Diversity type laser vibration measurement optical system and multi-set type transmitting-receiving separation assembly

Abstract

The invention relates to a diversity type laser vibration measurement optical system and a multi-set type receiving and transmitting separation assembly, which can solve the problem that the signal to noise ratio of a signal is influenced by vibration signal distortion and signal burr caused by a laser speckle phenomenon. The diversity laser vibration measurement optical system comprises a heterodyne coherent light system, a transmit-receive optical system and a diversity balance detection system. The transmitting-receiving optical system is correspondingly arranged in a measuring light path of the heterodyne coherent light system, and the transmitting-receiving optical system is used for transmitting the measuring light and receiving the reflected receiving light. The diversity balance detection system is correspondingly arranged in a reference light path of the heterodyne coherent light system, and the diversity balance detection system comprises a balance detection plate and a frequency mixing light splitting assembly. The frequency mixing and light splitting assembly is used for carrying out frequency mixing and beam splitting processing on the receiving light and the reference light so as to form multiple paths of frequency mixing light. And the balance detection plate is used for carrying out balance detection on the multi-path frequency mixing light.

Description

Technical Field

[0001] This invention relates to the field of laser vibration measurement technology, and in particular to a diversity laser vibration measurement optical system and a multi-set transceiver separation component. Background Technology

[0002] While existing laser vibration measurement technology is relatively mature and can accurately measure the vibration information of objects within a certain range, and the use of balanced detection methods can effectively reduce noise and achieve a good signal-to-noise ratio for vibration signals, there are still some unfavorable factors in the vibration measurement process. For example, parasitic reflections from the end face can affect the demodulation of the balanced detection signal, and the laser coherence can cause laser speckle phenomenon due to optical path difference on rough surfaces, which can distort the vibration signal and produce burrs. These factors greatly affect the signal-to-noise ratio and effectiveness of laser vibration measurement.

[0003] However, existing optical systems for reducing or eliminating laser speckle are typically used in laser projection, not laser vibrometers. For example, Chinese utility model patent CN210954585U discloses a laser projection system for reducing laser speckle, which includes a laser array, a focusing array assembly, a homogenizing assembly, and a half-wave speckle reduction assembly placed between the laser array and the focusing array assembly. The half-wave speckle reduction assembly consists of half-wave plates and light-transmitting plates arranged at rectangular and annular intervals, respectively. A multi-angle atomizing diffuser with multiple atomization angles is provided on the output light path of the homogenizing assembly. While this effectively eliminates speckle and improves image quality by reducing the mutual interference between laser beams emitted from the laser array, the system is complex and difficult to implement to achieve the desired effect.

[0004] In addition, Chinese utility model patent CN213717246U discloses a speckle-eliminating line structured light laser, which includes an optical fiber and a micro-stroke vibration device. The moving parts of the micro-stroke vibration device generate an action to drive the optical fiber to move, thereby eliminating laser speckle. This eliminates the speckle phenomenon of the line structured light laser from the light source and improves the laser measurement performance. However, its applicability is relatively limited and cannot be applied to the field of laser vibration measurement technology. Summary of the Invention

[0005] One advantage of this invention is that it provides a diversity laser vibration optical system and a multi-set transceiver separation component, which can solve the problem of vibration signal distortion and signal glitches caused by laser speckle phenomenon due to laser interference, thereby affecting the signal-to-noise ratio.

[0006] Another advantage of the present invention is that it provides a diversity laser vibration measurement optical system and a multi-set transceiver separation component. In one embodiment of the present invention, the multi-set transceiver separation component can combine multiple receiving optical paths into a single detection optical path for laser vibration measurement while ensuring that the transmitting optical path and the receiving optical path are spatially separated from each other. This effectively reduces or even eliminates the influence of laser speckle on signal distortion and glitches, and improves the vibration signal-to-noise ratio.

[0007] Another advantage of the present invention is that it provides a diversity laser vibrometer optical system and a multi-set transceiver separation component. In one embodiment of the present invention, the multi-set transceiver separation component can achieve absolute isolation between the transmitting and receiving optical paths through a light shield, avoid crosstalk between the transmitting and receiving beams, and help eliminate parasitic scattering interference caused by lens scattering at the lens end.

[0008] Another advantage of the present invention is that it provides a diversity laser vibrometer optical system and a multi-channel transceiver separation component. In one embodiment of the present invention, the multi-channel transceiver separation component can realize simultaneous reception of multiple channels in order to reduce signal interruption and glitches caused by random signal attenuation due to laser coherent speckle effect.

[0009] Another advantage of the present invention is that it provides a diversity laser vibrometric optical system and a multi-channel transceiver separation component. In one embodiment of the present invention, the diversity laser vibrometric optical system can use multi-channel mixed light for balanced detection, which helps to reduce signal interruption and glitches caused by laser random speckle effect.

[0010] Another advantage of the present invention is that it provides a diversity laser vibrometric optical system and a multi-channel transceiver separation component. In one embodiment of the present invention, the diversity laser vibrometric optical system can use multiple optical paths for laser vibrometric measurement, so that even if one or more optical signals are distorted due to laser speckle, the other optical signals can still carry vibration information, thereby effectively eliminating the influence of laser speckle on signal distortion and glitches, and improving the signal-to-noise ratio of the vibration signal.

[0011] Another advantage of the present invention is that it provides a diversity laser vibration measurement optical system and a multi-set transceiver separation component. In one embodiment of the present invention, the diversity laser vibration measurement optical system can split the received light and the reference light into multiple mixed light to achieve diversity detection of the balanced detector, which helps to improve the vibration measurement effect.

[0012] Another advantage of this invention is that it provides a diversity laser vibrometric optical system and a multi-channel transceiver separation assembly, wherein, to achieve the above objectives, expensive materials or complex structures are not required. Therefore, this invention successfully and effectively provides a solution that not only offers a simple diversity laser vibrometric optical system and a multi-channel transceiver separation assembly, but also increases the practicality and reliability of said diversity laser vibrometric optical system and multi-channel transceiver separation assembly.

[0013] To achieve at least one of the above-mentioned advantages or other benefits and objectives of the present invention, the present invention provides a diversity laser vibrometer optical system, comprising:

[0014] A heterodyne coherent optical system, wherein the heterodyne coherent optical system has a mutually separate measurement optical path and a reference optical path for providing measurement light propagating along the measurement optical path and reference light propagating along the reference optical path;

[0015] A transceiver optical system, wherein the transceiver optical system is correspondingly disposed in the measurement optical path of the heterodyne coherent optical system, and the transceiver optical system has a transmitting optical path communicating with the measurement optical path and a receiving optical path opposite to the transmitting optical path, for transmitting the measurement light along the transmitting optical path and receiving the reflected receiving light along the receiving optical path; and

[0016] A diversity balanced detection system is provided, wherein the diversity balanced detection system is correspondingly disposed in the reference optical path of the heterodyne coherent optical system, and the diversity balanced detection system includes a balanced detection plate and a mixing and splitting assembly, wherein the mixing and splitting assembly is used to mix and split the received light received via the transceiver optical system and the reference light provided via the heterodyne coherent optical system to form multiple mixed beams, wherein the balanced detection plate is correspondingly disposed in the mixing and splitting optical path of the mixing and splitting assembly for balanced detection of the multiple mixed beams.

[0017] According to one embodiment of this application, the mixing and splitting assembly includes a mixing element and a splitting element, wherein the mixing element is located in the reference optical path of the heterodyne coherent optical system, and the mixing element is optically connected to the transceiver optical system for reflecting a portion of the received light and the reference light, and transmitting another portion of the received light and the reference light to form two mixed beams; wherein the splitting element is located on the reflection side or the transmission side of the mixing element for further splitting one mixed beam into two mixed beams.

[0018] According to one embodiment of this application, both the mixing element and the beam splitting element are semi-reflective and semi-transparent prisms.

[0019] According to one embodiment of this application, the two beam splitting elements are respectively disposed on the reflection side and the transmission side of the mixing element, and the two balanced detector plates are respectively corresponding to the reflection side and the transmission side of the mixing element.

[0020] According to one embodiment of this application, the transceiver optical system includes a multi-set transceiver separation component and a lens assembly. The multi-set transceiver separation component includes a multi-set receiving optics and a transmission channel passing through the multi-set receiving optics. The transmission channel is located in the measurement optical path of the heterodyne coherent optical system to define the transmission optical path of the transceiver optical system. The lens assembly is correspondingly disposed in the transmission optical path. The multi-set receiving optics is used to combine multiple parallel sub-receiver optical paths into a parent receiving optical path.

[0021] According to one embodiment of this application, the lens assembly includes a front lens group and a rear lens group, wherein the front lens group and the rear lens group are arranged coaxially in the emission optical path to form a Keplerian system with a focal point in the middle or a Galilean system without a focal point in the middle.

[0022] According to one embodiment of this application, the heterodyne coherent optical system includes a laser, a beam splitter, and a frequency shifter. The beam splitter is correspondingly disposed in the optical path between the laser and the transceiver optical system to split the laser emitted by the laser into a measurement beam that propagates along the measurement optical path and a reference beam that propagates along the reference optical path. The frequency shifter is correspondingly disposed in the reference optical path to perform frequency shifting processing on the reference beam that propagates along the reference optical path, so that the frequency-shifted reference beam propagates to the diversity balanced detection system.

[0023] According to one embodiment of this application, the heterodyne coherent optical system further includes a first reflective element and a second reflective element, wherein the first reflective element is disposed in the optical path between the laser and the beam splitter for reflecting the laser emitted via the laser to propagate to the beam splitter, and the second reflective element is disposed in the optical path between the beam splitter and the frequency shifter for reflecting the reference light split by the beam splitter to propagate to the frequency shifter.

[0024] According to one embodiment of this application, the first reflective element and the second reflective element are selected from an external reflective prism, an internal reflective prism, and a pentaprism.

[0025] According to another aspect of this application, this application further provides a multi-set transceiver separation component, comprising:

[0026] A multi-channel receiving optical device, wherein the multi-channel receiving optical device has multiple light-receiving surfaces for defining multiple sub-receiving optical paths, multiple anti-transmission functional surfaces, and a light-emitting surface for defining a parent receiving optical path, and the multiple anti-transmission functional surfaces are located between the multiple light-receiving surfaces and the light-emitting surface, for reflecting or transmitting the multiple sub-receiving optical paths to form a parent receiving optical path; and

[0027] A transmission channel, wherein the transmission channel extends through the multi-collection receiving optics and the central axis of the transmission channel is perpendicular to the multiple light-receiving surfaces of the multi-collection receiving optics, for defining a transmission optical path parallel to the sub-receiving optical path.

[0028] According to one embodiment of this application, the light-emitting surface of the multi-collector optical device is perpendicular to the plurality of light-receiving surfaces.

[0029] According to one embodiment of this application, the multi-channel receiving optical device comprises three beam-splitting prisms and three total internal reflection prisms arranged in an L-shape. One of the beam-splitting prisms provides a light-emitting surface and a light-reflecting surface, and the other two beam-splitting prisms respectively provide a light-receiving surface and a light-reflecting surface. The three total internal reflection prisms are respectively disposed on the sides of the three beam-splitting prisms to provide two light-emitting surfaces and three light-reflecting surfaces.

[0030] According to one embodiment of this application, the beam splitter is a semi-reflective semi-transparent prism, and the total internal reflection prism is a total internal reflection right-angle prism.

[0031] According to one embodiment of this application, the transmitting channel extends through the intersection between the plurality of receiving surfaces, so that the plurality of sub-receiving optical paths are located around the transmitting optical path.

[0032] According to one embodiment of this application, the multi-set transceiver separation assembly further includes a light shield disposed on the transmission channel to isolate the transmission optical path and the sub-receive optical path through the light shield. Attached Figure Description

[0033] Figure 1 This is a block diagram of a diversity laser vibrometer optical system according to an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the optical path of the diversity laser vibrometer optical system according to the above embodiment of the present invention is shown;

[0035] Figure 3 A schematic diagram of the optical path of the transceiver optical system in the diversity laser vibrometer optical system according to the above embodiment of the present invention is shown.

[0036] Figure 4 and Figure 5 Three-dimensional schematic diagrams from different perspectives are shown in the transceiver optical system according to the above embodiments of the present invention.

[0037] Explanation of key component symbols: 1. Diversity laser vibrometer optical system; 10. Heterodyne coherent optical system; 101. Measurement optical path; 102. Reference optical path; 11. Laser; 12. Beam splitter; 13. Frequency shifter; 14. First reflective element; 15. Second reflective element; 20. Transceiver optical system; 201. Transmitting optical path; 202. Receiving optical path; 2021. Sub-receiving optical path; 2022. Mother receiving optical path; 21. Multi-collection transceiver separation assembly; 211. Multi-collection receiving optics; 2101. Receiving surface; 2101a. First receiving surface; 2101b. Second receiving surface; 2101c. Third receiving surface; 2101d. Fourth receiving surface ; 2102, Anti-transmission functional surface; 2103, Light-emitting surface; 2111, Beam splitter prism; 2111a, First beam splitter prism; 2111b, Second beam splitter prism; 2111c, Third beam splitter prism; 2112, Total internal reflection prism; 2112a, First total internal reflection prism; 2112b, Second total internal reflection prism; 2112c, Third total internal reflection prism; 212, Emission channel; 213, Light shield; 22, Lens assembly; 221, Front mirror group; 222, Rear mirror group; 30, Diversity balance detection system; 31, Balance detection plate; 32, Mixing beam splitter assembly; 320, Mixing beam splitter optical path; 321, Mixing element; 322, Beam splitter element.

[0038] The above description of the main component symbols, together with the accompanying drawings and specific embodiments, provides a more detailed explanation of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] To address the problems in existing laser vibratory measurement technologies, such as laser speckle due to laser interference leading to vibration signal distortion and glitches, which in turn affect the signal-to-noise ratio, this application provides a diversity laser vibratory measurement optical system and a multi-set transceiver separation component. This system employs multi-channel mixed light for balanced detection, helping to reduce signal interruptions and glitches caused by random laser speckle effects and improving laser vibratory measurement performance. Furthermore, the multi-set transceiver separation component not only eliminates parasitic scattering interference caused by lens scattering at the lens end face through spatial separation of the receiving and transmitting light paths, but also further reduces signal interruptions and glitches caused by random signal attenuation due to laser coherent speckle effects through multi-set reception of echo signals.

[0043] Specifically, see the attached document. Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a diversity laser vibrometer optical system 1, which may include a heterodyne coherent optical system 10, a transceiver optical system 20, and a diversity balanced detection system 30. The heterodyne coherent optical system 10 has a mutually separate measurement optical path 101 and a reference optical path 102. The transceiver optical system 20 and the diversity balanced detection system 30 are respectively disposed in the measurement optical path 101 and the reference optical path 102 of the heterodyne coherent optical system 10, respectively, for providing measurement light propagating along the measurement optical path 101 and reference light propagating along the reference optical path 102. The transceiver optical system 20 has a transmission optical path 201 connected to the measurement optical path 101 and a receiving optical path 202 opposite to the transmission optical path 201, for emitting the measurement light from the transceiver optical system 20 to the object under test along the transmission optical path 201, and receiving the received light reflected back from the object under test along the receiving optical path 202. The diversity balanced detection system 30 includes a balanced detection plate 31 and a mixing and splitting component 32. The mixing and splitting component 32 is used to mix and split the received light received via the transceiver optical system 20 and the reference light provided via the heterodyne coherent optical system 10 to form multiple mixed beams. The balanced detection plate 31 is correspondingly disposed in the mixing and splitting optical path 320 of the mixing and splitting component 32 to perform balanced detection on the multiple mixed beams to achieve diversity balanced detection. This helps to reduce signal interruptions and glitches caused by laser random speckle effect and improve laser vibration measurement effect.

[0044] More specifically, such as Figure 2 As shown, the mixing and splitting component 32 of the diversity balanced detection system 30 of this application may include a mixing element 321 and a splitting element 322. The mixing element 321 is located in the reference optical path 102 of the heterodyne coherent optical system 10, and the mixing element 321 is optically connected to the transceiver optical system 20 to reflect a portion of the received light and the reference light, and transmit another portion of the received light and the reference light to form two mixed light paths. The splitting element 322 is located on the reflection side or the transmission side of the mixing element 321 and is used to split one mixed light path into two mixed light paths.

[0045] Preferably, both the mixing element 321 and the beam splitting element 322 of the mixing and beam splitting assembly 32 are implemented as semi-reflective and semi-transparent prisms, used to reflect half of the light and transmit the other half, so that the two split mixed beams are perpendicular to each other and have equal light energy. It is understood that in the above embodiments of this application, the semi-reflective and semi-transparent prism may, but is not limited to, consist of two right-angle prisms and a semi-reflective and semi-transparent film. In other examples of this application, the mixing element 321 and the beam splitting element 322 may also be implemented as other transparent substrates such as plane mirrors or prisms coated with a semi-reflective and semi-transparent film, which will not be elaborated further in this application.

[0046] Exemplary, in the above embodiments of this application, such as Figure 2 As shown, the mixing and splitting assembly 32 may include, but is not limited to, two splitting elements 322, one of which is correspondingly disposed on the reflective side of the mixing element 321, and the other is correspondingly disposed on the transmission side of the mixing element 321. Thus, the two splitting elements 322 will split the two mixed beams mixed by the mixing element 321 into four mixed beams of equal energy, and these four mixed beams are parallel to each other.

[0047] Accordingly, such as Figure 2As shown, the diversity balanced detection system 30 of this application includes two balanced detection plates 31, which correspond to the reflection side and transmission side of the mixer element 321, respectively, for receiving two parallel sub-mixed beams for balanced detection. It is understood that, compared to ordinary photodetectors, each balanced detection plate 31 of this application has at least two photodiodes, enabling excellent common-mode rejection ratio (CMRR), increasing signal amplitude, and reducing noise. This allows for the extraction of minute changes in the vibration signal from interference noise. Furthermore, subsequent signal conditioning reveals that the two differential signals (i.e., the two sub-mixed beams) exhibit signal discontinuities or glitches at different times in the field of view. This is caused by the random speckle effect of the laser, but it provides a basis for subsequent signal processing to address signal loss, intensity differences, and glitches, allowing for signal discrimination and selection to mitigate the effects of the speckle effect.

[0048] It is worth noting that in another example of this application, the mixing and splitting assembly 32 may also include one splitting element 322, wherein the splitting element 322 is correspondingly disposed on the reflection side or transmission side of the mixing element 321, for splitting the one mixed light beam mixed by the mixing element 321 into two sub-mixed light beams with equal light energy. In this case, the one mixed light beam and one sub-mixed light beam that are parallel to each other are received by the balance detection plate 31, and balance detection can still be performed. Of course, in other examples of this application, the mixing and splitting assembly 32 may also include three or more splitting elements 322 to further split one sub-mixed light beam into two sub-mixed light beams, thereby obtaining more pairs of sub-mixed light beams for the balance detection plate 31 to perform balance detection respectively. This application will not elaborate further on this.

[0049] Furthermore, the transceiver optical system 20 described in this application can be implemented as a transceiver system equipped with a Cassegrain system, or it can be implemented as a conventional transceiver system, as long as it can emit measurement light and receive echo light to provide the required receiving light for the diversity balanced detection system 30. This application will not elaborate further on this.

[0050] However, in order to further address the problem of vibration signal distortion and signal glitches caused by laser speckle, which in turn affect the signal-to-noise ratio, such as... Figure 1 and Figure 2As shown, the transceiver optical system 20 of this application may include a multi-set transceiver separation component 21 and a lens assembly 22. The multi-set transceiver separation component 21 may include a multi-set receiving optics 211 and a transmission channel 212 passing through the multi-set receiving optics 211. The transmission channel 212 is adapted to be located in the measurement optical path 101 of the heterodyne coherent optical system 10 to define the transmission optical path 201 of the transceiver optical system 20. The lens assembly 22 is correspondingly disposed in the transmission optical path 201.

[0051] At the same time, such as Figure 2 and Figure 3 As shown, the multi-channel receiving optics 211 is used to combine multiple parallel sub-receiving optical paths 2021 into a single parent receiving optical path 2022 to define the complete receiving optical path 202. It is also used to combine multiple received beams propagating along the multiple sub-receiving optical paths 2021 into a single received beam propagating along the parent receiving optical path 2022, which is then supplied to the diversity balanced detection system 30 for diversity balanced detection. It is understood that the receiving optical path 202 of the transceiver optical system 20 of this application consists of multiple sub-receiving optical paths 2021 and a parent receiving optical path 2022, and the multiple sub-receiving optical paths 2021 are preferably parallel to the transmitting optical path 201.

[0052] Specifically, such as Figure 2 and Figure 3 As shown, the multi-channel receiving optical device 211 may have multiple light-receiving surfaces 2101 for defining multiple sub-receiving optical paths 2021, multiple anti-transmission functional surfaces 2102, and a light-emitting surface 2103 for defining the parent receiving optical path 2022. The multiple light-receiving surfaces 2101 are perpendicular to the central axis of the transmitting channel 212, and the multiple anti-transmission functional surfaces 2102 are located between the multiple light-receiving surfaces 2101 and the light-emitting surface 2103, for reflecting or transmitting the sub-receiving optical paths 2021 to form a parent receiving optical path 2022. In other words, multiple received lights propagating along the multiple sub-receiving optical paths 2021 are reflected or transmitted through the corresponding light-receiving surfaces 2101 and then through the anti-transmission functional surfaces 2102 to synthesize a single received light propagating along the parent receiving optical path 2022, which is then used by the diversity balanced detection system 30 for diversity balanced detection. It is understood that the sub-receiving optical path 2021 mentioned in this application refers to the optical path perpendicular to the light-receiving surface 2101, and the mother receiving optical path 2022 refers to the optical path perpendicular to the light-emitting surface 2103. Furthermore, the anti-transmitting functional surface 2102 mentioned in this application can be a semi-reflective and semi-transmitting functional surface that reflects 50% of the light and transmits 50% of the light, or it can be a total internal reflection functional surface that reflects 100% of the light.

[0053] More specifically, the light-emitting surface 2103 of the multi-collector optical device 211 is perpendicular to the multiple light-receiving surfaces 2101, so that the received light propagating along the parent receiving optical path 2022 can be kept away from the transmitting optical path 201, thus avoiding crosstalk between the received light and the measurement light.

[0054] Exemplarily, in one example of this application, such as Figure 4 and Figure 5 As shown, the multi-channel receiving optical device 211 can be composed of three beam-splitting prisms 2111 and three total internal reflection prisms 2112. For ease of description, the three beam-splitting prisms 2111 are referred to as the first beam-splitting prism 2111a, the second beam-splitting prism 2111b, and the third beam-splitting prism 2111c, and the three total internal reflection prisms 2112 are referred to as the first total internal reflection prism 2112a, the second total internal reflection prism 2112b, and the third total internal reflection prism 2112c, respectively. The first beam splitter 2111a, the second beam splitter 2111b, and the third beam splitter 2111c are arranged in an L-shape. The first beam splitter 2111a provides the light-emitting surface 2103 and the anti-transmission functional surface 2102. The second beam splitter 2111b and the third beam splitter 2111c each provide a light-receiving surface 2101 and an anti-transmission functional surface 2102. The first total internal reflection prism 2112a, the second total internal reflection prism 2112b, and the third total internal reflection prism 2112c are respectively disposed on the sides of the first beam splitter 2111a, the second beam splitter 2111b, and the third beam splitter 2111c to provide an anti-transmission functional surface 2102. The second total internal reflection prism 2112b and the third total internal reflection prism 2112c each provide a light-receiving surface 2101. In this way, the received light transmitted from each of the light-receiving surfaces 2101 will pass through two or more of the anti-transmission functional surfaces 2102 in succession to propagate to the light-emitting surface 2103 for convergence, thus forming a single received light path that propagates along the parent received light path 2022.

[0055] Preferably, the beam splitter 2111 is implemented as a semi-reflective and semi-transparent prism, and the total internal reflection prism 2112 is implemented as a total internal reflection right-angle prism.

[0056] In other words, such as Figure 4 and Figure 5As shown, taking the first light-receiving surface 2101a, the second light-receiving surface 2101b, the third light-receiving surface 2101c, and the fourth light-receiving surface 2101d as examples, respectively corresponding to the second beam splitter prism 2111b, the third beam splitter prism 2111c, the second total internal reflection prism 2112b, and the third total internal reflection prism 2112c: one path of received light incident from the first light-receiving surface 2101a is first partially transmitted by the second beam splitter prism 2111b, and then partially reflected by the first beam splitter prism 2111a to exit from the light-emitting surface 2103; one path of received light incident from the second light-receiving surface 2101b is first partially transmitted by the third beam splitter prism 2111c, and then partially reflected by the first total internal reflection prism 2112a. The light received from the third light-receiving surface 2101c is first totally reflected by the second totally reflecting prism 2112b, then partially transmitted by the second beam splitter prism 2111b, and finally partially reflected by the first beam splitter prism 2111a to exit from the light-emitting surface 2103; the light received from the fourth light-receiving surface 2101d is first totally reflected by the third totally reflecting prism 2112c, then partially transmitted by the third beam splitter prism 2111c, then totally reflected by the first totally reflecting prism 2112a, and finally partially transmitted by the first beam splitter prism 2111a to exit from the light-emitting surface 2103. In this way, the energy ratio of each received light before and after entering and exiting the multi-collector optical device 211 is 4:1, so that the energy of the converged received light basically contains one-quarter of the received light incident from each of the light-collecting surfaces 2101, which helps to reduce signal interruption and glitches caused by random signal attenuation due to laser coherent speckle effect.

[0057] It is understood that in other examples of this application, the multi-channel receiving optical device 211 may also consist of two beam-splitting prisms 2111 and one total internal reflection prism 2112 to converge two received beams into one received beam; or the multi-channel receiving optical device 211 may include a greater number of beam-splitting prisms 2111 and total internal reflection prisms 2112 to converge more received beams into one received beam, which will not be elaborated further in this application. Furthermore, since the multi-channel receiving optical device 211 of this application can receive multiple received beams from different regions for balanced detection, it is equivalent to simultaneously using multiple beams for laser vibration measurement. Therefore, even if some beams exhibit laser speckle and cause signal distortion, other beams will still carry vibration information, thereby effectively eliminating the influence of laser speckle on signal distortion and glitches, and improving the signal-to-noise ratio of the vibration signal.

[0058] According to the above embodiments of this application, as Figure 5As shown, the transmitting channel 212 of the multi-group transceiver separation component 21 preferably passes through the intersection between the multiple light-receiving surfaces 2101, so that the multiple light-receiving surfaces 2101 are located around the transmitting channel 212. That is, the multiple sub-receiving optical paths 2021 are located around the transmitting optical path 201, so as to collect the received light reflected back by the object under test from all directions.

[0059] More preferably, such as Figures 3 to 5 As shown, the multi-set transceiver separation component 21 further includes a light shield 213 disposed in the transmission channel 212, so as to achieve absolute isolation between the transmission optical path 201 and the receiving optical path 202 through the light shield 213, avoid crosstalk between the transmitted and received beams, help eliminate parasitic scattering interference caused by lens scattering light at the lens end, and better achieve the transceiver separation effect.

[0060] Optionally, the light shield 213 may be made of, but is not limited to, a light-absorbing material such as a high-absorption plastic material for the laser band or anodized black aluminum. For example, the light shield 213 may be implemented as a hollow tube made of a black material, and the light shield 213 penetrates the multi-set receiving optics 211, allowing measurement light to pass through the light shield 213 for emission. It is understood that the emission channel 212 of the multi-set transceiver separation assembly 21 may be implemented as a light channel formed by an air medium within the light shield 213, or as a light channel formed by a light-transmitting medium such as a glass medium placed within the light shield 213.

[0061] It is worth noting that, such as Figure 2 and Figure 3 As shown, the lens assembly 22 of the transceiver optical system 20 of this application may include a front lens group 221 and a rear lens group 222 coaxially arranged in the transmitting optical path 201. The front lens group 221 and the rear lens group 222 are correspondingly arranged to form a Kepler system with a central focal point. By adjusting the distance between the front lens group 221 and the rear lens group 222, the measurement light passing through the transmitting channel 212 can be focused at different distances, improving its vibration measurement range. Simultaneously, the received light, after passing through the front lens group 221 and the rear lens group 222, is received and coupled by the multi-beam receiving optics 211, thereby achieving a lens-compatible transceiver separation function and realizing multi-beam receiving light coupling to reduce the probability of speckle effect. It is understood that the lens assembly 22 may further provide an aperture stop at the focal point between the front lens group 221 and the rear lens group 222 to eliminate stray light.

[0062] It is understood that in other examples of this application, the front mirror group 221 and the rear mirror group 222 can also be arranged accordingly to form a Galilean system with no central focus, which can still achieve focusing of the measurement light at different distances. This application will not elaborate further on this.

[0063] Furthermore, the front lens group 221 and the rear lens group 222 of this application may be composed of one or more lenses, and the lenses may include at least spherical or aspherical lenses. For example, the front lens group 221 or the rear lens group 222 may be implemented as a single lens to modulate the measuring light and multiple receiving lights correspondingly using different regions of the lens; or the front lens group 221 or the rear lens group 222 may be implemented as a combination of multiple local lenses coaxially joined together to modulate the measuring light and multiple receiving lights correspondingly through different local lenses, which will not be elaborated further in this application.

[0064] According to the above embodiments of this application, as Figure 1 and Figure 2 As shown, the heterodyne coherent optical system 10 of the diversity laser vibrometer optical system 1 may include a laser 11 for emitting laser light, a beam splitter 12, and a frequency shifter 13. The beam splitter 12 is correspondingly disposed in the optical path between the laser 11 and the transceiver optical system 20, and is used to split the laser light emitted via the laser 11 into a measurement light propagating along the measurement optical path 101 and a reference light propagating along the reference optical path 102, so that the measurement light propagates to the transceiver optical system 20. The frequency shifter 13 is correspondingly disposed in the reference optical path 102 of the heterodyne coherent optical system 10, and is used to perform frequency shifting processing on the reference light propagating along the reference optical path 102, thereby allowing the frequency-shifted reference light to propagate to the diversity balanced detection system 30.

[0065] Optionally, the laser 11 described in this application may be used, but is not limited to, to emit a line laser with a wavelength of 632.8 nm. Alternatively, the laser 11 may also be used to emit various lasers in other visible or infrared spectra.

[0066] Optionally, the beam splitter 12 of this application is used to split the measurement light and the reference light into beams with different power ratios. For example, the beam splitting ratio of the beam splitter 12 can be, but is not limited to, 99:1, 90:10, or 80:20, etc.

[0067] Optionally, the frequency shifter 13 of this application may use a single device with different carrier frequencies, or it may use two or more devices for differential adjustment, thereby helping to reduce carrier frequency interference in the Doppler signal frequency spectrum.

[0068] It is worth noting that, such as Figure 2 As shown, the heterodyne coherent optical system 10 according to the above embodiments of this application may further include a first reflective element 14, wherein the first reflective element 14 is disposed in the optical path between the laser 11 and the beam splitter 12, for reflecting the laser emitted by the laser 11 to propagate to the beam splitter 12, thereby deflecting the optical path between the laser 11 and the beam splitter 12, which facilitates improving the compactness of the structure of the heterodyne coherent optical system 10.

[0069] In addition, such as Figure 2 As shown, the heterodyne coherent optical system 10 may further include a second reflective element 15, wherein the second reflective element 15 is disposed in the optical path between the beam splitter 12 and the frequency shifter 13, for reflecting the reference light split by the beam splitter 12 to propagate to the frequency shifter 13, thereby deflecting the optical path between the laser 11 and the beam splitter 12, which facilitates further improvement in the compactness of the structure of the heterodyne coherent optical system 10 and reduces its volume.

[0070] Optionally, the first reflective element 14 and the second reflective element 15 may be implemented as optical devices such as external reflective prisms, internal reflective prisms or pentaprisms for 90° turning optical paths.

[0071] It is worth noting that, in the above embodiments of this application, such as Figure 2 As shown, the mixing element 321 of the diversity balanced detection system 30 is preferably located at the intersection between the reference optical path 102 of the heterodyne coherent optical system 10 and the receiving optical path 202 of the transceiver optical system 20, and the reference light from the heterodyne coherent optical system 10 and the receiving light from the transceiver optical system 20 are perpendicular to each other at the mixing element 321 so that they are mixed by the mixing element 321 and split into two mixed light beams.

[0072] It is understood that although the diversity laser vibrometer optical system 1 described in the above embodiments of this application uses spatial light to achieve optical transmission between systems and between components within a system, this is merely an example. In other examples of this application, the heterodyne coherent optical system 10 and the diversity balanced detection system 30 in the diversity laser vibrometer optical system 1 can also achieve optical transmission through all-fiber or partially-fiber optical fibers, while still achieving the aforementioned effects and advantages of this application. For example, the received light received by the transceiver optical system 20 can be transmitted through an optical fiber to the mixing element 321 of the diversity balanced detection system 30 for mixing, which facilitates greater flexibility in the positional arrangement between the transceiver optical system 20 and the diversity balanced detection system 30.

[0073] It is worth mentioning that, according to another aspect of this application, such as Figures 3 to 5 As shown, this application further provides a multi-set transceiver separation component 21, which may include a multi-set receiving optics 211 and a transmitting channel 212. The multi-set receiving optics 211 has multiple light-receiving surfaces 2101 for defining multiple sub-receiving optical paths 2021, multiple anti-transmission functional surfaces 2102, and a light-emitting surface 2103 for defining a parent receiving optical path 2022. The multiple anti-transmission functional surfaces 2102 are located between the multiple light-receiving surfaces 2101 and the light-emitting surface 2103, and are used to reflect or transmit the multiple sub-receiving optical paths 2021 to form a parent receiving optical path 2022. The transmitting channel 212 passes through the multi-set receiving optics 211, and the central axis of the transmitting channel 212 is perpendicular to the multiple light-receiving surfaces 2101 of the multi-set receiving optics 211, and is used to define a transmitting optical path 201 parallel to the sub-receiving optical paths 2021. It is understood that other structural features of the multi-set transceiver separation component 21 described in this application can be referred to the multi-set transceiver separation component in the diversity laser vibrometer optical system 1 described above, and will not be repeated here.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A diversity laser vibrometer optical system, characterized in that, include: A heterodyne coherent optical system, wherein the heterodyne coherent optical system has a mutually separate measurement optical path and a reference optical path for providing measurement light propagating along the measurement optical path and reference light propagating along the reference optical path; A transceiver optical system, wherein the transceiver optical system is correspondingly disposed in the measurement optical path of the heterodyne coherent optical system, and the transceiver optical system has an emission optical path communicating with the measurement optical path and a receiving optical path opposite to the emission optical path, for emitting the measurement light along the emission optical path and receiving the reflected light along the receiving optical path; as well as A diversity balanced detection system is provided, wherein the diversity balanced detection system is correspondingly disposed in the reference optical path of the heterodyne coherent optical system, and the diversity balanced detection system includes a balanced detection plate and a mixing and splitting assembly, wherein the mixing and splitting assembly is used to mix and split the received light received via the transceiver optical system and the reference light provided via the heterodyne coherent optical system to form multiple mixed beams, wherein the balanced detection plate is correspondingly disposed in the mixing and splitting optical path of the mixing and splitting assembly for balanced detection of the multiple mixed beams.

2. The diversity laser vibrometer optical system as described in claim 1, characterized in that, The mixing and splitting assembly includes a mixing element and a splitting element. The mixing element is located in the reference optical path of the heterodyne coherent optical system and is optically connected to the transceiver optical system. It is used to reflect a portion of the received light and the reference light and transmit another portion of the received light and the reference light to form two mixed beams. The splitting element is located on the reflection side or the transmission side of the mixing element and is used to further split one mixed beam into two mixed beams.

3. The diversity laser vibrometer optical system as described in claim 2, characterized in that, Both the mixing element and the beam splitting element are semi-reflective and semi-transparent prisms.

4. The diversity laser vibrometer optical system as described in claim 3, characterized in that, The two beam splitting elements are respectively disposed on the reflection side and the transmission side of the mixing element, and the two balanced detector plates are respectively corresponding to the reflection side and the transmission side of the mixing element.

5. The diversity laser vibrometer optical system as described in any one of claims 1 to 4, characterized in that, The transceiver optical system includes a multi-set transceiver separation component and a lens assembly. The multi-set transceiver separation component includes a multi-set receiving optics and a transmission channel passing through the multi-set receiving optics. The transmission channel is located in the measurement optical path of the heterodyne coherent optical system to define the transmission optical path of the transceiver optical system. The lens assembly is correspondingly disposed in the transmission optical path. The multi-set receiving optics is used to combine multiple parallel sub-receiver optical paths into a parent receiving optical path.

6. The diversity laser vibrometer optical system as described in claim 5, characterized in that, The lens assembly includes a front lens group and a rear lens group, wherein the front lens group and the rear lens group are arranged coaxially in the emission optical path to form a Keplerian system with a focal point in the middle or a Galilean system without a focal point in the middle.

7. The diversity laser vibrometer optical system as described in any one of claims 1 to 4, characterized in that, The heterodyne coherent optical system includes a laser, a beam splitter, and a frequency shifter. The beam splitter is correspondingly disposed in the optical path between the laser and the transceiver optical system to split the laser emitted by the laser into a measurement beam that propagates along the measurement optical path and a reference beam that propagates along the reference optical path. The frequency shifter is correspondingly disposed in the reference optical path to perform frequency shifting processing on the reference beam that propagates along the reference optical path, so that the frequency-shifted reference beam propagates to the diversity balanced detection system.

8. The diversity laser vibrometer optical system as described in claim 7, characterized in that, The heterodyne coherent optical system further includes a first reflective element and a second reflective element, wherein the first reflective element is disposed in the optical path between the laser and the beam splitter for reflecting the laser emitted by the laser to propagate to the beam splitter, and the second reflective element is disposed in the optical path between the beam splitter and the frequency shifter for reflecting the reference light split by the beam splitter to propagate to the frequency shifter.

9. The diversity laser vibrometer optical system as described in claim 8, characterized in that, The first reflective element and the second reflective element are selected from one of an external reflective prism, an internal reflective prism, and a pentaprism.

10. A multi-unit transceiver separation component, characterized in that, include: A multi-collector optical device, wherein the multi-collector optical device has multiple light-receiving surfaces for defining multiple sub-receiving optical paths, multiple anti-transmission functional surfaces, and a light-emitting surface for defining a parent receiving optical path, and the multiple anti-transmission functional surfaces are located between the multiple light-receiving surfaces and the light-emitting surface, for reflecting or transmitting multiple sub-receiving optical paths to form a parent receiving optical path; and A transmission channel, wherein the transmission channel extends through the multi-collection receiving optics and the central axis of the transmission channel is perpendicular to the multiple light-receiving surfaces of the multi-collection receiving optics, for defining a transmission optical path parallel to the sub-receiving optical path.

11. The multi-set transceiver separation component as described in claim 10, characterized in that, The light-emitting surface of the multi-collector optical device is perpendicular to the multiple light-receiving surfaces.

12. The multi-set transceiver separation component as described in claim 11, characterized in that, The multi-channel receiving optical device consists of three beam-splitting prisms and three total internal reflection prisms arranged in an L-shape. One of the beam-splitting prisms provides a light-emitting surface and a light-receiving surface, and the other two beam-splitting prisms each provide a light-receiving surface and a light-receiving surface. The three total internal reflection prisms are respectively disposed on the sides of the three beam-splitting prisms to provide two light-emitting surfaces and three light-receiving surfaces.

13. The multi-set transceiver separation component as described in claim 12, characterized in that, The beam splitter is a semi-reflective, semi-transparent prism, and the total internal reflection prism is a total internal reflection right-angle prism.

14. The multi-set transceiver separation component as described in any one of claims 10 to 13, characterized in that, The transmitting channel extends through the intersection between the multiple receiving surfaces, so that the multiple sub-receiving optical paths are located around the transmitting optical path.

15. The multi-set transceiver separation component as described in any one of claims 10 to 13, characterized in that, The multi-set transceiver separation assembly further includes a light shield disposed in the transmission channel to isolate the transmission optical path and the sub-receive optical path through the light shield.

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