Tunable optical attenuator

Abstract

The invention belongs to the technical field of optical passive devices, and discloses a tunable optical attenuator which comprises a variable-focus objective lens mechanism and a light guide assembly, and light in the light guide assembly penetrates through the variable-focus objective lens assembly. The variable-focus objective lens mechanism comprises a lens barrel, and a lens assembly is arranged in the lens barrel; an adjusting assembly is arranged on the lens barrel, the lens assembly is in transmission connection with the adjusting assembly, the lens assembly can be adjusted, and the angle of light penetrating through the lens assembly is changed; the lens assembly comprises a fixed lens fixedly connected in the lens barrel, two sides of the fixed lens are respectively provided with a first movable lens and a second movable lens which are in sliding connection with the lens barrel, and the adjusting assembly is respectively in transmission connection with the first movable lens and the second movable lens. The device is simple in structure, convenient to use, high in reliability and stability, easy to implement and convenient to popularize, has the characteristics of high-precision light attenuation, accuracy and variability, large dynamic range and small wavelength dependent loss, and does not have very high requirements on technologies and processes.

Description

Technical Field

[0001] The invention relates to the technical field of optical passive devices, and in particular to a tunable optical attenuator. Background Art

[0002] Optical fiber communication technology has been developing rapidly, fiber to the home has gradually matured, and all-optical networks are also advancing. It is the development trend of the new generation of communication networks. In the entire all-optical network communication, the optical attenuator is one of the important passive components in the communication network and one of the indispensable basic components. At the same time, the optical attenuator has gradually been widely used in optical sensing, signal processing and other optical systems of laser transmission. It mainly plays the role of precise control of dynamic adjustment of power size, dynamic gain flatness and channel power gain balancing in dense wavelength division multiplexing communication systems. Therefore, the variable optical attenuator has broad application prospects in the fields of optical fiber communication, optical sensing and laser transmission optical systems.

[0003] However, although the current variable optical attenuators have diverse principles and types, including mechanical, magneto-optical, micro-electromechanical systems and liquid crystal, they still have complex structures, high production costs, and insufficient optical performance. Some even rely on foreign technology. Therefore, high-precision, large dynamic range attenuation, low wavelength-related loss, simple and compact structure and low-cost variable optical attenuators are the main focus of researchers, promoting the rapid development of technologies in related fields.

[0004] Therefore, the present application designs a tunable optical attenuator to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a tunable optical attenuator to solve the problems existing in the prior art.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides a tunable optical attenuator, comprising a variable focus objective lens mechanism, wherein both ends of the variable focus objective lens assembly are detachably connected with light guide assemblies through which light passes, and light in the light guide assembly passes through the variable focus objective lens assembly;

[0007] The variable focus objective lens mechanism comprises a lens barrel coaxially connected to the light guide assembly, a lens assembly is arranged in the lens barrel, and light is emitted after passing through the lens assembly;

[0008] The lens barrel is provided with an adjustment assembly, the lens assembly is in transmission connection with the adjustment assembly, and the lens assembly can be adjusted to change the angle of light passing through the lens assembly;

[0009] The lens assembly includes a fixed lens fixed in the lens barrel, a first movable lens and a second movable lens slidably connected to the lens barrel are respectively arranged on both sides of the fixed lens, and the adjustment assembly is respectively transmission-connected to the first movable lens and the second movable lens.

[0010] Preferably, the fixed lens housing is provided with a fixed sleeve, and the outer wall of the fixed sleeve is embedded and fixedly connected to the inner cavity of the lens barrel.

[0011] Preferably, the outer wall of the first movable lens is sleeved with a first movable sleeve, the outer wall of the first movable sleeve is slidably connected to the inner wall of the lens barrel, and the adjustment assembly is transmission-connected to the first movable sleeve.

[0012] Preferably, a guide block is fixedly connected to the outer wall of the first movable sleeve, a guide groove matched with the guide block is formed on the inner wall of the lens barrel, and the guide block is slidably connected in the guide groove.

[0013] Preferably, the outer wall of the first movable sleeve is provided with a driving block, the inner wall of the lens barrel is provided with a driving groove adapted to the driving block, the driving block is slidably connected in the driving groove, and the adjustment assembly extends into the driving groove and is drivingly connected to the driving block.

[0014] Preferably, the adjustment assembly includes an adjustment rod rotatably connected to the lens barrel, the adjustment rod extends into the driving slot and is transmission-connected to an adjustment gear, and the adjustment gear meshes with an adjustment rack fixed to the bottom end of the driving block for transmission.

[0015] Preferably, a limiting groove connected to the driving groove is formed on the lens barrel, and the adjusting rack is adapted to the limiting groove and is slidably connected in the limiting groove.

[0016] Preferably, the adjusting gear is arranged corresponding to the middle part of the driving slot, and the length of the adjusting rack is greater than half of the driving slot.

[0017] Preferably, the light guide assembly comprises a fiber optic collimator connected to the inlet of the lens barrel, and the outlet of the fiber optic collimator is coaxially arranged with the lens barrel.

[0018] Preferably, the light guide assembly comprises a fiber optic jumper head connected to the outlet of the lens barrel, and the incident port of the fiber optic jumper head is coaxially arranged with the lens barrel.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects: the present invention discloses a tunable optical attenuator, wherein a variable-focus objective lens mechanism capable of changing the optical path is arranged on a light guide assembly, and the light incident on the lens barrel is refracted by the lens assembly, and the optical path of the light is changed, and the light is finally emitted; the transparent assembly is designed to be movable and immovable, and by moving all or part of the first movable lens and the second movable lens of the lens assembly, the parallel light incident on the lens barrel is finally focused on the same position, that is, the focus or focal plane position of the lens system remains unchanged, but the incident parallel light is focused after passing through the objective lens system. The convergence angle of the light at the point changes, and finally the incident angle of the light converging to the light guide component changes, thereby realizing the change of the light coupling efficiency between the variable focus objective lens mechanism and the light guide component, and realizing different attenuation amounts; the change of the incident angle of the light on the end face of the light guide component is realized by moving the position of the movable lens of the lens assembly, and tunable attenuation is realized, that is, an optical objective lens system that can dynamically adjust the coupling efficiency of light and optical fiber is designed; multiple movable lenses can change the convergence angle of the light and keep the focal position of the lens system unchanged, and also ensure that the light attenuator is suitable for the use of optical fiber routes with different numerical apertures by adjusting the convergence angle.

[0020] The present invention has a simple structure, is easy to use, has the characteristics of high-precision optical attenuation, precise variability, a large dynamic range, and small wavelength-related loss, has good reliability and stability, does not have particularly high requirements on technology and process, is easy to implement, and is convenient to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 An axial view of the tunable optical attenuator of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the tunable optical attenuator of the present invention;

[0024] Figure 3 is a schematic diagram of the structure of the first movable lens of the present invention;

[0025] Figure 4 For the present invention Figure 3 A partial enlarged view of middle A;

[0026] Figure 5 It is a schematic diagram of the matching between the limit groove and the adjusting gear of the present invention;

[0027] Figure 6 It is a schematic diagram of the optical path of the tunable optical attenuator of the present invention;

[0028] Figure 7 A comparison diagram of the optical path changes caused by the adjustment component of the present invention;

[0029] In the figure: 1. lens barrel; 2. optical fiber; 3. optical fiber collimator; 4. optical fiber jumper head; 5. incident end face; 6. exit end face; 7. fixed lens; 8. first movable lens; 9. second movable lens; 10. fixed sleeve; 11. first movable sleeve; 12. guide block; 13. guide groove; 14. drive block; 15. drive groove; 16. adjustment rod; 17. adjustment gear; 18. adjustment rack; 19. limit groove; 20. hand wheel; 21. stabilizing bar; 22. stabilizing groove; 23. incident optical fiber; 24. exit optical fiber; 25. second movable sleeve. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figure 1-Figure 7 As shown, this embodiment provides a tunable optical attenuator, including a variable focus objective lens mechanism, both ends of the variable focus objective lens assembly are detachably connected with light guide assemblies through which light passes, and the light in the light guide assembly passes through the variable focus objective lens assembly;

[0033] The variable focus objective lens mechanism comprises a lens barrel 1 coaxially connected to the light guide assembly, a lens assembly is arranged in the lens barrel 1, and light is emitted after passing through the lens assembly;

[0034] The lens barrel 1 is provided with an adjustment assembly, and the lens assembly is in transmission connection with the adjustment assembly, and the lens assembly can be adjusted to change the angle of light passing through the lens assembly;

[0035] The lens assembly includes a fixed lens 7 fixed in the lens barrel 1, and a first movable lens 8 and a second movable lens 9 slidably connected to the lens barrel 1 are respectively arranged on both sides of the fixed lens 7, and the adjustment assembly is transmission-connected to the first movable lens 8 and the second movable lens 9 respectively.

[0036] The present invention discloses a tunable optical attenuator. A variable-focus objective lens mechanism capable of changing the optical path is arranged on a light guide assembly. After the light incident on a lens barrel 1 is refracted by a lens assembly, the optical path of the light is changed and the light is finally emitted. The transparent assembly is designed to be movable and immovable. By moving all or part of a first movable lens 8 and a second movable lens 9 of the lens assembly, the parallel light incident on the lens barrel 1 is finally focused on the same position, that is, the focus or focal plane position of the lens assembly remains unchanged, but the convergence angle of the incident parallel light on the focus changes after passing through the objective lens system. The optical attenuation of the optical fiber 2 is adjusted by changing the angle of incidence of the light beams that converge to the optical guide assembly, thereby changing the optical coupling efficiency between the variable focus objective lens mechanism and the optical guide assembly, and achieving different attenuation amounts; the change of the angle of incidence of the light beams at the end face of the optical guide assembly is achieved by moving the position of the movable lens of the lens assembly, and tunable attenuation is achieved, that is, an optical objective lens system that can dynamically adjust the coupling efficiency of light and optical fiber 2 is designed; multiple movable lenses can change the convergence angle of the light beams and keep the focal position of the lens assembly unchanged, and also adjust the convergence angle to ensure that the optical attenuator is suitable for use in optical fiber 2 routes with different numerical apertures. The present invention has a simple structure, is easy to use, has the characteristics of high-precision optical attenuation, precise variability, large dynamic range, and small wavelength-related loss, has good reliability and stability, and has no particularly high requirements on technology and process, is easy to implement, and is convenient to promote.

[0037] In one embodiment of the present application, referring to the attached Figure 2 Schematic diagram of the structure of a tunable optical attenuator, the lens assembly is composed of multiple convex lenses and concave lenses, some lenses can be moved along the optical axis, and some lenses are fixed. By moving the movable part of the lens, the parallel light incident on the lens assembly is finally focused on the same position, that is, the focus or focal plane position of the lens assembly remains unchanged, but the convergence angle of the parallel light at the focus changes after passing through the objective system.

[0038] In one embodiment of the present application, all lens surfaces are coated with a broadband high-transmittance film to increase the power loss of light.

[0039] In a further optimized solution, a fixed sleeve 10 is provided on the outer sleeve of the fixed lens 7, and the outer wall of the fixed sleeve 10 is embedded and fixedly connected to the inner cavity of the lens barrel 1. The fixed lens 7 is provided with a fixed sleeve 10 on the outer sleeve, which improves the protection of the fixed lens 7 and prevents the edge from being damaged by impact; and the outer wall of the fixed sleeve 10 is embedded and fixedly connected to the inner cavity of the lens barrel 1, and the fixed lens 7 is embedded in the inner cavity of the lens barrel 1, which is convenient for fixing.

[0040] In a further optimized solution, the outer wall of the first movable lens 8 is sleeved with a first movable sleeve 11, the outer wall of the first movable sleeve 11 is slidably connected to the inner wall of the lens barrel 1, and the adjustment component is transmission-connected to the first movable sleeve 11. The outer wall of the first movable lens 8 is sleeved with the first movable sleeve 11, which improves the protection of the first movable lens 8 and prevents the edge from being damaged by impact; and the first movable sleeve 11 is slidably connected to the inner cavity of the lens barrel 1 and is transmission-connected to the adjustment component, and the position of the first movable lens 8 in the lens barrel 1 can be adjusted by the adjustment component to achieve the change of the optical path of the light passing through the first movable lens 8.

[0041] In one embodiment of the present application, a second movable sleeve 25 is provided on the outer wall of the second movable lens 9, which improves the protection of the second movable lens 9 and prevents the edge from being damaged by impact; and the second movable sleeve 25 is slidably connected to the inner cavity of the lens barrel 1 and is transmission-connected to the adjustment component. The position of the second movable lens 9 in the lens barrel 1 can be gradually adjusted by the second adjustment component, thereby realizing the change of the optical path of the light passing through the second movable lens 9.

[0042] In one embodiment of the present application, the first movable lens 8 is a convex lens, and the second movable lens 9 is a concave lens; the type and quantity of the lenses can also be adjusted according to usage requirements.

[0043] In a further optimized solution, a guide block 12 is fixedly connected to the outer wall of the first movable sleeve 11, and a guide groove 13 matching the guide block 12 is provided on the inner wall of the lens barrel 1, and the guide block 12 is slidably connected in the guide groove 13. The cooperation of the guide block 12 and the guide groove 13 further enhances the stability of the movement of the first movable lens 8 and prevents the first movable lens 8 from deflecting during the movement.

[0044] In a further optimized solution, a driving block 14 is provided on the outer wall of the first movable sleeve 11, a driving groove 15 adapted to the driving block 14 is provided on the inner wall of the lens barrel 1, the driving block 14 is slidably connected in the driving groove 15, and the adjustment component extends into the driving groove 15 and is transmission-connected with the driving block 14. The driving block 14 is provided at an end of the first movable sleeve 11 opposite to the guide block 12, the driving block 14 extends into the driving groove 15 in the lens barrel 1, and the adjustment component extends into the driving groove 15, and the position of the first movable sleeve 11 inside can be adjusted by adjusting the adjustment component outside the lens barrel 1, so as to achieve unlimited adjustment.

[0045] In one embodiment of the present application, a stabilizing groove 22 is provided at the bottom end of the driving block 14 , and a stabilizing bar 21 matched with the stabilizing groove 22 is provided at the bottom end of the driving groove 15 , thereby improving the stability of the driving block 14 .

[0046] In a further optimized solution, the adjustment assembly includes an adjustment rod 16 rotatably connected to the lens barrel 1, the adjustment rod 16 extends into the driving slot 15 and is transmission-connected with an adjustment gear 17, and the adjustment gear 17 is meshed and transmitted with an adjustment rack 18 fixed to the bottom end of the driving block 14. The adjustment rod 16 is rotatably connected to the lens barrel 1, one end of which extends into the driving slot 15 and drives the adjustment gear 17 to rotate, and the other end extends out of the lens barrel 1 and is provided with a hand wheel 20 to facilitate the rotation of the adjustment rod 16; when adjustment is required, the adjustment gear 17 is rotated by the adjustment rod 16, and then the adjustment rack 18 meshing with the adjustment gear 17 is translated, thereby driving the driving block 14 to slide in the driving slot 15, providing the first movable sleeve 11 with the power for adjustment.

[0047] In a further optimized solution, a limiting groove 19 connected to the driving groove 15 is provided on the lens barrel 1, and the adjusting rack 18 is adapted to the limiting groove 19 and slidably connected in the limiting groove 19; the adjusting gear 17 is arranged corresponding to the middle of the driving groove 15, and the length of the adjusting rack 18 is greater than half of the driving groove 15. The limiting groove 19 is arranged at the bottom end of the driving groove 15, and the sliding of the adjusting rack 18 in the limiting groove 19 prevents the deviation of the adjusting rack 18 during the adjustment process, thereby enhancing the stability and reliability of the adjustment; and the adjusting gear 17 corresponds to the middle of the driving groove 15, and the length of the adjusting rack 18 is greater than half of the length of the driving groove 15, so that when the driving block 14 moves to the edge of the driving groove 15, the adjusting gear 17 and the adjusting rack 18 will not be disengaged.

[0048] In one embodiment of the present application, the second movable sleeve 25 moves in the same moving and limiting manner as the first movable sleeve 11, which will not be repeated here.

[0049] In one embodiment of the present application, the movement direction and position of each lens are controlled by different adjustment components, so as to achieve a change in the convergence angle of the light at the focus within a certain range. The change in the convergence angle of the light achieves a change in the coupling efficiency between the optical attenuator and the optical fiber 2, and ultimately achieves tunable attenuation of the optical attenuator.

[0050] In one embodiment of the present application, referring to the attached Figure 7 As shown, no matter how the movable lens moves, the focal position or focal plane of the entire lens assembly composed of the movable lens and the fixed lens 7 remains unchanged, that is, the focal length of the entire variable-focus objective lens mechanism changes, but the focal position remains unchanged, and is still focused on the same position. The multiple movable lenses not only change the light convergence angle and keep the focal position of the lens assembly unchanged, but also adjust the convergence angle to ensure that the light attenuator is suitable for the use of optical fiber 2 routes with different numerical apertures. For details, please refer to the formula:

[0051]

[0052] In the above formula, D is the spot diameter of the parallel light beam emitted by the fiber collimator, w0 is the mode field radius of the single-mode fiber, f is the focal length, and λ is the wavelength.

[0053] A further optimized solution is that the light guide assembly includes a fiber collimator 3 connected to the inlet of the lens barrel 1, and the exit port of the fiber collimator 3 is coaxially arranged with the lens barrel 1; the light guide assembly includes a fiber jumper head 4 connected to the outlet of the lens barrel 1, and the entrance port of the fiber jumper head 4 is coaxially arranged with the lens barrel 1. In front of the lens barrel 1 is a fiber collimator 3 connected to the optical fiber 2, and the fiber collimator 3 is fixed to the incident end face 5 of the inlet of the lens barrel 1 by an adapter, so that the incident optical fiber 23 is connected to the lens barrel 1, and the optical axis of the incident optical fiber 23 is coaxial with the lens assembly, and its end face is coated with a broadband high-transmittance film, and the emitted parallel light beam is focused at the focal position by the lens assembly. A fiber 2 jumper connected to the optical fiber 2 is arranged at the outlet of the lens barrel 1, and is fixed to the exit end face 6 of the lens barrel 1 by an adapter. When the exit optical fiber 24 is fixed to the attenuator, the exit optical fiber 24 is coaxial with the lens assembly, and the end face of the exit optical fiber 24 coincides with the focal plane of the lens assembly, and the objective lens system is Figure 6 The convergent light is coupled into optical fiber 2 at an angle shown.

[0054] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0055] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A tunable optical attenuator, characterized in that: It comprises a variable focus objective lens mechanism, wherein both ends of the variable focus objective lens assembly are detachably connected with light guide assemblies through which light passes, and light in the light guide assembly passes through the variable focus objective lens assembly; The variable focus objective lens mechanism comprises a lens barrel (1) coaxially connected to the light guide assembly, a lens assembly is arranged in the lens barrel (1), and light rays are emitted after passing through the lens assembly; The lens barrel (1) is provided with an adjustment component, the lens component is in transmission connection with the adjustment component, and the lens component can be adjusted to change the angle of light passing through the lens component; The lens assembly comprises a fixed lens (7) fixedly connected in the lens barrel (1), a first movable lens (8) and a second movable lens (9) slidably connected to the lens barrel (1) are respectively arranged on both sides of the fixed lens (7), and the adjustment assembly is respectively connected in transmission with the first movable lens (8) and the second movable lens (9).

2. The tunable optical attenuator according to claim 1, characterized in that: The fixed lens (7) is provided with a fixed sleeve (10) on its outer shell, and the outer wall of the fixed sleeve (10) is embedded and fixedly connected to the inner cavity of the lens barrel (1).

3. The tunable optical attenuator according to claim 1, characterized in that: The outer wall of the first movable lens (8) is sleeved with a first movable sleeve (11), the outer wall of the first movable sleeve (11) is slidably connected to the inner wall of the lens barrel (1), and the adjustment component is transmission-connected to the first movable sleeve (11).

4. The tunable optical attenuator according to claim 3, characterized in that: A guide block (12) is fixedly connected to the outer wall of the first movable sleeve (11), a guide groove (13) adapted to the guide block (12) is formed on the inner wall of the lens barrel (1), and the guide block (12) is slidably connected in the guide groove (13).

5. The tunable optical attenuator according to claim 3, characterized in that: The outer wall of the first movable sleeve (11) is provided with a driving block (14), the inner wall of the lens barrel (1) is provided with a driving groove (15) adapted to the driving block (14), the driving block (14) is slidably connected in the driving groove (15), and the adjustment component extends into the driving groove (15) and is drivingly connected to the driving block (14).

6. The tunable optical attenuator according to claim 5, characterized in that: The adjustment assembly comprises an adjustment rod (16) rotatably connected to the lens barrel (1); the adjustment rod (16) extends into the driving slot (15) and is transmission-connected to an adjustment gear (17); the adjustment gear (17) is meshed with an adjustment rack (18) fixed to the bottom end of the driving block (14) for transmission.

7. The tunable optical attenuator according to claim 6, characterized in that: The lens barrel (1) is provided with a limiting groove (19) which is in communication with the driving groove (15); the adjusting rack (18) is adapted to the limiting groove (19) and is slidably connected in the limiting groove (19).

8. The tunable optical attenuator according to claim 7, characterized in that: The adjusting gear (17) is arranged corresponding to the middle part of the driving slot (15), and the length of the adjusting rack (18) is greater than half of the driving slot (15).

9. The tunable optical attenuator according to claim 1, characterized in that: The light guide assembly comprises a fiber optic collimator (3) connected to the inlet of the lens barrel (1); the outlet of the fiber optic collimator (3) is coaxially arranged with the lens barrel (1).

10. The tunable optical attenuator according to claim 9, characterized in that: The light guide assembly comprises an optical fiber jumper head (4) connected to the outlet of the lens barrel (1); the incident port of the optical fiber jumper head (4) is coaxially arranged with the lens barrel (1).

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