arranged between the light source 02 and the half-wave plate 41, and the Faraday optical isolator 44 isolates the first wavelength laser reflected by the convex lens 43, the first plano-concave mirror 11, the frequency doubling crystal 13 and the second plano-concave mirror 12, thereby preventing the reflected first wavelength laser from entering the light source 02.

[0036] like Figure 2 As shown, in some embodiments, the detection system 100 also includes a third plano-concave mirror 05 arranged opposite to the signal acquisition device 03, the focus of the third plano-concave mirror 05 is located at the center of the sample chamber, and the line connecting the third plano-concave mirror 05 and the signal acquisition device 03 is perpendicular to the line connecting the first plano-concave mirror 11 and the second plano-concave mirror 12, and the third plano-concave mirror 05 collects the sample signal excited in the sample chamber and outputs the collected sample signal to the signal acquisition device 03.

[0037] Specifically, the third plano-concave mirror 05 can be used as a collecting reflector to further collect the sample signal and output it to the signal acquisition device 03. The third plano-concave mirror 05, the first plano-concave mirror 11, the second plano-concave mirror 12, and the convex lens 43 are co-focused at the center of the sample chamber.

[0038] like Figure 2 As shown, in some embodiments, the signal acquisition device 03 includes an Edge filter 31, a spectrometer 32 and a CCD camera 33 arranged along a straight line; wherein the Edge filter 31 is arranged opposite to the third plano-concave mirror 05, the Edge filter 31 collects the sample signal excited in the sample chamber and filters out the stray light in the sample signal, so that the effective signal in the sample signal is high-pass; the spectrometer 32 is arranged between the Edge filter 31 and the CCD camera 33, the spectrometer 32 collects the effective signal by line integration and analyzes the spectral information of the effective signal; the CCD camera 33 converts the spectral information into an electrical signal.

[0039] Specifically, the edge filter 31 is used to filter out stray light mixed in the collected sample signal, so that the effective signal of the excited sample is high-pass. The spectrometer 32 and the CCD camera 33 are combined to split, collect and analyze the signal. By exciting the sample with laser line and then collecting by line integration, the signal intensity is further improved.

[0040] like Figure 2As shown, in some embodiments, the signal acquisition device 03 also includes a collimating lens 34 and a focusing lens 35 arranged on the straight line; wherein the collimating lens 34 is arranged between the sample chamber and the Edge filter 31, and the collimating lens 34 collects the sample signal excited by the center of the sample chamber and converts the sample signal into parallel light; the focusing lens 35 is arranged between the Edge filter 31 and the spectrometer 32, and the focusing lens 35 converges the effective signal passing through the Edge filter 31 onto the slit 32a of the spectrometer 32.

[0041] In order to better understand the present application, the sample signal enhancement device and detection system provided by the present application are introduced in detail below through a specific embodiment.

[0042] This embodiment takes 1064nm pulse laser pumping frequency-doubled output 532nm laser for excitation as an example, wherein, Figure 2 As shown, the detection system 100 includes a light source 02, a Faraday optical isolator 44, a half-wave plate 41, a reflector 42, a convex lens 43, a first plano-concave mirror 11, a frequency doubling crystal 13, a second plano-concave mirror 12, a third plano-concave mirror 05, a collimating lens 34, a focusing lens 35, an edge filter 31, a spectrometer 32 and a CCD camera 33.

[0043] Among them, the light source 02 is a 1064nm actively Q-switched pulsed laser; the Faraday optical isolator 44 is used to isolate the 1064nm laser reflected by the convex lens 43, the first plano-concave mirror 11, the frequency doubling crystal 13 and the second plano-concave mirror 12 from entering the light source 02 to avoid damage to the light source 02; the half-wave plate 41 is used to adjust the polarization direction of the laser to achieve phase matching with the frequency doubling crystal 13 to achieve the best frequency doubling efficiency; the reflector 42 is a 1064nm high-reflection mirror, which is used to vertically pass the laser through the convex lens 43 and converge to the first In the resonant cavity formed by the plano-concave mirror 11 and the second plano-concave mirror 12; the flat surface of the first plano-concave mirror 11 is coated with a 1064nm high-transmittance film, and the concave surface is coated with a 532nm high-reflection film, so that the pump 1064nm laser is transmitted, while the frequency-doubled 532nm laser is highly reflected; the concave surface of the second plano-concave mirror 12 is coated with a 532nm high-reflection film, so that the 532nm laser generated by the pump 1064nm laser through the frequency-doubling crystal 13 can circulate almost infinitely in the resonant cavity and continuously cyclically excite the sample, thereby achieving the doubling of the sample signal.

[0044] The third plano-concave mirror 05 is used as a collecting reflector to further collect the sample signal and output it to the signal collection end. In addition, the third plano-concave mirror 05 is co-focused at the center of the sample chamber with the first plano-concave mirror 11, the second plano-concave mirror 12, the convex lens 43 and the collimating lens 34. The collimating lens 34 is used to convert the excited sample signal into parallel light. The focusing lens 35 is used to converge the sample signal onto the slit 32a of the spectrometer 32. The edge filter 31 is a 535nm high-pass filter, which is used to filter out stray light below 535nm doped in the collected sample signal, so that the excited sample effective signal is high-pass. The spectrometer 32 and the CCD camera 33 form a signal acquisition device 03, which is used to split, collect and analyze the signal.

[0045] Thus, the detection system 100 can realize the power doubling of the 532nm laser generated by the frequency doubling crystal 13 in the resonant cavity after pumping the 1064nm laser. The power of the 532nm laser generated by the frequency doubling crystal 13 in the resonant cavity is stable when the power is the same as the loss in the cavity. By increasing the 1064nm pump power and the frequency doubling efficiency, and controlling the loss in the cavity (the reflection and diffraction loss of the device in the cavity and the absorption and scattering loss of the sample), the power of the 532nm laser in the cavity can be multiplied by an order of magnitude. In this way, the sample signal intensity is doubled, which greatly reduces the requirements for the signal acquisition device 03, thereby achieving the purpose of reducing the system cost.

[0046] The detection system provided in this embodiment uses the method of infinite gain resonance of the excitation light in the cavity to achieve the multiplication of the excitation light to improve the excitation efficiency, greatly improve the sample signal intensity and pulse duration, effectively reduce the requirements for the subsequent signal acquisition device, and use a conventional signal acquisition device to realize the collection of combustion gas sample signals. As a result, the limited excitation of samples (gas, liquid, solid) with a certain transparency to the laser is improved to a nearly infinite excitation method, achieving the multiplication of the signal by an order of magnitude; the point excitation of samples (gas, liquid, solid) with a certain transparency to the laser is improved to a line excitation method (the existing excitation scheme is that the laser is focused on the focal position located at the center of the sample chamber through four reflectors in space to achieve the point excitation method; the device of this embodiment adjusts the position of the two cavity mirrors in the resonant cavity so that the excitation light is reciprocated along a straight line in the resonant cavity and passes through the sample. Due to the volume and size of the measured sample itself, the line excitation of the excitation light to the measured sample is achieved), achieving the multiplication of the signal by an order of magnitude; and also solves the problem of high requirements for the signal acquisition device and high system cost. It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 a limitation to the present application. 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 an indirect connection 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 this application can be understood according to specific circumstances.

[0047] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In the description of this specification, the description of reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradiction.

[0048] Specific embodiments are used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core idea of ​​this application. At the same time, for those skilled in the art, according to the idea of ​​this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.

Claims

1. A sample signal enhancement device, characterized in that: include: A first plano-concave mirror and a second plano-concave mirror are arranged opposite to each other, the first plano-concave mirror and the second plano-concave mirror are co-focused at the center of the sample chamber, wherein the sample chamber is arranged between the first plano-concave mirror and the second plano-concave mirror, the plane surface of the first plano-concave mirror is coated with a first wavelength laser transmission film, the concave surface is coated with a second wavelength laser reflection film, and the concave surface of the second plano-concave mirror is coated with a second wavelength laser reflection film; A frequency doubling crystal is arranged between the first plano-concave mirror and the sample chamber, and converts the laser light of the first wavelength passing through the first plano-concave mirror into the laser light of the second wavelength, so that the laser light of the second wavelength is cyclically reflected between the first plano-concave mirror and the second plano-concave mirror and excites the sample in the sample chamber to generate a sample signal.

2. The sample signal enhancement device according to claim 1, characterized in that: The sample includes at least one of the following: gas, liquid, solid.

3. The sample signal enhancement device according to claim 1, characterized in that: The transmittance of the first wavelength laser transmitting film to the first wavelength laser is above 99%; The reflectivity of the second wavelength laser reflective film to the second wavelength laser is greater than 99%.

4. A detection system, characterized in that: The sample signal enhancement device according to any one of claims 1 to 3, further comprising: A light source, which outputs laser light of the first wavelength; A signal acquisition device collects and analyzes the sample signal.

5. The detection system according to claim 4, characterized in that: The optical component is arranged between the light source and the first plano-concave mirror, and the optical component guides the laser light of the first wavelength emitted by the light source into the first plano-concave mirror.

6. The detection system according to claim 5, characterized in that: The optical component includes a half-wave plate, a reflector and a convex lens; wherein, The half-wave plate is arranged on the optical path of the laser light of the first wavelength output by the light source, and the half-wave plate adjusts the polarization direction of the laser light of the first wavelength output by the light source to achieve phase matching with the frequency doubling crystal; The reflector is arranged on the optical path of the outgoing light from the half-wave plate, and reflects the laser light adjusted by the half-wave plate to the convex lens, so that the laser light passes through the convex lens vertically; The convex lens converges the laser reflected by the reflector to the first plano-concave mirror / the frequency doubling crystal / between the first plano-concave mirror and the frequency doubling crystal.

7. The detection system according to claim 6, characterized in that: The optical component also includes a Faraday optical isolator arranged between the light source and the half-wave plate, and the Faraday optical isolator isolates the laser of the first wavelength reflected by the convex lens, the first plano-concave mirror, the frequency doubling crystal and the second plano-concave mirror to prevent the reflected laser of the first wavelength from entering the light source.

8. The detection system according to claim 5, characterized in that: It also includes a third plano-concave mirror arranged opposite to the signal acquisition device, the focus of the third plano-concave mirror is located at the center of the sample chamber, and the line connecting the third plano-concave mirror and the signal acquisition device is perpendicular to the line connecting the first plano-concave mirror and the second plano-concave mirror, and the third plano-concave mirror collects the sample signal excited in the sample chamber and outputs the collected sample signal to the signal acquisition device.

9. The detection system according to claim 8, characterized in that: The signal acquisition device includes an edge filter, a spectrometer and a CCD camera arranged along a straight line; wherein, The Edge filter is arranged opposite to the third plano-concave mirror, and the Edge filter collects the sample signal excited in the sample chamber and filters out stray light in the sample signal, so that the effective signal in the sample signal is high-passed; The spectrometer is arranged between the Edge filter and the CCD camera, and the spectrometer collects the effective signal and analyzes the spectral information of the effective signal by means of line integration; The CCD camera converts the spectral information into electrical signals.

10. The detection system according to claim 9, characterized in that: The signal acquisition device further includes a collimating lens and a focusing lens arranged on the straight line; wherein, The collimating lens is arranged between the sample chamber and the edge filter, and the collimating lens collects the sample signal excited by the center of the sample chamber and converts the sample signal into parallel light; The focusing lens is arranged between the Edge filter and the spectrometer, and the focusing lens converges the effective signal passing through the Edge filter onto the slit of the spectrometer.

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