Tunable optical filter

Abstract

The invention provides a tunable optical filter. The tunable optical filter comprises a light emitting and receiving unit (1), a first lens module (2), a diffraction module (3), a second lens module (4) and a micro reflector (5), an optical signal outputs divergent light through the light emitting and receiving unit (1), the divergent light is converted into parallel light through the first lens module (2), the parallel light enters the diffraction module (3) to be dispersed into diffracted light, the diffracted light enters the second lens module (4) to be focused to the micro-reflecting mirror (5) to form reflected light, and the reflected light is reflected by the micro-reflecting mirror (5). The reflected light returns according to an original light path and is received by the light emitting and receiving unit (1); wherein the diffraction module (3) can change the direction of a light path.

Description

Technical Field

[0001] The present application relates to filtering technology, and in particular to a tunable optical filter. Background Art

[0002] Tunable optical filters (TOF) are important components in modern intelligent optical networks. Their research and development are crucial for the flexible selection and dynamic monitoring of optical channels. However, existing filter designs are complex, large in size, and expensive. Summary of the Invention

[0003] The embodiments of the present application provide a tunable optical filter, a signal processing device, and a signal processing method, which can make the filter structure simple and compact, and reduce size and cost.

[0004] The technical solution of the embodiment of the present application is implemented as follows:

[0005] The embodiment of the present application provides a tunable optical filter, comprising: a light emitting and receiving unit 1, a first lens module 2, a diffraction module 3, a second lens module 4 and a micro-reflector 5;

[0006] The optical signal outputs divergent light through the optical transmitting and receiving unit 1, and the divergent light is converted into parallel light by the first lens module 2. The parallel light is incident on the diffraction module 3 and dispersed into diffracted light. The diffracted light is incident on the second lens module 4 and focused to the micro-reflector 5 to form reflected light. The reflected light returns along the original optical path and is received by the optical transmitting and receiving unit 1.

[0007] The diffraction module 3 is capable of changing the direction of the light path.

[0008] In the above solution, the first lens module 2 includes a first lens 21, which is arranged in the light emitting direction of the light emitting and receiving unit 1 and is used to convert the scattered light signal emitted by the light emitting and receiving unit 1 into a parallel light signal; the diffraction module 3 is arranged in the light emitting direction of the first lens 21 and is used to disperse the parallel light signal to obtain the diffracted light;

[0009] The direction of the parallel light emitted by the first lens 21 is not perpendicular to the light incident surface of the diffraction module 3 .

[0010] In the above scheme, the second lens module 4 includes a first micro-electromechanical system 41 and a second lens 42; the first micro-electromechanical system 41 is arranged in the light emitting direction of the diffraction module 3; the first micro-electromechanical system 41 carries a first reflector for reflecting the diffracted light to the second lens 42; the second lens 42 is arranged between the first reflector and the micro-reflector 5, for focusing the diffracted light reflected by the first reflector to the micro-reflector 5; wherein, the first micro-electromechanical system 41 can change the direction of the light path.

[0011] In the above scheme, the first lens module 2 includes a third lens 22, a second micro-electromechanical system 23 and a telescope module 24; the third lens 22 is arranged in the light emitting direction of the light emitting and receiving unit 1, and is used to convert the scattered light signal emitted by the light emitting and receiving unit 1 into a parallel light signal; the second micro-electromechanical system 23 is arranged in the light emitting direction of the third lens 22, and the second micro-electromechanical system 23 carries a second reflector, which is used to reflect the parallel light emitted by the third lens 2 to the telescope module 24; the telescope module 24 is arranged between the second micro-electromechanical system 23 and the diffraction module 3; wherein, the second micro-electromechanical system 23 can change the direction of the light path.

[0012] In the above solution, the second lens module 4 includes a fourth lens 43 . The fourth lens 43 is disposed between the diffraction module 3 and the micro-reflector 5 and is used to focus the diffracted light onto the micro-reflector 5 .

[0013] In the above solution, the telescope module 24 includes a fifth lens 241 and a sixth lens 243 , and each of the fifth lens 241 and the sixth lens 243 includes a flat surface and a convex surface;

[0014] The plane of the fifth lens 241 is arranged opposite to the plane of the sixth lens 243 .

[0015] In the above solution, the micro-mirror 5 includes a plurality of micro-mirror arrays 51 arranged at intervals on the same straight line, and each micro-mirror array 51 has a different width.

[0016] In the above solution, the micro-reflector 5 includes a plurality of micro-reflector arrays 52 arranged in an annular pattern and spaced apart from each other, and each micro-reflector array 52 has a different width.

[0017] In the above solution, the optical transmitting and receiving unit 1 includes a plurality of optical fiber arrays 11 .

[0018] In the above solution, the second lens 42 is spherical or cylindrical.

[0019] The tunable optical filter provided in the embodiment of the present application includes a light emitting and receiving unit 1, a first lens module 2, a diffraction module 3, a second lens module 4 and a micro-reflector 5; the optical signal outputs divergent light through the light emitting and receiving unit 1, the divergent light is converted into parallel light through the first lens module 2, the parallel light is incident on the diffraction module 3 and dispersed into diffracted light, the diffracted light is incident on the second lens module 4 and focused to the micro-reflector 5 to form reflected light, and the reflected light returns along the original optical path and is received by the light emitting and receiving unit 1; wherein, the diffraction module 3 is capable of changing the direction of the optical path; by changing the direction of the optical path, the filter structure is simple and compact, reducing size and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0021] Figure 2 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0022] Figure 3 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0023] Figure 4 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0025] Figure 6 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application;

[0026] Figure 7 This is a schematic diagram of an optional structure of a micro-reflector provided in an embodiment of the present application;

[0027] Figure 8 This is a schematic diagram of an optional structure of a micro-reflector provided in an embodiment of the present application;

[0028] Figure 9 This is a schematic diagram of an optional structure of a lens provided in an embodiment of the present application;

[0029] Figure 10 Schematic diagram of the corresponding bandwidth spectrum generated by micro-mirror filtering optical paths with different widths. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0032] In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0034] Tunable optical filters are important components in modern intelligent optical networks. Their research and development are crucial for the flexible selection and dynamic monitoring of optical channels. However, related technical solutions suffer from complex structures, large size, and high costs.

[0035] Based on this, an embodiment of the present application provides a tunable optical filter, which uses optical fibers, reflectors, lenses, gratings, micro-electromechanical systems, etc. to achieve a simple and compact filter structure, reducing size and cost.

[0036] The following describes the tunable optical filter provided in the embodiment of the present application. Figure 1 , Figure 1This is an optional structural diagram of the tunable optical filter provided in an embodiment of the present application. The tunable optical filter provided in an embodiment of the present application includes: a light emitting and receiving unit 1, a first lens module 2, a diffraction module 3, a second lens module 4 and a micro-reflector 5; the optical signal outputs divergent light through the light emitting and receiving unit 1, the divergent light is converted into parallel light by the first lens module 2, the parallel light is incident on the diffraction module 3 and dispersed into diffracted light, the diffracted light is incident on the second lens module 4 and focused to the micro-reflector 5 to form reflected light, and the reflected light returns along the original light path and is received by the light emitting and receiving unit 1; wherein the diffraction module 3 is capable of changing the direction of the light path; the first lens module 2 and / or the second lens module 4 is capable of changing the direction of the light path.

[0037] In actual implementation, the optical circulator 6 includes three ports, namely PORT1, PORT2 and PORT3. Among them, PORT1 and PORT2 are input ports, and PORT3 is an output port. Multiple optical signals with a wide wavelength range are input through PORT1 of the optical circulator 6, enter the light emitting and receiving unit 1 through PORT2 of the optical circulator 6, and are output as divergent light. They are converted into parallel light by the first lens module 2. The parallel light is incident on the diffraction module 3, and each wavelength of light is emitted according to a different diffraction angle, and then incident on the second lens module 4. It is focused by the second lens module 4 to the micro-reflector 5 to form reflected light. The reflected light returns along the original optical path and is received by the light emitting and receiving unit 1. Specifically, the reflected light emitted by the micro-reflector 5 passes through the second lens module 4, the diffraction module 3 and the first lens module 2 in sequence and then reaches the light emitting and receiving unit 1. Here, the diffraction module 3 can be a grating.

[0038] In the embodiment of the present application, the diffraction module 3 is a flat plate structure. The diffraction module 3 forms a first angle with the output light of the first lens module 2. The diffraction module 3 forms a second angle with the second lens module 4. Here, the sum of the first angle and the second angle can be the target angle. For example, the target angle can be 90°, and the first angle and the second angle can both be 45°.

[0039] In the embodiment of the present application, the diffraction module 3 can change the direction of the light path. In addition, the micro-reflector 5 can return the light path to its original path, thereby greatly reducing the size of the filter, thereby reducing the cost and making the filter structure compact.

[0040] In some embodiments, see Figure 2 , Figure 2This is a schematic diagram of an optional structure of the tunable optical filter provided in an embodiment of the present application. The first lens module 2 includes a first lens 21, which is arranged in the light emission direction of the light emitting and receiving unit 1 and is used to convert the scattered light signal emitted by the light emitting and receiving unit 1 into a parallel light signal; the diffraction module 3 is arranged in the light emission direction of the first lens 21 and is used to disperse the parallel light signal to obtain the diffracted light; wherein the direction of the parallel light emitted by the first lens 21 is not perpendicular to the light incident surface of the diffraction module 3.

[0041] In some embodiments, see Figure 3 , Figure 3 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application. The second lens module 4 includes a first micro-electromechanical system 41 and a second lens 42; the first micro-electromechanical system 41 is arranged in the light emission direction of the diffraction module 3; the first micro-electromechanical system 41 carries a first reflector for reflecting the diffracted light to the second lens 42; the second lens 42 is arranged between the first reflector and the micro-reflector 5, for focusing the diffracted light reflected by the first reflector onto the micro-reflector 5; wherein the first micro-electromechanical system 41 is capable of changing the direction of the optical path.

[0042] In actual implementation, multiple optical signals covering a wide wavelength range are input through port 1 of circulator 6, enter optical transmission and reception unit 1 through port 2 of circulator 6, and are output as divergent light. This light is then converted to parallel light by first lens 21. This parallel light is then incident on diffraction module 3, where each wavelength of light emerges at a different diffraction angle and strikes the reflector of first micro-electro-mechanical system 41. Here, diffraction module 3 is a grating. The reflector of first micro-electro-mechanical system 41 reflects the diffracted light to second lens 42, which focuses each wavelength of light onto its focal plane.

[0043] In the horizontal direction, the reflector of the first MEMS 41 rotates to a specific angle so that only light with a specific diffraction angle can be focused on the micro-reflector 5, reflected back to the optical path by the micro-reflector 5 and ultimately received by the light emitting and receiving unit 1, thus realizing the tunable filter function. By setting the horizontal width of the micro-reflector 5, the filter bandwidth received by the light emitting and receiving unit 1 can be flexibly controlled. The wider the micro-reflector 5, the wider the bandwidth of the returned spectrum, and the more the filter waveform tends to be flat-topped. The narrower the micro-reflector, the narrower the bandwidth of the returned spectrum, and the more the filter waveform tends to be Gaussian. Here, if the reflector of the first MEMS 41 is far away from the second lens 42, when the angle of the reflector of the first MEMS 41 is rotated, the focused main light incident on the micro-reflector 5 cannot be guaranteed to be absolutely 0 degrees of incidence, resulting in filter signal loss and spectral degradation. In the embodiment of the present application, the distance between the reflector of the first MEMS 41 and the surface of the second lens 42 is less than or equal to the distance threshold, so that the reflector of the first MEMS 41 is close to the surface of the second lens 42. Here, the distance threshold may be a smaller value set by those skilled in the art based on actual experience, and is not limited here.

[0044] The embodiments of the present application realize the function of a tunable optical filter through a combination of optical components such as optical fibers, lenses, gratings, and micro-electromechanical systems and circulators. The size of the filter bandwidth can be changed or tuned in real time by simply changing the horizontal width of the micro-reflector, and a Gaussian or flat-top spectrum can be achieved. The optical path is simple, efficient, and low-cost.

[0045] In some embodiments, see Figure 4 , Figure 4 This is a schematic diagram of an optional structure of a tunable optical filter provided in an embodiment of the present application. The first lens module 2 includes a third lens 22, a second micro-electromechanical system 23, and a telescope module 24; the third lens 22 is arranged in the light emission direction of the light emitting and receiving unit 1, and is used to convert the scattered light signal emitted by the light emitting and receiving unit 1 into a parallel light signal; the second micro-electromechanical system 23 is arranged in the light emission direction of the third lens 22, and the second micro-electromechanical system 23 carries a second reflector for reflecting the parallel light emitted by the third lens 2 to the telescope module 24; the telescope module 24 is arranged between the second micro-electromechanical system 23 and the diffraction module 3; wherein the second micro-electromechanical system 23 is capable of changing the direction of the optical path.

[0046] In some embodiments, see Figure 5 , Figure 5 This is an optional structural diagram of the tunable optical filter provided in the embodiment of the present application. Figure 4The second lens module 4 includes a fourth lens 43 , which is disposed between the diffraction module 3 and the micro-reflector 5 and is used to focus the diffracted light onto the micro-reflector 5 .

[0047] In some embodiments, the telescope module 24 includes a fifth lens 241 and a sixth lens 243 , each of the fifth lens 241 and the sixth lens 243 including a flat surface and a convex surface; wherein the flat surface of the fifth lens 241 is opposite to the flat surface of the sixth lens 243 .

[0048] In actual implementation, multiple optical signals across a wide wavelength range are input through port 1 of circulator 6, enter optical transmission and reception unit 1 through port 2 of circulator 6, and are output as divergent light. This light is then converted into parallel light by third lens 22 and incident on the reflector of second MEMS 23. The center of the reflector of second MEMS 23 is located above the focal point of telescope module 24, and the reflector of second MEMS 23 reflects the parallel light toward telescope module 24.

[0049] The center of diffraction module 3 is located above the other focal point of telescope module 24. Parallel light emitted by telescope module 24 is incident on the center of diffraction module 3. Diffraction module 3 converts the incident parallel light into parallel light of various wavelengths at different diffraction angles. Only the parallel light of a specific wavelength is perpendicularly incident on fourth lens 43, where it is focused onto micromirror 5 located at the center of its focal plane. Micromirror 5 then reflects the incident light of the specific wavelength and returns it along the optical path to light transmitting and receiving unit 1. Diffraction module 3 is a grating.

[0050] In the horizontal direction, the telescope module 24, composed of the fifth lens 241 and the sixth lens 243, converts the light signal emitted from the reflector of the MEMS 03 into a light signal focused at the center of the grating 3. Therefore, rotating the reflector of the second MEMS 23 by any angle only changes the wavelength of the diffracted light vertically incident on the second lens module 4, without causing positional shift. This allows light with a specific diffraction angle to be focused onto the micro-reflector 5, reflected back into the optical path by the micro-reflector 5, and ultimately received by the light transmitting and receiving unit 1, thus achieving a tunable filter function. The output filter spectrum and bandwidth are closely related to the size of the light spot incident on the grating. By adjusting the focal length ratio of the fifth lens 241 and the sixth lens 243 to expand or contract the light spot, the size of the light spot incident on the grating can be flexibly changed, thereby changing the output filter spectrum and bandwidth. By setting the horizontal width of the micro-reflector 5, the filter bandwidth received by the light transmitting and receiving unit 1 can be flexibly controlled. The wider the micro-reflector 5 is, the wider the bandwidth of the returned spectrum is, and the more the filtering waveform tends to be flat-top. The narrower the micro-reflector 5 is, the narrower the bandwidth of the returned spectrum is, and the more the filtering waveform tends to be Gaussian.

[0051] The embodiments of the present application realize the function of a tunable optical filter through a combination of optical components such as optical fibers, lenses, gratings, and micro-electromechanical systems and circulators. The filter bandwidth can be changed or tuned in real time by simply changing the horizontal width of the micro-reflector, and a Gaussian or flat-top spectrum can be achieved. The optical path is simple, efficient, and low-cost. After adding a telescope system, it becomes an ideal tuning optical path, eliminating wavelength-related losses caused by position deviation.

[0052] In some embodiments, see Figure 6 , Figure 6 This is an optional structural diagram of the tunable optical filter provided in the embodiment of the present application. Figure 2 The second lens module 4 includes a fourth lens 43 , which is disposed between the diffraction module 3 and the micro-reflector 5 and is used to focus the diffracted light onto the micro-reflector 5 .

[0053] In actual implementation, the micro-reflector 5 can also be a plurality of micro-reflectors of different widths arranged laterally. The micro-reflector of a specific width is moved laterally to the focal plane of the lens 5 by a stepper motor or piezoelectric ceramics, thereby controlling the filtering bandwidth and filtering wavelength of the tunable optical filter.

[0054] In actual implementation, multiple optical signals with a wide wavelength range are output as divergent light by the optical transmitting and receiving unit 01, which is converted into parallel light by the first lens 21. The parallel light is incident on the grating 3. Light of each wavelength is emitted at a different diffraction angle and is incident on the lens 43. The lens 43 focuses the light of each wavelength to different positions on its focal plane.

[0055] In the focal plane direction, the micro-mirror 5 driven by a stepping motor or piezoelectric ceramics can move left and right, so that only light with a specific diffraction angle can be focused on the micro-mirror 5, reflected back to the optical path by the micro-mirror 5 and finally received by the light transmitting and receiving unit 1, realizing the function of a tunable filter;

[0056] By setting the horizontal width of the micro-reflector 5, the filtering bandwidth received by the light transmitting and receiving unit 1 can be flexibly controlled. The wider the micro-reflector 5, the wider the bandwidth of the returned spectrum, and the more the filtering waveform tends to be flat-topped. The narrower the micro-reflector 5, the narrower the bandwidth of the returned spectrum, and the more the filtering waveform tends to be Gaussian.

[0057] In some embodiments, see Figure 7 , Figure 7 1 is an optional structural diagram of a micro-reflector provided in an embodiment of the present application. The micro-reflector 5 comprises a plurality of micro-reflector arrays 51 arranged at intervals on the same straight line, and each micro-reflector array 51 has a different width.

[0058] In some embodiments, see Figure 8 , Figure 8 1 is an optional structural diagram of a micro-reflector provided in an embodiment of the present application. The micro-reflector 5 comprises a plurality of micro-reflector arrays 52 arranged in an annular pattern and spaced apart from each other, and each micro-reflector array 52 has a different width.

[0059] In the embodiment of the present application, the micro-mirrors 5 are multiple micro-mirrors of varying widths (20 to 200 μm) arranged laterally or annularly. A stepper motor or piezoelectric ceramic is used to laterally move or rotate the micro-mirrors of a specific width to the focal point of the second lens module 4, thereby controlling the filtering bandwidth of the tunable optical filter. The optical transmitting and receiving unit 1 can be a single optical fiber, and the lenses of the second lens module 4 (such as the second lens 42) can be spherical or aspherical lenses. The filtered signal is reflected by the micro-mirrors 5 and returned along the original optical path to the optical transmitting and receiving unit 1, where it is output by the optical circulator 6 connected to the optical transmitting and receiving unit 1.

[0060] In some embodiments, see Figure 9 , Figure 9 The optical transmitting and receiving unit 1 includes a plurality of optical fiber arrays 11 .

[0061] Here, the optical transmitting and receiving unit 1 can also be an array of multiple optical fibers arranged up and down. The optical signal is emitted by the transmitting optical fiber of the optical transmitting and receiving unit 1, and the filtered signal is reflected by the micro-reflector 5 and received by the receiving optical fiber that is symmetrical with the center of the transmitting optical fiber of the optical transmitting and receiving unit 1, thereby achieving multi-channel input and output and realizing a multi-channel tunable optical filter.

[0062] In some embodiments, the second lens 42 is spherical or cylindrical.

[0063] In the examples of this application, see Figure 10 , Figure 10 The following diagram shows the corresponding bandwidth spectra generated by micromirror filter paths of varying widths. The theoretical filter spectra corresponding to several micromirror widths are listed here. The width of the micromirror determines the filter bandwidth and spectral shape. A wider micromirror increases the filter bandwidth and the spectrum approaches a flat-top shape. A smaller micromirror width results in a narrower filter bandwidth and a more Gaussian spectrum.

[0064] The tunable optical filter provided in the embodiment of the present application includes a light emitting and receiving unit 1, a first lens module 2, a diffraction module 3, a second lens module 4 and a micro-reflector 5; the optical signal outputs divergent light through the light emitting and receiving unit 1, the divergent light is converted into parallel light through the first lens module 2, the parallel light is incident on the diffraction module 3 and dispersed into diffracted light, the diffracted light is incident on the second lens module 4 and focused to the micro-reflector 5 to form reflected light, and the reflected light returns along the original optical path and is received by the light emitting and receiving unit 1; wherein, the diffraction module 3 is capable of changing the direction of the optical path; by changing the direction of the optical path, the filter structure is simple and compact, reducing size and cost.

[0065] In summary, the embodiments of the present application can make the filter structure simple and compact, reducing size and cost.

[0066] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, and improvements made within the spirit and scope of the present application are included in the scope of protection of the present application.

Claims

1. A tunable optical filter, characterized in that: include: A light emitting and receiving unit (1), a first lens module (2), a diffraction module (3), a second lens module (4) and a micro-reflector (5); The optical signal outputs divergent light through the optical emission and receiving unit (1), the divergent light is converted into parallel light through the first lens module (2), the parallel light is incident on the diffraction module (3) and is dispersed into diffracted light, the diffracted light is incident on the second lens module (4) and is focused onto the micro-reflector (5) to form reflected light, and the reflected light returns along the original optical path and is received by the optical emission and receiving unit (1); Wherein, the diffraction module (3) is capable of changing the direction of the light path.

2. The tunable optical filter according to claim 1, wherein The first lens module (2) comprises a first lens (21), the first lens (21) being arranged in the light emitting direction of the light emitting and receiving unit (1) and being used to convert the scattered light signal emitted by the light emitting and receiving unit (1) into a parallel light signal; the diffraction module (3) being arranged in the light emitting direction of the first lens (21) and being used to disperse the parallel light signal to obtain the diffracted light; The direction of the parallel light emitted by the first lens (21) is not perpendicular to the light incident surface of the diffraction module (3).

3. The tunable optical filter according to claim 2, wherein: The second lens module (4) comprises a first micro-electromechanical system (41) and a second lens (42); the first micro-electromechanical system (41) is arranged in the light emitting direction of the diffraction module (3); the first micro-electromechanical system (41) carries a first reflector for reflecting the diffracted light to the second lens (42); the second lens (42) is arranged between the first reflector and the micro-reflector (5) for focusing the diffracted light reflected by the first reflector to the micro-reflector (5); wherein the first micro-electromechanical system (41) is capable of changing the direction of the light path.

4. The tunable optical filter according to claim 1, wherein: The first lens module (2) comprises a third lens (22), a second micro-electromechanical system (23) and a telescope module (24); the third lens (22) is arranged in the light emitting direction of the light emitting and receiving unit (1) and is used to convert the scattered light signal emitted by the light emitting and receiving unit (1) into a parallel light signal; the second micro-electromechanical system (23) is arranged in the light emitting direction of the third lens (22), and the second micro-electromechanical system (23) carries a second reflector and is used to reflect the parallel light emitted by the third lens (2) to the telescope module (24); the telescope module (24) is arranged between the second micro-electromechanical system (23) and the diffraction module (3); wherein the second micro-electromechanical system (23) is capable of changing the direction of the light path.

5. The tunable optical filter according to claim 2 or 4, characterized in that: The second lens module (4) comprises a fourth lens (43), and the fourth lens (43) is arranged between the diffraction module (3) and the micro-reflector (5) and is used to focus the diffracted light onto the micro-reflector (5).

6. The tunable optical filter according to claim 4, wherein: The telescope module (24) includes a fifth lens (241) and a sixth lens (243), and the fifth lens (241) and the sixth lens (243) each include a flat surface and a convex surface; Wherein, the plane of the fifth lens (241) is arranged opposite to the plane of the sixth lens (243).

7. The tunable optical filter according to claim 1, wherein: The micro-reflector (5) comprises a plurality of micro-reflector arrays (51) arranged at intervals on the same straight line, and each micro-reflector array (51) has a different width.

8. The tunable optical filter according to claim 1, wherein: The micro-reflector (5) comprises a plurality of micro-reflector arrays (52) arranged in an annular pattern at intervals, and each micro-reflector array (52) has a different width.

9. The tunable optical filter according to claim 1, wherein: The light emitting and receiving unit (1) comprises a plurality of optical fiber arrays (11).

10. The tunable optical filter according to claim 3, wherein: The second lens (42) is spherical or cylindrical.

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