Wavelength division multiplexing device, amplification module and adjustment module

Abstract

The utility model relates to a wavelength division multiplexing device, an amplification module and an adjustment module. The wavelength division multiplexing device comprises a dual-core pin with a first optical fiber and a second optical fiber; the first fiber is used for receiving first signal light, and the second fiber is used for receiving second laser; the lens is used for receiving and adjusting the first signal light and the second laser; the filter is used for receiving the first signal light and the second laser which are adjusted by the lens, reflecting the second laser and transmitting the first signal light; the second laser is reflected to the lens, is adjusted again by the lens and then enters the first optical fiber of the double-core contact pin; the polarization rotation unit is used for receiving the first signal light, rotating the polarization direction of the first signal light by a first angle and then reflecting the first signal light to the filter; the first signal light whose polarization direction is rotated by a first angle passes through the filter and the lens again and then enters the first optical fiber of the dual-core pin. According to the wavelength division multiplexing device, the polarization state of the first signal light is changed, and the wavelength division multiplexing device is suitable for a scene where the polarization state needs to be changed in a wind finding radar.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical devices, in particular to a wavelength division multiplexing device, an amplification module and an adjustment module. BACKGROUND

[0002] With the development of laser radar technology, laser radar wind measurement technology appears. The wind measurement laser radar obtains the inversion wind speed by measuring the Doppler frequency shift of the aerosol particle backscattering signal.

[0003] In some wind measurement application scenarios, not only is it necessary to improve the gain of the optical signal, but also the polarization state of the input and output light is required, so as to reduce the cost, volume and power consumption of the wind measurement laser radar. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide a wavelength division multiplexing device, an amplification module and an adjustment module which can reduce the cost, volume and power consumption of the wind measurement laser radar and meet the polarization state of the input and output light.

[0005] In a first aspect, the present application provides a wavelength division multiplexing device, comprising: a double-core pin comprising a first optical fiber and a second optical fiber; the first optical fiber is used for receiving first signal light, and the second optical fiber is used for receiving second laser; a lens is used for receiving the first signal light and the second laser and adjusting the first signal light and the second laser; a filter is used for receiving the first signal light and the second laser adjusted by the lens, reflecting the second laser and transmitting the first signal light; the second laser is reflected to the lens, and after being adjusted again by the lens, is incident into the first optical fiber of the double-core pin; a polarization rotation unit is used for receiving the first signal light, rotating the polarization direction of the first signal light by a first angle, and reflecting the first signal light with the polarization direction rotated by the first angle to the filter; the first signal light with the polarization direction rotated by the first angle is incident into the first optical fiber of the double-core pin again after passing through the filter and the lens.

[0006] In one of the embodiments, the polarization rotation unit comprises: a Faraday optical rotation unit, which is used for receiving the first signal light and rotating the polarization direction of the first signal light by a second angle under the action of a magnetic field; a mirror, which is used for receiving the first signal light with the polarization direction rotated by the second angle and reflecting the first signal light with the polarization direction rotated by the second angle back to the Faraday optical rotation unit; the first signal light with the polarization direction rotated by the second angle is incident onto the filter again after passing through the Faraday optical rotation unit again.

[0007] In one of the embodiments, a first gap is arranged between the double-core pin and the lens, so that the light emitting point of the first signal light passing through the first optical fiber is located on the focal plane of the lens, and the light emitting point of the second laser passing through the second optical fiber is located on the focal plane of the lens.

[0008] In one of the embodiments, the wavelength division multiplexing device further comprises a housing for accommodating the double-core pin, the lens, the filter and the polarization rotation unit; and the double-core pin, the lens and the housing are connected by ultraviolet glue.

[0009] In one of the embodiments, the mirror is fixed inside the housing.

[0010] In one of the embodiments, the lens is a gradient-index lens, comprising a first surface and a second surface, the first surface is an inclined surface, and the second surface is a planar surface.

[0011] In one of the embodiments, the double-core pin, the lens, the filter and the polarization rotation unit are sequentially and spacedly arranged in the first direction.

[0012] In one of the embodiments, the Faraday optical rotation unit comprises a first magnet, a second magnet and an optical rotator, the optical rotator is arranged between the first magnet and the second magnet.

[0013] In a second aspect, the application further provides an amplification module, comprising: a first light source, the first light source emits first laser light with a first wavelength; a second light source, the second light source emits second laser light with a second wavelength; an erbium-doped fiber, which receives and transmits the first laser light and the second laser light, and the first laser light is amplified along a first direction in the erbium-doped fiber under the action of the second laser light to obtain first signal light; the wavelength division multiplexing device of any one of the first aspect, the wavelength division multiplexing device receives the first signal light and the second laser light, and reflects the first signal light and the second laser light back to the erbium-doped fiber; the first signal light is amplified again along a second direction in the erbium-doped fiber under the action of the second laser light; the second direction is opposite to the first direction.

[0014] In a third aspect, the application further provides an adjustment module, comprising: a first light source, the first light source emits first laser light with a first wavelength; a second light source, the second light source emits second laser light with a second wavelength; an acousto-optic module, which receives the first laser light and modulates the frequency and pulse of the first laser light to obtain second signal light; an erbium-doped fiber, which receives and transmits the second signal light and the second laser light, and the second signal light is amplified along a first direction in the erbium-doped fiber under the action of the second laser light to obtain first signal light; the wavelength division multiplexing device of any one of the first aspect; the wavelength division multiplexing device receives the first signal light and the second laser light, and reflects the first signal light and the second laser light back to the erbium-doped fiber; the first signal light is amplified again along a second direction in the erbium-doped fiber under the action of the second laser light, and is incident into the acousto-optic module again, and the third signal light is obtained by frequency modulation and pulse modulation of the acousto-optic module; the second direction is opposite to the first direction.

[0015] In a fourth aspect, the application further provides a manufacturing method of a wavelength division multiplexing device, the method comprising:

[0016] The first surface of the filter plate is bonded to the second surface of the lens to form a lens assembly; the mirror is fixed to the shell to form a reflection assembly; the double-core pin is installed on the fine adjustment frame, the second optical fiber is connected to the second light source, and the first optical fiber is connected to the optical power meter; the lens assembly is fixed on the fixing clamp, and the end surface of the double-core pin is opposite to the first surface of the lens of the lens assembly; the distance between the double-core pin and the lens assembly is adjusted through the fine adjustment frame to form a first gap; the lens assembly and the double-core pin are fixed through the adhesive to form a light filtering assembly; the light filtering assembly is installed on the fixing clamp, and the shell of the reflection assembly is sleeved on the periphery of the light filtering assembly and then installed on the fine adjustment frame; the distance between the mirror of the reflection assembly and the Faraday optical rotation unit of the lens assembly is adjusted through the fine adjustment frame; and the reflection assembly and the light filtering assembly are fixed through the adhesive to form a wavelength division multiplexing device.

[0017] The wavelength division multiplexing device, the amplification module and the adjustment module described above comprise: a double-core pin comprising a first optical fiber and a second optical fiber; the first optical fiber is used for receiving first signal light, and the second optical fiber is used for receiving second laser light; a lens is used for receiving the first signal light and the second laser light and adjusting the first signal light and the second laser light; a filter plate is used for receiving the first signal light and the second laser light adjusted by the lens, reflecting the second laser light and transmitting the first signal light; the second laser light is reflected to the lens, enters the first optical fiber of the double-core pin after being adjusted again by the lens; a polarization rotation unit is used for receiving the first signal light, rotating the polarization direction of the first signal light by a first angle and reflecting the first signal light to the filter plate; the first signal light with the polarization direction rotated by the first angle enters the first optical fiber of the double-core pin again after passing through the filter plate and the lens again, so that the change of the polarization state of the first signal light is realized through the cooperation of the double-core pin, the lens, the filter plate and the polarization rotation unit, and the scene in which the polarization state needs to be changed in the wind-radar can be met. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments or the related art, the drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating labor.

[0019] Figure 1 It is a structural schematic diagram of the wavelength division multiplexing device in an embodiment;

[0020] Figure 2 It is an end surface structural schematic diagram of the double-core pin in an embodiment;

[0021] Figure 3A structure schematic diagram of a Faraday optical rotation unit in one embodiment;

[0022] Figure 4 A structure schematic diagram of an amplification module in one embodiment;

[0023] Figure 5 A structure schematic diagram of an adjustment module in one embodiment;

[0024] Figure 6 A flow schematic diagram of a manufacturing method of a wavelength division multiplexing device in one embodiment;

[0025] Figure 7 A coupling debugging schematic diagram of a reflection assembly and a filter assembly in one embodiment. DETAILED DESCRIPTION

[0026] In order to make the above object, characteristics and advantages of the present application more apparent, specific embodiments of the present application will be described in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the present application. The specific embodiments of the present application are not intended to be limiting, and reference is made to the appended claims to determine the scope of the present application.

[0027] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0029] In the utility model, unless another definite provision and limitation, the terms "mount", "link", "connect", "fix" and so on should do the broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through the intermediate medium, can be the communication of two elements or the interaction of two elements, unless another definite limitation.For the ordinary skilled person in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0030] In the utility model, unless another definite provision and limitation, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium.Moreover, the first feature "above", "above" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature.The first feature "below", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0031] It should be noted that when an element is referred to as "fixed to" or "provided on" another element, it can be directly on the other element or there can be a middle element.When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element.The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only implementation.

[0032] Reference Figure 1 , Figure 1 The utility model discloses an embodiment of a kind of wavelength division multiplexing devices 100 structure schematic diagram, an embodiment of the utility model provides wavelength division multiplexing device 100, comprising: double-core pin 1, including first optical fiber 11 and second optical fiber 12;First optical fiber 11 is used to receive first signal light, and second optical fiber 12 is used to receive second laser;Lens 2 receives first signal light and second laser, and adjusts first signal light and second laser;Filter sheet 3 receives the first signal light and second laser adjusted via lens 2, reflects second laser and transmits first signal light;Second laser is reflected to lens 2, and after being adjusted again via lens 2, it is incident in the first optical fiber 11 of double-core pin 1;Polarization rotation unit 4 receives first signal light, and after rotating the polarization direction of first signal light first angle, it is reflected to filter sheet 3;After the polarization direction of first signal light rotates first angle, it is incident in the first optical fiber 11 of double-core pin 1 after passing filter sheet 3 and lens 2 again.

[0033] Optical amplifier as the core part of optical communication and fiber laser is increasingly valued by the industry. And improve the gain is also an important part, so many technologies use double-pass amplification and backward pumping scheme. Therefore, in addition to the 980 / 1550nm wavelength division multiplexer, also introduced the mirror. At the same time, some application scenarios, also put forward the requirements of the input and output light polarization state, so the optical path at the same time increase the polarization rotation unit.

[0034] But in the conventional scheme, wavelength division multiplexer, mirror and Faraday optical rotation unit are discrete devices with tail fiber or spatial light, generally used are fusion splicing, there are problems of large overall volume, many fusion points, low production efficiency and so on.

[0035] Exemplary, in order to solve the above problems, an embodiment of the present application proposes a wavelength division multiplexing device 100, double core pin 1 includes two optical fibers, respectively, the first optical fiber 11 using polarization maintaining optical fiber and the second optical fiber 12 using 1060 or 1060flex optical fiber, respectively, for the first signal light of 1550nm wavelength and the second laser of 980nm wavelength transmission. Double core pin 1 is connected with lens 2, the other side of lens 2 is connected with filter 3, and the filter 3 is connected with polarization rotation unit 4. The first signal light and the second laser are incident on the filter 3 after being adjusted by the lens 2. Exemplary, the lens 2 focuses the first signal light and the second laser, the filter 3 reflects the second laser and transmits the first signal light, wherein the second laser is reflected to the lens 2, and the second laser is incident in the first optical fiber 11 of the double core pin 1, i.e. the common end, after being adjusted by the lens 2 again, while the first signal light is received by the polarization rotation unit 4, and the polarization direction of the first signal light is rotated by the polarization rotation unit 4 and the first signal light is reflected to the filter 3; the first signal light with the rotated polarization direction is incident in the first optical fiber 11 of the double core pin 1 again after passing through the filter 3 and the lens 2 again. Exemplary, the polarization direction is rotated by a first angle, and further exemplary, the first angle is 90°.

[0036] In the embodiment, the polarization state of the first signal light is changed by the cooperation of the double core pin 1, the lens 2, the filter 3 and the polarization rotation unit 4, which can meet the scene of changing the polarization state in the wind radar.

[0037] In one embodiment, the polarization rotation unit 4 includes: a Faraday optical rotation unit 41, configured to receive the first signal light and rotate the polarization direction of the first signal light by a second angle under the action of a magnetic field; a mirror 42, configured to receive the first signal light with the rotated polarization direction by the second angle and reflect the first signal light with the rotated polarization direction by the second angle back to the Faraday optical rotation unit 41; the first signal light with the rotated polarization direction by the second angle is incident on the filter 3 again after passing through the Faraday optical rotation unit 41 again.

[0038] For example, referring again to Figure 1 , Figure 1 The double-core ferrule 1 includes two optical fibers, a first optical fiber 11 using polarization maintaining optical fiber and a second optical fiber 12 using 1060 or 1060 flex optical fiber, etc., for transmitting a first signal light at a wavelength of 1550 nm and a second laser light at a wavelength of 980 nm, respectively. The double-core ferrule 1 is connected to a lens 2, and the other side of the lens 2 is connected to a filter 3, which is connected to a Faraday rotator 41. The first signal light and the second laser light are incident on the filter 3 after being adjusted by the lens 2, and the filter 3 reflects the second laser light and transmits the first signal light. The second laser light is reflected to the lens 2, and after being adjusted again by the lens 2, it is incident in the first optical fiber 11, i.e., the common end, of the double-core ferrule 1. The first signal light is received by the Faraday rotator 41, and its polarization direction is rotated by a second angle under the action of a magnetic field. The first signal light is then incident on a mirror 42 and is reflected back to the Faraday rotator 41. The Faraday rotator 41 rotates the polarization direction of the first signal light by the second angle again and then the first signal light is incident on the filter 3. The filter transmits the first signal light, which has been rotated by the Faraday rotator 41 by the second angle twice, and the lens 2, and the first signal light is incident in the first optical fiber 11 of the double-core ferrule 1.

[0039] In some embodiments, the second angle is half of the first angle. For example, when the first angle is 90°, the second angle is 45°.

[0040] For example, the Faraday rotator 41 includes a magnet and a magnetic rotatory material, which can achieve a 45° rotation of polarized light. The magnetic rotatory material can be BIG, YIG, etc.

[0041] In this embodiment, the Faraday rotator 41 and the mirror 42 are added to the original wavelength division device, and one coupling port and a fusion point are reduced, which improves the consistency and reliability of the product. By integrating the wavelength division multiplexer and the mirror 42 into one device, the number of collimators is reduced, the integration level of the device is improved, which is conducive to the miniaturization of the application system and the reduction of the number of production processes, and the reliability and stability of the system are improved.

[0042] In one embodiment, a first gap 5 is provided between the double-core ferrule 1 and the lens 2, so that the first signal light passes through the light exit point of the first optical fiber 11 on the focal plane of the lens 2, and the second laser light passes through the light exit point of the second optical fiber 12 on the focal plane of the lens 2.

[0043] For example, referring again to Figure 1 and Figure 2 , Figure 2Figure 2 is a schematic diagram of the end face structure of the double-core pin 1. The first optical fiber 11 and the second optical fiber 12 are wrapped in a glass rod, and the first optical fiber 11 further includes a stress rod for increasing the birefringence effect of the optical fiber by generating stress, so as to keep the polarization state of the light unchanged. After the first signal light and the second laser pass through the first optical fiber 11 and the second optical fiber 12, they are incident into the first gap 5, which is an air gap in the example. The size of the first gap 5 is set such that the light exit point of the first signal light passing through the first optical fiber 11 is located on the focal plane of the lens 2, and the light exit point of the second laser passing through the second optical fiber 12 is located on the focal plane of the lens 2.

[0044] In the embodiment, by setting the size of the first gap 5 such that the light exit point of the first signal light passing through the first optical fiber 11 is located on the focal plane of the lens 2, and the light exit point of the second laser passing through the second optical fiber 12 is located on the focal plane of the lens 2, the first signal light and the second laser can be focused after passing through the lens 2, so as to fully utilize the optical energy of the two beams of light.

[0045] In one of the embodiments, the wavelength division multiplexing device 100 further includes a housing 6 for accommodating the double-core pin 1, the lens 2, the filter 3, and the polarization rotation unit 4, and the double-core pin 1, the lens 2, and the housing 6 are connected by ultraviolet glue.

[0046] In the embodiment, by setting the housing 6 for accommodating the double-core pin 1, the lens 2, the filter 3, and the polarization rotation unit 4, the interference of external stray light on the optical path of the components inside the housing 6 can be avoided, and by connecting the double-core pin 1, the lens 2, and the housing 6 by ultraviolet glue, the distance between the double-core pin 1 and the lens 2 can be fixed.

[0047] In one of the embodiments, the mirror is fixed inside the housing 6.

[0048] In the embodiment, by integrating the double-core pin 1, the lens 2, the filter 3, the Faraday optical rotation unit 41, and the mirror 42 into the same device, the integration level of the device is improved.

[0049] In one of the embodiments, the lens 2 is a gradient-index lens 2, which includes a first surface 21 and a second surface 22. The first surface 21 is an inclined surface, and the second surface 22 is a planar surface.

[0050] In the example, the lens 2 is a gradient-index lens 2, which includes a first surface 21 and a second surface 22. The first surface 21 is an inclined surface, and the second surface 22 is a planar surface. The first surface 21 is opposite to the light exit end face of the double-core pin 1, and the second surface 22 is connected with the color filter.

[0051] In one of the embodiments, the double-core pin 1, the lens 2, the filter 3 and the polarization rotation unit 4 are sequentially and spacedly arranged in the first direction.

[0052] In one of the embodiments, the Faraday optical rotation unit 41 comprises a first magnet 411, a second magnet 412 and an optical rotation sheet 413, and the optical rotation sheet 413 is arranged between the first magnet 411 and the second magnet 412.

[0053] For example, refer to Figure 3 , Figure 3 Figure 4 is a structural schematic diagram of the Faraday optical rotation unit 41 in one of the embodiments, wherein the Faraday optical rotation unit 41 comprises a first magnet 411, a second magnet 412 and an optical rotation sheet 413, and the optical rotation sheet 413 is arranged between the first magnet 411 and the second magnet 412. When the first signal light passes through the optical rotation sheet 413 of the Faraday optical rotation unit 41, a magnetic field is formed between the first magnet 411 and the second magnet 412, so that the optical rotation sheet 413 with magnetic optical rotation material produces optical rotation effect on the first signal light under the action of the magnetic field, thereby causing the polarization direction of the first signal light to be deflected.

[0054] In one of the embodiments, as shown in Figure 4 , an amplification module is provided, comprising: a first light source 7, the first light source 7 emits first laser light with a first wavelength; a second light source 8, the second light source 8 emits second laser light with a second wavelength; an erbium-doped fiber 9, which receives and transmits the first laser light and the second laser light, and the first laser light is amplified along a first direction in the erbium-doped fiber 9 under the action of the second laser light to obtain first signal light; a wavelength division multiplexing device 100 according to any one of the preceding embodiments, the wavelength division multiplexing device 100 receives the first signal light and the second laser light, and reflects the first signal light and the second laser light back to the erbium-doped fiber 9; the first signal light is amplified again along a second direction in the erbium-doped fiber 9 under the action of the second laser light; the second direction is opposite to the first direction.

[0055] For example, refer to Figure 4As shown, the first laser can be 1550nm laser with P light polarization state, the first laser is input from the first port of the circulator and output from the second port of the circulator and enters the erbium-doped fiber 9; meanwhile, the second laser such as 980LD pump source is input from the second optical fiber 12 and reversely enters the erbium-doped fiber 9 under the action of the wavelength division multiplexing device 100; the first laser such as 1550nm laser forms optical amplification in the erbium-doped fiber 9 with the second laser, and then the amplified gain signal, i.e. the first signal light, enters the wavelength division multiplexing device 100, and the polarization direction is rotated by 45° after being transmitted through the Faraday optical rotation unit 41 in the first direction. After passing through the mirror 42, the first signal light reenters the Faraday optical rotation unit 41, is transmitted through the Faraday optical rotation unit 41 in the second direction, and the polarization direction is rotated by 45° again. Compared with the original P light, the polarization state is rotated by 90° to become S light, enters the 2nd port of the circulator, and is then output by the 3rd port.

[0056] In the embodiment, by using the erbium-doped fiber 9 and the wavelength division multiplexing device 100, not only the gain amplification of the signal light is realized, but also the polarization state of the signal light is changed, which is beneficial to expand the application scenarios and has high integration and realizes miniaturization.

[0057] In another exemplary embodiment, a regulating module is provided, which comprises: a first light source 7, a second light source 8 emitting a first laser with a first wavelength; a second light source 8, the second light source 8 emitting a second laser with a second wavelength; an acousto-optic module 10 receiving the first laser and performing frequency modulation and pulse modulation on the first laser to obtain a second signal light; an erbium-doped fiber 9 receiving and transmitting the second signal light and the second laser, and the second signal light being amplified in the erbium-doped fiber 9 in the first direction under the action of the second laser to obtain a first signal light; a wavelength division multiplexing device 100 as in any of the preceding embodiments; the wavelength division multiplexing device 100 receiving the first signal light and the second laser and reflecting the first signal light and the second laser back to the erbium-doped fiber 9; the first signal light being amplified in the erbium-doped fiber 9 in the second direction again under the action of the second laser and being incident into the acousto-optic module 10 again, and the acousto-optic module 10 performing frequency modulation and pulse modulation on the first signal light to obtain a third signal light; the second direction being opposite to the first direction.

[0058] As shown, the wavelength division multiplexing device 100 is used to receive the first signal light and the second laser and reflect the first signal light and the second laser back to the erbium-doped fiber 9. Figure 5 As shown, it is a structural schematic diagram of the regulating module in an embodiment. Figure 5In the embodiment, the first light source 7 emits first laser light with a first wavelength, which is transmitted to the acousto-optic module 10. The acousto-optic module 10 shifts the frequency of the incident continuous light and chops the continuous light into second signal light, i.e., pulsed light, which is then incident on the erbium-doped fiber 9. The second light source 8 emits second laser light with a second wavelength, which is transmitted to the wavelength division multiplexing device 100. The wavelength division multiplexing device 100 reflects the second laser light back to the erbium-doped fiber 9. The second signal light is amplified in the erbium-doped fiber 9 in a first direction under the action of the second laser light, and first signal light is obtained. The lens 2 of the wavelength division multiplexing device 100 receives the first signal light and the second laser light, adjusts the first signal light and the second laser light, and then reflects the second laser light and transmits the first signal light to the filter 3. The filter 3 receives the first signal light and the second laser light adjusted by the lens 2, reflects the second laser light and transmits the first signal light, and the second laser light is reflected to the lens 2 and then incident on the erbium-doped fiber 9 again after being adjusted by the lens 2. The first signal light transmitted through the filter 3 is incident on the polarization rotation unit 4, which receives the first signal light, rotates the polarization direction of the first signal light by 90 degrees, and then reflects the first signal light to the filter 3 again. The first signal light is amplified in the erbium-doped fiber 9 in a second direction under the action of the second laser light, and then incident on the acousto-optic module 10 again. The acousto-optic module 10 modulates the frequency and the pulse of the second signal light, and third signal light is obtained. The second direction is opposite to the first direction.

[0059] In the embodiment, the first signal light is processed by the wavelength division multiplexing device 100, the polarization state is rotated by 90 degrees, and then the first signal light is amplified again in the erbium-doped fiber 9. Then, the third signal light is obtained by turning off the ASE in the adjacent pulse interval part by using the turn-off function of the acousto-optic module 10. Then, the third signal light is emitted into the atmosphere, and the backscattering signal, i.e., the echo signal, is received after receiving the aerosol. The echo signal is transmitted to the detection module for detection, and the wind speed signal of the target to be detected is obtained. Therefore, the gain amplification of the light is realized, the frequency and the chopping of the light are realized, the ASE in the adjacent pulse interval part is turned off, and the polarization state is changed, which is beneficial to the detection of the wind speed by the laser radar, and the integration degree is high, which is also conducive to the miniaturization of the laser radar.

[0060] Based on the same inventive concept, the embodiment of the present application also provides a manufacturing method of the wavelength division multiplexing device 100. Figure 6 , Figure 6 The flowchart of the manufacturing method of the wavelength division multiplexing device 100 provided by the embodiment includes steps 602 to 614.

[0061] In step 602, the first surface of the filter 3 is bonded to the second surface 22 of the lens 2, and the second surface of the filter 3 is bonded to the Faraday optical rotation unit 41, to form a lens 2 assembly.

[0062] Step 604, the mirror 42 is fixed with the shell 6, forming a reflection assembly.

[0063] Step 606, the double-core pin 1 is installed to the fine adjustment frame 200, the second optical fiber 12 is connected with the second light source 8, and the first optical fiber 11 is connected with the optical power meter 500.

[0064] Step 608, the lens 2 assembly is fixed on the fixing clamp 300, and the end surface of the double-core pin 1 is opposite to the first surface 21 of the lens 2 of the lens 2 assembly, the distance between the double-core pin 1 and the lens 2 assembly is adjusted through the fine adjustment frame 200, forming the first gap 5.

[0065] Step 610, the lens 2 assembly and the double-core pin 1 are fixed by adhesive, forming the optical filter assembly 400.

[0066] Step 612, the optical filter assembly 400 is installed to the fixing clamp 300, and the shell 6 of the reflection assembly is sleeved to the periphery of the optical filter assembly 400 and then installed to the fine adjustment frame 200.

[0067] Step 614, the distance between the mirror 42 of the reflection assembly and the Faraday optical rotation unit 41 of the lens 2 assembly is adjusted through the fine adjustment frame 200, and in the case that the optical power meter 500 displays the maximum value, the reflection assembly and the optical filter assembly 400 are fixed by adhesive, forming the wavelength division multiplexing device 100.

[0068] Please refer to Figure 7 , Figure 7 It is a coupling debugging schematic diagram of the reflection assembly and the optical filter assembly 400.

[0069] Firstly, the lens 2 assembly is made, which comprises the lens 2, the filter 3 and the Faraday optical rotation unit 41, the first surface of the filter 3 is bonded to the second surface of the lens 2, and the second surface of the filter 3 is bonded to the Faraday optical rotation unit 41; wherein the lens 2 is a gradient index lens 2, which comprises a first surface 21 and a second surface 22, the first surface 21 is an inclined surface, and the second surface 22 is a plane surface. Secondly, the reflector 42 is fixed with the shell 6 to make a reflection assembly. Thirdly, the double-core pin 1 is mounted on the fine adjustment frame 200, the second optical fiber 12 is connected with the second light source 8, and the first optical fiber 11 is connected with the optical power meter 500; then the lens 2 assembly is fixed on the fixing clamp 300, the end surface of the double-core pin 1 is opposite to the first surface 21 of the lens 2 in the filter 3 assembly, the relative position of the double-core pin 1 and the lens 2 assembly is adjusted through the fine adjustment frame 200 to form the first gap 5 which makes the optical power meter 500 display the maximum power; then the lens 2 assembly and the double-core pin 1 are fixed by glue to form the light filtering assembly 400; after being removed, the light filtering assembly 400 is mounted on the fixing clamp 300, the shell 6 of the reflection assembly is sleeved on the periphery of the light filtering assembly 400 and then is mounted on the fine adjustment frame 200, the distance between the reflector 42 of the reflection assembly and the Faraday optical rotation unit 41 of the lens 2 assembly is adjusted through the fine adjustment frame 200, in the case that the optical power meter 500 displays the maximum value, the reflection assembly and the light filtering assembly 400 are fixed by glue to form the wavelength division multiplexing device 100. Since the fine adjustment frame 200 and the fixing clamp 300 are conventional operations, they will not be discussed in detail again.

[0070] Optionally, the assembling method comprises firstly completing the bonding of the lens 2, the filter and the Faraday optical rotation unit 41 to form the lens 2 assembly; fixing the reflector 42 and the packaging shell 6 to form the reflection assembly; then realizing the reflection coupling debugging with the double-core pin 1, and realizing the overall assembly of the device after the debugging is completed.

[0071] The manufacturing method of the wavelength division multiplexing device provided in the embodiment integrates the wavelength division multiplexer, the Faraday optical rotation unit 41 and the reflector 42 into the same device, improves the integration degree of the device, and the assembling method is simple and reliable, reduces the multiple couplings and debuggings, has high debugging efficiency, is beneficial to improving the production efficiency, reduces the number of devices and melting points, and improves the system reliability and stability.

[0072] It should be understood that, although the steps in the flowcharts involved in the embodiments described above are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences. Moreover, at least some of the steps in the flowcharts involved in the embodiments described above can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least some of the other steps or the steps or stages in the other steps.

[0073] The technical features of the above embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, but it should be understood that any combination of the technical features is within the scope of the present disclosure as long as there is no contradiction.

[0074] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A wavelength division multiplexing apparatus, characterized by comprising: The application relates to a wavelength division multiplexing device. The device comprises: a double-core ferrule, which comprises a first optical fiber and a second optical fiber; the first optical fiber is used for receiving first signal light, and the second optical fiber is used for receiving second laser light; a lens, which receives the first signal light and the second laser light and adjusts the first signal light and the second laser light; a filter, which receives the first signal light and the second laser light adjusted by the lens, reflects the second laser light and transmits the first signal light; the second laser light is reflected to the lens, is adjusted again by the lens, and is incident into the first optical fiber of the double-core ferrule; a polarization rotation unit, which receives the first signal light, rotates the polarization direction of the first signal light by a first angle, and reflects the first signal light to the filter; 2. The wavelength division multiplexing apparatus according to claim 1, wherein the first signal light with the polarization direction rotated by the first angle is incident into the first optical fiber of the double-core ferrule after passing through the filter and the lens again. The polarization rotation unit comprises: a Faraday optical rotation unit, which is used for receiving the first signal light and rotating the polarization direction of the first signal light by a second angle under the action of a magnetic field; 3. The wavelength division multiplexing apparatus according to claim 1, wherein a mirror, which receives the first signal light with the polarization direction rotated by the second angle, and reflects the first signal light with the polarization direction rotated by the second angle back to the Faraday optical rotation unit; the first signal light with the polarization direction rotated by the second angle is incident into the filter after passing through the Faraday optical rotation unit again and rotating the polarization direction by the second angle again.

4. The wavelength division multiplexing apparatus according to claim 2, wherein A first gap is arranged between the double-core ferrule and the lens, so that the light emitting point of the first signal light passing through the first optical fiber is located on the focal plane of the lens, and the light emitting point of the second laser light passing through the second optical fiber is located on the focal plane of the lens. The device further comprises: a shell, which is used for accommodating the double-core ferrule, the lens, the filter and the polarization rotation unit; 5. The wavelength division multiplexing apparatus according to claim 4, wherein the double-core ferrule, the lens and the shell are connected by ultraviolet glue.

6. The wavelength division multiplexing apparatus according to claim 1, wherein The mirror is fixed in the shell.

7. The wavelength division multiplexing apparatus according to claim 2, wherein The lens is a gradient refractive index lens, which comprises a first surface and a second surface; the first surface is an inclined surface, and the second surface is a plane surface.

8. The wavelength division multiplexing apparatus according to claim 1, wherein The Faraday optical rotation unit comprises a first magnet, a second magnet and an optical rotation sheet; the optical rotation sheet is arranged between the first magnet and the second magnet.

9. An amplification module characterized by, The double-core ferrule, the lens, the filter and the polarization rotation unit are sequentially and spacedly arranged in a first direction. The device comprises: a first light source, which emits first laser light with a first wavelength; a second light source, which emits second laser light with a second wavelength; an erbium-doped optical fiber, which receives and transmits the first laser light and the second laser light, and amplifies the first laser light in the first direction in the erbium-doped optical fiber under the action of the second laser light to obtain first signal light; The wavelength division multiplexing device according to any one of claims 1-8 receives the first signal light and the second laser light, and reflects the first signal light and the second laser light back to the erbium-doped optical fiber; the first signal light is amplified and transmitted in the second direction in the erbium-doped optical fiber under the action of the second laser light again; the second direction is opposite to the first direction.

10. A regulating module, characterized by Comprise: a first light source emitting a first laser light having a first wavelength; a second light source emitting a second laser light having a second wavelength; an acousto-optic module receiving the first laser light and frequency modulating and pulse modulating the first laser light to obtain a second signal light; an erbium-doped fiber receiving and transmitting the second signal light and the second laser light, and the second signal light being amplified along a first direction in the erbium-doped fiber under the action of the second laser light to obtain a first signal light; the wavelength division multiplexing device according to any one of claims 1-8; the wavelength division multiplexing device receiving the first signal light and the second laser light and reflecting the first signal light and the second laser light back to the erbium-doped fiber; the first signal light being amplified again along a second direction in the erbium-doped fiber under the action of the second laser light and being incident into the acousto-optic module again, and the acousto-optic module frequency modulating and pulse modulating the first signal light to obtain a third signal light; the second direction being opposite to the first direction.

Images