Pulse laser collimation and beam combination device based on multi-component online detection system

Abstract

The invention discloses a pulse laser collimation and beam combination device based on a multi-component on-line detection system, which comprises a workbench, the workbench is connected with a mounting seat, the upper end of the mounting seat is connected with a measuring cell incident end optical adjusting frame, the workbench is provided with a measuring cell and a measuring cell heating mechanism, and the measuring cell heating mechanism is connected with the mounting seat. A pool incident port is formed in the side wall of the measuring side, a pool front-stage reflector group and a pool rear-stage reflector group are arranged on the two sides of the measuring pool respectively, and an off-axis parabolic mirror and an adjusting frame of the off-axis parabolic mirror are arranged on the portion, on one side of the pool rear-stage reflector group, of the workbench. According to the invention, the collimation precision is improved, the difficulty brought by debugging is reduced, the time required for beam combination is shortened, and not only can a plurality of QCL lasers be combined, but also a near-infrared laser can be combined.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pulse lasers, in particular to a pulse laser collimation and beam combination device based on a multi-component online detection system. BACKGROUND

[0002] In recent years, the state has introduced a number of environmental protection policies and vigorously supports the development of domestic manufacturing, which has brought opportunities and challenges to the environmental detection field. In order to protect the safety of workers and meet the needs of national emission policies, some environments need to be detected in real time, such as petrochemical industry, biomass power plant, coal mining, etc. There are some limitations for traditional gas detection methods such as electrochemical method, chemical analysis method, gas chromatography method, etc. Therefore, in the CEMS online detection system, the emission concentration of gaseous pollutants (mainly the detection of NO, NO2, SO2, CO2 gas) is detected in real time by laser spectroscopy. The mid-infrared quantum cascade laser is widely used in the CEMS online monitoring system due to its narrow linewidth, high power, fast response speed and other characteristics, and can detect the concentration of single or multiple components of gas at the same time. Therefore, in a complex environment, multiple lasers are needed to detect multiple gases, and laser collimation and beam combination are essential preliminary work.

[0003] The purpose of the present application is to reduce the error generated by the laser during collimation and multi-laser beam combination and to reduce the debugging time. Therefore, a pulse laser collimation and beam combination device based on a multi-component online detection system is proposed. SUMMARY

[0004] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0005] In view of the above problems of the existing pulse laser collimation and beam combination device based on a multi-component online detection system, the present application is proposed.

[0006] Therefore, the purpose of the present application is to provide a pulse laser collimation and beam combination device based on a multi-component online detection system, which improves the collimation accuracy, reduces the difficulty caused by debugging and shortens the time required for beam combination. Not only can multiple QCL lasers be combined, but also near-infrared lasers can be combined.

[0007] To solve the above technical problems, the application provides the following technical scheme: a pulse laser collimation beam combining device based on a multi-component online detection system, comprising a workbench, a mounting seat connected to the workbench, a measurement pool incident end optical adjustment frame connected to the upper end of the mounting seat, a measurement pool and a measurement pool heating mechanism arranged on the workbench, a pool incident port arranged on the side wall of the measurement side, a pool front-stage mirror group and a pool rear-stage mirror group arranged on the two sides of the measurement pool, and an off-axis parabolic mirror and an adjustment frame provided with the off-axis parabolic mirror arranged on one side of the workbench of the pool rear-stage mirror group. A light substrate is connected to one side of the measurement pool incident end optical adjustment frame, and a plurality of laser mounting bases are arranged on the light substrate, a standard optical adjustment frame is connected to one side of the laser mounting base, a QCL laser is connected to the laser mounting base, and a QCL laser gas shell is sleeved outside the QCL laser; a red light laser is connected to one of the laser mounting bases, and a red light collimation head is arranged on the side wall of the red light laser; a first gold-plated mirror is arranged on one side of the standard optical adjustment frame of one of the laser mounting bases, the measurement pool incident end optical adjustment frame is provided with a second gold-plated mirror opposite to the first gold-plated mirror, and a first dichroic mirror and a second dichroic mirror with different transmittances are arranged on the standard optical adjustment frame between the first gold-plated mirror and the second gold-plated mirror. A collimation beam combining unit for collimating the QCL laser is arranged on the workbench; a first light diaphragm and a second light diaphragm are arranged opposite to each other on the light substrate and the upper end of the mounting seat, and the collimation beam combining unit comprises a cage structure, a collimation adjustment module and an optical adjustment frame, and the cage structure is connected between the first light diaphragm and the second light diaphragm.

[0008] As a preferred scheme of the pulse laser collimation beam combining device based on the multi-component online detection system, the measurement pool heating mechanism comprises two heating aluminum blocks arranged on the upper end of the measurement pool, a platinum resistance is arranged on the side wall of the measurement pool, and a temperature switch connected to the heating aluminum block is arranged on the other side of the measurement pool.

[0009] As a preferred scheme of the pulse laser collimation beam combining device based on the multi-component online detection system, a VIGO detector is arranged in the measurement pool, a detector shell is connected to the outside of the VIGO detector, and the lower end of the detector shell is fixed to the measurement pool through a detector mounting base.

[0010] As a preferred scheme of the pulse laser collimation beam combination device based on the multi-component online detection system, the second gold-plated mirror is installed on the measuring pool incident end optical adjustment frame, a three-axis precision adjustment knob is arranged on the measuring pool incident end optical adjustment frame, and the three-axis precision adjustment knob has a self-locking structure to prevent loosening caused by vibration during long-term operation and transportation, so that the optical path changes.

[0011] As a preferred scheme of the pulse laser collimation beam combination device based on the multi-component online detection system, the first dichroic mirror, the second dichroic mirror and the first gold-plated mirror are installed at an angle of 45°, the QCL laser exit light is reflected by 45°, then enters the measuring pool through the measuring pool incident port, and the exit light is reflected by the measuring pool rear mirror group to reach the off-axis parabolic mirror after multiple reflections in the measuring pool.

[0012] As a preferred scheme of the pulse laser collimation beam combination device based on the multi-component online detection system, the measuring pool is made of 7075 T6 / 316L material, and the measuring pool body will expand by 1mm due to thermal deformation at high temperature. The laser spatial beam combination needs to be performed at high temperature.

[0013] As a preferred scheme of the pulse laser collimation beam combination device based on the multi-component online detection system, the mounting seat and the lower end of the measuring pool are both provided with high-temperature-resistant base support columns connected with the workbench.

[0014] The beneficial effects of the present application are: the present application completes the collimation and beam combination on one optical mechanical plate, avoiding the uncertainty error caused by moving the collimated light on the optical platform to the optical mechanical plate; the collimation and beam combination device improves the collimation precision, reduces the difficulty caused by debugging, and shortens the time required for beam combination. It can not only combine multiple QCL lasers, but also combine near-infrared lasers. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them: Fig. 1 It is the top view of the QCL laser spatial arrangement and collimation module of the pulse laser collimation beam combination device based on the multi-component online detection system of the present application.

[0016] Fig. 2The top view of the system beam combination after the QCL laser collimation of the pulse laser collimation beam combination device based on the multi-component online detection system of the application.

[0017] Fig. 3 The side view of the system collimation beam combination structure of the pulse laser collimation beam combination device based on the multi-component online detection system of the application. DETAILED DESCRIPTION

[0018] In order to make the above objectives, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0019] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the application, but the application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the application, so the application is not limited by the specific embodiments disclosed below.

[0020] Secondly, "one embodiment" or "embodiment" referred to herein means that a specific feature, structure or characteristic can be included in at least one implementation of the application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is separate or alternative to other embodiments.

[0021] Thirdly, the application is described in detail in conjunction with the schematic diagram, and in the detailed description of the embodiments of the application, the cross-sectional view of the device structure is partially enlarged without general proportion for the convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the application herein. In addition, three-dimensional spatial dimensions including length, width and depth should be included in actual manufacture.

[0022] REFERENCE Figs. 1-3 A pulse laser collimation beam combination device based on a multi-component online detection system is provided, comprising a workbench, a mounting seat 3 connected to the workbench, a measurement pool incident end optical adjustment frame 1 connected to the upper end of the mounting seat 3, a measurement pool and a measurement pool heating mechanism arranged on the workbench, a pool incident port 28 arranged on the measurement side wall, a pool front-stage mirror group 27 and a pool rear-stage mirror group 30 arranged on both sides of the measurement pool, an off-axis parabolic mirror 25 and an adjustment frame 26 provided with the off-axis parabolic mirror arranged on one side of the workbench of the pool rear-stage mirror group 30; the material of the measurement pool is selected to be 7075 T6 / 316L, the measurement pool body will expand 1mm due to thermal change at high temperature, and the process of laser spatial beam combination needs to be carried out at high temperature; the lower end of the mounting seat 3 and the measurement pool is provided with a high-temperature-resistant base support column 29 connected to the workbench.

[0023] The side workbench of the optical adjustment frame 1 at the incident end of the measuring pool is connected with a light substrate 7, and a plurality of laser installation bases 18 are arranged on the light substrate 7; a standard optical adjustment frame is connected to the side of the light substrate 7 of the laser installation base; a QCL laser 20 is connected to the laser installation base 18; and a QCL laser gas shell 19 is sleeved outside the QCL laser 20; a red light laser 17 is connected to one of the laser installation bases 18, and a red light collimation head 16 is arranged on the side wall of the red light laser 17; a first gold-plated mirror 10 is arranged on the side of the standard optical adjustment frame of one of the laser installation bases 18; the optical adjustment frame 1 at the incident end of the measuring pool is provided with a second gold-plated mirror 2 opposite to the first gold-plated mirror 10; and a first dichroic mirror 8 and a second dichroic mirror 9 with different transmittances are arranged on the standard optical adjustment frame between the first gold-plated mirror 10 and the second gold-plated mirror 2. The collimation beam combining unit for collimating the QCL laser 20 is arranged on the workbench; the light substrate 7 and the mounting seat 3 are respectively connected with a first light diaphragm 4 and a second light diaphragm 6 arranged oppositely; the collimation beam combining unit comprises a cage structure 5, a collimation adjustment module 11 and an optical adjustment frame 12, and the cage structure 5 is connected between the first light diaphragm 4 and the second light diaphragm 6.

[0024] The measuring pool heating mechanism comprises two heating aluminum blocks 23 arranged at the upper end of the measuring pool; a platinum resistance 22 is arranged on the side wall of the measuring pool; and a temperature switch 24 connected with the heating aluminum block 23 is arranged on the other side of the measuring pool.

[0025] Further, a VIGO detector 13 is arranged in the measuring pool; a detector shell 14 is connected to the outside of the VIGO detector 13; and the lower end of the detector shell 14 is fixed to the measuring pool through a detector mounting base 15.

[0026] Specifically, the second gold-plated mirror 2 is arranged on the optical adjustment frame 1 at the incident end of the measuring pool; a three-axis precision adjustment knob 21 is arranged on the optical adjustment frame 1 at the incident end of the measuring pool; the three-axis precision adjustment knob 21 has a self-locking structure to prevent loosening caused by vibration during long-term operation and transportation, so as to change the optical path; the first dichroic mirror 8, the second dichroic mirror 9 and the first gold-plated mirror 10 are arranged at an angle of 45°; the emitted light of the QCL laser 20 is reflected by 45°, then enters the measuring pool through the incident port 28 of the measuring pool, is reflected multiple times in the measuring pool, and then is reflected by the rear mirror group 30 of the measuring pool to reach the off-axis parabolic mirror 25.

[0027] In use, first, the temperature of the optical engine plate 7 is controlled at 50°C, and after stabilization, the plurality of QCL lasers 20 are collimated, wherein the indicated laser is installed at the first position, the adjustment knobs of the optical adjustment frame are adjusted until the dichroic mirror or the gold-coated mirror is at 45° with the light, the first diaphragm 4 and the second diaphragm 6 of the cage structure 5 are adjusted from large to small, when the first diaphragm 4 and the second diaphragm 6 are small, the light is perpendicular to the front end mirror group 27 of the measuring cell, the height of the light-sensitive surface of the detector is consistent with the height of the laser, the pitch angle and the yaw angle are adjusted, and the signal amplitude of the upper computer software is observed until the signal is saturated. Then, the QCL lasers 20 are collimated respectively, the size of the first diaphragm 4 and the second diaphragm 6 is constrained, and the Z-axis is adjusted to determine the focal point position, the X-axis and the Y-axis are adjusted to debug the pitch angle and the yaw, and the signal amplitude is observed until saturation.

[0028] Next, taking three lasers as an example, in order to prevent interference, the dichroic mirror is made with a 0.8° wedge angle, after the laser 1 is removed, the laser 2 and the laser 3 are adjusted according to the operation steps of the laser 1, the three-axis knobs of the dichroic mirror and the gold-coated mirror are adjusted, and then installed on the laser 2 and the laser 3, according to the adjustment sequence from top to bottom, after the laser 1 is installed, the dichroic mirror of the laser 2 is adjusted, if the collimation is correct, the three-axis adjustment knobs are adjusted to appear a weak signal, and the signal strength is maximized by fine-tuning the knobs in each direction. Finally, the laser 3 is adjusted, since the two previous stages are dichroic mirrors with wedge angles, the adjustment range is larger, and the same is true for the laser 3, that is, the beam combination of the plurality of QCL lasers 20 in space is completed.

[0029] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A pulse laser collimation and beam combining device based on a multi-component online detection system, characterized in that: The invention comprises a workbench, a mounting seat (3) is connected to the workbench, an upper end of the mounting seat (3) is connected to a measuring cell incident end optical adjustment frame (1), a measuring cell and a measuring cell heating mechanism are arranged on the workbench, a cell incident port (28) is arranged on the measuring side wall, a cell front-stage reflector group (27) and a cell rear-stage reflector group (30) are respectively arranged on both sides of the measuring cell, and an off-axis parabolic mirror (25) and an adjustment frame (26) provided with the off-axis parabolic mirror are arranged on the workbench on one side of the cell rear-stage reflector group (30); An optical base plate (7) is connected to a workbench on one side of the optical adjustment frame (1) at the incident end of the measuring cell, and a plurality of laser mounting bases (18) are provided on the optical base plate (7); a standard optical adjustment frame is connected to the optical base plate (7) on one side of the laser mounting base; a QCL laser (20) is connected to the laser mounting base (18); and a QCL laser gas shell (19) is sleeved on the outer side of the QCL laser (20); and a red light laser (17) is connected to one of the laser mounting bases (18). A red light collimating head (16) is provided on the side wall of the red light laser (17); a first gold-plated reflector (10) is provided on a standard optical adjustment frame on one side of the laser mounting base (18); a second gold-plated reflector (2) opposite to the first gold-plated reflector (10) is provided on the optical adjustment frame (1) at the incident end of the measuring cell; and a first dichroic mirror (8) and a second dichroic mirror (9) with different transmittances are provided on the standard optical adjustment frame between the first gold-plated reflector (10) and the second gold-plated reflector (2); The workbench is provided with a collimating beam combining unit for collimating the QCL laser (20); the optical substrate (7) and the upper end of the mounting seat (3) are respectively connected to a first aperture (4) and a second aperture (6) arranged opposite to each other; the collimating beam combining unit comprises a cage structure (5), a collimating adjustment module (11) and an optical adjustment frame (12); the cage structure (5) is correspondingly connected between the first aperture (4) and the second aperture (6).

2. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 1, characterized in that: The measuring cell heating mechanism comprises two heating aluminum blocks (23) arranged at the upper end of the measuring cell, a platinum resistor (22) is arranged on the side wall of the measuring cell, and a temperature switch (24) connected to the heating aluminum block (23) is arranged on the other side of the measuring cell.

3. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 2, characterized in that: A VIGO detector (13) is installed in the measuring cell, the outer side of the VIGO detector (13) is connected to a detector housing (14), and the lower end of the detector housing (14) is fixed to the measuring cell via a detector mounting base (15).

4. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 1, characterized in that: The second gold-plated reflector (2) is mounted on an optical adjustment frame (1) at the incident end of the measuring cell. A three-axis precision adjustment knob (21) is provided on the optical adjustment frame (1) at the incident end of the measuring cell. The three-axis precision adjustment knob (21) has a self-locking structure to prevent loosening caused by vibration during long-term operation and transportation, thereby preventing changes in the optical path.

5. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 4, characterized in that: The first dichroic mirror (8), the second dichroic mirror (9) and the first gold-plated reflector (10) are installed at a 45-degree angle. The outgoing light of the QCL laser (20) is reflected at a 45-degree angle and then passes through the incident port (28) of the measuring cell and is incident into the measuring cell. After multiple reflections, the outgoing light is reflected by the post-reflector group (30) of the measuring cell and reaches the off-axis parabolic mirror (25).

6. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 1, characterized in that: The measuring cell is made of 7075 T6 / 316L. Under high temperature, the measuring cell body will undergo thermal deformation, causing the cell body to expand by 1mm. The laser spatial beam combining process needs to be carried out at high temperature.

7. The pulse laser collimation and beam combining device based on a multi-component online detection system according to claim 1, characterized in that: The lower ends of the mounting seat (3) and the measuring cell are both provided with a height-resistant base support column (29) connected to the workbench.

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