Multi-channel double-optical-comb distance measuring device

Abstract

The invention discloses a multichannel double-optical-comb distance measuring device, which comprises a double-optical-comb light source, an optical fiber light path, a distance measuring space probe, a measuring cube-corner prism and a signal detection and acquisition processing module, and is characterized in that the double-optical-comb light source emits signal light and local oscillation light to 1 * n beam splitting light paths, and the 1 * n beam splitting light paths divide the signal light and the local oscillation light into n paths of light signals with the same energy; the n paths of local oscillation light are respectively emitted to each coupler; n paths of signal light are transmitted to the distance measurement space probe through each circulator, each distance measurement space probe and the measurement cube-corner prism serving as a measured target construct a reference light signal and a measurement light signal, and the reference light signal and the measurement light signal return along the original path and are output to the coupler through the circulators; the measurement optical signal and the reference optical signal are respectively coupled with the local oscillator light in the coupler to generate interference to generate a reference interference signal and a measurement interference signal; and the signal detection and acquisition processing module acquires n paths of reference interference signals and measurement interference signals for parallel processing, and calculates a plurality of distance measurement results in real time.

Description

Technical Field

[0001] This invention relates to the field of optical precision metrology, and specifically to a multi-channel dual-comb ranging device. Background Technology

[0002] Dual-comb ranging technology leverages the narrow linewidth and high frequency stability of optical combs to achieve high-precision ranging through the beat frequency signals of two optical combs (a signal comb and a local oscillator comb). It boasts advantages such as high ranging accuracy, fast measurement speed, and a large unambiguous distance range, making it a research hotspot in the field of high-precision ranging. The measured distance can be obtained through the time delay between the envelopes of the reference interference signal and the measured interference signal. The accuracy of this method is typically on the order of micrometers to hundreds of nanometers. Further improvements to the nanometer level can be achieved by using the phase difference between the carrier envelopes of the reference and measured interference signals.

[0003] However, most existing dual-comb ranging technologies are single-path ranging architectures, meaning that a single dual-comb system can only measure the distance to a single target. In scenarios requiring simultaneous ranging of multiple targets, such as multi-target tracking, deformation detection of large spatial structures, and spatial accuracy calibration of large machine tools, multiple independent dual-comb ranging systems are typically required, resulting in bulky equipment, high costs, and complex system integration. Furthermore, when multiple systems operate simultaneously, mutual interference can easily occur, affecting ranging accuracy; and the synchronization control between systems is complex, making it difficult to guarantee the temporal consistency of multi-target measurement data, thus limiting its application in multi-target collaborative measurement scenarios. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, in response to the above-mentioned problems, the object of the present invention is to provide a multi-channel dual-comb ranging device with a compact structure, strong resistance to environmental disturbances, controllable cost, high measurement accuracy, and the ability to achieve multi-channel ranging.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: In a first aspect, the present invention provides a multi-channel dual-comb ranging device, which includes a dual-comb light source, an optical fiber path, a ranging spatial probe, a measuring corner cube prism, and a signal detection and acquisition processing module. The optical fiber path includes two sets of 1×n beam-splitting optical paths and n sets of optical fiber interference optical paths. Each optical fiber interference optical path includes a circulator and a coupler. The number of ranging spatial probes and measuring corner cube prisms is n, wherein: The dual-comb light source emits signal light and local oscillator light to the 1×n beam splitting optical path respectively. Each of the 1×n beam splitting optical paths divides the signal light and local oscillator light into n optical signals with the same energy. n local oscillator beams are emitted into each of the couplers; n-channel signal light is transmitted through each of the circulators to the corresponding ranging space probe. Each of the ranging space probes and the corresponding measuring corner prism, which is the target being measured, constructs a reference light signal and a measurement light signal. The reference light signal and the measurement light signal return along the original path and are output to the corresponding coupler through the circulator. The measurement light signal and the reference light signal are coupled with the local oscillator light in the coupler to generate a reference interference signal and a measurement interference signal, respectively. The signal detection and acquisition processing module acquires n reference interference signals and measurement interference signals for parallel processing, and calculates multiple ranging results in real time.

[0006] In some possible implementations, the signal detection and acquisition processing module includes n sets of photoelectric detection modules and 1 set of multi-channel compatible signal acquisition processing module, wherein: Each of the aforementioned photoelectric detection modules is used to receive reference interference signals and measurement interference signals from each of the aforementioned fiber optic interference paths and convert them into electrical signals. The detection bandwidth of the photoelectric detection module is greater than [missing information]. f r2 ,in, f r2 This indicates the repetition frequency of the local oscillator light; The signal acquisition and processing module is implemented using an FPGA to acquire and process multiple electrical signals in parallel, and to calculate multiple ranging results in real time. The sampling rate of the signal detection and processing module must satisfy the Nyquist sampling theorem and be greater than 2. f r2 .

[0007] Secondly, the present invention also provides a multi-channel dual-comb ranging device, comprising a dual-comb light source, an optical fiber path, a ranging spatial probe, a measuring corner cube prism, and a signal detection and acquisition processing module. The optical fiber path includes an optical fiber interference path and n optical switches, which can selectively output signals by switching. Each optical fiber interference path includes a circulator and a coupler. The number of ranging spatial probes and measuring corner cube prisms is n. The dual optical comb light source emits signal light and local oscillator light; The local oscillator light is emitted to the coupler; After being switched by the circulator and the n-way optical switches, the signal light is transmitted to the corresponding ranging space probe. The ranging space probe and the measuring corner cube prism, which is the target being measured, construct a reference light signal and a measuring light signal. The reference light signal and the measuring light signal return along the original path and are output to the coupler via the n-way optical switches and the circulator. The measuring light signal and the reference light signal are coupled with the local oscillator light respectively and interfere to generate a set of reference interference signals and measuring interference signals. The signal detection and acquisition processing module acquires the reference interference signal and the measurement interference signal, processes them separately, and calculates multiple ranging results.

[0008] In some possible implementations, the signal detection and acquisition processing module includes a photoelectric detection module and a signal acquisition processing module; The photoelectric detection module is used to receive the reference interference signal and the measurement interference signal of the fiber optic interference path and convert them into electrical signals. The detection bandwidth of the photoelectric detection module is greater than... f r2 ,in, f r2 This indicates the repetition frequency of the local oscillator light; The signal acquisition and processing module is used to acquire and process electrical signals one by one, and to solve multiple ranging results. The sampling rate of the signal detection and processing module must satisfy the Nyquist sampling theorem and be greater than 2. f r2 .

[0009] In some possible implementations, the fiber optic interference path further includes a filter for selective output of a specified wavelength and bandwidth, wherein the center wavelength should be approximately equal to the center wavelength of the dual-comb light source, and the bandwidth Δv comb Should be smaller f r1 f r2 / 2(Δ f r To ensure that spectral aliasing does not occur with the dual optical comb, among which, f r1 Indicates the repetition frequency of the signal light. f r2 Δ represents the repetition frequency of the local oscillator light. f r This represents the frequency difference between the local oscillator light and the signal light.

[0010] In some possible implementations, the circulator is used to realize unidirectional circular transmission of optical signals, enabling light to be transmitted from port ① → port ② → port ③.

[0011] In some possible implementations, each of the ranging spatial probes includes an optical fiber collimator, a beam splitter, and a reference cornerstone prism. The signal light from the optical fiber interference path is shaped into spatially collimated light by the optical fiber collimator. The spatially collimated light is split into two beams by the beam splitter: one beam is incident on the reference cornerstone prism as a reference beam; the other beam is incident on the measurement cornerstone prism at the target location as a measurement beam. The two beams are reflected by their respective cornerstone prisms and then rejoined at the beam splitter, collected by the optical fiber collimator, and returned to the circulator of the optical fiber interference path.

[0012] In some possible implementations, the signal detection and acquisition processing module is also connected to an air sensor to receive measured air temperature, humidity and pressure information, calculate the air refractive index according to the air refractive index calculation formula, and correct the ranging results.

[0013] In some possible implementations, the formula for calculating the ranging result is as follows: ; in, Indicates the distance measurement result. v g Δ represents the pulse group velocity. t To reference the time delay between the interferometric signal and the measured interferometric signal, f r1 Δ represents the repetition frequency of the signal light. f r This represents the frequency difference between the local oscillator light and the signal light.

[0014] In some possible implementations, the formula for calculating the ranging result is as follows: ; in, Indicates the distance measurement result. λ c Indicates the carrier wavelength in the air. N c Integer period representing the half-carrier wavelength This represents the carrier phase difference between the reference interference signal and the measured interference signal.

[0015] Because the present invention adopts the above technical solution, it has the following characteristics: 1. This invention includes a dual-comb light source, an optical fiber path, a ranging spatial probe, a measuring corner cube prism, and a signal detection and acquisition processing module. Through a multi-channel ranging optical path design, only one set of dual-comb light sources is needed. By splitting the light through optical fibers, multiple interference signals are solved in real time by the measurement signal detection and processing module. This enables real-time measurement of absolute ranging results at multiple points and ensures the time consistency of multi-target measurement data. It also enables multi-target collaborative measurement. Furthermore, for scenarios where real-time performance of multiple channels is not critical, this invention proposes a multi-channel ranging device based on optical switch switching. This device has a simple structure and can also achieve multi-target collaborative measurement.

[0016] 2. The multi-channel ranging spatial probe of the present invention adopts a spatial optical path design to ensure extremely high relative stability of the measuring light and the reference light, reduce the influence of thermal drift and other factors, and improve long-term ranging stability and resistance to environmental disturbances.

[0017] 3. This invention can improve the accuracy of multi-path ranging from the micrometer level to the nanometer level through the carrier interferometric ranging algorithm, covering the needs of higher precision ranging scenarios.

[0018] In summary, this invention offers controllable cost and high measurement accuracy, making it suitable for scenarios such as simultaneous distance measurement of multiple targets, spatial accuracy calibration of large machine tools, and deformation detection of large structural components. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a structural diagram of a multi-channel dual-comb ranging device according to an embodiment of the present invention; Figure 2 This is a structural diagram of an optical fiber interference path according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a ranging spatial probe according to an embodiment of the present invention; Figure 4 This is a structural diagram of a multi-channel dual-comb ranging device according to another embodiment of the present invention. Detailed Implementation

[0020] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0021] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0022] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "above," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure.

[0023] Existing dual-comb ranging technologies are mostly single-path ranging architectures. If multiple independent dual-comb ranging systems need to be deployed, it is difficult to guarantee the temporal consistency of multi-target measurement data, limiting its application in multi-target collaborative measurement scenarios. This invention provides a multi-channel dual-comb ranging device, including a dual-comb light source, an optical fiber path, a ranging space probe, a measuring corner prism, and a signal detection and acquisition processing module. The optical fiber path includes two 1×n beam-splitting optical paths and n sets of optical fiber interference optical paths. Each optical fiber interference optical path includes a circulator and a coupler. The number of ranging space probes and measuring corner prisms is n. The dual-comb light source emits signal light and local oscillator light, which are respectively sent to the 1×n beam-splitting optical paths. Each 1×n beam-splitting optical path divides the signal light and local oscillator light into n optical signals of equal energy. The n local oscillator lights are then... The signal is transmitted to each coupler; n-channel signal light is transmitted through each circulator to the corresponding ranging space probe. Each ranging space probe and the corresponding measuring corner prism, which serves as the target, construct a reference light signal and a measurement light signal. The reference light signal and the measurement light signal return along the original path and are output to the corresponding coupler via the circulator. The measurement light signal and the reference light signal are coupled with the local oscillator light in the coupler, respectively, and interference occurs to generate a reference interference signal and a measurement interference signal. The signal detection and acquisition processing module acquires the n-channel reference interference signal and the measurement interference signal and processes them in parallel to calculate multiple ranging results in real time. Therefore, this invention only requires one set of dual-comb light sources to split the multiple interference signals through optical fibers. The measurement signal detection and processing module then calculates the results in real time for multiple points of absolute ranging.

[0024] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0025] Example 1: As Figure 1 , Figure 2 As shown, the multi-channel dual-comb ranging device provided in this embodiment includes a dual-comb light source 1, an optical fiber path 2, a ranging spatial probe 3, a measuring corner cube prism 4, and a signal detection and acquisition processing module 5. The dual-comb light source 1 is used to provide a repetition frequency of... f r1 The signal light and repetition frequency are f r2 = f r1 + Δ f r The local oscillator light, Δ f r The frequency difference is considered. Fiber optic path 2 is used to split the signal light and local oscillator light, transmit and receive the signal light, and construct the interference optical path between the signal light and the local oscillator light. The ranging spatial probe 3 is used to construct the reference optical signal and the measurement optical signal. The measuring corner cube prism 4 serves as the target being measured and is used to directionally reflect the measurement optical signal back. The signal detection and acquisition processing module 5 is used to detect and acquire the interference signal formed by the dual optical combs and calculate the ranging result in real time.

[0026] Furthermore, the fiber optic path 2 includes two sets of 1×n beam splitting optical paths 21 and n sets of fiber interference optical paths 22. Each set of fiber interference optical paths 22 includes a circulator 221, a coupler 222, and a filter 223. The circulator 221 is used to realize unidirectional ring transmission of optical signals, enabling light transmission from port ① to port ② to port ③ with extremely high reverse isolation. The coupler 222 is used to couple two input signals to one output. The filter 223 is used for selective output of a specified wavelength and bandwidth, wherein the center wavelength should be approximately equal to the center wavelength of the dual-comb light source 1, and the bandwidth Δv comb Should be smaller f r1 f r2 / 2(Δ f r This is to ensure that spectral aliasing of the dual optical comb does not occur.

[0027] During ranging, the dual-comb light source 1 emits signal light and local oscillator light to 1×n beam splitting optical paths 21, respectively. Each 1×n beam splitting optical path 21 divides the signal light and local oscillator light into n optical signals of equal energy. The n local oscillator lights are emitted into each coupler 222. The n signal lights are transmitted to the corresponding ranging space probe 3 via port ①→port ② of each circulator 221. Each ranging space probe 3 and the corresponding measuring corner cube prism 4, which serves as the target, construct a reference light signal and a measurement light signal. The reference light signal and the measurement light signal return along the original path via port ②→port ③ of the circulator 221 to the corresponding coupler 222. The measurement light signal and the reference light signal are coupled with the local oscillator light in the coupler 222. At every 1 / Δ f r Within a time period, a set of reference interference signals and measurement interference signals are generated. The optical signal is filtered by filter 223. The signal detection and acquisition processing module 5 acquires n reference interference signals and measurement interference signals for parallel processing and calculates multiple ranging results in real time.

[0028] In a preferred embodiment of the present invention, such as Figure 3 As shown, each ranging spatial probe 3 includes an optical fiber collimator 31, a beam splitter prism 32, and a reference cornerstone prism 33. The optical fiber collimator 31 converts the diverging light output from the optical fiber in the optical fiber interference path 2 into parallel light, and also efficiently couples external parallel light to the optical fiber. The beam splitter prism 32 splits or combines the incident light; its splitting ratio is not strictly limited and can be set according to specific conditions. The reference cornerstone prism 33 reflects the beam along its original path. During ranging, the signal light from the optical fiber interference path 2 is shaped into spatially collimated light by the optical fiber collimator 31, and then split into two beams by the beam splitter prism 32 at a specific ratio: one beam serves as the reference light and is incident on the reference cornerstone prism 33; the other beam serves as the measurement light and is incident on the measurement cornerstone prism 4 at the target location. After being reflected by the cornerstone prisms, the two beams converge again at the beam splitter prism 32, are collected by the optical fiber collimator 31, and coupled back into the optical fiber, returning to the optical fiber interference path 2 along its original path.

[0029] In a preferred embodiment of the present invention, the signal detection and acquisition processing module 5 includes n sets of photoelectric detection modules 51 and one set of multi-channel compatible signal acquisition processing module 52, wherein: the photoelectric detection module 51 is used to receive interference light signals from the fiber optic interference optical path 2 and convert them into electrical signals; the signal acquisition processing module 52 is based on an FPGA and includes the FPGA and its peripheral configuration circuits. The parallel operation architecture of the FPGA enables it to simultaneously acquire and process multiple types of data, to acquire electrical signals and perform analog signal and digital conversion, and to perform parallel calculations on the ranging results in real time. Finally, the n ranging results are transmitted to the host computer 6 through the communication interface.

[0030] Furthermore, the signal detection and acquisition processing module 5 is also connected to an air sensor 7. It can also use the air temperature, humidity and pressure information measured by the air sensor 7 to calculate the air refractive index according to the air refractive index calculation formula, which is used to correct the ranging results.

[0031] Furthermore, the detection bandwidth of the photoelectric detection module 51 is generally greater than [missing information]. f r2 The sampling rate of the signal detection and processing module 52 must satisfy the Nyquist sampling theorem, and is generally greater than 2. f r2 .

[0032] Furthermore, the process of converting the acquired electrical signals from analog to digital and then calculating the ranging results in real time using the time-of-flight method is as follows: Every 1 / Δ f r A set of reference interference signals and measurement interference signals are generated within a time period, first the distance being measured. D TOF The time delay Δ between the reference interference signal and the measured interference signal can be used to determine the time delay. t get:

[0033] in, v g Indicates the pulse group velocity, with a time delay Δ. t It can be calculated from the phase slope of the sub-frequency comb. This method has the characteristics of a large non-ambiguity range, and the measurement accuracy can usually reach the micrometer level or even the hundred nanometer level.

[0034] Furthermore, for higher precision measurement requirements, the measured distance value can be obtained through carrier interferometry. D c The carrier phase difference between the reference interference signal and the measured interference signal can be used to determine the interference signal. Find:

[0035] in, λ c The carrier wavelength in the air is obtained using a wavelength meter; N c Indicates half-carrier wavelength ( λ c / 2) integer period, when the ranging accuracy of the time-of-flight method is better than λ c When the value is 4, the result can be uniquely determined. λ c Integer period of 2 N cThis allows for direct integration of the time-of-flight method with the carrier interferometry method, achieving high-precision distance measurement over a large unambiguous range through combined ranging:

[0036] The INT symbol indicates rounding down.

[0037] Example 2: For scenarios where real-time requirements for multi-channel measurements are not high, the complexity of the device can be further simplified by... Figure 1 Simplified to: Figure 4 The structure shown in this embodiment differs from that in Embodiment 1 as follows: 1) The fiber optic interference optical path 2 consists of a fiber optic interference optical path 22 and an n-way optical switch 23. The signal light and local oscillator light output from the dual-comb light source 1 are directly input into the fiber optic interference optical path 22; the signal light is transmitted to the n-way optical switch 23. By switching the optical switch, the signal light can be selected to be output to a corresponding ranging space probe 3 for continued measurement.

[0038] 2) The signal detection and acquisition processing module 5 includes a photoelectric detection module 51 and a signal acquisition processing module 52. In this embodiment, only one photoelectric detection module 5 is required, and the signal acquisition processing module 52 only needs to have single-channel acquisition and processing capabilities. Its function is consistent with that of implementation scheme 1. At any given time, the signal acquisition processing module 52 only needs to process the sampled and processed measurement signals returned by a set of ranging space probes.

[0039] It should be noted that other contents not described in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0040] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In the description of this specification, the terms "a preferred embodiment," "furthermore," "specifically," "in this embodiment," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments in this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-channel dual optical comb ranging device, characterized in that, The device comprises a dual optical comb light source, a fiber optical path, a ranging space probe, a measuring corner cube prism and a signal detection and acquisition processing module, the fiber optical path comprises two sets of 1x n beam splitting optical paths and n groups of fiber interference optical paths, each fiber interference optical path comprises a circulator and a coupler, the number of the ranging space probes and the measuring corner cube prisms is n, wherein: The dual optical comb light source emits signal light and local oscillator light to the 1x n beam splitting optical paths, each 1x n beam splitting optical path divides the signal light and the local oscillator light into n paths of optical signals with the same energy; The n paths of local oscillator light are respectively emitted into each coupler; The n paths of signal light are transmitted to the corresponding ranging space probes through each circulator, each ranging space probe and the corresponding measuring corner cube prism as a measured target construct reference light signals and measuring light signals, the reference light signals and the measuring light signals return along the original path and are output to the corresponding coupler through the circulator, the measuring light signals and the reference light signals are coupled in the coupler to generate reference interference signals and measuring interference signals; The signal detection and acquisition processing module acquires n paths of reference interference signals and measuring interference signals for parallel processing and real-time calculation of multiple ranging results.

2. The multi-channel dual-comb ranging apparatus of claim 1, wherein, The signal detection and acquisition processing module comprises n groups of photoelectric detection modules and one group of signal acquisition processing modules compatible with multiple paths, wherein: Each of the photoelectric detection modules is configured to receive and convert the reference interference signal and the measurement interference signal from each of the fiber interference optical paths into an electrical signal, and the photoelectric detection module has a detection bandwidth greater than f r2 wherein, f r2 represents the repetition frequency of the local light. The signal acquisition and processing module is realized by using FPGA, is used for collecting and processing multiple electric signals in parallel, and solves multiple ranging results in real time, and the sampling rate of the signal detection and processing module needs to meet the Nyquist sampling law, is greater than 2 f r2 .

3. A multi-channel dual optical comb ranging device, characterized in that, The device comprises a dual optical comb light source, a fiber optical path, a ranging space probe, a measuring corner cube prism and a signal detection and acquisition processing module, wherein the fiber optical path comprises a fiber interference optical path and n optical switches, the n optical switches can select to output signals by switching, the fiber interference optical path comprises a circulator and a coupler, the number of the ranging space probes and the measuring corner cube prisms is n, wherein: The dual optical comb light source emits signal light and local oscillator light; The local oscillator light is emitted to the coupler; The signal light is transmitted to the corresponding ranging space probe after switching through the circulator and the n optical switches, the ranging space probe and the measuring corner cube prism as a measured target construct reference light signals and measuring light signals, the reference light signals and the measuring light signals return along the original path and are output to the coupler through the n optical switches and the circulator, the measuring light signals and the reference light signals are coupled to generate a group of reference interference signals and measuring interference signals; The signal detection and acquisition processing module acquires the reference interference signals and the measuring interference signals for processing, respectively, and calculates multiple ranging results.

4. The multi-channel dual-comb ranging device of claim 3, wherein, The signal detection and acquisition processing module comprises one photoelectric detection module and a signal acquisition processing module; The photoelectric detection module is configured to receive the reference interference signal and the measurement interference signal of the fiber optic interference optical path and convert them into electrical signals, and the photoelectric detection module has a detection bandwidth greater than f r2 wherein, f r2 represents the repetition frequency of the local light. The signal acquisition and processing module is used for acquiring and processing the electric signals one by one, and resolving the multiple ranging results respectively. The sampling rate of the signal detection and processing module needs to meet the Nyquist sampling law and be greater than 2 f r2 .

5. The multi-channel dual-comb ranging apparatus of claim 1 or 3, wherein, The optical fiber interference optical paths also comprise filters for selective output of a specified wavelength and bandwidth, wherein the center wavelength should be approximately equal to the center wavelength of the dual optical comb light source, and the bandwidth Δv comb Should be less than f r1 f r2 / 2(Δ f r , to ensure that no dual optical comb spectrum aliasing occurs, wherein, f r1 represents the repetition frequency of the signal light, f r2 represents the repetition frequency of the local light, Δ f r represents the repetition frequency difference between the local light and the signal light.

6. The multi-channel dual-comb ranging apparatus of claim 1 or 3, wherein, The circulator is used for realizing one-way ring transmission of optical signals, realizing transmission of light from port ① to port ② to port ③.

7. The multi-channel dual-comb ranging device of claim 1, wherein, Each of the ranging space probes comprises a fiber collimator, a light splitting prism and a reference corner cube prism, wherein the signal light from the fiber interference optical path is shaped by the fiber collimator into spatially collimated light, the spatially collimated light is split into two beams by the light splitting prism, one of the two beams is incident on the reference corner cube prism as reference light, and the other is incident on the measuring corner cube prism at the target as measuring light, the two beams are reflected by the corresponding corner cube prisms and then converge again at the light splitting prism, and the light is collected by the fiber collimator and returned to the fiber interference optical path ring.

8. The multi-channel dual-comb ranging apparatus of claim 1 or 3, wherein, The signal detection and acquisition processing module is further connected with an air sensor for receiving measured air temperature, humidity and pressure information, calculating the air refractive index according to an air refractive index calculation formula, and correcting the ranging result.

9. The multi-channel dual-comb ranging apparatus of claim 1 or 3, wherein, The calculation formula of the ranging result is: ； wherein, represents a ranging result, v g represents a group velocity of the pulse, Δ t is a time delay between the reference interference signal and the measurement interference signal, f r1 represents a repetition frequency of the signal light, Δ f r represents a repetition frequency difference between the local light and the signal light.

10. The multi-channel dual-comb ranging apparatus of claim 1 or 3, wherein, The calculation formula of the ranging result is: ； wherein represents the ranging result, λ c represents the carrier wavelength in air, N c represents an integer number of carrier wavelengths in air, represents the carrier phase difference between the reference and the measurement interference signals.

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