Optical signal processor, radar and optical signal processing method

Abstract

The embodiment of the application provides an optical signal processor and an optical signal processing method, which can be applied to the fields of laser radar, Internet of Vehicles and the like. The method comprises the following steps: a signal beam splitting component is used for receiving a return light signal and respectively outputting a main light path signal and a differential light path signal; wherein the return light signal comprises a probe light signal and a noise signal; the wavelength band of the main light path signal comprises the wavelength band of the probe light signal, and the wavelength band of the differential light path signal does not overlap with the wavelength band of the probe light signal; a differential detector is used for respectively receiving the main light path signal and the differential light path signal, and extracting probe information in the main light path signal according to the main light path signal and the differential light path signal. The technical scheme provided by the application can avoid the problem of false warning caused by noise.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical signal processing, and in particular to an optical signal processor, a radar and an optical signal processing method. BACKGROUND

[0002] When it is necessary to detect whether an object exists in a target area, various laser-based detection technologies can be used.

[0003] In one application, a detection device emits laser light to the target area, and if an object exists in the target area, the laser light is reflected when it reaches the object, and the detection device can receive the reflected light signal.

[0004] However, when the detection device is disturbed, the light signal received by the detection device can fluctuate, and the detection device cannot determine whether the reflected light signal is received. SUMMARY

[0005] The present application provides an optical signal processor, a radar and an optical signal processing method, which can avoid the problem of false alarm caused by noise.

[0006] In a first aspect, an embodiment of the present application provides an optical signal processor, comprising:

[0007] a signal splitting component, configured to receive a return light signal and output a main light path signal and a differential light path signal respectively; wherein the return light signal comprises a detection light signal and a noise signal; a wave band of the main light path signal comprises a wave band of the detection light signal, and a wave band of the differential light path signal does not overlap with the wave band of the detection light signal;

[0008] a differential detector, configured to receive the main light path signal and the differential light path signal respectively, and extract detection information in the main light path signal according to the main light path signal and the differential light path signal.

[0009] In an embodiment of the present application, since the main light path signal contains the detection light signal and the noise signal, and the differential light path signal contains only the noise signal, differential operation according to the main light path signal and the differential light path signal can remove the noise signal in the main light path signal, and obtain the real detection light signal, so that the detection information in the detection light signal can be extracted more accurately.

[0010] In an example, the optical signal processor can be a laser radar.

[0011] In an optional implementation, the optical signal processor further comprises a laser, configured to emit the detection light signal.

[0012] In an optional embodiment, the wavelength band of the probe light signal is N-X to N+X, wherein N is the central wavelength of the probe light signal, X is half of the spectral width of the probe light signal, and X is less than N;

[0013] The wavelength band of the differential light path signal is N-Y to N-X, and / or N+X to N+Y, wherein Y is half of the signal extraction spectral width, Y is less than N, and Y is greater than X.

[0014] In an optional embodiment, the wavelength band of the main light path signal is the wavelength band of the probe light signal.

[0015] In the embodiments of the present application, when the wavelength band of the differential light path signal is located on both sides of the wavelength band of the main light path signal and is relatively close to the wavelength band of the main light path signal, the intensity distribution of the noise signal in the wavelength band of the differential light path signal is closer to the intensity distribution of the noise signal in the wavelength band of the main light path signal, and based on this, the noise signal in the main light path signal can be removed more accurately.

[0016] In an optional embodiment, the signal splitting assembly comprises a light splitting assembly, a main light path assembly, and a differential light path assembly.

[0017] The light splitting assembly is configured to output the echo light signal to the main light path assembly and the differential light path assembly, respectively.

[0018] The main light path assembly is configured to output the echo light signal in the wavelength band range of the main light path signal to the differential detector.

[0019] The differential light path assembly is configured to output the echo light signal in the wavelength band range of the differential light path signal to the differential detector.

[0020] In an optional embodiment, the differential light path assembly comprises:

[0021] A first filter is configured to filter the received echo light signal and output the echo light signal in a signal extraction wavelength band to a notch filter, wherein the signal extraction wavelength band comprises the wavelength band of the differential light path signal.

[0022] The notch filter is configured to filter the received echo light signal in the signal extraction wavelength band and filter out the echo light signal outside the wavelength band range of the differential light path signal in the signal extraction wavelength band, and output the echo light signal in the wavelength band range of the differential light path signal.

[0023] In an example, the signal extraction waveband can be composed of the waveband of the differential optical path signal and the waveband of the main optical path signal, and the waveband of the differential optical path signal does not overlap with the waveband of the main optical path signal, for example, the signal extraction waveband is N-Y to N+Y, the waveband of the main optical path signal is N-X to N+X, and the waveband of the differential optical path signal is N-Y to N-X and N+X to N+Y, and the notch filter can filter out the echo optical signal in the waveband range of the main optical path signal in the signal extraction waveband, and output the echo optical signal in the waveband range of the differential optical path signal.

[0024] In an alternative embodiment, the main optical path assembly comprises:

[0025] The second filter is configured to filter the received echo optical signal, and output the echo optical signal in the waveband range of the main optical path signal to the differential detector.

[0026] In an alternative embodiment, the light splitting assembly comprises a light splitting prism and a reflecting prism.

[0027] The light splitting prism is configured to receive the echo optical signal, and output the echo optical signal to the reflecting prism and the main optical path assembly, respectively.

[0028] The reflecting prism is configured to reflect the received echo optical signal to the differential optical path assembly.

[0029] In the embodiments of the present application, the light splitting prism and the reflecting prism are used to make the main optical path and the differential optical path in the optical signal processor point to the same direction, so that part of the structure can be shared, for example, because the output directions of the main optical path signal and the differential optical path signal are parallel to each other, the light sensitive surfaces of the two detectors can be arranged in one differential detector, which is equivalent to arranging the light sensitive surfaces of the two detectors at the same position, which is beneficial to reducing the overall volume of the optical signal processor or the laser radar, and further realizing the rapid integration of the product.

[0030] In an alternative embodiment, the light splitting assembly comprises:

[0031] The fiber beam splitter is configured to receive the echo optical signal, and output the echo optical signal to the main optical path assembly and the differential optical path assembly through optical fibers, respectively.

[0032] In the embodiments of the present application, the fiber beam splitter is used to replace the light splitting prism and the reflecting prism, and because the light direction is not limited when the optical fiber emits light, the structure of the optical signal processor is easier to design.

[0033] In an optional embodiment, the differential detector comprises a first photosensitive surface and a second photosensitive surface in the same plane, wherein the first photosensitive surface is located in the output direction of the main light path signal, and the second photosensitive surface is located in the output direction of the differential light path signal. Exemplarily, the output directions of the main light path signal and the differential light path signal are parallel to each other and perpendicular to the plane in which the first photosensitive surface and the second photosensitive surface are located.

[0034] In an optional embodiment, the optical signal processor is a radar.

[0035] The differential detector is specifically configured to perform differential operation on the main light path signal and the differential light path signal, determine a decision threshold, and extract detection information in the main light path signal according to the decision threshold.

[0036] In an example, the differential detector can convert the main light path signal and the differential light path signal from optical signals to electrical signals, perform differential operation on the converted main light path signal and the converted differential light path signal, remove noise signals in the converted main light path signal to obtain an electrical signal corresponding to the detection light signal, determine a decision threshold according to the electrical signal corresponding to the detection light signal, and extract detection information in the electrical signal corresponding to the detection light signal according to the decision threshold. In this way, background light can be removed, and the decision threshold and the detection information can be determined by using an electrical processor.

[0037] In an optional embodiment, the optical signal processor further comprises a laser for emitting the detection light signal and an auxiliary light signal, wherein the wavelength band of the auxiliary light signal does not overlap with the wavelength band of the detection light signal.

[0038] In an optional embodiment, the echo light signal further comprises an auxiliary light signal, wherein the wavelength band of the auxiliary light signal does not overlap with the wavelength band of the detection light signal.

[0039] The signal splitting assembly is specifically configured to output the first main light path signal and the first differential light path signal, and output the second main light path signal and the second differential light path signal, respectively, wherein the wavelength band of the first main light path signal comprises the wavelength band of the detection light signal, the wavelength band of the second main light path signal comprises the wavelength band of the auxiliary light signal, the wavelength band of the first differential light path signal does not overlap with the wavelength band of the detection light signal and the wavelength band of the auxiliary light signal, and the wavelength band of the second differential light path signal does not overlap with the wavelength band of the detection light signal and the wavelength band of the auxiliary light signal.

[0040] The differential detector is specifically configured to extract detection information in the first main light path signal or the second main light path signal according to the first main light path signal and the first differential light path signal, and the second main light path signal and the second differential light path signal.

[0041] In an alternative embodiment, the wavelength band of the first main optical path signal and the wavelength band of the second main optical path signal are respectively the wavelength band of the probe light signal and the wavelength band of the auxiliary light signal.

[0042] In an alternative embodiment, the wavelength band of the first differential optical path signal and the wavelength band of the second differential optical path signal are respectively a first adjacent wavelength band and a second adjacent wavelength band. In an example, the minimum value of the first adjacent wavelength band is equal to the maximum value of the wavelength of the probe light signal, or the maximum value of the first adjacent wavelength band is equal to the minimum value of the wavelength of the probe light signal. The minimum value of the second adjacent wavelength band is equal to the maximum value of the wavelength of the auxiliary light signal, or the maximum value of the second adjacent wavelength band is equal to the minimum value of the wavelength of the auxiliary light signal.

[0043] In an alternative embodiment, the differential detector can convert each signal into an electrical signal, perform differential operation on the first main optical path signal and the first differential optical path signal to obtain a noise signal in the wavelength band of the probe light signal, perform differential operation on the second main optical path signal and the second differential optical path signal to obtain a noise signal in the wavelength band of the auxiliary light signal; compare the noise signals in the wavelength band of the probe light signal and the wavelength band of the auxiliary light signal, if the amplitude of the noise signal in the wavelength band of the probe light signal is lower than the amplitude of the wavelength band of the auxiliary light signal, perform differential operation on the first main optical path signal and the first differential optical path signal to determine a decision threshold, and extract the probe information from the probe light signal; if the amplitude of the noise signal in the wavelength band of the probe light signal is higher than the amplitude of the wavelength band of the auxiliary light signal, perform differential operation on the second main optical path signal and the second differential optical path signal to determine a decision threshold, and extract the probe information from the auxiliary light signal.

[0044] With this embodiment, the problem of false alarm caused by other interference noise in the wavelength band of the probe light signal, such as narrowband interference noise from other radars, can be avoided.

[0045] In a second aspect, the embodiments of the present application provide a radar, comprising: a laser and any of the light signal processors in the first aspect; wherein the laser is configured to emit the probe light signal.

[0046] In an alternative embodiment, the laser is further configured to emit the auxiliary light signal; the return light signal further comprises the auxiliary light signal; wherein the wavelength band of the auxiliary light signal does not overlap with the wavelength band of the probe light signal.

[0047] The signal splitting component of the optical signal processor is specifically configured to output the first main optical path signal and the first differential optical path signal, and the second main optical path signal and the second differential optical path signal, respectively; wherein the wavelength band of the first main optical path signal includes the wavelength band of the probe optical signal, the wavelength band of the second main optical path signal includes the wavelength band of the auxiliary optical signal, the wavelength band of the first differential optical path signal does not overlap with the wavelength band of the probe optical signal and the wavelength band of the auxiliary optical signal, and the wavelength band of the second differential optical path signal does not overlap with the wavelength band of the probe optical signal and the wavelength band of the auxiliary optical signal.

[0048] The differential detector of the optical signal processor is specifically configured to extract the probe information in the first main optical path signal or the second main optical path signal according to the first main optical path signal and the first differential optical path signal and the second main optical path signal and the second differential optical path signal.

[0049] In a third aspect, an embodiment of the present application provides an optical signal processing method, which comprises:

[0050] The optical signal processor receives a return optical signal; wherein the return optical signal includes a probe optical signal and a noise signal; the return optical signal is subjected to signal splitting processing to obtain a main optical path signal and a differential optical path signal; wherein the wavelength band of the main optical path signal includes the wavelength band of the probe optical signal, and the wavelength band of the differential optical path signal does not overlap with the wavelength band of the probe optical signal; and the probe information in the main optical path signal is extracted according to the main optical path signal and the differential optical path signal.

[0051] In an optional embodiment, the wavelength band of the probe optical signal is N-X to N+X; wherein N is the center wavelength of the probe optical signal, X is half of the spectral width of the probe optical signal, and X is less than N; the wavelength band of the differential optical path signal includes N-Y to N-X and / or N+X to N+Y; wherein Y is half of the signal extraction spectral width, Y is less than N and Y is greater than X.

[0052] In an optional embodiment, the wavelength band of the main optical path signal is the wavelength band of the probe optical signal.

[0053] In an optional embodiment, the signal splitting processing of the return optical signal to obtain the main optical path signal and the differential optical path signal comprises:

[0054] The return optical signal is subjected to optical splitting processing to obtain the return optical signal of the main optical path and the return optical signal of the differential optical path;

[0055] The return optical signal of the main optical path is subjected to optical filtering processing to output the return optical signal in the wavelength band range of the main optical path signal;

[0056] filtering the echo optical signal of the differential optical path to output the echo optical signal within the wavelength range of the differential optical path signal.

[0057] In an optional implementation, the filtering the echo optical signal of the differential optical path to output the echo optical signal within the wavelength range of the differential optical path signal comprises: filtering the echo optical signal of the differential optical path to output the echo optical signal of a signal extraction wavelength band; filtering the echo optical signal of the signal extraction wavelength band to filter out the echo optical signal outside the wavelength range of the differential optical path signal in the signal extraction wavelength band, and outputting the echo optical signal within the wavelength range of the differential optical path signal.

[0058] In an optional implementation, the filtering the echo optical signal of the main optical path to output the echo optical signal within the wavelength range of the main optical path signal comprises: filtering the echo optical signal of the main optical path to output the echo optical signal within the wavelength range of the main optical path signal.

[0059] In an optional implementation, the splitting the echo optical signal to obtain the echo optical signal of the main optical path and the echo optical signal of the differential optical path comprises: splitting the echo optical signal of the first direction to obtain the echo optical signal of the main optical path of the first direction and the echo optical signal of the differential optical path of the second direction; reflecting the echo optical signal of the differential optical path of the second direction to obtain the echo optical signal of the differential optical path of the first direction.

[0060] In an optional implementation, the splitting the echo optical signal to obtain the echo optical signal of the main optical path and the echo optical signal of the differential optical path comprises: splitting the echo optical signal to output the echo optical signal of the main optical path through a first optical fiber output end and output the echo optical signal of the differential optical path through a second optical fiber output end.

[0061] In an optional implementation, the extracting the detection information in the main optical path signal according to the main optical path signal and the differential optical path signal comprises: performing differential operation processing on the main optical path signal and the differential optical path signal to determine a decision threshold; and extracting the detection information in the main optical path signal according to the decision threshold.

[0062] In an optional implementation, before the optical signal processor receives the echo optical signal, the method further comprises: emitting the detection optical signal.

[0063] In an alternative embodiment, before the optical signal processor receives the echo optical signal, the method further comprises: transmitting an assisting optical signal, wherein the wavelength band of the assisting optical signal does not overlap with the wavelength band of the probe optical signal.

[0064] In an alternative embodiment, the echo optical signal further comprises an assisting optical signal; and the signal splitting processing of the echo optical signal to obtain the main optical path signal and the differential optical path signal comprises: signal splitting processing of the echo optical signal to obtain a first main optical path signal, a first differential optical path signal, a second main optical path signal and a second differential optical path signal; wherein the wavelength band of the first main optical path signal comprises the wavelength band of the probe optical signal, the wavelength band of the second main optical path signal comprises the wavelength band of the assisting optical signal, the wavelength band of the first differential optical path does not overlap with the wavelength band of the probe optical signal and the wavelength band of the assisting optical signal, and the wavelength band of the second differential optical path does not overlap with the wavelength band of the probe optical signal and the wavelength band of the assisting optical signal.

[0065] The extracting of the probe information in the main optical path signal according to the main optical path signal and the differential optical path signal comprises: extracting the probe information in the first main optical path signal or the second main optical path signal according to the first main optical path signal, the first differential optical path signal, the second main optical path signal and the second differential optical path signal. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1A Fig. 1 is a schematic diagram of an application scenario related to the embodiments of the present application;

[0067] Figure 1B Fig. 2 is a waveform diagram of an echo optical signal in the embodiments of the present application;

[0068] Figure 1C Fig. 3 is a schematic diagram of an application scenario related to the embodiments of the present application; Figure Two ;

[0069] Figure 2 Fig. 4 is a structural schematic diagram of an optical signal processor provided by the embodiments of the present application;

[0070] Figure 3A Fig. 5 is a schematic diagram of the wavelength band of a main optical path signal and the wavelength band of a differential optical path signal in the embodiments of the present application;

[0071] Figure 3B Fig. 6 is a schematic diagram of the wavelength band of a main optical path signal and the wavelength band of a differential optical path signal in the embodiments of the present application; Figure Two ;

[0072] Figure 3C Fig. 7 is a schematic diagram of the wavelength band of a main optical path signal and the wavelength band of a differential optical path signal in the embodiments of the present application;

[0073] Figure 3D Waveform diagram of the main light path signal and the differential light path signal in the embodiment of the present application Figure Four

[0074] Figure 3E Waveform diagram of removing noise signal in echo light signal by differential operation in the embodiment of the present application

[0075] Figure 4 Structure diagram of the optical signal processor provided by the embodiment of the present application Figure Two

[0076] Figure 5 Spectrum diagram of the optical signal processor provided by the embodiment of the present application adopting double light path filtering

[0077] Figure 6A Assembled structure diagram of the optical signal processor Figure 4

[0078] Figure 6B Assembled structure diagram of the optical signal processor Figure 4 Figure Two

[0079] Figure 6C Assembled structure diagram of the optical signal processor Figure 4

[0080] Figure 6D Assembled structure diagram of the optical signal processor Figure 4 Figure Four

[0081] Figure 6E Assembled structure diagram of the optical signal processor Figure 4 Figure Five

[0082] Figure 6F Assembled structure diagram of the optical signal processor Figure 4

[0083] Figure 6G Assembled structure diagram of the optical signal processor Figure 4 Figure Seven

[0084] Figure 6H Assembled structure diagram of the optical signal processor Figure 4

[0085] Figure 6I Assembled structure diagram of the optical signal processor Figure 4

[0086] Figure Seven ​​​​​​​​​​​​​​​Figure 3 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application;

[0087] Figure 8A Figure 4 shows an assembly structural schematic diagram of the optical signal processor shown in Figure 1; Figure 7

[0088] Figure 8B Figure 5 shows an assembly structural schematic diagram of the optical signal processor shown in Figure 2; Figure 7 Figure Two

[0089] Figure 9A Figure 6 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application; Figure Four

[0090] Figure 9B Figure 7 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application; Figure 9A

[0091] Figure 9C Figure 8 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application; Figure 9A Figure Two

[0092] Figure 9D Figure 9 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application; Figure 9A

[0093] Figure 9E Figure 10 shows a structural schematic diagram of the optical signal processor according to an embodiment of the present application; Figure 9A Figure Four

[0094] Figure 10 Figure 11 shows a flow schematic diagram of an optical signal processing method according to an embodiment of the present application. DETAILED DESCRIPTION

[0095] The terms used in the embodiment part of the present application are only used for explaining the specific embodiments of the present application, and are not intended to limit the present application.

[0096] The present application provides an optical signal processor. The optical signal processor can remove background noise in the received optical signal, so as to more accurately extract useful information carried in the received optical signal, and avoid the problem of false alarm caused by noise.

[0097] Embodiment one

[0098] First, the application scenario of the optical signal processor provided by the embodiments of the present application is exemplarily described below.

[0099] For example, the optical signal processor of the embodiments of the present application can be applied to the field of laser-based radar detection technology.

[0100] Figure 1A ​​​​​​​​​​This is a schematic diagram illustrating an application scenario involved in an embodiment of this application. For example... Figure 1A As shown in the embodiments of this application, the lidar may include a transmitting device and a receiving device.

[0101] For example, a transmitting device can be used to emit a probe light signal. This probe light signal can be used to detect the presence of an object in a target area and to acquire information about the detected object. In one example, the transmitting device can be a laser, which emits a probe light signal through a transmission window towards the target area. The probe light signal can be a laser beam with a specific frequency. If an object exists in the target area, the probe light signal undergoes diffuse reflection upon reaching the object's surface. A portion of the reflected light signal is reflected along the original optical path and enters the receiving window of the receiving device. The receiving device can be used to receive the echo light signal and extract the detection information from it. For example, see [link to example]. Figure 1A As shown, the receiving device can determine the flight time of the entire optical signal propagation process based on the transmission time of the probe optical signal and the reception time represented by the echo optical signal. Then, the distance between the object and the optical signal processor can be determined based on the flight time and the speed of light. For example, the distance d = flight time * speed of light / 2.

[0102] In practical applications, a decision threshold can be preset. When an echo light signal higher than the decision threshold is detected, it can be determined that there is an object and information about the object in the target area. Figure 1B This is a waveform diagram of the echo optical signal in an embodiment of this application. When there is no object in the target area, such as... Figure 1B As shown at time t0, the amplitude of the echo signal is below the decision threshold, at which point it can be determined that there is no object in the target area. Figure 1B As shown at time t1, the amplitude of the echo light signal is higher than the decision threshold, at which point it can be determined that there is an object in the target area.

[0103] In this embodiment of the application, the noise signal in the echo optical signal may change abruptly, which may lead to erroneous judgments of false alarm or missed alarm types. Figure 1C This is an illustration of an application scenario involved in the embodiments of this application. Figure Two ,like Figure 1C As shown in Scene 1 and Scene 2, the noise signal can originate from sunlight reflected off the water surface and sunlight emitted from mirrored objects.

[0104] In one example, when the background light entering the receiving device changes, see reference... Figure 1B As shown at time t2, the waveform of the echo light signal is higher than the decision threshold. This situation, in which an object is judged to exist in the target area even though it does not actually exist, can be called a false alarm.

[0105] In another example, if the decision threshold is set high, see [link to example]. Figure 1BThe decision threshold represented by a dashed line between time t2 and time t3. At time t3, since the amplitude of the echo light signal at time t3 is lower than the decision threshold, the case that an actually existing object is determined as a non-existing object can be referred to as a false negative.

[0106] The optical signal processor provided in the embodiments of the present application can avoid the above-mentioned type of false decision when the noise signal changes.

[0107] The optical signal processor provided in the embodiments of the present application and the related processing method are exemplarily described below.

[0108] Figure 2 The structure diagram one of the optical signal processor provided in the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the optical signal processor 1000 provided in the embodiments of the present application can include a signal splitting assembly 100 and a differential detector 200. Figure 2

[0109] The signal splitting assembly 100 is configured to receive an echo light signal and output a main light path signal and a differential light path signal respectively; wherein the echo light signal includes a probe light signal and a noise signal; the wave band of the main light path signal includes the wave band of the probe light signal, and the wave band of the differential light path signal does not overlap with the wave band of the probe light signal.

[0110] The differential detector 200 is configured to receive the main light path signal and the differential light path signal respectively, and extract the probe information in the main light path signal according to the main light path signal and the differential light path signal.

[0111] In the embodiments of the present application, the optical signal processor 1000 can further include a laser 300, which is configured to emit the probe light signal. It should be noted that the laser 300 is not a necessary component in the optical signal processor 1000. In an alternative embodiment, the optical signal processor 1000 can also be configured to receive the probe light signal emitted by a laser located outside the optical signal processor 1000. In the embodiments of the present application, the laser can continuously emit the probe light signal, and the optical signal receiver can continuously receive the echo light signal, and determine the information of the object in the target region within a period of time according to the waveform of the echo light signal. The following is described by taking the laser located in the optical signal processor 1000 as an example.

[0112] In the embodiments of the present application, the echo light signal entering the optical signal processor includes the reflected probe light signal and the noise signal. The wave band of the probe light signal is a narrow band, and exemplarily, the center wavelength of the probe light signal can be N and the bandwidth can be 2X. The noise signal can be wide spectrum, and exemplarily, the wave band of the noise signal can be the full wave band.

[0113] ​In the embodiment of the present application, the optical signal processor 1000 can further comprise a preprocessing component (not shown in the figure), which can be used to input the echo optical signal into the signal splitting component. In actual application, the preprocessing component can also be used to perform convergence and shaping on the echo optical signal.

[0114] In the embodiment of the present application, the signal splitting component 100 has various implementation manners. For example, the signal splitting component 100 can comprise three parts, a light splitting component, a main optical path component, and a differential optical path component.

[0115] The light splitting component is used to split the echo optical signal received from outside the signal splitting component into two optical signals, and input the two optical signals into the main optical path component and the differential optical path component respectively. In an example, the light splitting component can be implemented by using a light splitting prism or a fiber splitter, and the light splitting component can also output the two echo optical signals to the main optical path component and the differential optical path component respectively according to a certain light splitting ratio. The main optical path component is used to filter out the part of the first echo optical signal received from the light splitting component that belongs to the waveband of the main optical path signal, and output the echo optical signal within the waveband of the main optical path signal to the differential detector. In an example, the main optical path component can be implemented by using a filter or a filter film. The differential optical path component is used to filter out the part of the second echo optical signal received from the light splitting component that belongs to the waveband of the differential optical path signal, and output the echo optical signal within the waveband of the differential optical path signal to the differential detector. In an example, the differential optical path component can be implemented by using a filter and a wave trap. In another example, the differential optical path component can also be implemented by using a light splitting prism, a filter, and a combiner. The implementation manners of the signal splitting component will be described in detail in other embodiments of the present application.

[0116] In the embodiment of the present application, the signal splitting component outputs the echo optical signal within the waveband of the main optical path signal and the differential optical path signal according to the received echo optical signal. The waveband of the main optical path signal contains the waveband of the probe optical signal, and the waveband of the differential optical path signal does not overlap with the waveband of the main optical path signal. The main optical path signal actually contains the probe optical signal and the noise signal, and the differential optical path signal actually contains only the noise signal. Therefore, the noise signal in the differential optical path signal can be used to perform differential calculation to remove the noise signal in the main optical path signal, and obtain the real probe optical signal in the echo optical signal.

[0117] In the embodiment of the present application, the waveband of the main optical path signal and the waveband of the differential optical path signal have various implementation manners.

[0118] Taking the waveband of the probe optical signal as N-X to N+X, X being half of the spectral width of the probe optical signal, Table 1 is one example of the relationship between the waveband of the main optical path signal and the waveband of the differential optical path signal in the embodiment of the present application.

[0119] Table 1

[0120]

[0121] In the embodiments of the present application, when the wavelength band of the main optical path signal or the wavelength band of the differential optical path signal contains N-X, X is less than N, and when the wavelength band of the main optical path signal or the wavelength band of the differential optical path signal contains N-Y, Y is less than N and greater than X. In an alternative embodiment of the embodiments of the present application, Y can be equal to 2W or an integer multiple of W, W is greater than X and W is less than Y.

[0122] In the embodiments of the present application, when the filter and the wave trap are used to implement the differential optical path assembly, the signal extraction wavelength band can be the filter wavelength band of the filter in the differential optical path assembly. The filter in the differential optical path assembly can filter the echo light signal received from the light splitting assembly, output the echo light signal of the signal extraction wavelength band, and then the wave trap filters the echo light signal of the signal extraction wavelength band, removes the echo light signal outside the wavelength band range of the differential optical path signal, and outputs the echo light signal in the wavelength band range of the differential optical path signal.

[0123] In an alternative embodiment, the signal extraction wavelength band can contain the wavelength band of the main optical path signal and the wavelength band of the differential optical path signal, and the center wavelength of the signal extraction wavelength band can be the same as the center wavelength of the probe light signal. For example, Y is half of the signal extraction spectral width, and the signal extraction wavelength band can be N-Y to N+Y. The wavelength band of the main optical path signal and the wavelength band of the differential optical path signal can not overlap or partially overlap. Details are as follows

[0124] For the division mode No. 1, the signal extraction wavelength band is N-Y to N+Y, and the wavelength band of the main optical path signal is N-W to N+W, which can be seen from Figure 3A The center wavelength of the probe light signal, the center wavelength of the main optical path signal, and the center wavelength of the signal extraction wavelength band coincide. In this embodiment, since the wavelength band of the differential optical path signal is adjacent to the wavelength band of the main optical path signal, the noise signal energy distribution of the wavelength band of the differential optical path signal in the echo light signal is close to the noise signal energy distribution level in the wavelength band of the main optical path signal, which is conducive to more accurately removing the noise signal from the main optical path signal.

[0125] For the division mode No. 2, please refer to Figure 3BAs shown, the wavelength band of the main light path signal is N-X to N+X, which is the wavelength band of the probe light signal. At this time, both the probe light signal and the noise signal in the main light path signal cover the entire wavelength band of the main light path signal. With this embodiment, the proportion of the noise signal in the main light path signal can be more accurately determined, and thus the noise signal can be more accurately removed from the main light path. The removal process will be described in detail in other parts of the present application.

[0126] For the division mode numbered 4, refer to Figure 3C As shown, the wavelength band of the differential light path can be located on only one side of the wavelength band of the main light path, for example, the signal extraction wavelength band is N-X to N+Y, the wavelength band of the main light path signal can be N-X to N+X, and the wavelength band of the differential light path signal can be N+X to N+Y. The division mode numbered 3 is similar to the division mode numbered 4. Both of these two modes can also obtain the main light path signal and the differential light path signal used for differential operation.

[0127] For the division mode numbered 5, refer to Figure 3D As shown, the wavelength band of the main light path signal can partially overlap with the signal of the differential light path. This mode can also obtain the main light path signal and the differential light path signal used for differential operation.

[0128] In the embodiments of the present application, the difference between Y and X can be greater than a preset energy capture width threshold, so as to ensure that the noise signal in the wavelength band of the differential signal in the differential light path signal has sufficient energy. In an example, when X is 20 nm, Y can be 20 to 40 nm. Similarly, the difference between Y and W can be greater than the energy capture width threshold.

[0129] In the embodiments of the present application, the differential probe 200 can be specifically configured to perform differential operation according to the main light path signal and the differential light path signal, determine a decision threshold, and extract the probe information in the main light path signal according to the decision threshold. In an example, after the main light path signal and the differential light path signal enter the differential probe, the differential probe can convert the main light path signal and the differential light path signal from optical signals to electrical signals. In an example, the decision threshold can be a statistical average of the amplitude of the optical signal in a period of time.

[0130] Figure 3E A simulation waveform diagram for removing the noise signal in the echo light signal through differential operation in the embodiments of the present application is shown. As shown in Figure 3E The main light path signal φ1 is:

[0131] φ1=f(t)+f(b)

[0132] Wherein, f(t) is the reflected probe light signal at t, i.e. the real laser echo signal, and f(b) is the noise signal, i.e. the background light signal.

[0133] The differential optical path signal φ2 is:

[0134]

[0135] Wherein, k represents the ratio of the intensity of the background light in the main optical path signal and the differential optical path signal. Exemplarily, the value of k can be obtained from the system calibration of the laser radar.

[0136] The signal after differential operation of the two is:

[0137] f(t) = φ1-k*φ2

[0138] The signal after differential operation only contains the laser echo signal f(t) and does not contain the background light signal f(b), thereby realizing the removal of the interference of strong background light and avoiding the problem that the decision threshold cannot be accurately calculated.

[0139] It should be noted that a mathematical simulation model can be established for the detection light signal based on the following conditions:

[0140] On the one hand, the laser signal satisfies the Gaussian function:

[0141]

[0142] Wherein, A1 is the pulse amplitude, ti is the pulse peak time, and τ is the half width.

[0143] On the other hand, the background light is divided into a direct current component and a noise component, the direct current component is simulated using an arbitrary Gaussian waveform, and the noise component is white noise.

[0144]

[0145] Wherein, b is the noise mean square error, and d(t) is an arbitrary Gaussian waveform.

[0146] Based on the above model, the simulation waveform as shown in Figure 3E It can be seen that when the noise of the main optical path signal fluctuates greatly, if the threshold decision is directly made according to the main optical path signal, the decision threshold cannot timely follow the fluctuation of the direct current component in the noise and thus misjudgment will be caused, but through differential operation, part of the noise signal in the main optical path signal can be removed, and the energy distribution of this part of the noise signal in the waveband of the main optical path signal and the waveband of the differential optical path signal is relatively close or the same. Therefore, in the signal after differential operation, the overall trend of the noise is stable, the decision threshold determined according to the signal after differential operation is always stable, and based on the stable decision threshold, the decision whether the target region exists is made, which can reduce the possibility of misjudgment.

[0147] The light signal processor provided in the embodiments of the present application can be applied to a detection environment where the noise source is relatively complex, or the intensity of the noise signal is prone to change, for example, the field of automobile driving, etc. The light signal processor provided in the embodiments of the present application can be used to remove various sudden noises in the echo light signal. In an actual detection scene, for example, the noise signal can be the light emitted by a peripheral light source directly into the receiving window of the light signal processor, or the light emitted by a peripheral light source reflected into the receiving window of the light signal processor through a reflecting surface. The peripheral light source can be the sun, a lamp, a flame, other broad-spectrum light sources, etc.

[0148] It should be noted that the light signal processor provided in the embodiments of the present application can be used to remove the noise signal with sudden change in intensity in the detection environment. For example, the noise signal can suddenly change in various scenes. In an example, when a light source suddenly turns on or off around the receiving window, the noise signal in the echo light signal will suddenly change. In another example, the laser can continuously emit a detection light signal in a scanning manner, wherein the emission direction of the detection light signal and the receiving direction of the receiving window for receiving the echo light signal can have a certain corresponding relationship. If the emission direction of the detection light signal rotates to a certain emission direction, the light of the peripheral light source enters the receiving device, which also causes the noise signal in the echo light signal to suddenly change. For example, in the scanning process of the laser radar, the emission direction of the detection laser scans the water surface or the mirror surface in the scene shown in FIG. 1. Figure 1C

[0149] The light signal processor provided in the embodiments of the present application can remove the noise signal caused by the rapidly changing background light by performing differential operation on the main light path signal and the differential light path signal extracted from the echo light signal, so that the detection information carried in the received light signal can be accurately extracted, the problem that the decision threshold cannot be accurately calculated when the strong background light changes rapidly is avoided, the detection rate is improved, and the false alarm and false alarm probability are reduced.

[0150] In addition, in the technical solution provided in the embodiments of the present application, the echo light signal is filtered and split, and only one set of optical receiving system is used to complete the separation of the real reflected light and the environmental noise light, thereby reducing the complexity of the light signal processor and reducing the hardware cost of the light signal processor.

[0151] Embodiment two

[0152] The composition structure of the light signal processor provided in the embodiments of the present application will be exemplarily described below.

[0153] Figure 4 FIG. 1 is a structural schematic diagram of the light signal processor provided in the embodiments of the present application. ​

[0154] As Figure 4 shown in the figure, on the basis of the optical signal processor shown in the figure, Figure 2 The signal beam splitting assembly 100 in the optical signal processor 1000 of the embodiment of the application can include a light splitting prism 111 and a light reflecting prism 112, a first filter 121, a wave-trap filter 122, and a second filter 131.

[0155] The light splitting prism 111 is configured to receive the echo optical signal and output the echo optical signal to the light reflecting prism and the second filter respectively; the light reflecting prism 112 is configured to reflect the received echo optical signal to the first filter.

[0156] The first filter 121 is configured to filter the received echo optical signal and output the echo optical signal in the signal extraction wavelength band to the wave-trap filter; the wave-trap filter 122 is configured to filter the received echo optical signal in the signal extraction wavelength band and output the echo optical signal in the wavelength band range of the differential optical path signal to the differential detector 200.

[0157] The second filter 131 is configured to filter the received echo optical signal and output the echo optical signal in the wavelength band range of the main optical path signal to the differential detector 200.

[0158] The differential detector 200 can include a first detector 201 and a second detector 202, and a differential processor 203. The first detector 201 and the second detector 202 can be configured to respectively convert the main optical path signal and the differential optical path signal from an optical signal to an electrical signal, and input the converted electrical signals to the differential processor respectively; the differential processor 203 can be configured to perform differential operation according to the converted main optical path signal and the differential optical path signal, and extract detection information from the signal after differential operation. In an example, the differential processor 203 can determine a decision threshold according to the signal after differential operation, and extract detection information according to the decision threshold.

[0159] In the embodiment of the application, the echo optical signal includes a detection optical signal and a wide-spectrum noise signal, the center wavelength of the detection optical signal is N, the bandwidth is 2X, and the wavelength band of the main optical path signal is equal to the wavelength band of the detection optical signal. Figure 5 The optical signal processor provided in the embodiment of the application adopts a spectrum diagram of double optical path filtering.

[0160] As Figure 5As shown, the implementation process of the dual optical path filtering of the optical signal processor in the embodiment of the present application includes: using a beam splitter prism to divide the echo optical signal into two paths, i.e., a main optical path and a differential optical path, according to a predetermined ratio. On the main optical path, after the main optical path signal passes through the second filter 131 for second filtering, the wavelength range of the optical signal in the main optical path signal becomes (N-X)~(N+X). On the differential optical path, the differential optical path signal passes through a mirror, so that the direction of the differential optical path signal is consistent with the direction of the main optical path signal. By using this arrangement, the volume of the entire optical signal processor can be reduced, and the two detectors at the rear end can be arranged adjacent to each other. Then, the differential optical path signal passes through the first filter 121 for first filtering, and the wavelength range becomes (N-Y)~(N+Y), where Y>X. Then, after the differential optical path passes through the second-order wave trap 122 for wave trap filtering, the wavelength range becomes (N-Y)~(N-X), (N+X)~(N+Y). Finally, the filtered main optical path signal and the filtered differential optical path signal enter the first detector and the second detector, respectively.

[0161] In an example, Y is 20 nm, and X is 25-40 nm. The value of Y can be slightly greater than X to ensure that the collected optical signal has a certain energy density.

[0162] Figures 6A to 6I For Figure 4 As shown, the assembly structure of the optical signal processor is shown in a set of schematic diagrams. As shown Figure 6A As shown, the constituent elements of the optical signal processor 100 in the embodiment of the present application can include:

[0163] The window cover plate 401 is used to provide an optical inlet and sealing function for the optical signal processor.

[0164] The signal beam splitting assembly 100, which can also be referred to as a beam splitting and filtering assembly, is used to realize the functions of beam splitting, filtering, wave trap, etc.

[0165] The differential detector 200 is used to convert two optical signals into electrical signals, and output the differential operation data through a pin. The differential detector 200 can include two photosensitive elements, an internal differential circuit (not shown in the figure), a structural base, and a signal pin, etc.

[0166] The shell 402 is used to seal and protect the entire optical signal processor. Exemplarily, the window cover plate can be a circular plate with an optical inlet, and the shell 402 can be a circular cylinder with a containing cavity inside.

[0167] In the embodiment of the present application, the constituent elements of the signal beam splitting assembly 100 can include a beam splitting and reflecting prism 110, a first filter 121, a wave trap 122, and a second filter 131, as shown. Figures 6B to 6D

[0168] ​The beam-splitting and reflecting prism 110 includes a beam-splitting surface and a reflecting surface, used to achieve beam splitting and refraction of the light path. The beam-splitting and reflecting prism can be glued or clipped onto the base 141. It should be noted that the beam-splitting and reflecting prism 110 can be used to achieve... Figure 4 The functions of the beam splitter prism 111 and the reflecting prism 112.

[0169] The second filter 131 can be disposed on the light-emitting surface of the direct light path of the beam-splitting reflector 110. For example, the second filter can be bonded to the light-emitting surface of the beam-splitting reflector with photosensitive adhesive.

[0170] The first filter 121 can be disposed on the light-emitting surface of the beam-splitting reflector 110. For example, the first filter 121 can be bonded to the light-emitting surface of the beam-splitting reflector 110 by photosensitive adhesive.

[0171] The notch filter 122 can be disposed on the side of the first filter away from the beam-splitting reflector. For example, the notch filter can be fixed in the positioning groove of the base 141 by adhesive.

[0172] The base 141 is used to fix the optical components, the beam-splitting reflector 110 and the notch filter 122. Exemplarily, the base 141 can be fixed to the base 2010 of the optical signal processor with adhesive. See also... Figure 6D The cross-section shown is the connection surface between the base 141 and the base 2010.

[0173] In the embodiments of this application, see Figure 6D As shown, the beam-splitting reflector 110 includes a rhombus prism 1101 and a right-angle prism 1102. The 45° inclined plane of the right-angle prism 1102 and the beam-splitting surface of the rhombus prism 1101 are intersected. Figure 6D The upper inclined surface of the rhombic prism 1101 is glued together. A reflective film is provided on the bottom 45° inclined surface of the rhombic prism 1101. Anti-reflective films can be provided on the other light-incident and light-outcrystal surfaces of the beam-splitting reflective prism 110. A beam-splitting film can be provided between the beam-splitting surface of the rhombic prism 1101 and the glued surface of the right-angle prism 1102. The second filter 131 is glued to the light-outcrystal surface of the right-angle prism 1102; the first filter 121 is glued to the rear light-outcrystal surface of the rhombic prism 1101.

[0174] It should be noted that the right-angle prism 1102 is not a necessary component in the beam-splitting reflector prism 110. When the right-angle prism 1102 is not present in the beam-splitting reflector prism 110, in one example, the second filter 131 can be directly fixed on the base 141.

[0175] In the embodiments of this application, such as Figure 6B As shown, the base 141 can be a cylinder with a semi-circular base. See also...Figure 6D The bottom surface of the column is a fixed connection surface, which is fixedly connected with the base 2010 of the differential detector 200. For reference Figure 6B and Figure 6F The surface of the base 141 away from the arc surface is a mounting surface, which is used to mount the light splitting and reflecting prism 110 and the wave plate 122. In an example, a groove can be provided on the mounting surface. The groove is used to limit the wave plate 122, and the wave plate 122 can be fixedly bonded to the base 141 by using glue. The light splitting and reflecting prism 110 can be fixed on the mounting surface by using glue and is not adjacent to the fixed connection surface.

[0176] As shown in Figure 6D , 6G and 6H, the differential detector 200 includes a first light sensitive surface 2011, a second light sensitive surface 2012, four pins 2020, and a base 2010. The signal splitting assembly 100 is fixedly connected with the base 2010 of the differential detector 200. For example, as shown in Figure 6D , the base 141 can be bonded to the base 2010.

[0177] As shown in Figure 6I , the signal splitting assembly 100, the differential detector 200, the window cover plate 401, and the shell 402 are combined and packaged into an integrated optical signal processor. The shell is bonded to the window cover plate and the base of the differential detector, respectively, to form a sealed structure. It should be noted that, for ease of description, Figure 6I , the upper half of the shell structure of the optical signal processor is hidden.

[0178] The working optical path of the optical signal processor is shown in Figure 6E . The incident light enters the device through the light entrance window of the window cover plate 401, as shown in process 01. After the light wave is split by the light splitting surface in the light splitting and reflecting prism 110 of the signal splitting assembly 100, it becomes two beams, as shown in process 02. One of the beams passes through the second filter 131 and reaches the first light sensitive surface 2011, as shown in process 03. The other beam is reflected to the first filter 121 by the reflecting surface of the light splitting and reflecting prism 110, as shown in process 04. After passing through the first filter 121 and the wave plate 122, the beam reaches the second light sensitive surface 2012, as shown in process 05.

[0179] In the present application, a differential optical path is added, in which the optical signal of the differential optical path is background light without containing laser. The composite signal containing laser and background light in the main optical path is operated with the background light signal, so that optical path level noise reduction can be achieved, and more background light can be removed. Compared with digital signal processing based on only the composite light containing laser and background, the noise reduction effect is obviously improved.

[0180] In the embodiment of the present application, after the spectral information of the main light path signal and the differential light path signal is obtained through the light splitting element and the filter, the spectral information can be further converted into an electrical signal for differential operation. With this structure, the rapidly changing strong background light can be removed, thereby solving the problem that when the detection threshold is affected by the rapid change of the background light noise during echo detection, the detection threshold is inaccurate, causing false detection and missed detection. Moreover, the above optical structure makes the main light path and the differential light path point to the same direction, and the optical components and structural components can be shared. For example, since the output directions of the main light path signal and the differential light path signal are parallel to each other, the two light sensitive surfaces can be arranged in a differential detector, which is equivalent to arranging two detectors at the same position, which is beneficial to reducing the overall volume of the optical signal processor or the laser radar and realizing rapid integration of the product.

[0181] Embodiment three

[0182] The embodiment of the present application also provides an optical signal processor.

[0183] Figure Seven Structure of the optical signal processor provided by the embodiment of the present application Figure Two As shown in Figure Seven , on the basis of the optical signal processor shown in Figure 2 , the signal beam splitting assembly 100 in the optical signal processor 1000 of the embodiment of the present application can include a fiber beam splitter 113, a first filter 121, a wave trap 122, and a second filter 131.

[0184] The fiber beam splitter 113 is configured to receive the echo light signal and output the echo light signal to the first filter 121 and the second filter 131 through an optical fiber.

[0185] The first filter 121 is configured to filter the received echo light signal and output the echo light signal in the signal extraction wave band to the wave trap. The wave trap 122 is configured to filter the received echo light signal in the signal extraction wave band and output the echo light signal in the wave band range of the differential light path signal to the differential detector 200.

[0186] The second filter 131 is configured to filter the received echo light signal and output the echo light signal in the wave band range of the main light path signal to the differential detector 200.

[0187] In the embodiment of the present application, the optical signal processor 1000 can further include a differential detector 200. Figure 5Taking the band division shown as an example, the echo optical signal is coupled to the optical fiber, and then split into a main optical path and a differential optical path by the optical fiber beam splitter. After the main optical path is filtered by the second filter 131, the wavelength range of the main optical path optical signal becomes (NX)~(N+X); after the differential optical path is filtered by the combination of the first filter 121 and the notch filter 122, the wavelength range of the differential optical path optical signal becomes (NY)~(NX), (N+X)~(N+Y); the two beams of light enter the differential detector 200 respectively, are converted into electrical signals, and then output after differential operation.

[0188] In this embodiment, an optical fiber beam splitter is used instead. Figure 4 The implementation of the beam splitter and reflector in the optical fiber makes it easier to design the structure of the optical signal processor because the direction of light output is not limited when the optical fiber outputs light.

[0189] Figures 8A to 8B for Figure Seven A set of schematic diagrams showing the assembly structure of the optical signal processor.

[0190] like Figure 8A As shown, the components of the optical signal processor in this embodiment may include: a window cover plate 401, a signal beam splitter assembly 100, a differential detector 200, and a housing 402. Wherein:

[0191] The signal beam splitter 100 can be used to implement optical path filtering and notch filtering functions.

[0192] The differential detector 200 can adopt the same structure as in the aforementioned embodiments.

[0193] Window cover 401 is used to provide an inlet for the split fiber and to provide a sealing function.

[0194] The outer casing 402 can adopt the same structure as in the aforementioned embodiments.

[0195] The signal beam splitting assembly 100 may include: an optical fiber beam splitter 113, a first filter 121, a notch filter 122, a second filter 131, and a base 141. The optical fiber beam splitter 113 is used to achieve the "one-to-two" beam splitting function and can also be called a beam splitting fiber.

[0196] like Figure 8A As shown, the fiber optic beam splitter 113 includes: a front-end fiber 1131, a fiber optic beam splitter 1132, and rear-end fibers 1133 and 1134. Exemplarily, the front-end and rear-end fibers can be communication fibers. The window cover 401 includes: two fiber optic connectors 4011 and 4012. Exemplarily, the fiber optic connectors can be standard communication fiber optic interfaces. The fiber optic beam splitter 113 is connected to the window cover 401 via the two fiber optic connectors to ensure that the light beam passes through the housing and enters the assembly interior via fiber optic transmission.

[0197] The mounting surface of the base 141 of the signal splitting assembly can be provided with positioning grooves, and the first filter 121, the second filter 131 and the notch filter 122 can be fixed in the grooves by bonding or clamping to ensure correct installation.

[0198] The signal splitting assembly 100, the differential detector 200, the window cover plate 401 and the shell 402 can be combined to form an integrated optical signal processor, and the shell can be bonded with the window cover plate and the base to form a sealed structure.

[0199] The working optical path of the optical signal processor in the embodiment of the present application is shown in Figure 8B .

[0200] The incident light enters the front-end optical fiber 1131, as shown in process 01; the light wave becomes two beams after passing through the optical fiber splitting part 1132, and the two beams of light enter two other rear-end optical fibers 1132, as shown in processes 02 and 03; one of the beams of light passes through the window cover plate 401, and then passes through the second filter 131 to reach the first light-sensitive surface 2011 of the differential detector 200, as shown in process 04; the other beam of light passes through the window cover plate 401, and then passes through the first filter 121 and the notch filter 122 to reach the second light-sensitive surface 2012 of the differential detector 200, as shown in process 05.

[0201] Unlike the spatial coupling mode in the foregoing embodiments, in the embodiment of the present application, an optical fiber splitter is used instead of a lens or prism type splitter, and optical fiber coupling is used in optical path coupling. On the one hand, this avoids optical path loss caused by a reflecting mirror, and on the other hand, directly using optical fiber coupling can simplify optical tuning, which is conducive to reducing the product size. In addition, in cooperation with the differential selection filter and the detector circuit, differential operation can be performed to remove rapidly changing strong background light and achieve background light denoising.

[0202] Embodiment Four

[0203] The embodiment of the present application also provides an optical signal processor which can be used to avoid the problem of false alarm caused by narrowband interference noise.

[0204] In the embodiment of the present application, the laser can be used to emit an assistance light signal in addition to emitting a detection light signal; the wave band of the assistance light signal can not overlap with the wave band of the detection light signal. Correspondingly, when the assistance light signal encounters an object in a detection area, the assistance light signal can also be reflected by the object, and the echo light signal can include the assistance light signal in addition to the detection light signal and noise signals.

[0205] Figure 9A The structure of the optical signal processor provided in the embodiment of the present application is shown in Figure Four . As shown in Figure 9AThe light signal processor shown in any of the foregoing embodiments can further include:

[0206] The signal splitting component 910 is specifically configured to output the first main light path signal and the first differential light path signal, and the second main light path signal and the second differential light path signal, respectively. The wavelength band of the first main light path signal includes the wavelength band of the probe light signal, and the wavelength band of the second main light path signal includes the wavelength band of the auxiliary light signal. The wavelength band of the first differential light path signal does not overlap with the wavelength band of the probe light signal and the wavelength band of the auxiliary light signal, and the wavelength band of the second differential light path signal does not overlap with the wavelength band of the probe light signal and the wavelength band of the auxiliary light signal.

[0207] The differential detector 920 is specifically configured to extract the probe information in the first main light path signal or the second main light path signal according to the first main light path signal and the first differential light path signal, and the second main light path signal and the second differential light path signal.

[0208] In the embodiments of the present application, for example, similar to the foregoing embodiments, the wavelength band of the first main light path signal and the wavelength band of the second main light path signal can be the wavelength band of the probe light signal and the wavelength band of the auxiliary light signal, respectively. The wavelength band of the first differential light path signal and the wavelength band of the second differential light path signal can be the first adjacent wavelength band and the second adjacent wavelength band, respectively. In an example, the minimum value of the first adjacent wavelength band is equal to the maximum value of the wavelength of the probe light signal, or the maximum value of the first adjacent wavelength band is equal to the minimum value of the wavelength of the probe light signal. The minimum value of the second adjacent wavelength band is equal to the maximum value of the wavelength of the auxiliary light signal, or the maximum value of the second adjacent wavelength band is equal to the minimum value of the wavelength of the auxiliary light signal.

[0209] For example, the wavelength band of the probe light signal can be N1-X to N1+X, the wavelength band of the auxiliary light signal can be N2-X to N2+X, the first adjacent wavelength band can include N1-Y to N1-X and N1+X to N1+Y, and the second adjacent wavelength band can include N2-Y to N2-X and N2+X to N2+Y. N1+X is less than N2-X, or N1-X is greater than N2+X. It should be noted that the first adjacent wavelength band and the second adjacent wavelength band can partially overlap or not overlap. When the two adjacent wavelength bands do not overlap, N1-Y can be greater than N2+Y, or N1+Y can be less than N2-Y.

[0210] In the embodiments of the present application, for example, the differential detector can convert the first main light path signal, the first differential light path signal, the second main light path signal, and the second differential light path signal into electrical signals, respectively, perform differential operation according to the converted electrical signals, determine a decision threshold, and then extract the probe information in the converted first main light path signal or the second main light path signal according to the decision threshold.

[0211] In an example, the differential detector can convert the respective signals into electrical signals, perform differential operation on the first main light path signal and the first differential light path signal to obtain a noise signal in the wavelength range of the probe light signal, perform differential operation on the second main light path signal and the second differential light path signal to obtain a noise signal in the wavelength range of the auxiliary light signal, compare the noise signals in the wavelength range of the probe light signal and the wavelength range of the auxiliary light signal, if the amplitude of the noise signal in the wavelength range of the probe light signal is lower than the amplitude of the wavelength range of the auxiliary light signal, determine the decision threshold according to the signal after differential operation on the first main light path signal and the first differential light path signal, and extract the probe information from the first main light path signal after removing the noise signal, if the amplitude of the noise signal in the wavelength range of the probe light signal is higher than the amplitude of the wavelength range of the auxiliary light signal, determine the decision threshold according to the signal after differential operation on the second main light path signal and the second differential light path signal, and extract the probe information from the second main light path signal after removing the noise signal.

[0212] With this implementation, the problem of false alarm caused by other interference noise in the wavelength range of the probe light signal, such as narrowband interference noise from other radars, can be avoided.

[0213] In an optional implementation, the optical signal processor can further include a laser for emitting the probe light signal and the auxiliary light signal.

[0214] The optical signal processor provided by the embodiments of the present application is described below.

[0215] As shown in Figure 9A In the embodiments of the present application, the signal splitting assembly 100 can include a light splitting assembly 901, a first main light path assembly 911, a first differential light path assembly 912, a second main light path assembly 921, and a second differential light path assembly 922. The differential detector 920 can include a first detector 931, a second detector 932, a third detector 941, a fourth detector 942, and a differential processor 951.

[0216] In an optional implementation of the signal splitting assembly 910,

[0217] The light splitting assembly 901 can be configured to receive the echo light signal, perform light splitting processing on the echo light signal to obtain four echo light signals, and input the four echo light signals into the first main light path assembly 911, the first differential light path assembly 912, the second main light path assembly 921, and the second differential light path assembly 922, respectively.

[0218] The first main light path component 911, the first differential light path component 912, the second main light path component 921, and the second differential light path component 922 are configured to filter the received echo light signal, and output a first main light path signal, a first differential light path signal, a second main light path signal, and a second differential light path signal, respectively.

[0219] In the embodiments of the present application, the first main light path component 911 can adopt the structure of any one of the main light path components in the foregoing embodiments, the first differential light path component 912 can adopt the structure of any one of the differential light path components in the foregoing embodiments, the second main light path component can adopt a similar structure to the first main light path component 911, and the second differential light path component 922 can adopt a similar structure to the first differential light path component 912. Details will be described below.

[0220] Figures 9B to 9E For Figure 9A a group of structural schematic diagrams of the light signal processor. As Figure 9B shown, in an example, the light splitting component 901 can include a two-stage fiber beam splitting structure, which includes three fiber beam splitting parts. Four fiber output ends of the light splitting component 901 are connected to the window cover plate.

[0221] Referring to Figure 9C a side view, Figure 9D a cross-sectional view 1, the second main light path component 921 and the second differential light path component 922 can be arranged above the first main light path component 911 and the first differential light path component 912, and the two groups of structures can include similar elements and be symmetrically arranged. In this arrangement, the output light of the signal beam splitting component 901 is parallel to each other and arranged in two rows, which facilitates the arrangement of the four light sensitive surfaces 2011 to 2014 in the differential detector 920.

[0222] In an example, the waveband of the first main light path signal is N1-X to N1+X, the waveband of the second main light path signal is N2-X to N2+X, the first adjacent waveband is N1-Y to N1-X and N1+X to N1+Y, and the second adjacent waveband is N2-Y to N2-X and N2+X to N2+Y. The first filter 131 in the first main light path component 911 can be configured to filter the echo light signal and output the echo light signal in the waveband of N1-X to N1+X to the first light sensitive surface 2011. The second filter 121 in the first differential light path component 911 can be configured to filter the echo light signal and output the echo light signal in the waveband of N1-Y to N1+Y to the notch filter 122 in the first differential light path component 921, which can be configured to notch filter the received echo light signal and output the echo light signal in the waveband of N1-Y to N1-X and N1+X to N1+Y to the second light sensitive surface 2012. Similarly, the first filter 131 in the second main light path component 921 can be configured to filter the echo light signal and output the echo light signal in the waveband of N2-X to N2+X to the third light sensitive surface 2013. The second filter 121 in the second differential light path component 921 can be configured to filter the echo light signal and output the echo light signal in the waveband of N2-Y to N2+Y to the notch filter 122 in the second differential light path component 921, which can be configured to notch filter the received echo light signal and output the echo light signal in the waveband of N2-Y to N2-X and N2+X to N2+Y to the fourth light sensitive surface 2014.

[0223] In an alternative embodiment of the differential detector 920:

[0224] The differential detector 920 comprises a first light sensitive surface 2011, a second light sensitive surface 2012, a third light sensitive surface 2013, a fourth light sensitive surface 2014, and a base 2010, the first light sensitive surface 2011, the second light sensitive surface 2012, the third light sensitive surface 2013, and the fourth light sensitive surface 2014 are configured to convert the received light signal into an electrical signal and output to the differential processor 951 in the base 2010 via the pin 2020. Figure 9A

[0225] Reference can be made to the side view of Figure 9C Figure 9D ​​As shown in the cross-sectional view 1, four light-sensitive surfaces are arranged on the base 2010, wherein the first light-sensitive surface 2011 is located on the output light path of the first main light path assembly 911, the second light-sensitive surface 2012 is located on the output light path of the first differential light path assembly 912, the third light-sensitive surface 2013 is located on the output light path of the second main light path assembly 921, and the fourth light-sensitive surface 2014 is located on the output light path of the second differential light path assembly 922. In this way, the four light-sensitive surfaces share one base, which can reduce the volume of the signal processor.

[0226] It should be noted that in another optional embodiment of the light splitting assembly 901, the light splitting assembly can include two receiving windows for receiving the echo light signal, and the two received echo light signals are respectively subjected to light splitting processing. Based on the first echo light signal, the echo light signal is respectively output to the first main light path assembly and the first differential light path assembly. Based on the second echo light signal, the echo light signal is respectively output to the second main light path assembly and the second differential light path assembly. The present application does not limit this.

[0227] In the embodiment of the present application, when the laser emits two wave bands of laser, the decision threshold or the detection information can be determined based on the converted electrical signal corresponding to any one of the two wave bands. In this way, on the basis of solving the false alarm and missing alarm problem caused by sudden wide spectrum noise, on the one hand, a wide spectrum detector can be realized by sending composite color laser of different wave bands in the multi-color spectrum, and then using the signal beam splitting assembly to split different color light paths to extract detection information from laser of different wavelengths. On the other hand, the anti-interference ability of the product against narrow band noise can be improved.

[0228] For example, in the embodiment of the present application, the noise signal in the echo light signal can include wide spectrum noise signal and narrow band noise signal from the surrounding environment. For example, the narrow band noise signal can be narrow band detection laser from the surrounding radar. In an example, in the scanning mode, when the background light of the surrounding environment enters the receiving window, the wave band of the narrow band noise signal can only overlap with one of the wave band of the detection light signal or the wave band of the assistance light signal.

[0229] Taking the example that the wave band of the noise signal overlaps with the wave band of the detection light signal, after the echo light signal received by the light signal processor is output by the signal beam splitting assembly, the first main light path signal A1 actually contains the detection light signal a1 of the wave band of the detection light signal and the noise signal c1, and the first differential light path signal B1 actually contains the noise signal c2 of the first adjacent wave band; the second main light path signal A2 includes the assistance light signal a2 of the wave band of the assistance light signal and the noise signal c3, and the second differential light path signal B2 contains the noise signal c4 of the second adjacent wave band.

[0230] Assuming that c1 and c2 contain narrow-band noise interference at the same time or c3 and c4 contain narrow-band noise interference at the same time when narrow-band noise interference is received, the differential detector can further determine which of the probe light signals and the auxiliary light signals is less interfered by narrow-band noise while removing wide-band noise.

[0231] For example, first, the differential operation method in the foregoing embodiment can be used to remove wide-band noise in A1 according to A1 and B1, and remove wide-band noise in A2 according to A2 and B2. Second, c1 can be determined according to A1 and B1, and c3 can be determined according to A2 and B2. Since the wide-band noise in c1, c2, c3 and c4 can be considered to be uniformly distributed, when c1 is greater than c3, it can be considered that the narrow-band noise in c1 and c2 is more than that in c3 and c4. It should be noted that the intensities of the probe light signals and the auxiliary light signals when emitted can be set to be approximately equal.

[0232] After determining the light signal with less narrow-band noise, for example, when the second main light path signal contains less narrow-band noise, the decision threshold and the probe information can be extracted according to A2 with the wide-band noise removed.

[0233] Other technical details and technical effects of other technical solutions of the embodiments of the present application are the same as those of the foregoing embodiments, and can refer to the related descriptions in the foregoing embodiments.

[0234] Embodiment Five

[0235] The embodiments of the present application also provide an optical signal processing method.

[0236] Figure 10 A flowchart of the optical signal processing method provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the steps of the embodiments of the present application can include: Figure 10

[0237] S1001, an optical signal processor receives a return light signal; wherein the return light signal includes a probe light signal and a noise signal;

[0238] S1002, the return light signal is subjected to signal beam splitting processing to obtain a main light path signal and a differential light path signal; wherein the wavelength band of the main light path signal includes the wavelength band of the probe light signal, and the wavelength band of the differential light path signal does not overlap with the wavelength band of the probe light signal;

[0239] S1003, according to the main light path signal and the differential light path signal, probe information in the main light path signal is extracted.

[0240] In an optional embodiment, the wavelength band of the probe light signal is N-X to N+X; wherein N is the center wavelength of the probe light signal, and X is half of the spectral width of the probe light signal, and X is less than N.​

[0241] The wave band of the differential optical path signal comprises N-Y to N-X and / or N+X to N+Y; wherein Y is a signal extraction spectral width, Y is less than N and Y is greater than X.

[0242] In an optional embodiment, the wave band of the main optical path signal is the wave band of the probe light signal.

[0243] The embodiments of the wave band of the main optical path signal and the wave band of the differential optical path signal that can be used in the embodiments of the present application can refer to the descriptions in other embodiments of the present application.

[0244] In an optional embodiment, the signal splitting processing on the echo light signal to obtain the main optical path signal and the differential optical path signal comprises:

[0245] The echo light signal is split to obtain the echo light signal of the main optical path and the echo light signal of the differential optical path;

[0246] The echo light signal of the main optical path is filtered to output the echo light signal in the wave band range of the main optical path signal;

[0247] The echo light signal of the differential optical path is filtered to output the echo light signal in the wave band range of the differential optical path signal.

[0248] In an optional embodiment, the filtering processing on the echo light signal of the differential optical path to output the echo light signal in the wave band range of the differential optical path signal comprises: filtering the echo light signal of the differential optical path to output the echo light signal of a signal extraction wave band; filtering the echo light signal of the signal extraction wave band to filter out the echo light signal outside the wave band range of the differential optical path signal in the signal extraction wave band, and outputting the echo light signal in the wave band range of the differential optical path signal.

[0249] In an optional embodiment, the filtering processing on the echo light signal of the main optical path to output the echo light signal in the wave band range of the main optical path signal comprises: filtering the echo light signal of the main optical path to output the echo light signal in the wave band range of the main optical path signal.

[0250] In an optional implementation, the splitting processing of the echo optical signal to obtain the echo optical signal of the main optical path and the echo optical signal of the differential optical path comprises: splitting processing of the echo optical signal of the first direction to obtain the echo optical signal of the main optical path of the first direction and the echo optical signal of the differential optical path of the second direction; reflecting the echo optical signal of the differential optical path of the second direction to obtain the echo optical signal of the differential optical path of the first direction.

[0251] In an optional implementation, the splitting processing of the echo optical signal to obtain the echo optical signal of the main optical path and the echo optical signal of the differential optical path comprises: splitting processing of the echo optical signal, outputting the echo optical signal of the main optical path through a first optical fiber output end and outputting the echo optical signal of the differential optical path through a second optical fiber output end.

[0252] In an optional implementation, the extracting of the detection information in the main optical path signal according to the main optical path signal and the differential optical path signal comprises:

[0253] performing differential operation processing according to the main optical path signal and the differential optical path signal to determine a decision threshold;

[0254] extracting the detection information in the main optical path signal according to the decision threshold.

[0255] In an optional implementation, before the optical signal processor receives the echo optical signal, the method further comprises: emitting the detection optical signal.

[0256] In an optional implementation, before the optical signal processor receives the echo optical signal, the method further comprises: emitting the detection optical signal and an auxiliary optical signal.

[0257] The echo optical signal further comprises: the auxiliary optical signal.

[0258] The signal splitting processing of the echo optical signal to obtain the main optical path signal and the differential optical path signal comprises:

[0259] The signal splitting processing of the echo optical signal to obtain the first main optical path signal and the first differential optical path signal, and the second main optical path signal and the second differential optical path signal; wherein the waveband of the first main optical path signal comprises the waveband of the detection optical signal, the waveband of the second main optical path signal comprises the waveband of the auxiliary optical signal, the waveband of the first differential optical path signal does not overlap with the waveband of the detection optical signal and the waveband of the auxiliary optical signal, and the waveband of the second differential optical path signal does not overlap with the waveband of the detection optical signal and the waveband of the auxiliary optical signal.

[0260] The extracting the detection information in the main light path signal according to the main light path signal and the differential light path signal comprises: extracting the detection information in the first main light path signal or the second main light path signal according to the first main light path signal, the first differential light path signal, the second main light path signal and the second differential light path signal.

[0261] In an optional implementation of the embodiment of the application, the noise signal in the main light path signal can also be removed according to the main light path signal and the differential light path signal when the laser continuously emits the detection light signal in the scanning mode, and then the decision threshold is determined according to the main light path signal after the noise signal is removed, and then the detection information is extracted from the main light path signal according to the decision threshold.

[0262] Other technical solution details and technical effects of the embodiment of the application can be referred to the description in other embodiments of the application. Exemplarily, the method of the embodiment of the application can be executed by any of the light signal processors in the foregoing embodiments.

[0263] For example, the technical solution provided by the embodiment of the application can be applied to various laser radar detection scenes, such as vehicle-mounted driving, airborne measurement, security monitoring, map surveying and mapping, etc. In an example, the light signal processor can be a vehicle-mounted radar, etc.

[0264] In the foregoing embodiments, the technical solution can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When the processing method is executed, it can be realized in the form of a computer program product in whole or in part. The computer program product comprises one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the flow or function described in the application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk), etc.

Claims

1. An optical signal processor, characterized in that, include: A signal beam splitter is used to receive echo optical signals and output main optical path signals and differential optical path signals respectively; wherein, the echo optical signals include probe optical signals and noise signals; the wavelength band of the main optical path signals includes the wavelength band of the probe optical signals, and the wavelength band of the differential optical path signals does not overlap with the wavelength band of the probe optical signals; A differential detector is used to receive the main optical path signal and the differential optical path signal respectively, and to extract the detection information in the main optical path signal based on the main optical path signal and the differential optical path signal; The echo optical signal further includes: an assist optical signal; wherein the wavelength of the assist optical signal does not overlap with the wavelength of the probe optical signal; The signal beam splitter is specifically used to output a first main optical path signal and a first differential optical path signal, as well as a second main optical path signal and a second differential optical path signal; wherein the wavelength of the first main optical path signal includes the wavelength of the probe optical signal, the wavelength of the second main optical path signal includes the wavelength of the assist optical signal, the wavelength of the first differential optical path signal does not overlap with the wavelength of the probe optical signal and the wavelength of the assist optical signal, and the wavelength of the second differential optical path signal does not overlap with the wavelength of the probe optical signal and the wavelength of the assist optical signal; The differential detector is specifically used to extract detection information from the first main optical path signal or the second main optical path signal based on the first main optical path signal, the first differential optical path signal, the second main optical path signal, and the second differential optical path signal.

2. The optical signal processor according to claim 1, characterized in that, The wavelength range of the detection optical signal is from N× to N+X; where N is the center wavelength of the detection optical signal, X is half the spectral width of the detection optical signal, and X is less than N. The bands of the differential optical path signal include: NY to NX, and / or, N+X to N+Y; wherein Y is half of the signal extraction spectral width, Y is less than N and Y is greater than X.

3. The optical signal processor according to claim 1, characterized in that, The band of the main optical path signal is the same as the band of the probe optical signal.

4. The optical signal processor according to claim 1, characterized in that, The signal beam splitting assembly includes: a beam splitting assembly, a main optical path assembly, and a differential optical path assembly. The beam splitter is used to output the echo light signal to the main optical path component and the differential optical path component respectively; The main optical path component is used to output the echo optical signal within the band range of the main optical path signal to the differential detector; The differential optical path component is used to output the echo optical signal within the band range of the differential optical path signal to the differential detector.

5. The optical signal processor according to claim 4, characterized in that, The differential optical path component includes: A first filter is used to filter the received echo light signal and output the echo light signal of the signal extraction band to a notch filter; wherein, the signal extraction band includes the band of the differential optical path signal; The notch filter is used to filter the echo light signal in the signal extraction band, filter out the echo light signal outside the band range of the differential optical path signal in the signal extraction band, and output the echo light signal within the band range of the differential optical path signal to the differential detector.

6. The optical signal processor according to claim 4 or 5, characterized in that, The main optical path component includes: The second filter is used to filter the received echo light signal and output the echo light signal within the band range of the main optical path signal to the differential detector.

7. The optical signal processor according to claim 4, characterized in that, The beam-splitting component includes: a beam-splitting prism and a reflecting prism. The beam splitter is used to receive the echo light signal and output the echo light signal to the reflecting prism and the main optical path assembly, respectively. The reflective prism is used to reflect the received echo light signal to the differential optical path component.

8. The optical signal processor according to claim 4, characterized in that, The beam-splitting component includes: An optical fiber beam splitter is used to receive the echo optical signal and output the echo optical signal to the main optical path component and the differential optical path component respectively through optical fiber.

9. The optical signal processor according to any one of claims 1-5 and 7-8, characterized in that, The differential detector is specifically used to perform differential operation processing based on the main optical path signal and the differential optical path signal to determine a decision threshold, and to extract the detection information in the main optical path signal based on the decision threshold.

10. A radar, characterized in that, include: A laser, and an optical signal processor as described in any one of claims 1-9; wherein the laser is used to emit a probe optical signal; The laser is also used to emit an assisting optical signal; the echo optical signal further includes the assisting optical signal; wherein the wavelength of the assisting optical signal does not overlap with the wavelength of the probe optical signal. The signal beam splitting component of the optical signal processor is specifically used to output a first main optical path signal and a first differential optical path signal, as well as a second main optical path signal and a second differential optical path signal; wherein, the wavelength of the first main optical path signal includes the wavelength of the probe optical signal, the wavelength of the second main optical path signal includes the wavelength of the assist optical signal, the wavelength of the first differential optical path signal does not overlap with the wavelength of the probe optical signal and the wavelength of the assist optical signal, and the wavelength of the second differential optical path signal does not overlap with the wavelength of the probe optical signal and the wavelength of the assist optical signal; The differential detector of the optical signal processor is specifically used to extract detection information from the first main optical path signal or the second main optical path signal based on the first main optical path signal, the first differential optical path signal, the second main optical path signal, and the second differential optical path signal.

11. An optical signal processing method, characterized in that, include: An optical signal processor receives an echo optical signal; wherein the echo optical signal includes a probe optical signal and a noise signal; The echo optical signal is subjected to signal beam splitting processing to obtain a main optical path signal and a differential optical path signal; wherein, the wavelength band of the main optical path signal includes the wavelength band of the probe optical signal, and the wavelength band of the differential optical path signal does not overlap with the wavelength band of the probe optical signal; Based on the main optical path signal and the differential optical path signal, the detection information in the main optical path signal is extracted; The echo optical signal further includes: an assist optical signal; wherein the wavelength of the assist optical signal does not overlap with the wavelength of the probe optical signal; The step of performing signal beam splitting processing on the echo optical signal to obtain the main optical path signal and the differential optical path signal includes: The echo optical signal is subjected to signal beam splitting processing to form a first main optical path signal and a first differential optical path signal, as well as a second main optical path signal and a second differential optical path signal; wherein, the wavelength band of the first main optical path signal includes the wavelength band of the probe optical signal, the wavelength band of the second main optical path signal includes the wavelength band of the assist optical signal, the wavelength band of the first differential optical path signal does not overlap with the wavelength band of the probe optical signal and the wavelength band of the assist optical signal, and the wavelength band of the second differential optical path signal does not overlap with the wavelength band of the probe optical signal and the wavelength band of the assist optical signal; The step of extracting detection information from the main optical path signal based on the main optical path signal and the differential optical path signal includes: extracting detection information from the first main optical path signal or the second main optical path signal based on the first main optical path signal, the first differential optical path signal, the second main optical path signal, and the second differential optical path signal.

12. The method according to claim 11, characterized in that, The wavelength range of the detection optical signal is from N× to N+X; where N is the center wavelength of the detection optical signal, X is half the spectral width of the detection optical signal, and X is less than N. The bands of the differential optical path signal include: NY to NX, and / or, N+X to N+Y; wherein, Y is half of the signal extraction spectral width, Y is less than N and Y is greater than X.

13. The method according to claim 11, characterized in that, The band of the main optical path signal is the same as the band of the probe optical signal.

14. The method according to claim 11, characterized in that, The step of performing signal beam splitting processing on the echo optical signal to obtain the main optical path signal and the differential optical path signal includes: The echo light signal is split into two beams to obtain the echo light signal in the main optical path and the echo light signal in the differential optical path. The echo light signal of the main optical path is filtered to output the echo light signal within the wavelength range of the main optical path signal. The echo light signal of the differential optical path is filtered to output the echo light signal within the wavelength range of the differential optical path signal.

15. The method according to claim 14, characterized in that, The step of filtering the echo optical signal of the differential optical path to output the echo optical signal within the wavelength range of the differential optical path signal includes: The echo light signal of the differential optical path is filtered, and the echo light signal of the output signal is extracted in the band. The echo light signal in the signal extraction band is filtered to remove the echo light signal outside the band range of the differential optical path signal in the signal extraction band, and the echo light signal within the band range of the differential optical path signal is output.

16. The method according to any one of claims 11-15, characterized in that, The step of extracting the detection information from the main optical path signal based on the main optical path signal and the differential optical path signal includes: Differential operation processing is performed on the main optical path signal and the differential optical path signal to determine the decision threshold; Based on the decision threshold, the detection information in the main optical path signal is extracted.

17. The method according to any one of claims 11-15, characterized in that, Before the optical signal processor receives the echo optical signal, the method further includes: transmitting the probe optical signal and the assist optical signal.

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