Vacuum displacement measurement system

Abstract

This utility model provides a vacuum displacement measurement system, relating to the technical field of displacement measurement systems. It includes a vacuum chamber for providing a vacuum environment, a transmission component mounted on the vacuum chamber, and a component to be measured placed inside the chamber; a laser module located on the outside of the vacuum chamber, including a laser; a collimation module located on the outside of the vacuum chamber to receive orthogonally linearly polarized laser beams emitted from the laser and transmit them into the vacuum chamber; an interferometry processing module including a signal processing component located outside the vacuum chamber and an interference structure located inside the vacuum chamber; the collimation module includes a beam splitter, and the compensation light split by the beam splitter is transmitted to the signal processing component via optical fiber; and a coupling component for coupling the orthogonally linearly polarized laser beam. This invention solves the problem in the prior art where complex interferometer arrangements are difficult to implement in a vacuum environment due to space constraints.

Description

Technical Field

[0001] This utility model relates to the field of displacement measurement system technology, and more specifically, to a vacuum displacement measurement system. Background Technology

[0002] With the continuous advancement of technology, high-precision displacement measurement plays an increasingly important role in precision manufacturing, scientific research, and engineering. Especially in high-end equipment and systems, the accuracy of displacement measurement directly affects the quality and performance of the final product. Laser interferometers, as the mainstream tool for high-precision displacement measurement, offer undeniable advantages in measurement accuracy. However, the performance of laser interferometers is easily affected by environmental factors, particularly temperature, pressure, and airflow disturbances. These factors can lead to variations in laser wavelength and instability in the optical path, thus affecting the accuracy of displacement measurements.

[0003] In a vacuum environment, the accuracy of laser interferometry can be significantly improved due to the absence of refraction and disturbance from air molecules. However, placing a laser interferometer completely within a vacuum chamber presents a significant challenge. On the one hand, the optical path and components of a laser interferometer are relatively complex, requiring considerable space; on the other hand, to achieve a high vacuum state, the design of the vacuum chamber needs to minimize its volume to improve vacuuming efficiency. This contradiction between space requirements and volume constraints has become a major challenge in the design of vacuum displacement measurement systems. Utility Model Content

[0004] The main objective of this invention is to provide a vacuum displacement measurement system to solve the problem in the prior art where it is difficult to arrange complex interferometers in a vacuum environment due to space limitations.

[0005] To achieve the above objectives, according to one aspect of the present invention, a vacuum displacement measurement system is provided, comprising:

[0006] A vacuum chamber is used to provide a vacuum environment. A transmission component is installed on the vacuum chamber, and the object to be tested is placed inside it.

[0007] A laser module, located on the outside of the vacuum chamber, includes a laser for generating orthogonally linearly polarized laser beams.

[0008] The collimation module is located on the outside of the vacuum chamber to receive the orthogonally polarized laser beam emitted from the laser and transmit the orthogonally polarized laser beam into the vacuum chamber through the transmission component;

[0009] The interference processing module includes a signal processing component located outside the vacuum chamber and an interference structure located inside the vacuum chamber. The interference structure receives an orthogonally polarized laser beam and generates interference signal light with the object under test. The interference signal light is transmitted to the signal processing component by an optical fiber.

[0010] The collimation module includes a beam splitter, and the compensation light split by the beam splitter is transmitted to the signal processing unit via optical fiber. It also includes a coupling unit for coupling the orthogonally linearly polarized laser beam.

[0011] Furthermore, the laser module also includes a coupling component for coupling orthogonally linearly polarized laser beams;

[0012] The supporting component has a supporting surface, and the coupling component and laser are both mounted on the supporting surface;

[0013] An optical fiber component, mounted on a coupling component, is used to collect orthogonally linearly polarized laser beams coupled by the coupling component.

[0014] Furthermore, the collimation module includes: a collimation component for recovering the orthogonally linearly polarized laser beam transmitted through the fiber optic component and collimating the orthogonally linearly polarized laser beam into an orthogonally linearly polarized laser beam of the target size;

[0015] A beam adjustment assembly is located between the collimation component and the transmission component to adjust the position and orientation of the collimated orthogonal linearly polarized laser beam.

[0016] The support component is located outside the vacuum chamber. The support component has a support surface, and the collimation component, beam adjustment assembly and beam splitting device are located on the support surface.

[0017] Furthermore, the support components are located on the outer wall of the vacuum chamber.

[0018] Furthermore, the interference structure includes: a support column disposed within the vacuum chamber;

[0019] An interferometer assembly, mounted on a support column, converts the received orthogonally linearly polarized laser beam into measurement and reference light.

[0020] The reflector is placed on the device under test to reflect the measurement light into the interferometer group and form an interference signal light with the reference light.

[0021] Furthermore, the support column includes a first support column and a second support column, wherein the extension direction of the first support column is perpendicular to the extension direction of the second support column;

[0022] There are at least two interferometer groups, which are respectively mounted on the first support column and the second support column;

[0023] There are at least two reflectors, which are set on the test piece in a one-to-one correspondence with the interference mirror group;

[0024] An intracavity beam splitter is provided between at least two interferometer groups and the transmission component, and orthogonally linearly polarized laser beams are incident into the interferometer groups through the intracavity beam splitter.

[0025] Furthermore, the interference mirror assembly includes: a corner cone mirror, a polarizing beam splitter, a quarter-wave plate, and a plane mirror;

[0026] The incident surface of the polarization beam splitter has an incident light aperture and an exit light aperture. The orthogonal linearly polarized laser beam emitted from the collimation module is illuminated by the incident light aperture, and the polarization beam splitter splits the orthogonal linearly polarized laser beam into a measurement beam and a reference beam.

[0027] The measuring light is transmitted through a quarter-wave plate, a reflecting mirror, and a corner cube before exiting through the exit aperture; the reference light is transmitted through a quarter-wave plate, a plane reflecting mirror, and a corner cube before exiting through the exit aperture. The measuring light and the reference light form an interference signal light at the exit aperture.

[0028] Furthermore, the number of collimation modules, fiber optic components, and transmission components is at least two, and they are arranged in a one-to-one correspondence.

[0029] Furthermore, the laser and the collimation module are aligned in a straight line, and the orthogonally polarized laser beam is spatial light that is directly incident into the collimation module.

[0030] Furthermore, the coupling component is a multidimensional coupler, which can be adjusted for axial rotation, radial yaw, and radial pitch; and / or, the optical fiber component is a polarization-maintaining fiber.

[0031] By applying the technical solution of this utility model, the interference structure is placed inside the vacuum chamber, which avoids the influence of the atmospheric environment on the path of the orthogonally linearly polarized laser beam, thus improving the accuracy of the measurement. The beam splitter added to the collimation module can split a compensation beam, which is transmitted to the signal processing unit through optical fiber for real-time monitoring and compensation of measurement errors caused by changes in external conditions. At the same time, the laser module, collimation module and interference processing module are respectively placed outside the vacuum chamber, reducing the complexity inside the vacuum chamber. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0033] Figure 1 A top view of a vacuum displacement measurement system according to an embodiment of this application is shown;

[0034] Figure 2The diagram shows the internal optical path of the interferometer group in the vacuum displacement measurement system according to an embodiment of this application;

[0035] Figure 3 A top view of a vacuum displacement measurement system according to an embodiment of this application, including multiple collimation modules, is shown.

[0036] Figure 4 An optical path diagram of the measurement light according to an embodiment of this application is shown;

[0037] Figure 5 An optical path diagram of the reference light according to an embodiment of this application is shown.

[0038] Figure 6 A schematic diagram of a vacuum displacement measurement system corresponding to another embodiment of this application is shown.

[0039] The above figures include the following reference numerals:

[0040] 1. Laser module; 11. Laser; 12. Coupling component; 13. Bearing component; 14. Fiber optic component;

[0041] 2. Collimation module; 21. Collimation component; 22. Support component; 23. Beam adjustment assembly; 24. Beam splitter;

[0042] 3. Interference processing module; 31. Support column; 32. Interference mirror group; 321. Cornerstone mirror; 322. Polarizing beam splitter; 323. Quarter-wave plate; 324. Plane mirror; 33. Mirror section; 34. Signal processing unit;

[0043] 4. Vacuum chamber; 5. Transmission component. Detailed Implementation

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] As mentioned in the background section, the main technical objective of this application is to provide a vacuum displacement measurement system, thereby solving the problem in the prior art that it is difficult to arrange complex interferometers in a vacuum environment due to space limitations.

[0046] like Figures 1 to 5 As shown, the vacuum displacement measurement system provided in this application includes a vacuum chamber 4, which provides a vacuum environment. A transmission component 5 is provided on the vacuum chamber 4, and the component to be tested is placed inside it.

[0047] Laser module 1 is located on the outside of vacuum chamber 4 away from the vacuum chamber 4. Laser module 1 includes laser 11 for generating orthogonally linearly polarized laser beams.

[0048] Collimation module 2 is located on the outside of vacuum chamber 4 to receive the orthogonally polarized laser beam emitted from laser 11 and transmit the orthogonally polarized laser beam into vacuum chamber 4 through transmission component 5.

[0049] The interference processing module 3 includes a signal processing component 34 located outside the vacuum chamber 4 and an interference structure located inside the vacuum chamber 4. The interference structure receives orthogonally polarized laser beams and generates interference signal light with the device under test. The interference signal light is transmitted to the signal processing component 34 by optical fiber.

[0050] The collimation module 2 includes a beam splitter 24, and the compensation light split by the beam splitter 24 is transmitted to the signal processing unit 34 by optical fiber.

[0051] like Figure 1 As shown, optionally, the laser module 1 in this technical solution is located on the outside of the vacuum chamber 4, which is relatively far away from the vacuum chamber 4, and is used to generate laser. The laser 11 is a high-frequency stable laser source, which can be a helium-neon frequency stabilized type. The helium-neon frequency stabilized type is further divided into laser frequency division technologies such as Zeeman effect, acousto-optic modulation, birefringence, and dual longitudinal mode. In this technical solution, the laser 11 is preferably a dual-frequency helium-neon Zeeman effect light source, and its output light is an orthogonally linearly polarized laser beam.

[0052] In some embodiments of this application, the beam splitter 24 is a beam splitter; the transmission component 5 is a transmission window, which can be of various types such as CF and KF. Because the transmission component 5 has advantages such as high surface quality, high transmittance and high leakage rate, it can realize the transmission of beam information in different levels of vacuum environment and atmospheric environment.

[0053] During use, the laser signal generated by laser module 1 is transmitted to collimation module 2. Collimation module 2 realizes the transmission of laser signals inside and outside the vacuum. Then, collimation module 2 transmits the laser signal to interference processing module 3. The interference structure in interference processing module 3 receives the laser signal and generates interference signal light with the object under test. The interference signal light is transmitted to signal processing unit 34. Signal processing unit 34 processes the interference signal light to convert it into displacement, so as to realize the real-time measurement of the displacement of the object under test in the vacuum chamber 4. In this embodiment, the laser signal is an orthogonally polarized laser beam.

[0054] In this application, by placing the interference structure inside the vacuum chamber 4, measurement errors caused by environmental factors such as air refractive index fluctuations, temperature changes, and airflow disturbances are significantly reduced, thus improving the accuracy of displacement measurement. The collimation module 2 automatically corrects the pointing and positional deviations of the orthogonal linearly polarized laser beam, maintaining the stability and consistency of the optical path. The beam splitter 24 in the collimation module 2 can split the orthogonal linearly polarized laser beam into a compensation beam. This compensation beam is transmitted as a compensation signal to the signal processing unit 34 for real-time correction of measurement errors caused by changes in the optical path, thereby improving the accuracy and reliability of the measurement results.

[0055] In this technical solution, the laser module 1, the collimation module 2 and the signal processing component 34 are placed outside the vacuum chamber 4, which helps to reduce the space occupied by the vacuum chamber 4.

[0056] like Figure 1 and Figure 3 As shown, the laser module 1 further includes a coupling component 12 for coupling orthogonally linearly polarized laser beams;

[0057] The support component 13 has a support surface, and the coupling component 12 and the laser 11 are both disposed on the support surface;

[0058] An optical fiber component 14 is disposed on the coupling component 12 to collect the orthogonally linearly polarized laser beam coupled by the coupling component 12.

[0059] The coupling component 12 ensures that the orthogonally linearly polarized laser beam generated from the laser 11 can enter the fiber component 14 to the maximum extent, thereby reducing the energy loss of the orthogonally linearly polarized laser beam during transmission. In this embodiment, the coupling component 12 is a multi-dimensional coupler. Since the multi-dimensional coupler can be adjusted in three degrees of freedom: axial rotation, radial deflection, and radial pitch, the specific design of the multi-dimensional coupler is prior art and will not be described here. By using the multi-dimensional coupler, the coupling component 12 can be efficiently coupled to the orthogonally linearly polarized laser beam.

[0060] In some embodiments of this application, the optical fiber component 14 disposed on the coupling component 12 can be disposed away from the interference processing module 3 to ensure the stable transmission of the orthogonal linearly polarized laser beam. Optionally, the optical fiber component 14 is a polarization-maintaining fiber. The optical fiber component 14 is a device that can maintain the polarization characteristics of polarized light and transmit it stably. It needs to exert its maximum advantage when the polarization axis is aligned with the polarization axis of the beam. The optical fiber component 14 in this application enables the orthogonal linearly polarized laser beam to be transmitted over long distances while maintaining its integrity, and reduces interference in the air.

[0061] In some embodiments of this application, the supporting component 13 is disposed on the ground or platform, and the supporting surface of the outer supporting component 13 is a high-precision flat plane to provide better stability for the laser 11.

[0062] Optionally, the supporting component 13 in this technical solution is made of a material with high rigidity, good thermal conductivity, and low coefficient of expansion. For example, the material of the supporting component 13 is indium steel. Since the laser 11 is a heat source, using the above-mentioned material can better transfer the heat of the laser 11, increase the contact surface with the atmosphere for heat exchange, and facilitate heat extraction or other forms of heat transfer.

[0063] like Figure 1 and Figure 3 As shown, the collimation module 2 further includes: a collimation component 21, used to recover the orthogonal linearly polarized laser beam transmitted through the fiber component 14 and collimate the orthogonal linearly polarized laser beam into an orthogonal linearly polarized laser beam of the target size;

[0064] The beam adjustment component 23 is located between the collimation component 21 and the transmission component 5 to adjust the position and orientation of the collimated orthogonal linearly polarized laser beam.

[0065] The support component 22 is located on the outside of the vacuum chamber 4. The support component 22 has a support surface, and the collimating component 21, the beam adjustment component 23 and the beam splitting device 24 are located on the support surface.

[0066] In some embodiments of this application, the collimation module 2 further includes a support component 22 disposed outside the vacuum chamber 4. The support component 22 is provided with a beam splitter 24, a collimation component 21 and a beam adjustment component 23. Optionally, the support component 22 is a support plate. Optionally, the support component 22 should be made of a material with high rigidity and low coefficient of thermal expansion to achieve high stability of the collimation module 2.

[0067] Optionally, in this technical solution, the collimating component 21 is a collimator, which is used to recover the orthogonally linearly polarized laser beam transmitted by the fiber optic component 14 and collimate the orthogonally linearly polarized laser beam into an orthogonally linearly polarized laser beam of the required size.

[0068] Optionally, the beam adjustment component 23 includes a beam position adjuster and a beam angle adjuster to adjust the position of the beam spot and adjust the direction of the orthogonal linearly polarized laser beam. After the vacuum chamber 4 is evacuated, the beam adjustment component 23 can be set to adjust the attitude and position of the orthogonal linearly polarized laser beam entering the vacuum chamber 4 directly from outside the vacuum chamber 4.

[0069] Optionally, the beam adjustment component 23 is positioned between the collimating component 21 and the beam splitter 24. This allows the variation in the orthogonally polarized laser beam caused by the beam adjustment component 23 to be included within the error correction range of the compensation light. Specifically, the compensation light can measure the phase information of the orthogonally polarized laser beam passing through the laser 11, coupling component 12, fiber component 14, collimating component 21, and beam adjustment component 23. Recording the phase information of the orthogonally polarized laser beam allows for parameter correction of the measurement results, adjusting for the phase difference of the laser's output fiber itself, the influence of the environment on the orthogonally polarized light in all paths before the beam splitter, and even the influence caused by the vibration of the vacuum chamber 4. This can greatly simplify the complexity of the interferometer.

[0070] like Figure 1 As shown, the support component 22 is further disposed on the outer wall of the vacuum chamber 4. Optionally, the support component 22 can be installed to the outer wall of the vacuum chamber 4 by welding or detachable connection. Optionally, when the support component 22 is detachably connected to the outer wall of the vacuum chamber 4, bolt connection, snap-fit, or adhesive bonding can be used. By using welding or detachable connection, the mechanical deformation and vibration caused by the additional support structure can be reduced, enhancing the stability of the collimation module 2; in addition, the support component 22 fixes the collimation module 2 to the vacuum chamber 4, reducing measurement errors caused by the vibration of the vacuum chamber 4.

[0071] like Figure 1 and Figure 3 As shown, the interference structure further includes: a support column 31, disposed within the vacuum chamber 4;

[0072] Interferometer group 32 is mounted on support column 31 to convert the received orthogonally polarized laser beam into measurement light and reference light;

[0073] The reflector section 33 is disposed on the device to be tested so as to reflect the measurement light into the interferometer group 32 and form an interference signal light with the reference light.

[0074] In some embodiments of this application, the interference mirror group 32 is placed inside the vacuum chamber 4, which reduces the influence of environmental factors on the propagation of the orthogonal linearly polarized laser beam, thereby reducing measurement errors and making the light propagation path of the orthogonal linearly polarized laser beam more stable in a vacuum environment.

[0075] Optionally, the support column 31 is disposed on the bottom surface of the vacuum chamber 4. The material of the support column 31 is selected to be a material with high rigidity, low expansion coefficient, high modality, and high stability. Specifically, the material of the support column 31 is indium steel.

[0076] By fixing the interferometer assembly 32 with the support column 31, the interferometer assembly 32 can remain stable even in high-frequency vibration or unstable working environments.

[0077] like Figure 1 and Figure 3 As shown, the support column 31 further includes a first support column and a second support column, wherein the extension direction of the first support column is perpendicular to the extension direction of the second support column.

[0078] There are at least two interferometer groups 32, and the two interferometer groups 32 are respectively disposed on the first support column and the second support column;

[0079] There are at least two reflector sections 33, which are arranged on the test piece in a one-to-one correspondence with the interference mirror group 32;

[0080] An intracavity beam splitter is provided between at least two interferometer groups 32 and the transmission component 5, and orthogonally polarized laser beams are incident into the interferometer groups 32 through the intracavity beam splitter.

[0081] In some embodiments of this application, the arrangement of the first support column and the second support column perpendicularly not only enables displacement measurement on multiple axes, but also makes full use of the space inside the vacuum chamber 4, and reduces interference between the two interferometer mirror groups 32.

[0082] Each interferometer group 32 corresponds to a reflecting mirror section 33. This arrangement ensures that the optical path difference between the measurement light and the reference light is minimized, thereby further reducing phase errors in interferometry and improving measurement accuracy and reliability. Simultaneously, placing the interferometer group 32 within the vacuum chamber 4 avoids the influence of air on the refractive index and reduces the impact of airflow disturbances on the beam detector surface, making the interferometer's measurement accuracy virtually unaffected by the medium.

[0083] The reflector part 33 is disposed on the test piece, enabling the interference structure to track the displacement change of the test piece in real time. Whether it is static displacement or dynamic displacement, continuous measurement data can be obtained. In addition, the reflector part 33 is closely related to the test piece. The reflection path of the measurement light directly reflects the real-time displacement of the test piece. At the same time, the path of the reference light remains constant, so that the interference signal of the reference light and the measurement light can accurately measure the displacement data.

[0084] like Figure 2 As shown, the interference mirror group 32 further includes: a corner cube mirror 321, a polarizing beam splitter 322, a quarter-wave plate 323, and a plane mirror 324;

[0085] The incident surface of the polarization beam splitter 322 has an incident light aperture and an exit light aperture. The orthogonal linearly polarized laser beam emitted from the collimation module 2 is irradiated by the incident light aperture, and the polarization beam splitter 322 splits the orthogonal linearly polarized laser beam into a measurement light and a reference light.

[0086] The measuring light is transmitted through a quarter-wave plate 323, a reflecting mirror 33, and a corner cube mirror 321 before being emitted through the exit light aperture; the reference light is transmitted through a quarter-wave plate 323, a plane reflecting mirror 324, and a corner cube mirror 321 before being emitted through the exit light aperture, and the measuring light and the reference light form an interference signal light at the exit light aperture.

[0087] Specifically, such as Figure 4 As shown, the orthogonally linearly polarized laser beam passes sequentially through polarizing beam splitter 322, quarter-wave plate 323, mirror section 33, quarter-wave plate 323, polarizing beam splitter 322, corner cube mirror 321, polarizing beam splitter 322, quarter-wave plate 323, plane mirror 324, quarter-wave plate 323, and polarizing beam splitter 322 to form measurement light.

[0088] Specifically, such as Figure 5 As shown, an orthogonally linearly polarized laser beam passes sequentially through a polarizing beam splitter 322, a quarter-wave plate 323, a plane mirror 324, a quarter-wave plate 323, a polarizing beam splitter 322, a corner cube mirror 321, a polarizing beam splitter 322, a quarter-wave plate 323, a plane mirror 324, a quarter-wave plate 323, and a polarizing beam splitter 322 to form a reference beam.

[0089] In this application, the interferometer group 32 is the simplest and most stable interference structure and optical path layout scheme. Since the reference light and the measurement light have the same transmission path length inside the interferometer group 32, and the only difference between the reference light and the measurement light is the optical path length of the reflector, the interferometer group 32 has high measurement stability and further reduces the space occupied by the interferometer group 32 in the vacuum chamber 4.

[0090] Preferably, the interferometer group 32 can be an N-axis mirror group to realize multi-degree-of-freedom displacement measurement, and its incident surface has N+1 small holes, one incident light hole, and N exit light holes.

[0091] like Figure 3 As shown, furthermore, the number of collimation module 2, fiber optic component 14, and transmission component 5 is at least two, and they are arranged in a one-to-one correspondence. Figure 3(Only the case where there are two collimation modules 2 is shown in the image). This arrangement allows the vacuum displacement measurement system to process multiple orthogonally polarized laser beams simultaneously, and each collimation module 2 and fiber component 14 corresponds to a transmission component 5. This arrangement reduces interference during the transmission of orthogonally polarized laser beams within the vacuum chamber 4, improves the quality of the orthogonally polarized laser beams and the accuracy of the measurement, and thus improves the accuracy when the measurement light and reference light form an interference signal.

[0092] In some embodiments, when there are two or more collimation modules 2, fiber optic components 14, and transmission components 5, the fiber optic component 14 is a one-to-many beam splitter. A single orthogonally linearly polarized laser beam is coupled into the coupling component 12, and after passing through the beam-splitting structure built into the fiber optic component 14, multiple orthogonally linearly polarized laser beams are split and transmitted to the two collimation modules 2. The two collimation modules 2 are respectively installed on the two side walls of the vacuum chamber 4, and their output optical axes are coaxial with the interferometer group 32 inside the vacuum chamber 4 to realize the transmission of optical signals inside and outside the vacuum chamber 4. Furthermore, setting multiple collimation modules 2 facilitates individual adjustment of the optical axis attitude and position, resulting in higher adjustment accuracy.

[0093] In other embodiments, the laser 11 and the collimation module 2 are aligned in a straight line, and the orthogonally polarized laser beam is spatial light and directly incident on the collimation module 2. For example... Figure 6 As shown, laser module 1 includes only laser 11 and carrier component 13. This arrangement simplifies coupling component 12 and fiber optic component 14, allowing the orthogonally polarized laser beam emitted by laser 11 to be directly received into collimation module 2, effectively reducing costs.

[0094] In some embodiments, the coupling component 12 is a multidimensional coupler, which can be adjusted for axial rotation, radial yaw, and radial pitch; and / or, the optical fiber component 14 is a polarization-maintaining optical fiber.

[0095] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0096] This application enables real-time monitoring and correction of measurement errors caused by factors such as laser 11 fluctuations and vacuum chamber 4 vibrations by setting a compensation optical path outside the vacuum chamber 4. In some embodiments of this application, the collimation module 2, interferometer group 32, and fiber optic component 14 can be arranged in multiple ways, forming a multi-channel measurement system, which improves the stability and reliability of the measurement system. The separate arrangement of laser module 1, collimation module 2, and interferometric processing module 3 can effectively utilize the limited space and reduce the volume of vacuum chamber 4.

[0097] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0098] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0099] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0100] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0101] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0102] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A vacuum displacement measurement system, characterized in that, include: A vacuum chamber (4) is provided to provide a vacuum environment. A transmission component (5) is provided on the vacuum chamber (4), and a test piece is placed inside it. A laser module (1) is located on the outside of the vacuum chamber (4) away from the vacuum chamber. The laser module (1) includes a laser (11) for generating orthogonally linearly polarized laser beams. Collimation module (2) is located on the outside of the vacuum chamber (4) to receive the orthogonally polarized laser beam emitted from the laser (11) and transmit the orthogonally polarized laser beam into the vacuum chamber (4) through the transmission component (5). The interference processing module (3) includes a signal processing component (34) located outside the vacuum chamber (4) and an interference structure located inside the vacuum chamber (4). The interference structure receives the orthogonally polarized laser beam and generates interference signal light with the object to be tested. The interference signal light is transmitted to the signal processing component (34) by an optical fiber. The collimation module (2) includes a beam splitter (24), and the compensation light split by the beam splitter (24) is transmitted to the signal processing unit (34) by optical fiber.

2. The vacuum displacement measurement system according to claim 1, characterized in that, The laser module (1) also includes: The coupling component (12) is used to couple the orthogonally linearly polarized laser beam; The carrier component (13) has a carrier surface, and the coupling component (12) and the laser (11) are both disposed on the carrier surface; An optical fiber component (14) is disposed on the coupling component (12) to collect the orthogonally polarized laser beam coupled by the coupling component (12).

3. The vacuum displacement measurement system according to claim 2, characterized in that, The collimation module (2) includes: Collimation component (21) is used to recover the orthogonal linearly polarized laser beam transmitted through the optical fiber component (14) and collimate the orthogonal linearly polarized laser beam to the target size. A beam adjustment component (23) is disposed between the collimation component (21) and the transmission component (5) to adjust the position and orientation of the collimated orthogonal linearly polarized laser beam; A support component (22) is disposed on the outside of the vacuum chamber (4). The support component (22) has a support surface. The collimating component (21), the beam adjustment assembly (23) and the beam splitter (24) are disposed on the support surface.

4. The vacuum displacement measurement system according to claim 3, characterized in that, The support component (22) is located on the outer wall of the vacuum chamber (4).

5. The vacuum displacement measurement system according to claim 1, characterized in that, The interference structure includes: A support column (31) is provided inside the vacuum chamber (4); An interferometer group (32) is mounted on the support column (31) to convert the received orthogonally polarized laser beam into measurement light and reference light; The reflector portion (33) is disposed on the test piece to reflect the measurement light into the interferometer group (32) and form the interference signal light with the reference light.

6. The vacuum displacement measurement system according to claim 5, characterized in that, The support column (31) includes a first support column and a second support column, wherein the extension direction of the first support column is perpendicular to the extension direction of the second support column; There are at least two interference mirror groups (32), and the two interference mirror groups (32) are respectively disposed on the first support column and the second support column; There are at least two reflector sections (33), which are disposed on the test piece in a one-to-one correspondence with the interference mirror group (32); An intracavity beam splitter is provided between at least two of the interferometer groups (32) and the transmission component (5), and the orthogonally polarized laser beams are incident into the interferometer groups (32) respectively through the intracavity beam splitter.

7. The vacuum displacement measurement system according to claim 5, characterized in that, The interference mirror assembly (32) includes: A corner cone (321), a polarizing beam splitter (322), a quarter-wave plate (323), and a plane mirror (324); The polarizing beam splitter (322) has an incident light aperture and an exit light aperture on its incident surface. The orthogonal linearly polarized laser beam emitted from the collimation module (2) is irradiated by the incident light aperture, and the polarizing beam splitter (322) splits the orthogonal linearly polarized laser beam into the measurement light and the reference light. The measurement light is transmitted through the quarter-wave plate (323), the mirror section (33), and the cornerstone (321) and then emitted through the exit aperture; the reference light is transmitted through the quarter-wave plate (323), the plane mirror (324), and the cornerstone (321) and then emitted through the exit aperture, and the measurement light and the reference light form the interference signal light in the exit aperture.

8. The vacuum displacement measurement system according to claim 2, characterized in that, The number of the collimation module (2), the optical fiber component (14), and the transmission component (5) is at least two, and they are arranged in a one-to-one correspondence.

9. The vacuum displacement measurement system according to claim 1, characterized in that, The laser (11) and the collimation module (2) are on a straight line, and the orthogonally polarized laser beam is spatial light and is directly incident into the collimation module (2).

10. The vacuum displacement measurement system according to claim 2, characterized in that, The coupling component (12) is a multi-dimensional coupler, which can be adjusted for axial rotation, radial yaw, and radial pitch; and / or, The optical fiber component (14) is a polarization-maintaining optical fiber.

Images