Laser vibration measurement device and coherent optical path chip

Abstract

The invention provides a laser vibration measurement device and a coherent light path chip, the laser vibration measurement device comprises a coherent light path module and a transmit-receive optical lens module, the coherent light path module comprises a laser and the coherent light path chip which are coupled, and the coherent light path chip is internally provided with a coherent light path system. The transmitting-receiving optical lens module is used for dividing the probe light of the laser into measuring light propagating along a measuring light path and reference light propagating along a reference light path, and the transmitting-receiving optical lens module is used for transmitting the measuring light to an object to be measured along a transmitting light path and receiving echo light reflected by the object to be measured along a receiving light path. According to the invention, the laser and the coherent optical path chip are coupled, the system is more integrated than a space optical path and is more stable than an optical fiber, and the coherent optical path system comprises a measurement optical path and a reference optical path which are separated, so that scattering echo signals, brought by a coaxial system, of a chip transmitting end face are effectively eliminated, and intermediate-frequency parasitic non-Doppler signals in the system are eliminated.

Description

Technical Field

[0001] The present disclosure relates to the technical field of laser vibration measurement, and in particular to a laser vibration measurement device and a coherent optical path chip. Background Art

[0002] With the increasing demand for structural health monitoring in industrial manufacturing, aerospace, civil engineering and other fields, accurate vibration measurement plays a vital role in material mechanics analysis, structural design and failure prediction.

[0003] Traditional vibration measurement methods mainly rely on contact sensors. Although these vibration measurement methods can achieve vibration measurement to a certain extent, they have some limitations in practical applications, such as complex installation, easy damage to sensors, and measurement accuracy is easily affected by environmental factors. In addition, contact measurement methods are difficult to apply in complex structures and extreme environments, which limits their scope of use.

[0004] In response to the above problems, non-contact measurement technology came into being. As an advanced non-contact measurement device, laser vibrometer can obtain vibration information of the measured object without contacting it through laser beam scanning, and further derive physical quantities such as displacement, velocity, acceleration, and stress.

[0005] Although the existing laser vibrometer technology is relatively complete and can accurately measure the vibration information of objects within a certain range, and the balanced detection method can effectively reduce noise, so that the vibration signal can obtain a better signal-to-noise ratio. However, there are also some unfavorable factors in the vibration measurement process. For example, the signal scattered by the emitted laser at the end face of the lens, the end face of the optical fiber and the structural parts is coupled back into the coherent optical path. Since such signals are not scattered echo signals of the measured object but echo signals inside the system and do not carry Doppler signals, this greatly affects the signal-to-noise ratio and effect of laser vibrometer. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the related art, the purpose of the present disclosure is to provide a laser vibration measurement device and a coherent optical path chip to solve the problems in the related art.

[0007] The first aspect of the present disclosure provides a laser vibration measuring device, comprising:

[0008] A coherent optical path module, comprising a coupled laser and a coherent optical path chip; the laser is used to generate detection light; the coherent optical path chip is built with a coherent optical path system and includes an output optical port and a receiving optical port, the coherent optical path system includes a measurement optical path and a reference optical path separated from each other, and is used to separate the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path, the output optical port is used to emit the measurement light, and the receiving optical port is used to receive the echo light of the measurement light; the echo light of the measurement light interferes with the reference light to form an interference optical signal for coherent detection, which is used to indirectly detect the vibration of the object to be measured;

[0009] The transceiver optical lens module has a transmitting optical path associated with the measuring optical path and a receiving optical path opposite to the transmitting optical path, and is used to transmit the measuring light to the object to be measured along the transmitting optical path and receive the echo signal light reflected by the object to be measured along the receiving optical path.

[0010] In certain examples of the first aspect, the coherent optical path module also includes: a photodetector coupled to the coherent optical path chip, for performing photoelectric conversion on the interference light signal formed by the coherent optical path chip; and a signal amplification module connected to the photodetector, for amplifying the electrical detection signal output by the photodetector.

[0011] In certain examples of the first aspect, the transceiver optical lens module includes: an emission light shaping lens group, arranged in the emission light path, for shaping the measuring light emitted by the coherent light path module; an indicator light module, for generating indicator light; a dichroic mirror, arranged in the emission light path, for reflecting the measuring light emitted by the emission light shaping lens group and transmitting the indicator light emitted by the indicator light module, and coupling the measuring light with the indicator light; a reflector and a common focusing lens assembly, for focusing the measuring light coupled with the indicator light to reach the object to be measured and focusing the echo light reflected by the object to be measured and coupling it to the coherent light path module.

[0012] In some examples of the first aspect, the indication light module includes: an indication laser, used to generate indication light; and an indication light shaping lens group, used to shape the indication light emitted by the indication laser.

[0013] In certain examples of the first aspect, the reflector and shared focusing mirror assembly includes a reflector and a shared focusing mirror, the reflector is arranged in the emission light path, the shared focusing mirror is arranged in the emission light path and the receiving light path, the reflector is arranged on the incident light side of the shared focusing mirror, and the center of the reflector is coaxial with the optical axis of the shared focusing mirror; the reflector is used to reflect the measuring light coupled with the indicator light and focus it through the shared focusing mirror to reach the object to be measured, and the shared focusing mirror is used to focus the echo light reflected by the object to be measured and couple it to the coherent optical path module.

[0014] In certain examples of the first aspect, the reflector and shared focusing mirror assembly includes a reflector and a shared focusing mirror, the reflector is arranged in the emission light path, the shared focusing mirror is arranged in the emission light path and the receiving light path, the reflector is arranged on the incident light side of the shared focusing mirror, and the center of the reflector is not coaxial with the optical axis of the shared focusing mirror; the reflector is used to reflect the measuring light coupled with the indicator light and focus it through the shared focusing mirror to reach the object to be measured, and the shared focusing mirror is used to focus the echo light reflected by the object to be measured and couple it to the coherent optical path module.

[0015] In certain examples of the first aspect, the reflector and shared focusing mirror assembly includes a shared focusing mirror and a reflector, the shared focusing mirror is arranged in the emitting light path and the receiving light path, the shared focusing mirror corresponds to the dichroic mirror, the reflector is arranged in the receiving light path, and the reflector is arranged on the emitting light side of the shared focusing mirror and is provided with a light-transmitting port; the shared focusing mirror is used to focus the measurement light coupled with the indicator light emitted by the dichroic mirror and transmitted through the light-transmitting port of the reflector to reach the object to be measured and to focus the echo light reflected by the object to be measured and reflect it through the reflector, so that the reflector couples the echo light reflection to the coherent optical path module.

[0016] In some examples of the first aspect, the emission light shaping lens assembly includes: a convex lens, arranged on the output light side of the coherent optical path module; a concave lens, arranged on the output light side of the convex lens, and the optical axis of the concave lens is coaxial with the optical axis of the convex lens.

[0017] In some examples of the first aspect, the emission light shaping lens group includes: a convex lens, arranged on the output light side of the coherent optical path module; a concave lens, arranged on the output light side of the convex lens, and the optical axis of the concave lens is perpendicular to the optical axis of the convex lens; a reflector, arranged on the output light side of the convex lens and on the incident light side of the concave lens.

[0018] A second aspect of the present disclosure provides a coherent optical path chip, comprising:

[0019] A coherent optical path system, comprising a measurement optical path and a reference optical path separated from each other, for dividing the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path;

[0020] An output light port, used to emit the measurement light; and

[0021] The receiving light port is used to receive the echo light of the measuring light.

[0022] In some examples of the second aspect, the coherent optical path system is a coherent optical path system with an acousto-optic modulation device or a homodyne coherent optical path system without other devices.

[0023] As described above, the present disclosure provides a laser vibration measurement device and a coherent optical path chip, the laser vibration measurement device includes a coherent optical path module and a transceiver optical lens module, the coherent optical path module includes a coupled laser and a coherent optical path chip, the coherent optical path chip has a built-in coherent optical path system and includes an output optical port and a receiving optical port, the coherent optical path system includes a measurement optical path and a reference optical path separated from each other, used to divide the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path; the transceiver optical lens module has an emission optical path associated with the measurement optical path and a receiving optical path opposite to the emission optical path, used to transmit the measurement light along the emission optical path to the object to be measured and receive the echo light reflected by the object to be measured along the receiving optical path. Compared with the related art, the laser vibration measurement device provided by the present disclosure couples the laser and the coherent optical path chip, is more integrated than the spatial optical path and more stable than the optical fiber, and is suitable for small space and high sensitivity scene applications. At the same time, the coherent optical path chip has a built-in coherent optical path system, which includes a measurement optical path and a reference optical path that are separated from each other, which can effectively eliminate the scattered echo signal of the chip transmitting end face brought by the coaxial system and eliminate the intermediate frequency parasitic non-Doppler signal in the system to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. 1 is a block diagram of a laser vibrometer device according to an embodiment of the present invention.

[0025] Figure 2 It is a schematic diagram of the structure of the laser vibration measuring device in one embodiment of the present invention.

[0026] Figure 3 Shown is a schematic diagram of the optical path of a transceiver optical lens module in the laser vibrometer device disclosed in one embodiment.

[0027] Figure 4 Shown is a schematic diagram of the structure of a transmission light shaping lens assembly in a transceiver optical lens module in a variation example.

[0028] Figure 5 Shown is a schematic diagram of the optical path of the transceiver optical lens module in the laser vibrometer device disclosed in another embodiment.

[0029] Figure 6 Shown is a schematic diagram of the optical path of a transceiver optical lens module in a laser vibrometer device disclosed in another embodiment. DETAILED DESCRIPTION

[0030] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0031] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0032] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of the present disclosure, "a group" means two or more, unless otherwise clearly and specifically defined.

[0034] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0035] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0036] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, modules, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0037] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0038] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0039] In the relevant laser vibration measurement technology, during the vibration measurement process, there will be signals scattered by the emitted laser at the end face of the lens, the end face of the optical fiber, and the structural parts, which will be coupled back into the coherent optical path. Since such signals are not scattered echo signals of the measured object but echo signals inside the system and do not carry Doppler signals, this greatly affects the signal-to-noise ratio and effect of laser vibration measurement. In view of this, a laser vibration measurement device is provided in an embodiment of the present disclosure, the laser vibration measurement device includes a coherent optical path module and a transceiver optical lens module, the coherent optical path module includes a coupled laser and a coherent optical path chip, the spatial optical path is more integrated and more stable than the optical fiber, and is suitable for small space and high sensitivity scene applications, and the coherent optical path system in the coherent optical path chip includes a measurement optical path and a reference optical path that are separated from each other, which can effectively eliminate the scattered echo signal of the chip transmitting end face brought by the coaxial system, and eliminate the intermediate frequency parasitic non-Doppler signal in the system to a certain extent.

[0040] See also Figure 1 , which is a schematic block diagram of the laser vibration measuring device disclosed in one embodiment.

[0041] like Figure 1 As shown, the laser vibration measurement device disclosed in the present invention includes a coherent optical path module 1 and a transceiver optical lens module 2.

[0042] The coherent optical path module 1 has a measurement optical path and a reference optical path separated from each other, and is used to provide measurement light propagating along the measurement optical path and reference light propagating along the reference optical path, wherein the measurement light can be used to emit to the object to be measured, and the reference light interferes with the echo light of the measurement light to form an interference light signal for coherent detection, which is used to indirectly detect the vibration of the object to be measured.

[0043] The transceiver optical lens module 2 has an emission light path associated with the measuring light path and a receiving light path opposite to the emission light path, for transmitting the measuring light to the object to be measured along the emission light path and receiving the echo light reflected by the object to be measured along the receiving light path.

[0044] In the laser vibration measurement device provided in the present disclosure, the coherent optical path module includes a measurement optical path and a reference optical path that are separated from each other, which can effectively eliminate the scattered echo signal of the chip transmitting end face brought by the coaxial system of the parasitic optical signal reflected back to the system, and eliminate the intermediate frequency parasitic non-Doppler signal to a certain extent.

[0045] See also Figure 2 , which is a schematic diagram of the structure of the laser vibration measuring device disclosed in one embodiment.

[0046] As Figure 2 As shown, the laser vibration measurement device disclosed in the present invention includes a coherent optical path module 1 and a transceiver optical lens module 2.

[0047] The coherent optical path module 1 comprises a laser 11 and a coherent optical path chip 13 which are coupled to each other.

[0048] The laser 11 is used to generate detection light. In some embodiments, the laser 11 may be, for example, a narrow line width laser, and the detection light generated includes but is not limited to a wavelength of 1550 nm, 1310 nm, or other coherent light source bands.

[0049] The coherent optical path chip 13 has a built-in coherent optical path system, which includes a measurement optical path and a reference optical path separated from each other, and is used to separate the detection light of the laser 11 into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path. In some embodiments, the coherent optical path chip 13 is designed to be etched with a Mach-Zehnder coherent optical path.

[0050] In some embodiments, the coherent optical path system is a coherent optical path system with an acousto-optic modulation device. In some embodiments, the coherent optical path system is a homodyne coherent optical path system without other devices.

[0051] The coherent optical path chip 13 includes an emitting optical port 131 and a receiving optical port 133. The emitting optical port 131 is used to emit the measuring light propagating along the measuring optical path, and the receiving optical port 133 is used to receive the echo light of the measuring light, wherein the reference light propagating along the reference optical path will interfere with the echo light of the measuring light received by the receiving optical port 133 to form an interference optical signal for coherent detection, and the vibration of the object to be measured can be indirectly detected by using the interference optical signal coupled with the reference light and the echo light.

[0052] In the coherent optical path module 1, the laser 11 and the coherent optical path chip 13 are used as light sources for optical coherence measurement. By coupling the laser 11 and the coherent optical path chip 13 and transmitting them in the coherent optical path chip 13 according to a predetermined interference optical path, the coupling alignment is more integrated and smaller in size than the spatial optical path, and is more stable than optical fiber transmission, and is suitable for small space and high-sensitivity scene applications.

[0053] In addition, the coherent optical path module 1 further includes: a photodetector 15 and a signal amplification module 17. The photodetector 15 is coupled to the coherent optical path chip 13, and is used to perform photoelectric conversion on the interference optical signal formed by the coherent optical path chip 13 to form an electrical detection signal. The signal amplification module 17 is connected to the photodetector 15, and is used to amplify the electrical detection signal output by the photodetector 15.

[0054] The transceiver optical lens module 2 comprises: a transmission light shaping lens group 21 , an indication light module 23 , a dichroic mirror 25 , and a reflector and common focusing lens assembly 27 .

[0055] The emission light shaping lens group 21 is arranged in the emission light path, and is used to shape the measurement light emitted by the coherent light path module 1. Specifically, the emission light shaping lens group 21 shapes the measurement light emitted by the emission light port 131 of the coherent light path chip 13 in the coherent light path module 1.

[0056] The indicator light module 23 is used to generate indicator light.

[0057] The dichroic mirror 25 is disposed in the emission light path, and is used to reflect the measuring light emitted by the emission light shaping lens group 21 and the indication light emitted by the transmission indication light module 23 , and couple the measuring light with the indication light.

[0058] The reflector and common focusing mirror assembly 27 is used to focus the measuring light coupled with the indicator light to reach the object to be measured 3 and to focus the echo light reflected by the object to be measured 3 and couple it to the coherent optical path module 1. Specifically, the echo light is coupled to the coherent optical path module after focusing, which means coupling to the receiving optical port 133 of the coherent optical path chip 13 in the coherent optical path module 1.

[0059] In the transceiver optical lens module 2, the measurement light is shaped by the emission light shaping lens group 21, and then the measurement light is focused by the reflector and the common focusing lens assembly 27 to reach the object to be measured 3, and the echo light reflected by the object to be measured 3 is focused and coupled to the coherent optical path module 2, which has a simple structure. In addition, the transceiver optical lens module 2 also includes an indicator light module 23, and the indicator light generated by the indicator light module 23 is coupled with the measurement light by using a dichroic mirror 25, which is convenient for actual focusing observation.

[0060] See also Figure 3 , which is a schematic diagram of the optical path of the transceiver optical lens module in the laser vibration measurement device disclosed in one embodiment.

[0061] Combination Figure 2 and Figure 3 As shown, the transmitting and receiving optical lens module includes: a transmission light shaping lens group 21, an indication light module 23, a dichroic mirror 25, and a reflector and a common focusing lens assembly 27.

[0062] The emission light shaping lens group 21 is arranged in the emission light path, and is used to shape the measurement light emitted by the coherent light path module 1 .

[0063] In some embodiments, the emission light shaping lens group 21 includes: a convex lens 211 and a concave lens 213. The convex lens 211 is arranged on the light-emitting side of the coherent optical path module 1, and specifically, the convex lens 211 is directly opposite to the light-emitting port 131 of the coherent optical path chip 13. The concave lens 213 is arranged on the light-emitting side of the convex lens 211, and the optical axis of the concave lens 213 is coaxial with the optical axis of the convex lens. In this way, the measurement light emitted from the light-emitting port 131 of the coherent optical path chip 13 is shaped by the emission light shaping lens group 21 including the convex lens 211 and the concave lens 213.

[0064] The emission light shaping lens assembly is not limited to Figure 3 The structure shown in the figure can still be changed in other ways. In some embodiments, Figure 4 As shown, the emission light shaping lens group 21' includes: a convex lens 211, a concave lens 213, and a reflector 212. The convex lens 211 is arranged on the light-emitting side of the coherent light path module 1, and specifically, the convex lens 211 is directly opposite to the light-emitting port 131 of the coherent light path chip 13. The concave lens 213 is arranged on the light-emitting side of the convex lens 211, and the optical axis of the concave lens 213 is perpendicular to the optical axis of the convex lens. The reflector 212 is arranged on the light-emitting side of the convex lens 211 and on the light-incident side of the concave lens 213. In this way, the emission light shaping lens group 21' including the convex lens 211, the reflector 212, and the concave lens 213 is used to shape the measurement light emitted from the light-emitting port 131 of the coherent light path chip 13 and realize the steering of the measurement light.

[0065] Continue back Figure 3 The indication light module includes: an indication laser 231 and an indication light shaping lens group 233.

[0066] The indicating laser 231 is used to generate indicating light, which is a visible light source, and may include but is not limited to visible light sources such as 520nm, 635nm, and 670nm.

[0067] The indicator light shaping lens group 233 is used to shape the indicator light emitted by the indicator laser 231 .

[0068] The indicator light shaping lens group 233 may include one or more glass lenses, which are used to focus the indicator light beam after shaping the indicator light emitted by the indicator laser 231 and the measuring light beam after shaping the measuring light by the emission light shaping lens group at the same position, providing favorable conditions for the rear reflector and the shared focusing lens assembly to achieve the achromatic function.

[0069] In some embodiments, the indicator light shaping lens group 233 may include a convex lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens and a concave lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens, a reflector, and a concave lens.

[0070] The reflecting mirror and common focusing mirror assembly 27 includes a reflecting mirror 271 and a common focusing mirror 273 .

[0071] The reflector 271 is arranged in the emission light path, and the common focusing mirror 273 is arranged in the emission light path and the receiving light path. The reflector 271 is arranged on the incident light side of the common focusing mirror 273, and the center of the reflector 271 is coaxial with the optical axis of the common focusing mirror 273. The reflector 271 is used to reflect the measuring light coupled with the indicator light and focus it through the common focusing mirror 273 to reach the object to be measured 3. The common focusing mirror 273 is used to focus the echo light reflected by the object to be measured 3 and couple it to the coherent light path module 1, that is, to the receiving light port 133 of the coherent light path chip 13. Among them, the object to be measured 3 corresponds to the receiving light port 133 of the coherent light path chip 13.

[0072] In the reflector and shared focusing mirror assembly 27, the reflector 271 cooperates with the dichroic mirror 25 to realize the turning effect of the measuring optical path, and at the same time, it is necessary to cooperate with the outgoing optical path distance and divergence angle range at the receiving optical port 133 of the coherent optical path chip 13. Since the center of the reflector 271 is coaxial with the optical axis of the shared focusing mirror 273, the center of the receiving optical path is blocked by the reflector 271, and the blocking range should be concentrated in the center area of ​​the entire light beam, which accounts for about 1 / 4 to 1 / 3 of the entire circular area, which will have a better effect.

[0073] The common focusing mirror 273 is used to achieve achromatic aberration of wavelengths of different spectra of the measuring light emitted by the laser 11 and the indicator light emitted by the indicator laser 231. At the same time, by adjusting the front and rear positions of the common focusing mirror, the emitted light can be focused at different positions, thereby obtaining higher echo signals at different distances.

[0074] In the above-mentioned transceiver optical lens module, the measurement light is shaped and coupled to the receiving end into the same lens, and only one common focusing mirror is needed to realize focusing adjustment. Compared with the related technology that needs to set up the transmitting focusing mirror and the receiving focusing mirror separately, the structure is simple, which not only eliminates the parasitic echo signal caused by the scattered echo light on the lens surface, but also uses a common focusing mirror to make the echo signal's analog-sound coupling matching effect better.

[0075] See also Figure 5 , which is a schematic diagram of the optical path of the transceiver optical lens module in the laser vibrometer device disclosed in another embodiment.

[0076] Combination Figure 2 and Figure 5 As shown, the transmitting and receiving optical lens module includes: a transmission light shaping lens group 21, an indication light module 23, a dichroic mirror 25, and a reflector and a common focusing lens assembly 27a.

[0077] The emission light shaping lens group 21 is arranged in the emission light path, and is used to shape the measurement light emitted by the differential coherent light path module 1 .

[0078] In some embodiments, the emission light shaping lens group 21 includes: a convex lens 211 and a concave lens 213. The convex lens 211 is arranged on the light-emitting side of the coherent optical path module 1, and specifically, the convex lens 211 is directly opposite to the light-emitting port 131 of the coherent optical path chip 13. The concave lens 213 is arranged on the light-emitting side of the convex lens 211, and the optical axis of the concave lens 213 is coaxial with the optical axis of the convex lens. In this way, the measurement light emitted from the light-emitting port 131 of the coherent optical path chip 13 is shaped by the emission light shaping lens group 21 including the convex lens 211 and the concave lens 213.

[0079] Of course, in other embodiments, the emission light shaping mirror group may include a convex lens, a concave lens, and a reflector. The emission light shaping mirror group including the convex lens, the reflector, and the concave lens is used to shape the measurement light emitted from the output light port of the coherent optical path chip and realize the steering of the measurement light.

[0080] The indicator light module includes an indicator laser 231 and an indicator light shaping lens group 233 .

[0081] The indicating laser 231 is used to generate indicating light, which is a visible light source, and may include but is not limited to visible light sources such as 520nm, 635nm, and 670nm.

[0082] The indicator light shaping lens group 233 is used to shape the indicator light emitted by the indicator laser 231 .

[0083] The indicator light shaping lens group 233 may include one or more glass lenses, which are used to focus the indicator light beam after shaping the indicator light emitted by the indicator laser 231 and the measuring light beam after shaping the measuring light by the emission light shaping lens group at the same position, providing favorable conditions for the rear reflector and the shared focusing lens assembly to achieve the achromatic function.

[0084] In some embodiments, the indicator light shaping lens group 233 may include a convex lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens and a concave lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens, a reflector, and a concave lens.

[0085] The reflecting mirror and common focusing mirror assembly 27 a includes a reflecting mirror 271 a and a common focusing mirror 273 .

[0086] The reflector 271a is arranged in the emission light path, and the common focusing mirror 273 is arranged in the emission light path and the receiving light path. The reflector 271a is arranged on the incident light side of the common focusing mirror 273, and the center of the reflector 271a is not coaxial with the optical axis of the common focusing mirror 273. For example, the reflector 271a is located as a whole below the optical axis of the common focusing mirror 273 and closer to the dichroic mirror 25. The reflector 271a is used to reflect the measuring light coupled with the indicator light and focus it through the common focusing mirror 273 to reach the object to be measured 3. The common focusing mirror 273 is used to focus the echo light reflected by the object to be measured 3 and couple it to the coherent light path module 1, that is, to the receiving light port 133 of the coherent light path chip 13. Among them, the object to be measured 3 corresponds to the receiving light port 133 of the coherent light path chip 13.

[0087] Since the center of the reflector 271a is not coaxial with the optical axis of the shared focusing mirror 273, that is, the beam of measuring light reflected by the reflector 271a occupies a non-central area of ​​the shared focusing mirror 273, it is more conducive to the receiving light port 133 of the coherent optical path chip 13 to receive more echo signals emitted from the central area of ​​the shared focusing mirror 273.

[0088] In the reflector and shared focusing mirror assembly 27a, the reflector 271a cooperates with the dichroic mirror 25 to realize the measurement light path turning function. At the same time, it is necessary to cooperate with the outgoing light path distance and divergence angle range at the receiving light port 133 of the coherent light path chip 13.

[0089] The common focusing mirror 273 is used to achieve achromatic aberration of wavelengths of different spectra of the measuring light emitted by the laser 11 and the indicator light emitted by the indicator laser 231. At the same time, by adjusting the front and rear positions of the common focusing mirror, the emitted light can be focused at different positions, thereby obtaining higher echo signals at different distances.

[0090] In the above-mentioned transceiver optical lens module, the measurement light is shaped and coupled to the receiving end into the same lens, and only one common focusing mirror is needed to realize the focusing adjustment. Compared with the related technology that needs to set up the transmitting focusing mirror and the receiving focusing mirror separately, the structure is simple, which not only eliminates the parasitic echo signal caused by the scattered echo light on the lens surface, but also uses a common focusing mirror to make the coupling matching effect of the echo signal better.

[0091] See also Figure 6 , which is a schematic diagram of the optical path of the transceiver optical lens module in the laser vibrometer device disclosed in another embodiment.

[0092] Combination Figure 2 and Figure 6 As shown, the transmitting and receiving optical lens module includes: a transmission light shaping lens group 21, an indication light module 23, a dichroic mirror 25, and a reflector and common focusing lens assembly 26.

[0093] The emission light shaping lens group 21 is arranged in the emission light path, and is used to shape the measurement light emitted by the differential coherent light path module 1 .

[0094] In some embodiments, the emission light shaping lens group 21 includes: a convex lens 211 and a concave lens 213. The convex lens 211 is arranged on the light-emitting side of the coherent optical path module 1, and specifically, the convex lens 211 is directly opposite to the light-emitting port 131 of the coherent optical path chip 13. The concave lens 213 is arranged on the light-emitting side of the convex lens 211, and the optical axis of the concave lens 213 is coaxial with the optical axis of the convex lens. In this way, the measurement light emitted from the light-emitting port 131 of the coherent optical path chip 13 is shaped by the emission light shaping lens group 21 including the convex lens 211 and the concave lens 213.

[0095] Of course, in other embodiments, the emission light shaping mirror group may include a convex lens, a concave lens, and a reflector. The emission light shaping mirror group including the convex lens, the reflector, and the concave lens is used to shape the measurement light emitted from the output light port of the coherent optical path chip and realize the steering of the measurement light.

[0096] The indicator light module includes an indicator laser 231 and an indicator light shaping lens group 233 .

[0097] The indicating laser 231 is used to generate indicating light, which is a visible light source, and may include but is not limited to visible light sources such as 520nm, 635nm, and 670nm.

[0098] The indicator light shaping lens group 233 is used to shape the indicator light emitted by the indicator laser 231 .

[0099] The indicator light shaping lens group 233 may include one or more glass lenses, which are used to focus the indicator light beam after shaping the indicator light emitted by the indicator laser 231 and the measuring light beam after shaping the measuring light by the emission light shaping lens group at the same position, providing favorable conditions for the rear reflector and the shared focusing lens assembly to achieve the achromatic function.

[0100] In some embodiments, the indicator light shaping lens group 233 may include a convex lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens and a concave lens. In some embodiments, the indicator light shaping lens group 233 may include a convex lens, a reflector, and a concave lens.

[0101] The reflecting mirror and common focusing mirror assembly 26 includes a common focusing mirror 261 and a reflecting mirror 263 .

[0102] The common focusing mirror 261 is arranged in the emission light path and the receiving light path, and the common focusing mirror 261 corresponds to the dichroic mirror 25 and the object to be measured 3. The reflector 263 is arranged in the receiving light path, and the reflector 263 is arranged on the light emitting side of the common focusing mirror 261 and has a light transmission port 262. In some embodiments, the light transmission port 262 of the reflector 263 may be opened in the central area of ​​the reflector 263, so that the light transmission port 262 may correspond to the central area of ​​the common focusing mirror 261. However, this is not limited to this. In some embodiments, the light transmission port 262 of the reflector may also be opened in the non-central area of ​​the reflector, so that the light transmission port 262 may correspond to the non-central area of ​​the common focusing mirror.

[0103] The shared focusing mirror 261 is used to focus the measurement light coupled with the indicator light emitted by the dichroic mirror 25 and transmitted through the light-transmitting port of the reflector 263, and then the measurement light reaches the object to be measured 3. That is, the measurement light coupled with the indicator light emitted by the dichroic mirror 25 passes through the light-transmitting port of the reflector 263 and is transmitted to the shared focusing mirror 261, and the shared focusing mirror 261 focuses the measurement light and then reaches the object to be measured 3, wherein the object to be measured 3 corresponds to the dichroic mirror 25. In addition, the shared focusing mirror 261 is used to focus the echo light reflected by the object to be measured 3 and reflect it through the reflector 263, and the reflector 263 reflects and couples the echo light to the coherent optical path module 1, that is, to the receiving optical port 133 of the coherent optical path chip 13.

[0104] In the reflector and common focusing mirror assembly 26 , the common focusing mirror 261 can directly correspond to the dichroic mirror 25 , and directly focus the measuring light coupled with the indicator light emitted by the dichroic mirror 25 to reach the object to be measured 3 .

[0105] Since the reflector 263 is disposed in the receiving optical path and located on the outgoing light side of the common focusing mirror 261 , the echo light focused by the common focusing mirror 261 will be transmitted unobstructed and reflected and coupled to the receiving optical port 133 of the coherent optical path chip 13 via the reflector 263 .

[0106] The common focusing mirror 261 is used to achieve achromatic aberration of wavelengths of different spectra of the measuring light emitted by the laser 11 and the indicator light emitted by the indicator laser 231. At the same time, by adjusting the front and rear positions of the common focusing mirror, the emitted light can be focused at different positions, thereby obtaining higher echo signals at different distances.

[0107] In the above-mentioned transceiver optical lens module, the measurement light is shaped and coupled to the receiving end into the same lens, and only one common focusing mirror is needed to realize the focusing adjustment. Compared with the related technology that needs to set up the transmitting focusing mirror and the receiving focusing mirror separately, the structure is simple, which not only eliminates the parasitic echo signal caused by the scattered echo light on the lens surface, but also uses a common focusing mirror to make the coupling matching effect of the echo signal better.

[0108] In summary, the present disclosure provides a laser vibration measurement device and a coherent optical path chip, the laser vibration measurement device includes a coherent optical path module and a transceiver optical lens module, the coherent optical path module includes a coupled laser and a coherent optical path chip, the coherent optical path chip has a built-in coherent optical path system and includes an output optical port and a receiving optical port, the coherent optical path system includes a measurement optical path and a reference optical path separated from each other, used to divide the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path; the transceiver optical lens module has an emission optical path associated with the measurement optical path and a receiving optical path opposite to the emission optical path, used to transmit the measurement light along the emission optical path to the object to be measured and receive the echo light reflected by the object to be measured along the receiving optical path. Compared with the related art, the laser vibration measurement device provided by the present disclosure couples the laser and the coherent optical path chip, is more integrated than the spatial optical path and more stable than the optical fiber, and is suitable for small space and high sensitivity scene applications. At the same time, the coherent optical path chip has a built-in coherent optical path system, which includes a measurement optical path and a reference optical path that are separated from each other, which can effectively eliminate the scattered echo signal of the chip transmitting end face brought by the coaxial system, and eliminate the intermediate frequency parasitic non-Doppler signal in the system to a certain extent. In addition, in the transceiver optical lens module, the measurement light is shaped and coupled to the receiving end into the same lens, and only a common focusing mirror is needed to achieve focus adjustment. Compared with the related technology that requires the separate setting of the transmitting focusing mirror and the receiving focusing mirror, the structure is simple, which not only eliminates the parasitic echo signal caused by the scattered echo light on the lens surface, but also uses a common focusing mirror to make the echo signal's model-sing coupling matching effect better.

[0109] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the protection scope of the present disclosure.

Claims

1. A laser vibration measuring device, characterized in that: include: A coherent optical path module, including a coupled laser and a coherent optical path chip; The laser is used to generate detection light; The coherent optical path chip is built with a coherent optical path system and includes an outgoing optical port and a receiving optical port. The coherent optical path system includes a measurement optical path and a reference optical path separated from each other, and is used to separate the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path. The outgoing optical port is used to emit the measurement light, and the receiving optical port is used to receive the echo light of the measurement light. The echo light of the measurement light interferes with the reference light to form an interference optical signal for coherent detection. as well as The transceiver optical lens module has an emission light path associated with the measuring light path and a receiving light path opposite to the emission light path, and is used to transmit the measuring light to the object to be measured along the emission light path and receive the echo light reflected by the object to be measured along the receiving light path.

2. The laser vibrometer according to claim 1, characterized in that: The coherent optical path module also includes: A photodetector, coupled to the coherent optical circuit chip, for performing photoelectric conversion on the interference optical signal formed by the coherent optical circuit chip; and The signal amplification module is connected to the photoelectric detector and is used to amplify the electrical detection signal output by the photoelectric detector.

3. The laser vibrometer according to claim 1, characterized in that: The transceiver optical lens module comprises: An emission light shaping lens group, arranged in the emission light path, for shaping the measurement light emitted by the coherent light path module; An indicator light module, used for generating an indicator light; A dichroic mirror is provided in the emission light path, and is used to reflect the measuring light emitted by the emission light shaping mirror group and transmit the indication light emitted by the indication light module, and couple the measuring light with the indication light; and The reflector and the common focusing mirror assembly are used to focus the measuring light coupled with the indicator light to reach the object to be measured and to focus the echo light reflected by the object to be measured to couple it to the coherent optical path module.

4. The laser vibrometer according to claim 3, characterized in that: The indicator light module comprises: a pointing laser for generating a pointing light; and The indicator light shaping lens group is used to shape the indicator light emitted by the indicator laser.

5. The laser vibrometer according to claim 3, characterized in that: The reflector and common focusing mirror assembly comprises a reflector and a common focusing mirror, wherein the reflector is arranged in the emission light path, the common focusing mirror is arranged in the emission light path and the receiving light path, the reflector is arranged on the incident light side of the common focusing mirror, and the center of the reflector is coaxial with the optical axis of the common focusing mirror; The reflector is used to reflect the measuring light coupled with the indicator light and focus the light through the common focusing mirror to reach the object to be measured. The common focusing mirror is used to focus the echo light reflected by the object to be measured and couple it to the coherent optical path module.

6. The laser vibrometer according to claim 3, characterized in that: The reflector and shared focusing mirror assembly comprises a reflector and a shared focusing mirror, wherein the reflector is arranged in the emission light path, the shared focusing mirror is arranged in the emission light path and the receiving light path, the reflector is arranged on the incident light side of the shared focusing mirror, and the center of the reflector is not coaxial with the optical axis of the shared focusing mirror; the reflector is used to reflect the measuring light coupled with the indicator light and focus it through the shared focusing mirror to reach the object to be measured, and the shared focusing mirror is used to focus the echo light reflected by the object to be measured and couple it to the coherent light path module.

7. The laser vibrometer according to claim 3, characterized in that: The reflector and shared focusing mirror assembly includes a shared focusing mirror and a reflector, wherein the shared focusing mirror is arranged in the emission light path and the receiving light path, the shared focusing mirror corresponds to the dichroic mirror, the reflector is arranged in the receiving light path, and the reflector is arranged on the light emitting side of the shared focusing mirror and is provided with a light transmission port; the shared focusing mirror is used to focus the measurement light coupled with the indicator light emitted by the dichroic mirror and transmitted through the light transmission port of the reflector to reach the object to be measured, and to focus the echo light reflected by the object to be measured and reflect it through the reflector, so that the reflector couples the echo light reflection to the coherent light path module.

8. The laser vibrometer according to claim 3, characterized in that: The emission light shaping lens assembly comprises: A convex lens, disposed on the light-emitting side of the coherent optical path module; and The concave lens is arranged on the light-emitting side of the convex lens, and the optical axis of the concave lens is coaxial with the optical axis of the convex lens.

9. The laser vibrometer according to claim 3, characterized in that: The emission light shaping lens assembly comprises: A convex lens, arranged on the light-emitting side of the coherent optical path module; a concave lens, disposed on the light-emitting side of the convex lens, wherein the optical axis of the concave lens is perpendicular to the optical axis of the convex lens; and The reflecting mirror is arranged on the light-emitting side of the convex lens and on the light-incident side of the concave lens.

10. A coherent optical path chip, characterized in that: include: A coherent optical path system, comprising a measurement optical path and a reference optical path separated from each other, for dividing the detection light of the laser into a measurement light propagating along the measurement optical path and a reference light propagating along the reference optical path; An output light port, used to emit the measuring light; as well as The receiving light port is used to receive the echo light of the measuring light.

11. The coherent optical circuit chip according to claim 10, characterized in that: The coherent optical path system is a coherent optical path system with an acousto-optic modulation device or a homodyne coherent optical path system without other devices.

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