Optical device with adjustable optical power

Abstract

The utility model discloses an optical device with adjustable optical power, which comprises a laser, a light splitting mechanism used for splitting a light beam output by the laser into a detection light beam and an output light beam, and a polarization state conversion prism matched with the transmission direction of the output light beam, and the MEMS reflection attenuator is matched with the polarization state conversion prism to adjust the optical power. According to the optical device with the adjustable optical power provided by the utility model, the polarization state conversion prism and the MEMS reflection attenuator are matched to carry out power adjustment, the MEMS reflection attenuator is based on a micro electro mechanical system technology, and the rotation of the micro reflection mirror is driven by electrostatic force to change the reflection direction of light, so that the adjustment of light attenuation is realized; the control mode is more electronic and automatic, and the attenuation can be accurately controlled through an electric signal, so that the continuous and accurate adjustment of the light attenuation is realized, and the rapid and high-precision adjustment of the light emitting power of the device is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber communication. More specifically, the utility model relates to an optical device with adjustable optical power. Background Art

[0002] In an optical fiber communication system, due to the complexity and diversity of application scenarios, the research on dynamically and intelligently adjusting the size of optical signals has been ongoing. In traditional optical devices, the size of the output optical power is a fixed parameter, and with the influence of factors such as time, temperature, and usage environment, the optical power will gradually deteriorate until it exceeds the usage parameter range and is discarded. During the transmission of optical signals, due to losses and modulation, etc., normal demodulation cannot be performed at the receiving end, and phenomena such as an increase in bit error rate and a decrease in sensitivity are likely to occur.

[0003] The utility model patent with the patent application number CN214706568U discloses a laser power dynamic monitoring and closed-loop correction device. Among them, the electric optical attenuator includes a half-wave plate, an electric mirror mount, and a polarization beam splitter prism. The half-wave plate is installed on the electric mirror mount and rotates with the electric mirror mount. The half-wave plate is arranged on the optical path of the laser output by the laser source, and the polarization beam splitter prism is arranged on the optical path of the laser output by the half-wave plate; the laser power monitor is arranged on the optical path of the vertically polarized light output by the polarization beam splitter prism; the laser power monitor is connected to the upper computer, the upper computer is connected to the controller, and the controller is connected to the electric mirror mount.

[0004] Although this device realizes the dynamic closed-loop correction and adjustment of optical power, this device adjusts the optical power by rotating the half-wave plate to reflect or refract a part of the light beam; the half-wave plate rotates with the electric mirror mount to rotate the angle of the half-wave plate, and the attenuation accuracy of the optical power may be affected by factors such as the manufacturing accuracy of the half-wave plate, the control accuracy of the rotation angle, and the matching accuracy with other optical elements, and the attenuation accuracy is low, and it cannot meet the requirements of the optical fiber communication system for high-precision adjustment of optical power. Summary of the Utility Model

[0005] An object of the utility model is to solve the above problems and / or defects and provide the advantages described hereinafter.

[0006] To achieve these objects and other advantages of the utility model, an optical device with adjustable optical power is provided, including: a laser, a beam splitting mechanism for splitting the beam output by the laser into a detection beam and an output beam, a lens I for collimating the beam arranged between the laser and the beam splitting mechanism, a photodetector matched with the transmission direction of the detection beam, a lens II for converging the output beam to the end face of the optical fiber, and further including: a polarization state conversion prism matched with the transmission direction of the output beam;

[0007] A MEMS reflection attenuator that cooperates with a polarization state conversion prism to complete the adjustment of optical power.

[0008] Preferably, the polarization state conversion prism includes: a triangular prism I, a triangular prism II, and a polarization wave plate;

[0009] Both the triangular prism I and the triangular prism II are configured as isosceles right triangles;

[0010] The hypotenuse and the planes of the two right sides of the triangular prism I are respectively: the incident surface, the reflection surface, and the polarization beam splitting surface;

[0011] The plane where the hypotenuse of the triangular prism II is located is in contact with the polarization beam splitting surface;

[0012] The plane of the triangular prism II that is perpendicular to the incident surface is in contact with the polarization wave plate, and the plane where the other right side of the triangular prism II is located is the exit surface.

[0013] Preferably, it further includes: a polarization isolator arranged behind the lens II.

[0014] Preferably, it further includes: a lens III arranged between the beam splitting mechanism and the photodetector to converge light on the photodetector.

[0015] The present utility model has at least the following beneficial effects: By setting a polarization state conversion prism and a MEMS reflection attenuator to cooperate for power adjustment, the MEMS reflection attenuator is based on microelectromechanical system technology. It drives the rotation of the micro mirror through electrostatic force to change the reflection direction of light, realizing the adjustment of optical attenuation. Its control method is more electronic and automated, and the attenuation amount can be accurately controlled through electrical signals, thereby realizing continuous and accurate adjustment of the optical attenuation amount and achieving fast and high-precision adjustment of the output optical power of the device.

[0016] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of an optical device with adjustable optical power in an embodiment of the present utility model;

[0018] Figure 2 It is a schematic structural diagram of a polarization state conversion prism of an optical device with adjustable optical power in an embodiment of the present utility model.

[0019] Markings in the figure: 1. Laser, 2. Lens I, 3. Beam splitting mechanism, 4. Lens III, 5. Photoelectric detector, 6. Polarization state conversion prism, 61. Triangular prism I, 611. Incident surface, 612. Reflection surface, 613. Polarizing beam splitting surface, 62. Triangular prism II, 621. Gluing surface, 622. Exit surface, 63. Polarization wave plate, 631. Transmission surface, 7. MEMS reflection attenuator, 8. Lens II, 9. Polarization isolator, 10. Optical fiber. Detailed implementation mode

[0020] The following further elaborates on the present utility model in conjunction with the attached drawings, so that those skilled in the art can implement it with reference to the text of the specification.

[0021] It should be understood that terms such as "having", "including", and "comprising" do not list the presence or addition of one or more other elements or their combinations.

[0022] It should be noted that in the description of the present utility model, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the attached drawings. This is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present utility model, unless otherwise clearly specified and defined, terms such as "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0024] In addition, in the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below", and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0025] Embodiment 1

[0026] An optical device with adjustable optical power, whose structure is as Figure 1-2 shown, including: a laser 1, a beam splitting mechanism 3 that splits the beam into two beams at the beam output end of the laser 1, a lens I 2 disposed between the laser 1 and the beam splitting mechanism 3 for collimating the beam, a photodetector 5 disposed at one end of the beam splitting mechanism 3 to receive one of the beams, a lens II 8 disposed at the output end of the optical device to converge the beam onto the end face of the optical fiber 10, and further including: a polarization state conversion prism 6 disposed at the other end of the beam splitting mechanism 3 to transmit the other beam thereof;

[0027] A MEMS reflection attenuator 7 disposed in cooperation with the polarization state conversion prism 6 to adjust the optical power.

[0028] In actual applications, the surface of the beam splitting mechanism 3 opposite to the laser 1 is coated with a film layer with a fixed transmittance, and the inclination angle of the beam splitting mechanism 3 is an anti-reflection structure, and its inclination angle is avoided to be 45 degrees with the incident optical path to prevent light reflection such as light transmission to the photodetector 5, Figure 1 and the inclination angle of the beam splitting mechanism 3 in it is 40 degrees.

[0029] Working principle: The MEMS reflection attenuator 7 utilizes microelectromechanical system technology and is provided with a movable micro mirror structure. When an external voltage is applied to the electrodes of the device, due to the action of electrostatic force, the micro mirror surface will undergo a slight angular rotation. When light is incident on the rotating micro mirror, the direction of the reflected light will change accordingly, resulting in attenuation. By precisely controlling the magnitude of the applied voltage, the rotation angle of the micro mirror can be precisely controlled, realizing continuous and precise adjustment of the optical attenuation amount. At the same time, the MEMS reflection attenuator 7 is small in size and high in integration, suitable for integration into miniaturized optical devices. Compared with directly modulating and controlling the magnitude of the current to adjust the light emission of the laser 1, whose power jitters near the threshold and has a small adjustment range, this device can achieve more stable output of low power and large width for the optical device.

[0030] During operation, the P-polarized light emitted by the laser 1 is divergent P-polarized light, which becomes parallel P-polarized light after being collimated by the lens I 2, and then is transmitted to the obliquely placed beam splitting mechanism 3; after passing through the beam splitting mechanism 3, a part of the P-polarized light passes through the beam splitting mechanism 3 and continues to be transmitted to the polarization state conversion prism 6, and another part of the P-polarized parallel light is transmitted to the photodetector 5 by the reflection of the front surface of the beam splitting mechanism 3 to monitor the light output of the laser 1; the P-polarized light transmitted to the polarization state conversion prism 6 is transmitted to the MEMS reflection attenuator 7 after passing through it; after the light intensity is adjusted by the MEMS reflection attenuator 7 and reflected back to the polarization state conversion prism 6, it becomes S-polarized light; the S-polarized light is reflected by the polarization state conversion prism 6 and then transmitted to the lens II 8. The lens II 8 has a converging effect, changing the parallel S-polarized light into converging S-polarized light, which converges on the end face of the optical fiber 10 for subsequent optical signal transmission.

[0031] By setting the polarization state conversion prism 6 and the MEMS reflection attenuator 7, and utilizing the characteristic that the light emitted by the laser 1 is linearly polarized light, the optical power coupled to the end face of the optical fiber 10 is dynamically adjusted. The MEMS reflection attenuator 7 is based on microelectromechanical system technology, and the rotation of the micro mirror is driven by electrostatic force to change the reflection direction of light, thereby realizing the adjustment of optical attenuation. Its control method is more electronic and automated, and the attenuation amount can be accurately controlled through an electrical signal, thereby realizing continuous and accurate adjustment of the optical attenuation amount, and realizing fast and high-precision adjustment of the output optical power of the device; at the same time, a photodetector 5 is added to the optical path, which not only monitors the light output of the laser 1 at any time, but also can judge the working condition of the entire optical communication link by comparing the optical power values of the photodetector 5 and the end face of the optical fiber 10, ensuring the stability and reliability of the entire link system and guaranteeing the normal operation of the optical fiber system.

[0032] Embodiment 2

[0033] As a preferred embodiment of the present invention, the specific structure of this Embodiment 2 is as Figure 1-2 shown, and the following improvements are disclosed on the basis of Embodiment 1: The polarization state conversion prism 6 includes: a triangular prism I 61, a triangular prism II 62, and a polarization wave plate 63;

[0034] Both the triangular prism I 61 and the triangular prism II 62 are configured as isosceles right triangles;

[0035] The hypotenuse and the planes of the two right-angled sides of the triangular prism I 61 are respectively: an incident surface 611, a reflection surface 612, and a polarization beam splitting surface 613;

[0036] The plane where the hypotenuse of the triangular prism II 62 is located is in contact with the polarization beam splitting surface 613;

[0037] The plane of the triangular prism II 62 perpendicular to the incident surface 611 is in contact with the polarization wave plate 63, and the plane where the other right-angled side of the triangular prism II 62 is located is an exit surface 622.

[0038] In practical applications, the surface of the triangular prism II 62 in contact with the polarization wave plate 63 is a bonding surface 621, and the surface of the polarization wave plate 63 opposite to the bonding surface 621 is a transmission surface 631.

[0039] The polarization beam splitting surface 613 is configured to be coated with a film layer that transmits P-polarized light and reflects S-polarized light; the incident surface 611, the bonding surface 621 where the triangular prism II 62 is bonded to the polarization wave plate 63, the exit surface 622, and the transmission surface 631 are all coated with AR antireflection films; the reflection surface 612 is coated with a reflection film, and total reflection occurs when light hits the reflection surface 612.

[0040] Working principle: The P-polarized light passes through the incident surface 611, is reflected by the reflection surface 612 to the polarization beam splitting surface 613, and then the P-polarized light continues to be transmitted through the polarization beam splitting surface 613 to the bonding surface 621, passes through the bonding surface 621, and then is transmitted to the specific polarization wave plate 63. After passing through the transmission surface 631, the P-polarized light becomes left-handed (right-handed) circularly polarized light. Finally, it is reflected by the reflection structure of the MEMS reflection attenuator 7, and the left-handed (right-handed) circularly polarized light becomes right-handed (left-handed) circularly polarized light. After being reflected, it passes through the polarization wave plate 63 again and becomes S-polarized light. Since the polarization beam splitting surface 613 transmits P-polarized light and reflects S-polarized light, the light changes its polarization state and is reflected at the polarization beam splitting surface 613. Finally, the S-polarized light is reflected by the polarization beam splitting surface 613 and continues to be transmitted through the exit surface 622.

[0041] Embodiment 3

[0042] As a preferred embodiment of the present utility model, the specific structure of this Embodiment 3 is as Figure 1 shown. On the basis of Embodiment 1, the following improvements are disclosed: It further includes: a polarization isolator 9 arranged behind the lens II 8. The influence of the reflected light is reduced.

[0043] Working principle: When the S-polarized light is transmitted to the lens II 8 later, the lens II 8 changes the parallel S-polarized light into converging S-polarized light. Finally, after passing through the polarization isolator 9, the S-polarized light converges on the end face of the optical fiber 10 for subsequent optical signal transmission.

[0044] Embodiment 4

[0045] As a preferred embodiment of the present utility model, the specific structure of this Embodiment 4 is as Figure 1 shown. On the basis of Embodiment 1, the following improvements are disclosed: It further includes: a lens III 4 arranged between the beam splitting mechanism 3 and the photodetector 5 to converge the light on the photodetector 5.

[0046] Working principle: After passing through the beam splitting mechanism 3, a part of the P-polarized light continues to be transmitted through the beam splitting mechanism 3 to the polarization state conversion prism 6, and another part of the P-polarized light is transmitted to the lens III 4 by the reflection of the front surface of the beam splitting mechanism 3. After the converging effect of the lens III 4, it converges on the photodetector 5 to monitor the light output situation of the laser 1.

[0047] The above solutions are only illustrations of a preferred example, but are not limited thereto. When implementing the present utility model, appropriate substitutions and / or modifications can be made according to the needs of the user.

[0048] The number of devices and the processing scale described here are used to simplify the description of the present utility model. The application, modification, and variation of the present utility model are obvious to those skilled in the art.

[0049] Although the embodiments of the present utility model have been disclosed as above, it is not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present utility model. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present utility model is not limited to the specific details and the illustrated examples here.

Claims

1. An optical device with adjustable optical power, comprising: A laser, a beam splitter for splitting the output beam of the laser into a detection beam and an output beam, a lens I arranged between the laser and the beam splitter for collimating the beam, a photoelectric detector matched with the transmission direction of the detection beam, and a lens II for converging the output beam to the end face of the optical fiber, characterized in that it also includes: a polarization state conversion prism matched with the transmission direction of the output beam; A MEMS reflection attenuator that works with a polarization conversion prism to adjust the optical power.

2. The optical device with adjustable optical power according to claim 1, characterized in that: The polarization state conversion prism comprises: triangular prism I, triangular prism II and polarization wave plate; The triangular prism I and the triangular prism II are both configured as isosceles right triangles; The planes where the hypotenuse and two right-angled sides of the triangular prism I are located are respectively: the incident plane, the reflection plane and the polarization splitting plane; The plane where the hypotenuse of the triangular prism II is located is in contact with the polarization splitting surface; The plane of the triangular prism II that is perpendicular to the incident surface is in contact with the polarization wave plate, and the plane where the other right-angled side of the triangular prism II is located is the exit surface.

3. The optical device with adjustable optical power according to claim 1, characterized in that: Also includes: A polarization isolator is placed after lens II.

4. The optical device with adjustable optical power according to claim 1, characterized in that: Also includes: Lens III is set between the light splitting mechanism and the photodetector to focus light on the photodetector.

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