Diversity laser vibrometer optical system and multi-set transceiver separation component

Abstract

The present invention relates to a diversity laser vibrometer optical system and a multi-collection transceiver separation component, which can solve the problem of vibration signal distortion and signal glitches caused by laser speckle phenomenon, thereby affecting the signal-to-noise ratio. The diversity laser vibrometer optical system includes a heterodyne coherent optical system, a transceiver optical system and a diversity balanced detection system. The transceiver optical system is correspondingly arranged in the measurement optical path of the heterodyne coherent optical system, and the transceiver optical system is used to transmit the measurement light and receive the reflected received light. The diversity balanced detection system is correspondingly arranged in the reference optical path of the heterodyne coherent optical system, and the diversity balanced detection system includes a balanced detection board and a mixing and splitting component. The mixing and splitting component is used to mix and split the received light and the reference light to form multi-channel mixed light. The balanced detection board is used to perform balanced detection on the multi-channel mixed light.

Description

Technical Field

[0001] The present invention relates to the technical field of laser vibration measurement, in particular to a diversified laser vibration measurement optical system and a multi-set transceiver separation component. Background Art

[0002] Although existing laser vibrometer 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, resulting in a better signal-to-noise ratio of the vibration signal; however, there are also some unfavorable factors in the vibration measurement process, such as parasitic reflections at the end face that affect the demodulation of the balanced detection signal, and laser speckle caused by the optical path difference on the rough surface due to laser coherence, which distorts the vibration signal and causes burrs. All of these greatly affect the signal-to-noise ratio and effect of laser vibrometer measurement.

[0003] However, existing optical systems designed to reduce or eliminate 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. The system comprises a laser array, a focusing array assembly, a light homogenizing assembly, and a half-wave speckle reduction assembly positioned between the laser array and the focusing array assembly. The half-wave speckle reduction assembly comprises half-wave plates and light-transmitting plates arranged in rectangular and annular arrays, respectively. Furthermore, a multi-angle atomizing diffuser with various atomization angles is positioned in the output light path of the light homogenizing assembly. While this system effectively eliminates speckle and improves imaging quality by reducing mutual interference between the laser beams emitted by the laser array, the system is relatively complex and difficult to achieve the desired effect.

[0004] Furthermore, Chinese utility model patent CN213717246U discloses a speckle-eliminating line structured light laser. The device comprises an optical fiber and a micro-stroke vibration device. The micro-stroke vibration device utilizes a moving component to generate movement, thereby driving the optical fiber to eliminate laser speckle. This eliminates the speckle phenomenon of the line structured light laser from the light source, improving laser measurement performance. However, its applicability is relatively limited and cannot be applied to the field of laser vibrometer technology. Summary of the Invention

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

[0006] Another advantage of the present invention is that it provides a distributed laser vibrometer optical system and a multi-collection transceiver separation component. In one embodiment of the present invention, the multi-collection transceiver separation component can, while ensuring spatial separation between the transmitting optical path and the receiving optical path, combine multiple receiving optical paths into a single detection optical path for laser vibrometer measurement, thereby effectively reducing or even eliminating the effects of laser speckle on signal distortion and glitches, thereby improving the vibration signal-to-noise ratio.

[0007] Another advantage of the present invention is that it provides a distributed laser vibrometer optical system and a multi-collection transceiver separation component. In one embodiment of the present invention, the multi-collection transceiver separation component can achieve absolute isolation between the transmitting light path and the receiving light path through a light shield, thereby avoiding crosstalk between the transmitting and receiving light beams, and helping to eliminate parasitic scattering interference caused by lens scattered light agent at the lens end.

[0008] Another advantage of the present invention is that it provides a diversified laser vibrometer optical system and a multi-collection transceiver separation component. In one embodiment of the present invention, the multi-collection transceiver separation component can achieve multi-channel synchronous reception to reduce signal discontinuities and glitches caused by random signal attenuation due to the laser coherent speckle effect.

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

[0010] Another advantage of the present invention is that it provides a diversified laser vibrometer optical system and a multi-channel transceiver separation component. In one embodiment of the present invention, the diversified laser vibrometer optical system can use multiple light channels for laser vibrometer measurement. This allows the optical signals of the other channels to still carry vibration information even if one or more of the optical signals are distorted due to the presence of laser speckle. This effectively eliminates the effects of laser speckle on signal distortion and glitches, thereby improving the signal-to-noise ratio of the vibration signal.

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

[0012] Another advantage of the present invention is that it provides a diversified laser vibrometer system and a multi-assembly transmitter-receiver splitter assembly that achieves the aforementioned objectives without the need for expensive materials or complex structures. Thus, the present invention successfully and effectively provides a solution that not only provides a simple diversified laser vibrometer system and a multi-assembly transmitter-receiver splitter assembly, but also increases the practicality and reliability of the diversified laser vibrometer system and the multi-assembly transmitter-receiver splitter assembly.

[0013] In order to achieve at least one of the above advantages or other advantages and purposes of the present invention, the present invention provides a diversified laser vibrometer optical system, comprising:

[0014] A heterodyne coherent optical system, wherein the heterodyne coherent optical system has a measurement optical path and a reference optical path separated from each other, for providing a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path;

[0015] a transceiver optical system, wherein the transceiver optical system is correspondingly arranged in the measuring optical path of the heterodyne coherent optical system, and the transceiver optical system has a transmitting optical path connected to the measuring optical path and a receiving optical path opposite to the transmitting optical path, and is used to transmit the measuring light along the transmitting optical path and receive the reflected received light along the receiving optical path; and

[0016] A diversity balanced detection system, wherein the diversity balanced detection system is correspondingly arranged in the reference optical path of the heterodyne coherent optical system, and the diversity balanced detection system includes a balanced detection board and a mixing and splitting component, wherein the mixing and splitting component 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 multi-path mixed light, wherein the balanced detection board is correspondingly arranged in the mixing and splitting optical path of the mixing and splitting component for performing balanced detection on the multi-path mixed light.

[0017] According to one embodiment of the present application, the mixing and splitting component 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 can be optically connected to the transceiver optical system, and is used to reflect a part of the received light and the reference light, and transmit the other part of the received light and the reference light to form two paths of mixed light; wherein the splitting element is located on the reflection side or the transmission side of the mixing element, and is used to further split one path of mixed light into two paths of mixed light.

[0018] According to an embodiment of the present application, the frequency mixing element and the light splitting element are both semi-reflective and semi-transparent prisms.

[0019] According to an embodiment of the present application, the two light splitting elements are respectively arranged on the reflection side and the transmission side of the frequency mixing element, and the two balanced detection boards respectively correspond to the reflection side and the transmission side of the frequency mixing element.

[0020] According to one embodiment of the present application, the transceiver optical system includes a multi-set transceiver separation component and a lens component, wherein the multi-set transceiver separation component includes a multi-set receiving optical device and a transmission channel running through the multi-set receiving optical device, and 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, wherein the lens component is correspondingly arranged in the transmission optical path, and the multi-set receiving optical device is used to combine multiple mutually parallel sub-receiving optical paths into a mother receiving optical path.

[0021] According to one embodiment of the present 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 coaxially arranged in the emission light path to form an intermediate focused Keplerian system or an intermediate afocal Galilean system.

[0022] According to one embodiment of the present application, the heterodyne coherent optical system includes a laser, a beam splitter and a frequency shifter, wherein the beam splitter is correspondingly arranged in the optical path between the laser and the transceiver optical system, and is used to split the laser emitted by the laser into the measurement light propagating along the measurement optical path and the reference light propagating along the reference optical path, wherein the frequency shifter is correspondingly arranged in the reference optical path, and is used to perform frequency shift processing on the reference light propagating along the reference optical path, so that the reference light after frequency shifting is propagated to the diversity balanced detection system.

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

[0024] According to one embodiment of the present application, 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.

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

[0026] A multi-collection receiving optical device, wherein the multi-collection receiving optical device has a plurality of light-receiving surfaces for defining a plurality of sub-receiving light paths, a plurality of reflective functional surfaces, and a light-emitting surface for defining a main receiving light path, and the plurality of reflective functional surfaces are located between the plurality of light-receiving surfaces and the light-emitting surface, and are used to reflect or transmit the plurality of sub-receiving light paths to form a main receiving light path; and

[0027] An emission channel, wherein the emission channel runs through the multi-set receiving optical device, and the central axis of the emission channel is perpendicular to the multiple light-receiving surfaces of the multi-set receiving optical device, and is used to define an emission light path parallel to the sub-receiving light path.

[0028] According to one embodiment of the present application, the light-emitting surface of the multi-collection receiving optical device is perpendicular to the multiple light-receiving surfaces.

[0029] According to one embodiment of the present application, the multi-collection receiving optical device is composed of three beam splitting prisms and three total reflection prisms arranged in an L shape, wherein one of the beam splitting prisms provides a light-emitting surface and one of the reflective functional surfaces, and the other two beam splitting prisms respectively provide a light-receiving surface and one of the reflective functional surfaces, wherein the three total reflection prisms are respectively arranged on the sides of the three beam splitting prisms to provide two light-emitting surfaces and three reflective functional surfaces.

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

[0031] According to one embodiment of the present application, the emission channel passes through the intersection between the multiple light-receiving surfaces, so that the multiple sub-receiving light paths are located around the emission light path.

[0032] According to one embodiment of the present application, the multi-set transmit-receive separation component further includes a light shield disposed on the transmit channel, so as to isolate the transmit optical path and the sub-receive optical path through the light shield. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic 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 Schematic diagrams of three-dimensional views of the multi-set transceiver separation components in the transceiver optical system according to the above embodiment of the present invention are respectively shown.

[0037] Explanation of the main component symbols: 1. Diversified 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 optical device; 2101. Light-receiving surface; 2101a. First light-receiving surface; 2101b. Second light-receiving surface; 2101c. Third light-receiving surface; 2101d. Fourth light-receiving surface ; 2102, anti-transmission functional surface; 2103, light-emitting surface; 2111, spectroscopic prism; 2111a, first spectroscopic prism; 2111b, second spectroscopic prism; 2111c, third spectroscopic prism; 2112, total reflection prism; 2112a, first total reflection prism; 2112b, second total reflection prism; 2112c, third total reflection prism; 212, emission channel; 213, light shield; 22, lens assembly; 221, front mirror group; 222, rear mirror group; 30, diversity balanced detection system; 31, balanced detection board; 32, mixing spectroscopic assembly; 320, mixing spectroscopic optical path; 321, mixing element; 322, spectroscopic element.

[0038] The above description of the main component symbols is combined with the accompanying drawings and specific embodiments to further illustrate the present invention in detail. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present 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 problem in existing laser vibrometer technology of laser speckle interference causing vibration signal distortion and glitches, which in turn affects the signal-to-noise ratio, the present application provides a diversified laser vibrometer optical system and a multi-collection transceiver separation assembly. These systems utilize multi-channel mixed-frequency light for balanced detection, helping to reduce signal discontinuities and glitches caused by the random laser speckle effect, thereby improving the effectiveness of laser vibrometer measurement. Furthermore, the multi-collection transceiver separation assembly not only eliminates parasitic scattering interference caused by lens scattering at the lens end face by spatially separating the transceiver and light paths, but also further reduces signal discontinuities and glitches caused by random signal attenuation due to the coherent laser speckle effect through multi-collection reception of echo signals.

[0043] Specifically, refer to the attached Figure 1 and Figure 2 As shown, one 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 measurement optical path 101 and a reference optical path 102, which are separated from each other. 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, and are configured to provide 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 transmitting optical path 201 connected to the measurement optical path 101 and a receiving optical path 202 opposite to the transmitting optical path 201. The system is configured to transmit the measurement light from the transceiver optical system 20 to the object under test along the transmitting optical path 201 and receive the received light reflected from the object under test along the receiving optical path 202. The diversity balanced detection system 30 includes a balanced detection board 31 and a frequency mixing and splitting component 32, wherein the frequency 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 multi-path mixed light; wherein the balanced detection board 31 is correspondingly arranged in the frequency mixing and splitting optical path 320 of the frequency mixing and splitting component 32 to perform balanced detection on the multi-path mixed light to achieve diversity balanced detection, which helps to reduce signal discontinuity and burr problems caused by the random speckle effect of the laser and improve the laser vibration measurement effect.

[0044] More specifically, if Figure 2 As shown, the mixing and splitting component 32 of the diversity balanced detection system 30 of the present application may include a mixing element 321 and a splitting element 322, wherein the mixing element 321 is located in the reference optical path 102 of the heterodyne coherent optical system 10, and the mixing element 321 can be optically connected to the transceiver optical system 20, and is used to reflect a part of the received light and the reference light, and transmit another part of the received light and the reference light to form two paths of mixed light; wherein 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 path of mixed light into two paths of mixed light.

[0045] Preferably, the mixing element 321 and the spectroscopic element 322 of the mixing and spectroscopic component 32 are both implemented as semi-reflective and semi-transparent prisms, which are used to reflect half of the light and transmit the other half of the light, so that the two paths of mixed light are perpendicular to each other and have equal light energy. It can be understood that in the above embodiments of the present application, the semi-reflective and semi-transparent prisms can be, but are not limited to, composed of two right-angle prisms and a semi-reflective and semi-transparent film. In other examples of the present application, the mixing element 321 and the spectroscopic element 322 can also be implemented as light-transmitting substrates of other shapes such as plane mirrors or prisms coated with semi-reflective and semi-transparent films, which will not be described in detail in this application.

[0046] For example, in the above embodiments of the present application, Figure 2 As shown, the mixing and splitting component 32 may include, but is not limited to, two splitting elements 322, one of which is correspondingly disposed on the reflection side of the mixing element 321, and the other of which is correspondingly disposed on the transmission side of the mixing element 321. Thus, the two splitting elements 322 split the two mixed light paths mixed by the mixing element 321 into four mixed light paths with equal optical energy, and the four mixed light paths are parallel to each other.

[0047] Accordingly, if Figure 2As shown, the diversity balanced detection system 30 of the present application includes two balanced detection boards 31, and the two balanced detection boards 31 correspond to the reflection side and the transmission side of the mixing element 321 respectively, and are used to respectively receive two mutually parallel sub-mixed lights for balanced detection. It can be understood that compared with ordinary photodetectors, each balanced detection board 31 of the present application has at least two photodiodes, which can achieve an excellent common mode rejection ratio (CMRR), improve the signal amplitude and reduce noise, so that small changes in the vibration signal can be obtained from the interference noise. In addition, through subsequent signal conditioning, it is found that the two differential signals (i.e., the two sub-mixed lights) have 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 can provide a basis for subsequent signal processing to solve signal loss, intensity difference, and glitches, so as to solve the influence of the speckle effect through signal screening and selection.

[0048] It is worth noting that in another example of the present application, the mixing and splitting component 32 may also include a splitting element 322, wherein the splitting element 322 is correspondingly arranged on the reflection side or the transmission side of the mixing element 321, and is used to split the one mixing light mixed by the mixing element 321 into two sub-mixing lights with equal light energy. At this time, the one mixing light and one sub-mixing light parallel to each other are received by a balanced detection board 31, and balanced detection can still be performed; of course, in other examples of the present application, the mixing and splitting component 32 may also include three or more splitting elements 322, so as to further split one sub-mixing light into two sub-mixing lights, thereby obtaining more pairs of sub-mixing lights for the balanced detection board 31 to perform balanced detection respectively. This application will not go into details about this.

[0049] In addition, the transceiver optical system 20 of the present application can be implemented as a transceiver system configured with a Cassegrain system, or as a traditional transceiver system, as long as it can transmit measurement light and receive echo light to provide the required receiving light for the diversity balanced detection system 30. This application will not go into details about this.

[0050] However, in order to further solve the problem of vibration signal distortion and signal glitches caused by laser speckle phenomenon, which in turn affects the signal-to-noise ratio, such as Figure 1 and Figure 2As shown, the transceiver optical system 20 of the present application may include a multi-set transceiver separation component 21 and a lens component 22, wherein the multi-set transceiver separation component 21 may include a multi-set receiving optical device 211 and an emission channel 212 passing through the multi-set receiving optical device 211, and the emission channel 212 is suitable for being located in the measurement optical path 101 of the heterodyne coherent optical system 10 to define the emission optical path 201 of the transceiver optical system 20, wherein the lens component 22 is correspondingly arranged in the emission optical path 201.

[0051] At the same time, if Figure 2 and Figure 3 As shown, the multi-collection receiving optical device 211 is used to combine multiple mutually parallel sub-receiving optical paths 2021 into a mother receiving optical path 2022 to define the complete receiving optical path 202, and is used to combine multiple receiving light paths propagating along the multiple sub-receiving optical paths 2021 into a single receiving light path propagating along the mother receiving optical path 2022, to be supplied to the diversity balanced detection system 30 for diversity balanced detection. It will be understood that the receiving optical path 202 of the transceiver optical system 20 of the present application is composed of multiple sub-receiving optical paths 2021 and one mother receiving optical path 2022, and the multiple sub-receiving optical paths 2021 are preferably parallel to the transmitting optical path 201.

[0052] Specifically, if Figure 2 and Figure 3 As shown, the multi-collection receiving optical device 211 may include a plurality of light-receiving surfaces 2101 for defining a plurality of sub-receiving optical paths 2021, a plurality of anti-transmissive functional surfaces 2102, and a light-emitting surface 2103 for defining the mother receiving optical path 2022. The plurality of light-receiving surfaces 2101 are perpendicular to the central axis of the transmitting channel 212, and the plurality of anti-transmissive functional surfaces 2102 are located between the plurality of light-receiving surfaces 2101 and the light-emitting surface 2103, and are configured to reflect or transmit the sub-receiving optical paths 2021 to form a mother receiving optical path 2022. In other words, the multiple received light paths propagating along the plurality of sub-receiving optical paths 2021 are respectively transmitted through the corresponding light-receiving surfaces 2101 and then reflected or transmitted by the anti-transmissive functional surface 2102 to synthesize a single received light path propagating along the mother receiving optical path 2022 for diversity balanced detection by the diversity balanced detection system 30. It is understood that the sub-receiving optical path 2021 mentioned in this application refers to an optical path perpendicular to the light receiving surface 2101, and the main receiving optical path 2022 refers to an optical path perpendicular to the light emitting surface 2103. In addition, the reflective functional surface 2102 mentioned in this application can be a semi-reflective and semi-transmissive functional surface for reflecting 50% of light and transmitting 50% of light, or a fully reflective functional surface for reflecting 100% of light.

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

[0054] For example, in one example of the present application, Figure 4 and Figure 5 As shown, the multi-collection receiving optical device 211 can be composed of three beam splitting prisms 2111 and three total reflection prisms 2112. For the convenience of description, the first beam splitting prism 2111a, the second beam splitting prism 2111b and the third beam splitting prism 2111c are used to represent the three beam splitting prisms 2111, and the first total reflection prism 2112a, the second total reflection prism 2112b and the third total reflection prism 2112c are used to represent the three total reflection prisms 2112 as an example. The first beam splitter prism 2111a, the second beam splitter prism 2111b and the third beam splitter prism 2111c are arranged in an L shape, the first beam splitter prism 2111a provides the light emitting surface 2103 and the reflective functional surface 2102, and the second beam splitter prism 2111b and the third beam splitter prism 2111c respectively provide a light receiving surface 2101 and a reflective functional surface 2102, wherein the first total reflection prism 2112a, the second total reflection prism 2112b and the third total reflection prism 2112c are respectively arranged on the sides of the first beam splitter prism 2111a, the second beam splitter prism 2111b and the third beam splitter prism 2111c to provide a reflective functional surface 2102 respectively, and the second total reflection prism 2112b and the third total reflection prism 2112c respectively 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 collection, thereby forming a path of received light propagating along the mother receiving light path 2022 .

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

[0056] In other words, if 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 an example, which correspond to the second beam-splitting prism 2111b, the third beam-splitting prism 2111c, the second total reflection prism 2112b and the third total reflection prism 2112c respectively: one path of received light incident from the first light-receiving surface 2101a is first semi-transmitted by the second beam-splitting prism 2111b, and then semi-reflected by the first beam-splitting prism 2111a to be emitted from the light-emitting surface 2103; one path of received light incident from the second light-receiving surface 2101b is first semi-transmitted by the third beam-splitting prism 2111c, and then semi-reflected by the first total reflection prism 2112a The light is totally reflected by the second total reflection prism 2112b, and then semi-transmitted by the second beam splitter prism 2111b, and finally semi-reflected by the first beam splitter prism 2111a to be emitted from the light exit surface 2103; the light received from the fourth light receiving surface 2101d is totally reflected by the third total reflection prism 2112c, and then semi-transmitted by the third beam splitter prism 2111c, and then totally reflected by the first total reflection prism 2112a, and finally semi-transmitted by the first beam splitter prism 2111a to be emitted from the light exit surface 2103. In this way, the energy ratio of each received light before and after entering and exiting the multi-set receiving optical device 211 is 4:1, so that the energy of the concentrated received light basically contains one-fourth of the received light incident from each of the light-receiving surfaces 2101, which helps to reduce signal discontinuity and burr problems caused by random signal attenuation caused by the laser coherent speckle effect.

[0057] It is understood that in other examples of the present application, the multi-collection receiving optical device 211 may also be composed of two beam splitting prisms 2111 and a total reflection prism 2112 to converge two paths of received light into one path of received light; or the multi-collection receiving optical device 211 may also include a larger number of beam splitting prisms 2111 and total reflection prisms 2112 to converge more paths of received light into one path of received light, which is not further described in this application. In addition, because the multi-collection receiving optical device 211 of the present application can receive multiple paths of received light from different regions for balanced detection, it is equivalent to using multiple paths of light for laser vibration measurement at the same time. Therefore, even if laser speckle appears in some branched optical signals and causes signal distortion, the optical signals of other branches will still carry vibration information, thereby effectively eliminating the influence of laser speckle on signal distortion and burrs, and improving the signal-to-noise ratio of the vibration signal.

[0058] According to the above embodiments of the present application, Figure 5As shown, the transmitting channel 212 of the multi-set transmitting and receiving 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 in all directions.

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

[0060] Optionally, the light shield 213 can be made of, but is not limited to, a light-absorbing material such as a highly absorbent plastic material in the laser wavelength band or an oxidized black aluminum. For example, the light shield 213 can be implemented as a hollow tube made of black material, and the light shield 213 passes through the multi-collection receiving optical device 211, so that the measurement light is emitted through the light shield 213. It is understood that the transmission channel 212 of the multi-collection transceiver separation component 21 can be implemented as an optical channel formed by an air medium within the light shield 213, or it can be implemented as an optical channel formed by a light-transmitting medium such as a glass medium placed within the light shield 213.

[0061] It is worth noting that Figure 2 and Figure 3 As shown, the lens assembly 22 of the transceiver optical system 20 of the present application may include a front lens group 221 and a rear lens group 222 coaxially arranged in the transmission optical path 201. The front lens group 221 and the rear lens group 222 are correspondingly arranged to form a Kepler system with intermediate focus. By adjusting the distance between the front lens group 221 and the rear lens group 222, the measurement light passing through the transmission channel 212 is focused at different distances, thereby improving its vibration measurement range. At the same time, after passing through the front lens group 221 and the rear lens group 222, the received light is received and coupled by the multi-beam receiving optical device 211, thereby achieving a single lens compatible with the transmission and reception separation functions and achieving the coupling of multiple beams of received light to reduce the probability of speckle effect. It is understood that the lens assembly 22 may further include an aperture at the focal point between the front lens group 221 and the rear lens group 222 to eliminate stray light.

[0062] It is understandable that in other examples of the present application, the front mirror group 221 and the rear mirror group 222 can also be arranged accordingly to form an intermediate afocal Galilean system, which can still achieve focusing of the measurement light at different distances. This application will not go into details.

[0063] In addition, the front lens assembly 221 and the rear lens assembly 222 of the present application can be composed of one or more lenses, and the lenses can include at least spherical or aspherical lenses. For example, the front lens assembly 221 or the rear lens assembly 222 can be implemented as a complete lens, so that different regions of the lens are used to correspondingly modulate the measurement light and the multi-path received light; or the front lens assembly 221 or the rear lens assembly 222 can be implemented as a plurality of partial lenses spliced ​​coaxially, so that different partial lenses are used to correspondingly modulate the measurement light and the multi-path received light. This application will not elaborate on this.

[0064] According to the above embodiments of the present application, 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 configured to split the laser light emitted by 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 configured to perform frequency shifting on the reference light propagating along the reference optical path 102, thereby propagating the frequency-shifted reference light to the diversity balanced detection system 30.

[0065] Optionally, the laser 11 of the present application can be used for, but not limited to, emitting a line laser with a wavelength of 632.8 nm. Alternatively, the laser 11 can also be used for emitting a variety of lasers in other visible or infrared spectra.

[0066] Optionally, the beam splitter 12 of the present application is used to split the measurement light and the reference light at different power ratios. For example, the beam splitter 12 may have a splitting ratio of, but is not limited to, 99:1, 90:10, or 80:20.

[0067] Optionally, the frequency shifter 13 of the present application may adopt a single device with different carrier frequencies, or may adopt 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 Figure 2 As shown, the heterodyne coherent optical system 10 according to the above embodiment of the present application may further include a first reflecting element 14, wherein the first reflecting element 14 is arranged in the optical path between the laser 11 and the beam splitter 12, and is used to reflect the laser emitted by the laser 11 to propagate to the beam splitter 12, so as to fold the optical path between the laser 11 and the beam splitter 12, so as to improve the compactness of the structure of the heterodyne coherent optical system 10.

[0069] In addition, if Figure 2 As shown, the heterodyne coherent optical system 10 may further include a second reflecting element 15, wherein the second reflecting element 15 is arranged in the optical path between the beam splitter 12 and the frequency shifter 13, and is used to reflect the reference light split by the beam splitter 12 to propagate to the frequency shifter 13, so as to fold the optical path between the laser 11 and the beam splitter 12, so as to further improve the compactness of the structure of the heterodyne coherent optical system 10 and reduce its volume.

[0070] Optionally, the first reflecting element 14 and the second reflecting element 15 may be implemented as, but not limited to, optical devices such as external reflecting prisms, internal reflecting prisms, or pentaprisms for turning the light path at 90°.

[0071] It is worth noting that in the above embodiments of the present application, 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 as to be mixed by the mixing element 321 and split into two mixed lights.

[0072] It will be appreciated that while the diversity laser vibrometer system 1 according to the above-described embodiment of the present application utilizes spatial light to achieve optical transmission between various systems and between various components within the system, this is merely an example. In other examples of the present application, the heterodyne coherent optical system 10 and the diversity balanced detection system 30 within the diversity laser vibrometer system 1 may also utilize all or part of an optical fiber for optical transmission, while still achieving the aforementioned effects and advantages of the present application. For example, light received by the transceiver optical system 20 may be transmitted via optical fiber to the mixing element 321 of the diversity balanced detection system 30 for mixing, thereby increasing the flexibility of the placement of the transceiver optical system 20 and the diversity balanced detection system 30.

[0073] It is worth mentioning that, according to another aspect of the present application, Figures 3 to 5 As shown, the present application further provides a multi-set receiving and transmitting separation component 21, which may include a multi-set receiving optical device 211 and a transmitting channel 212, wherein the multi-set receiving optical device 211 has a plurality of light-receiving surfaces 2101 for defining a plurality of sub-receiving optical paths 2021, a plurality of reflective functional surfaces 2102 and a light-emitting surface 2103 for defining a mother receiving optical path 2022, and the plurality of reflective functional surfaces 2102 are located between the plurality of light-receiving surfaces 2101 and the light-emitting surface 2103, for reflecting or transmitting the plurality of sub-receiving optical paths 2021 to form a mother receiving optical path 2022; wherein the transmitting channel 212 runs through the multi-set receiving optical device 211, and the central axis of the transmitting channel 212 is perpendicular to the plurality of light-receiving surfaces 2101 of the multi-set receiving optical device 211, for defining a transmitting optical path 201 parallel to the sub-receiving optical path 2021. It is understandable that other structural features of the multi-set transceiver separation component 21 of the present application can refer to the multi-set transceiver separation component in the diversified laser vibrometer optical system 1 implemented above, and this application will not elaborate on this.

[0074] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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 above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall 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 measurement optical path and a reference optical path separated from each other, for providing a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path; a transceiver optical system, wherein the transceiver optical system is correspondingly arranged in the measuring optical path of the heterodyne coherent optical system, and the transceiver optical system has a transmitting optical path connected to the measuring optical path and a receiving optical path opposite to the transmitting optical path, and is used to transmit the measuring light along the transmitting optical path and receive the reflected received light along the receiving optical path; as well as A diversity balanced detection system, wherein the diversity balanced detection system is correspondingly arranged in the reference optical path of the heterodyne coherent optical system, and the diversity balanced detection system includes a balanced detection board and a frequency mixing and splitting component, wherein the frequency mixing and splitting component 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 multi-channel mixed light, wherein the balanced detection board is correspondingly arranged in the frequency mixing and splitting optical path of the frequency mixing and splitting component to perform balanced detection on the multi-channel mixed light; The frequency mixing and splitting assembly includes a frequency mixing element and a beam splitting element, wherein the frequency mixing element is located in the reference optical path of the heterodyne coherent optical system and is optically connected to the transceiver optical system, and is configured 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 paths of mixed light; wherein the beam splitting element is located on the reflective side or the transmissive side of the frequency mixing element, and is configured to further split one path of mixed light into two paths of mixed light; The two light splitting elements are respectively arranged on the reflection side and the transmission side of the frequency mixing element, and the two balanced detection plates correspond to the reflection side and the transmission side of the frequency mixing element respectively; The transceiver optical system includes a multi-set transceiver separation component and a lens component, wherein the multi-set transceiver separation component includes a multi-set receiving optical device and a transmission channel running through the multi-set receiving optical device, and 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, wherein the lens component is correspondingly arranged on the transmission optical path, and the multi-set receiving optical device is used to combine multiple mutually parallel sub-receiving optical paths into a mother receiving optical path; The lens assembly includes a front lens group and a rear lens group, wherein the front lens group and the rear lens group are coaxially arranged in the emission light path to form an intermediately focused Keplerian system or an intermediately afocal Galilean system; The heterodyne coherent optical system includes a laser, a beam splitter, and a frequency shifter, wherein the beam splitter is correspondingly arranged in the optical path between the laser and the transceiver optical system, and is used to split the laser light emitted by the laser into the measurement light propagating along the measurement optical path and the reference light propagating along the reference optical path, wherein the frequency shifter is correspondingly arranged in the reference optical path, and is used to perform frequency shift processing on the reference light propagating along the reference optical path, so that the frequency-shifted reference light is propagated to the diversity balanced detection system; The heterodyne coherent optical system further includes a first reflecting element and a second reflecting element, wherein the first reflecting element is arranged in the optical path between the laser and the beam splitter, and is used to reflect the laser light emitted by the laser so as to propagate to the beam splitter, and the second reflecting element is arranged in the optical path between the beam splitter and the frequency shifter, and is used to reflect the reference light split by the beam splitter so as to propagate to the frequency shifter; The multi-collection receiving optical device is composed of three beam splitting prisms and three total reflection prisms arranged in an L shape, wherein one of the beam splitting prisms provides a light emitting surface and a reflective functional surface, and the other two beam splitting prisms respectively provide a light receiving surface and the reflective functional surface, wherein the three total reflection prisms are respectively arranged on the sides of the three beam splitting prisms to provide the two light emitting surfaces and the three reflective functional surfaces; The multi-set transmitting and receiving separation component further includes a light shield arranged on the transmitting channel, so as to isolate the transmitting optical path and the sub-receiving optical path through the light shield.

2. The diversity laser vibrometer optical system according to claim 1, wherein: The frequency mixing element and the light splitting element are both semi-reflective and semi-transparent prisms.

3. The diversity laser vibrometer optical system according to claim 1, wherein: 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.

4. The diversity laser vibrometer optical system according to claim 1, wherein: The multi-set transceiver separation component includes: A multi-collection receiving optical device, wherein the multi-collection receiving optical device has multiple light-receiving surfaces for defining multiple sub-receiving light paths, multiple reflective functional surfaces, and a light-emitting surface for defining a mother receiving light path, and the multiple reflective functional surfaces are located between the multiple light-receiving surfaces and the light-emitting surface, for reflecting or transmitting the multiple sub-receiving light paths to be assembled into one mother receiving light path; and an emission channel, wherein the emission channel runs through the multi-collection receiving optical device, and the central axis of the emission channel is perpendicular to the multiple light-receiving surfaces of the multi-collection receiving optical device, for defining an emission light path parallel to the sub-receiving light paths.

5. The diversity laser vibrometer optical system according to claim 4, wherein: The light emitting surface of the multi-collection receiving optical device is perpendicular to the multiple light receiving surfaces.

6. The diversity laser vibrometer optical system according to claim 5, wherein: The beam splitter prism is a semi-reflective and semi-transparent prism, and the total reflection prism is a total internal reflection right-angle prism.

7. The diversity laser vibrometer optical system according to claim 4 or 5, wherein: The emission channel passes through the intersections of the plurality of light-receiving surfaces, so that the plurality of sub-receiving light paths are located around the emission light path.

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