A tunable optical filter

Abstract

The present disclosure relates to a tunable optical filter, comprising: an optical transceiver module for emitting composite light; a first mirror for reflecting the composite light to a first lens; the first lens for converting the light reflected by the first mirror into parallel light and then incident to an angle-adjustable second mirror, and focusing the parallel light reflected by the angle-adjustable second mirror and then projecting to a light splitting module; the light splitting module for splitting the light focused by the first lens into monochromatic light of different wavelengths and then projecting to a light reflecting module; the light reflecting module for reflecting the monochromatic light of predetermined wavelength split by the light splitting module back to the optical transceiver module for receiving. The tunable optical filter of the present disclosure can effectively reduce the cost.

Description

Technical Field

[0001] This disclosure relates to the field of optical communication technology, and in particular to a tunable optical filter. Background Technology

[0002] Tunable optical filters are crucial components in modern intelligent optical networks, and their research and development are of great significance for the flexible selection and dynamic monitoring of optical channels. However, current tunable optical filters are complex in structure and expensive. Summary of the Invention

[0003] In view of this, embodiments of the present disclosure aim to provide a tunable optical filter.

[0004] The technical solution disclosed herein is implemented as follows:

[0005] The tunable optical filter includes, in sequence along the optical path: an optical transceiver module, a first reflector, a first lens, an angle-adjustable second reflector, a beam splitter, and a reflector; wherein,

[0006] The optical transceiver module is used to transmit composite light;

[0007] The first reflector is used to reflect the composite light to the first lens;

[0008] The first lens is used to convert the light reflected by the first reflector into parallel light and then incident it onto the angle-adjustable second reflector, and to focus the parallel light reflected by the angle-adjustable second reflector and project it onto the beam splitter module; wherein, the angle-adjustable second reflector is used to reflect the parallel light at a first predetermined angle;

[0009] The beam splitting module is used to decompose the light focused by the first lens into monochromatic light of different wavelengths and project it onto the reflective module;

[0010] The reflector module is used to reflect monochromatic light of a predetermined wavelength, which has been decomposed by the beam splitter module, back to the optical transceiver module for reception.

[0011] In some embodiments, the horizontal scanning direction of the angle-adjustable second reflector is parallel to that of the first lens.

[0012] In some embodiments, the beam-splitting module includes: a second lens and a grating; wherein,

[0013] The second lens is used to change the light spot after the light is focused by the first lens;

[0014] The grating is used to decompose the light after the spot transformation by the second lens into monochromatic light of different wavelengths and project it onto the reflective module.

[0015] In some embodiments, the distance between the second lens and the first lens is the sum of the focal lengths of the first lens and the second lens, wherein the focal length of the second lens is greater than the focal length of the first lens.

[0016] In some embodiments, the tunable optical filter further includes: a photodetector and a controller; wherein...

[0017] The photodetector is used to perform photoelectric conversion on monochromatic light of a predetermined wavelength received by the optical transceiver module 101 to obtain an electrical signal.

[0018] The controller is used to acquire the electrical signal output by the photodetector and monitor the optical performance based on the electrical signal.

[0019] In some embodiments, the photodetector includes a photodiode.

[0020] In some embodiments, the reflective module includes a reflector at a fixed angle.

[0021] In some embodiments, the reflective module includes: a light spot transformation component and an angle-adjustable third reflector, wherein,

[0022] The light spot transformation component is used to transform the monochromatic light of different wavelengths after being decomposed by the beam splitting module and project it onto the angle-adjustable third reflecting mirror.

[0023] The angle-adjustable third reflector is used to select the wavelength of the light after it has been transformed by the light spot transformation component at a second predetermined angle, and to reflect the monochromatic light of the predetermined wavelength back to the optical transceiver module for reception.

[0024] In some embodiments, the spot transformation component includes a third lens and a fourth lens; wherein,

[0025] The third lens is used to focus the monochromatic light of different wavelengths after it has been decomposed by the beam splitting module and project it onto the fourth lens;

[0026] The fourth lens is used to convert the light focused by the third lens into parallel light and project it onto the angle-adjustable third reflector.

[0027] In some embodiments, the angle of the angle-adjustable second reflector is adjusted by an electromechanical system.

[0028] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0029] In the embodiments of this disclosure, the combination of a first reflector and a first lens enables light to be incident parallel to an angle-adjustable second reflector and focused after exiting the angle-adjustable second reflector. Since the first reflector is inexpensive, the solution of the embodiments of this disclosure can effectively reduce the cost of the tunable optical filter. Attached Figure Description

[0030] Figure 1 This is a structural diagram of a tunable optical filter according to an embodiment of the present disclosure;

[0031] Figure 2 A schematic diagram of the horizontal direction of the optical path of a tunable optical filter provided in this embodiment of the present disclosure. Figure 1 ;

[0032] Figure 3 for Figure 2 A side view diagram of the corresponding tunable optical filter optical path;

[0033] Figure 4 A schematic diagram of an optical path for a tunable optical filter provided in this embodiment of the present disclosure. Figure 2 ;

[0034] Figure 5 A schematic diagram of an optical path for a tunable optical filter provided in this embodiment of the present disclosure. Figure 3 . Detailed Implementation

[0035] The technical solution of this disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] This disclosure provides a tunable optical filter. Figure 1 This is a structural diagram of a tunable optical filter shown in an embodiment of the present disclosure, such as... Figure 1 As shown in the embodiments of this disclosure, the tunable optical filter includes, in sequence along the optical path: an optical transceiver module 101, a first reflector 102, a first lens 103, an angle-adjustable second reflector 104, a beam splitter 105, and a reflector 106; wherein,

[0037] The optical transceiver module 101 is used to transmit composite light;

[0038] The first reflector 102 is used to reflect the composite light to the first lens 103;

[0039] The first lens 103 is used to convert the light reflected by the first reflector 102 into parallel light and then incident it onto the angle-adjustable second reflector 104, and to focus the parallel light reflected by the angle-adjustable second reflector 104 and project it onto the beam splitting module 105; wherein, the angle-adjustable second reflector 104 is used to reflect parallel light at a first predetermined angle.

[0040] The beam splitting module 105 is used to decompose the light after it has been focused by the first lens 103 into monochromatic light of different wavelengths and project it onto the reflector module 106.

[0041] The reflector module 106 is used to reflect monochromatic light of a predetermined wavelength, which has been decomposed by the beam splitter module 105, back to the optical transceiver module 101 for reception.

[0042] In this embodiment, the optical transceiver module 101 is used to transmit and receive light. The optical transceiver module 101 can be an optical fiber array. The optical fiber used to transmit light emits composite light, i.e., light with a wide wavelength range, and can be called the transmitting fiber. The optical fiber used to receive light receives monochromatic light after wavelength filtering, i.e., light with a narrow wavelength range, and can be called the receiving fiber. For example, the optical transceiver module 101 can transmit composite light through one optical fiber and receive monochromatic light through one or more other optical fibers. When the optical transceiver module 101 has multiple receiving optical fibers, one optical fiber can be used to receive one monochromatic light.

[0043] In this embodiment, the first reflector 102 reflects the composite light to the first lens 103. The first reflector 102 is a fixed-angle reflector, its function being to change the direction of the composite light emitted from the optical transceiver module 101. The first lens 103 converts the composite light reflected by the first reflector 102 into parallel light so that it can be received by the angle-adjustable second reflector 104. The first lens 103 also focuses the parallel light reflected by the angle-adjustable second reflector 104 and projects it onto the beam splitter module for light decomposition.

[0044] It should be noted that, in this embodiment, the first reflecting mirror 102 can be located at the front focal point of the first lens 103, thus the first lens 103 can convert the light reflected by the first reflecting mirror 102 into parallel light. Furthermore, the angle-adjustable second reflecting mirror 104 changes the angle of the light rays projected onto the first lens 103 by adjusting its angle, and further affects the angle of the light rays projected onto the beam splitter 105 after being focused by the first lens 103, i.e., changing the incident angle projected onto the beam splitter 105 to achieve wavelength selection. In this embodiment, the angle-adjustable second reflecting mirror 104 can support angle adjustment in the horizontal and / or vertical directions.

[0045] In some embodiments, the angle of the angle-adjustable second reflector 104 is adjusted by an electromechanical system. For example, the angle-adjustable second reflector 104 may be a micro-electro-mechanical system (MEMS) reflector.

[0046] In this embodiment, the beam splitting module 105 decomposes the light focused by the first lens 103 into monochromatic light of different wavelengths and projects it onto the reflector module 106. The beam splitting module 105 can be based on the principle of diffraction, for example, the beam splitting module 105 includes a diffraction grating; alternatively, the beam splitting module 105 can also utilize the principle of refraction, for example, the beam splitting module 105 includes a beam splitting prism.

[0047] In some embodiments, the reflective module 106 includes a mirror at a fixed angle. In other embodiments, the reflective module 106 may also be a component consisting of multiple optical elements.

[0048] In this embodiment, monochromatic light of different wavelengths, after being decomposed by the beam splitter 105, is projected onto the reflector 106, and then reflected back to the original optical path by the reflector 106 for reception by the optical transceiver 101. The original optical path refers to the optical path formed by the arrangement of the optical transceiver 101, the first reflector 102, the first lens 103, the angle-adjustable second reflector 104, the beam splitter 105, and the reflector 106. The propagation direction of the composite light emitted from the optical transceiver 101 is opposite to the propagation direction of the light reflected by the reflector 106.

[0049] It should be noted that, in this embodiment, when the angle-adjustable second reflector 104 is set to a specific angle, only light of a specific angle (e.g., emitted at a specific diffraction angle) can return from the reflector 106 to the original optical path and be transmitted / received by the transceiver 101 among the monochromatic lights of each wavelength after being decomposed by the beam splitter 105. Therefore, wavelength filtering, i.e., wavelength selection, can be achieved in this way. Furthermore, in this embodiment, the angle of the angle-adjustable second reflector 104 is tunable; therefore, wavelength tuning can be achieved by rotating the angle-adjustable second reflector 104 at different angles.

[0050] In related technologies, multiple lenses are combined to allow light to be incident parallel to a MEMS mirror and focused after exiting the MEMS mirror. In contrast, in this embodiment of the present disclosure, a combination of a first mirror and a first lens allows light to be incident parallel to an angle-adjustable second mirror and focused after exiting the angle-adjustable second mirror. Since the cost of the first mirror is lower than that of the lens, the solution of this embodiment of the present disclosure can effectively reduce the cost of the tunable optical filter.

[0051] In some embodiments, the horizontal scanning direction of the angle-adjustable second reflector 104 is parallel to that of the first lens 103.

[0052] In this embodiment, the angle-adjustable second reflector 104 supports horizontal angle adjustment. Since the horizontal scanning direction of the angle-adjustable second reflector 104 is parallel to the first lens 103, the parallel light converted by the first lens 103 can be incident perpendicularly on the angle-adjustable second reflector 104. Therefore, the angle-adjustable second reflector 104 receiving the parallel light converted by the first lens 103 will not be affected by the distance between the angle-adjustable second reflector 104 and the first lens 103. Thus, this embodiment can reduce the overall size of the tunable optical filter by setting the distance between the angle-adjustable second reflector 104 and the first lens 103 at a close distance through the above-mentioned setting method. In addition, since the parallel light converted by the first lens 103 can be incident perpendicularly on the angle-adjustable second reflector 104, the transmission window of the angle-adjustable second reflector 104 does not need to be set to be very large. Therefore, this embodiment can also save the cost of the angle-adjustable second reflector 104.

[0053] In some embodiments, the beam-splitting module 105 includes: a second lens 105a and a grating 105b; wherein,

[0054] The second lens 105a is used to change the light spot after the light is focused by the first lens 103;

[0055] The grating 105b is used to decompose the light after the light spot is transformed by the second lens 105a into monochromatic light of different wavelengths and project it onto the reflector module 106.

[0056] In this embodiment of the present disclosure, the second lens 105a and the grating 105b are arranged sequentially along the optical path. The second lens 105a transforms the light after it has been focused by the first lens 103, for example, by converting the focused light into divergent light to increase the light spot size, thereby facilitating the diffraction of the grating 105b to decompose it into monochromatic light of different wavelengths.

[0057] In some embodiments, the distance between the second lens 105a and the first lens 103 is the sum of the focal length of the first lens 103 and the focal length of the second lens 105a, wherein the focal length of the second lens 105a is greater than the focal length of the first lens 103.

[0058] The second lens 105a is used to convert the light focused by the first lens 103 into parallel light;

[0059] The grating 105b is used to decompose the parallel light converted by the second lens 105a into monochromatic light of different wavelengths and then project it onto the reflective module 106.

[0060] In this embodiment, the distance between the second lens 105a and the first lens 103 is the sum of the focal length of the first lens 103 and the focal length of the second lens 105a. The second lens 105a can convert the light focused by the first lens 103 into parallel light. Furthermore, the grating 105b can decompose the parallel light converted by the second lens 105a into monochromatic light of different wavelengths and then project it onto the reflector module 106.

[0061] In this embodiment of the present disclosure, the focal length of the second lens 105a is greater than that of the first lens 103, so that the spot diameter of the parallel light emitted from the second lens 105a is greater than the spot diameter of the parallel light incident on the first lens 103 (i.e., the parallel light reflected by the angle-adjustable second reflector 104). It can be understood that the first lens 103 and the second lens 105a constitute a telescope system.

[0062] In this embodiment, the telescope system is formed by the configuration of the first lens 103 and the second lens 105a, so that the light incident on the grating 105b is parallel light with a large spot size and uniform spot size, which is beneficial to the diffraction and beam splitting of the grating 105b and can further improve the filtering performance of the tunable optical filter.

[0063] In some embodiments, the tunable optical filter further includes: a photodetector 107 and a controller 108; wherein,

[0064] The photodetector 107 is used to perform photoelectric conversion on the monochromatic light of a predetermined wavelength received by the optical transceiver module 101 to obtain an electrical signal.

[0065] The controller 108 is used to acquire the electrical signal output by the photodetector and monitor the optical performance based on the electrical signal.

[0066] In this embodiment, the tunable optical filter can achieve optical performance monitoring based on a photodetector 107 and a controller 108. The photodetector 107 acquires monochromatic light of a predetermined wavelength received by the receiving optical fiber of the optical transceiver module 101, performs photoelectric conversion to obtain an electrical signal, and the controller 108 performs spectral integration based on this electrical signal to achieve the optical performance monitoring function. The photodetector 107 includes a photodiode. A photodiode is a semiconductor chip device composed of a PN junction, which can convert optical signals of a predetermined wavelength into current signals. The controller can be a microcontroller unit (MCU) or a central processing unit (CPU).

[0067] In this embodiment, the receiving optical fiber in the optical transceiver module 101 can be connected to the photodetector 107. The second reflector 104 with an adjustable angle can be controlled by the controller 108 to rotate rapidly, so that the photodetector 107 can quickly receive the first-pass filtered signals of all wavelengths and convert them into electrical signals. Then, the controller 108 can perform spectral integration to realize the optical performance monitoring function.

[0068] It is understood that, in the embodiments of this disclosure, the tunable optical filter can not only select the wavelength of the optical signal, but also has a built-in photodetector and controller, enabling the tunable optical filter to realize the optical performance monitoring function without the need for an external optical performance monitoring module. It has the advantages of simple structure but rich function.

[0069] Figure 2 A schematic diagram of the horizontal direction of the optical path of a tunable optical filter provided in this embodiment of the present disclosure. Figure 1 Wherein, 101a is the transmitting fiber in the optical transceiver module 101, 101b is the receiving fiber in the optical transceiver module 101, and 1016a is a reflector of a single optical element included in the beam splitter module 106, such as... Figure 2 As shown, the light emitted by the transmitting fiber 101a is reflected by the first reflector 102 to the first lens 103. The first lens converts the incident light into parallel light, which is then emitted to the angle-adjustable second reflector 104. The angle-adjustable second reflector 104 reflects the incident parallel light back to the first lens 103 at a specific reflection angle. The first lens 103 then focuses the received parallel light again and projects it onto the second lens 105a in the beam splitter module 105. As can be seen from the figure, the distance between the second lens 105a and the first lens 103 is the sum of their focal lengths, and the focal length of the second lens 105a is greater than that of the first lens 103. Therefore, the second lens 105a can convert the focused light into a large-spot parallel light and project it onto the grating 105b at a specific angle. The grating 105b uses the principle of multi-slit diffraction to disperse light, decomposing the parallel light (wide wavelength range parallel light) of the input large light spot into parallel light of different wavelengths emitted at different diffraction angles. The mirror 106a is used to reflect the diffracted light of a specific wavelength in each single wavelength monochromatic light diffracted by the grating 105b back to the optical path so that the receiving fiber 101b can receive it. Figure 2 In the process, photodiode 107 is connected to receiving optical fiber 101b to convert optical signals of a specific wavelength into current signals, thereby enabling the tunable optical filter to monitor optical performance. Figure 3 for Figure 2 A side-view diagram of the corresponding tunable optical filter path. Figure 3 In the middle, the optical transceiver module 101 includes Figure 2 The optical propagation process of 101a and 101b shown can be referred to Figure 2.

[0070] Figure 4 A schematic diagram of an optical path for a tunable optical filter provided in this embodiment of the present disclosure. Figure 2 ,like Figure 4 As shown, the composite light emitted by the transmitting fiber 01 is converted into parallel light by the lens 03 and then sent to the MEMS reflector 04. The MEMS reflector 04 projects the incident parallel light onto the lens 05 at a specific reflection angle. The lens 05 converts the parallel light into focused light and projects it onto the lens 06 at a specific angle. The lens 06 converts the focused light into a large spot of parallel light and projects it onto the grating 07 at a specific angle. The grating 07 decomposes the large spot of parallel light into parallel light of different wavelengths emitted at different diffraction angles. The reflector 08 reflects the diffracted light of a specific wavelength back to the optical path and receives it through the receiving fiber 02. The photodiode 09 obtains the optical signal of a specific wavelength from the receiving fiber and converts it into current.

[0071] contrast Figure 2 and Figure 4 As can be seen, in the embodiments of this disclosure Figure 2 The scheme in the middle is relatively Figure 4 Reducing the use of one lens can effectively lower the cost of tunable optical filters. Furthermore, Figure 4 In the proposed design, the angle between lens 03 and lens 05, as well as the distance between lens 03, lens 05, and MEMS mirror 04, will affect the transmission window of MEMS mirror 04 (e.g., Figure 4 The size of the portion indicated by L in the diagram. For example, the distance and angle between lenses 03 and 05 and the MEMS mirror 04 are limited by the dimensions of the three components and the optical path, making it impossible to effectively reduce the distance. The larger the angle between lenses 03 and 05, the larger the transmission window of the MEMS mirror 04 needs to be; and if the device wavelength tuning range is larger, the rotation range of the MEMS mirror 04 needs to be larger, and the size requirement for the transmission window is also higher. In addition, if the distance between lenses 03, 05 and the MEMS mirror 04 is large, the optical path of the entire device increases, which will increase the insertion loss of the device. At the same time, when tuning the filtered wavelength, the edge light rays incident on lens 05 are farther from the center of lens 05, which will increase the aberration of lens 05 in the optical path. In contrast, the embodiments of this disclosure... Figure 2As described above, in the proposed scheme, since the angle-adjustable second reflector 104 is arranged parallel to the first lens 103, the parallel light converted by the first lens 103 can be incident perpendicularly on the angle-adjustable second reflector 104. Therefore, the angle-adjustable second reflector 104 receiving the parallel light converted by the first lens 103 will not be affected by the distance between the angle-adjustable second reflector 104 and the first lens 103, thus helping to optimize the overall size of the tunable optical filter. At the same time, since the parallel light converted by the first lens 103 can be incident perpendicularly on the angle-adjustable second reflector 104, the transmission window of the angle-adjustable second reflector 104 does not need to be very large, thus effectively reducing the packaging requirements of the angle-adjustable second reflector 104 and saving the manufacturing cost of the angle-adjustable second reflector 104. Furthermore, the angle-adjustable second reflector 104 and its transmission window can be very close to the first lens 103. When the wavelength is tuned and filtered, the edge light rays incident on the first lens 103 are closer to the center of the first lens 103, which will minimize the aberration effect of the first lens 103 on the optical path.

[0072] As previously described, the reflective module 106 can also be a component composed of multiple optical elements. In some embodiments, the reflective module 106 includes: a light spot transformation component 106b and an angle-adjustable third reflector 106c, wherein,

[0073] The light spot transformation component 106b is used to transform the monochromatic light of different wavelengths after being decomposed by the beam splitting module 105 and project it onto the angle-adjustable third reflector 106c.

[0074] The angle-adjustable third reflector 106c is used to select the wavelength of the light after it has been transformed by the light spot transformation component at a second predetermined angle, and to reflect the monochromatic light of the predetermined wavelength back to the optical transceiver module 101 for reception.

[0075] In this embodiment, the reflective module 106 includes a light spot conversion component 106b and an angle-adjustable third reflector 106c. The light spot conversion component 106b can be formed based on a lens group, and the angle-adjustable third reflector 106c can be a MEMS reflector. The angle-adjustable third reflector 106c performs wavelength selection on the light after the light spot conversion component has performed the light spot conversion at a second predetermined angle, and then reflects the monochromatic light of the predetermined wavelength after the second wavelength selection back to the original optical path to be received by the optical transceiver module 101.

[0076] In this embodiment of the present disclosure, the receiving optical fiber in the optical transceiver module 101 can also be connected to the photodetector 107. The controller 108 controls the adjustable second reflector 104 and the adjustable third reflector 106c to rotate rapidly, so that the photodetector 107 can quickly receive the secondary filtered signals of all wavelengths and convert them into electrical signals. Then the controller 108 can perform spectral integration to realize the optical performance monitoring function.

[0077] In this embodiment, the monochromatic light of different wavelengths after being split by the beam splitting module 105 is not reflected back to the transceiver module 101 by the aforementioned reflector 106a. Instead, it is fed to the spot conversion component 106b and then subjected to wavelength selection again at a second predetermined angle by the angle-adjustable third reflector 106c. Assuming that the wavelength tuning range determined by the angle range of the angle-adjustable second reflector 104 is λ1, and the wavelength tuning range determined by the angle range of the angle-adjustable third reflector 106c is λ2, then in this embodiment, the wavelength range tuned by the two angle-adjustable reflectors is expanded to λ1 + λ2. It can be understood that this method can expand the wavelength tuning range and effectively alleviate the problem of limited wavelength tuning range caused by the angle limitation of the MEMS reflector.

[0078] In some embodiments, the spot transformation component 106b includes a third lens 106b1 and a fourth lens 106b2; wherein,

[0079] The third lens 106b1 is used to focus the monochromatic light of different wavelengths after being decomposed by the beam splitting module 105 and project it onto the fourth lens 106b2.

[0080] The fourth lens 106b2 is used to convert the light focused by the third lens 106b1 into parallel light and project it onto the angle-adjustable third reflector 106c.

[0081] It is understood that in this embodiment, the third lens 106b1 focuses the received monochromatic light of different wavelengths decomposed by the beam splitter 105 and projects it onto the fourth lens 106b2. The fourth lens 106b2 then converts the focused divergent light into parallel light with a small spot, so that it can be received by the angle-adjustable third reflector 106c. Since the angle-adjustable third reflector 106c receives parallel light with a small spot, a large transmission window is not required, which can effectively save the cost of the angle-adjustable third reflector 106c. In addition, in the return path, the third lens 106b1 and the fourth lens 106b2 form a telescope system, so that the monochromatic light of a specific wavelength after secondary tuning can return from the reflector 106 to the original optical path and be received by the optical transceiver module 101.

[0082] Figure 5A schematic diagram of an optical path for a tunable optical filter provided in this embodiment of the present disclosure. Figure 3 ,like Figure 5 As shown, relative to Figure 2 The parallel light of different wavelengths, after being decomposed by grating 105b, is focused and projected onto the third lens 106b1. The third lens 106b1 then focuses the light onto the fourth lens 106b2. The fourth lens 106b2 converts the focused light into parallel light and projects it onto the angle-adjustable third reflector 106c. The angle-adjustable third reflector 106c then reflects the monochromatic light of the predetermined wavelength, after secondary wavelength selection, back into the optical path for reception by the receiving fiber 101b.

[0083] Understandably, based on Figure 5 The tunable optical filter shown expands the tunable wavelength range while taking cost into account, and also supports optical performance monitoring.

[0084] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or modules can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0085] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0086] Furthermore, in the various embodiments of this disclosure, all functional units can be integrated into one processing module, or each unit can be a separate unit, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in a combination of hardware and software functional units. Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0087] The methods disclosed in the several method embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0088] The features disclosed in the several product embodiments provided in this disclosure can be combined arbitrarily without conflict to obtain new product embodiments.

[0089] The features disclosed in the several method or device embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0090] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A tunable optical filter, characterized by, The tunable optical filter comprises, sequentially arranged along an optical path: an optical transceiver module, a first mirror, a first lens, an angle-adjustable second mirror, a light splitting module, and a light reflecting module. The optical transceiver module is configured to emit composite light. The first mirror is configured to reflect the composite light to the first lens. The first lens is configured to convert the light reflected by the first mirror into parallel light and then focus the parallel light reflected by the angle-adjustable second mirror and project the focused parallel light to the light splitting module. The angle-adjustable second mirror is configured to reflect the parallel light at a first predetermined angle. The light splitting module is configured to split the light focused by the first lens into monochromatic light of different wavelengths and project the monochromatic light to the light reflecting module.

2. The tunable optical filter of claim 1, wherein, The light reflecting module is configured to reflect the monochromatic light of a predetermined wavelength split by the light splitting module back to the optical transceiver module for reception. The light splitting module comprises a second lens and a grating. The second lens is configured to perform spot transformation on the light focused by the first lens.

3. The tunable optical filter of claim 2, wherein, The grating is configured to split the light subjected to spot transformation by the second lens into monochromatic light of different wavelengths and project the monochromatic light to the light reflecting module.

4. The tunable optical filter of claim 1, wherein, The distance between the second lens and the first lens is the sum of the focal length of the first lens and the focal length of the second lens, and the focal length of the second lens is greater than the focal length of the first lens. The tunable optical filter further comprises a photodetector and a controller. The photodetector is configured to perform photoelectric conversion on the monochromatic light of a predetermined wavelength received by the optical transceiver module to obtain an electrical signal.

5. The tunable optical filter of claim 4, wherein, The controller is configured to acquire the electrical signal output by the photodetector and perform optical performance monitoring based on the electrical signal.

6. The tunable optical filter of claim 1, wherein, The photodetector comprises a photodiode.

7. The tunable optical filter of any of claims 1 to 5, wherein, The light reflecting module comprises a fixed-angle mirror. The light reflecting module comprises a spot transformation assembly and an angle-adjustable third mirror. The spot transformation assembly is configured to perform spot transformation on the monochromatic light of different wavelengths split by the light splitting module and project the light to the angle-adjustable third mirror.

8. The tunable optical filter of claim 7, wherein, The angle-adjustable third mirror is configured to select the wavelength of the light subjected to spot transformation by the spot transformation assembly at a second predetermined angle and reflect the monochromatic light of a predetermined wavelength back to the optical transceiver module for reception. The spot transformation assembly comprises a third lens and a fourth lens. The third lens is configured to focus the monochromatic light of different wavelengths split by the light splitting module and project the light to the fourth lens.

9. The tunable optical filter of claim 1, wherein, The fourth lens is configured to convert the light focused by the third lens into parallel light and then project the parallel light to the angle-adjustable third mirror. The angle of the angle-adjustable second mirror is adjusted by an electromechanical system.

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