A deskewing device

Abstract

The utility model relates to optical communication technical field, concretely relates to a depolarizer. Depolarizer includes double fiber subassembly, phase delay mirror group, polarization rotator mirror group and anti -reflection piece, and double fiber subassembly includes the incident optical fiber and the outgoing optical fiber of interval setting, phase delay mirror group sets up in one side of double fiber subassembly, and is located on the light path path of incident optical fiber and outgoing optical fiber, and phase delay mirror group is used for modulating the phase of light beam, polarization rotator mirror group sets up in one side of phase delay mirror group away from double fiber subassembly, and is located on the light path path of incident optical fiber and outgoing optical fiber, and polarization rotator mirror group is used for controlling the polarization angle of light beam, and anti -reflection piece is located in one side of polarization rotator mirror group away from phase delay mirror group. The application is through setting up phase delay mirror group and polarization rotator mirror group, makes light beam carry out phase delay and rotation, to promote the stability of depolarization performance and output light, and through setting up anti -reflection piece, promotes the space utilization of depolarizer light path, has reduced the volume of depolarizer.

Description

Technical Field

[0001] This utility model relates to the field of optical communication technology, and in particular to a depolarizer. Background Technology

[0002] In fiber optic communication, sensing, and laser systems, the high polarization characteristics of laser sources can lead to a series of inherent problems such as polarization mode dispersion, polarization-dependent loss, and polarization noise, severely limiting system performance. For example, in long-distance fiber optic communication, polarization mode dispersion directly causes pulse broadening, becoming one of the core limiting factors for improving transmission rate and distance. Therefore, effectively depolarizing the light source and reducing its polarization degree is a crucial preliminary step in improving the reliability and performance of related systems.

[0003] Currently, traditional depolarization schemes are mainly based on Lyot-type depolarizers, which introduce differentiated phase delays for different wavelengths of light by cascading birefringent crystals of varying thicknesses, thereby weakening polarization characteristics. However, this depolarizer has significant limitations: First, the depolarizer uses a unidirectional optical path, and to cover broadband light sources and meet their different wavelength phase delay requirements, multiple crystals typically need to be stacked, resulting in an excessively large device size; second, when there is backlighting inside the depolarizer, since the optical path remains unchanged, the backlighting interferes with the main optical path signal, causing a significant decrease in the depolarization effect. Utility Model Content

[0004] This utility model provides a depolarizer to solve the problems of poor depolarization effect and large size of depolarizers.

[0005] This utility model discloses a polarization depolarizer, comprising: A dual-fiber assembly comprising an incident fiber and an outgoing fiber spaced apart; A phase delay mirror assembly is disposed on one side of the dual-fiber assembly and located on the optical path between the incident fiber and the outgoing fiber. The phase delay mirror assembly is used to modulate the phase of the light beam. A polarization rotating mirror group is disposed on the side of the phase delay mirror group away from the dual-fiber assembly and located on the optical path between the incident fiber and the outgoing fiber. The polarization rotating mirror group is used to control the polarization angle of the light beam. A reflector is located on the side of the polarization rotating mirror group away from the phase delay mirror group, so that the incident light can be reflected back to the outgoing optical fiber in sequence via the polarization rotating mirror group and the phase delay mirror group.

[0006] In one embodiment, the phase delay mirror group includes a plurality of polarizing glass plates, which are arranged sequentially along the optical path.

[0007] In one embodiment, the polarizing glass slide has a fast axis, and there are two polarizing glass slides, the included angle between the fast axes of the two polarizing glass slides being greater than or equal to 30° and less than or equal to 60°.

[0008] In one embodiment, the ratio of the thickness of one polarizing glass plate farther from the dual-fiber assembly to the thickness of the other polarizing glass plate closer to the dual-fiber assembly is greater than or equal to 1.5 and less than or equal to 2.5.

[0009] In one embodiment, the polarization rotating mirror assembly includes a Faraday rotator and a magnetic ring, wherein the Faraday rotator is disposed at the center of the magnetic ring and is located on the optical path between the incident optical fiber and the outgoing optical fiber.

[0010] In one embodiment, the polarization rotation angle of the Faraday rotator is greater than or equal to 8° and less than or equal to 14°.

[0011] In one embodiment, the system further includes a tube body, on which the dual-fiber assembly, the phase delay mirror group, the polarization rotation mirror group, and the reflector are sequentially disposed along the length of the tube body.

[0012] In one embodiment, the dual-fiber assembly is a dual-fiber collimator, which further includes a collimating lens located between the incident fiber, the outgoing fiber, and the optical path of the phase delay mirror group.

[0013] In one embodiment, the reflector is disposed at the waist position of the optical path of the dual-fiber collimator.

[0014] In one embodiment, the distance between the incident optical fiber and the outgoing optical fiber is greater than or equal to 125 μm and less than or equal to 131 μm.

[0015] The beneficial effects of the depolarizer provided in this embodiment of the utility model are that it not only has good depolarization performance, but also has a smaller size.

[0016] Specifically, on the one hand, the phase delay mirror group first randomly modulates the polarization state of the beam, introducing a phase difference that changes rapidly with wavelength. The polarization rotation mirror group then applies rotation to the polarization state of the returning beam. Working together, the two not only break the coherence of the beam's polarization state but also avoid interference between the polarization states of the reflected and incident light. Furthermore, because the polarization rotation mirror group rotates the light, the reflected light path is offset from the incident light path, preventing interference even when the reflected light path returns, thus improving depolarization performance and the stability of the output light. On the other hand, this depolarizer employs a folded optical path design, folding the optical path back at the reflector, greatly improving space utilization and reducing the size of the depolarizer. Attached Figure Description

[0017] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is an internal schematic diagram of the depolarizer provided in this embodiment of the utility model; Figure 2 This is a schematic diagram of the polarization direction of the phase delay mirror group provided in this embodiment of the present invention.

[0018] The labels for the attached figures are as follows: 1000, Depolarizer; 10, Two-fiber assembly; 11, Incident fiber; 12, Outgoing fiber; 20, Phase delay mirror assembly; 21, Polarizing glass slide; 30, Polarizing rotation mirror assembly; 31, Faraday rotator; 32, Magnetic ring; 40, Reflector; 41, Reflecting surface; 50, Tube body. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0020] This utility model embodiment provides a polarization depolarizer 1000, such as Figure 1 As shown, the depolarizer 1000 includes a dual-fiber assembly 10, a phase delay mirror group 20, a polarization rotation mirror group 30, and a reflector 40. The dual-fiber assembly 10 includes an incident fiber 11 and an outgoing fiber 12 spaced apart. The phase delay mirror group 20 is disposed on one side of the dual-fiber assembly 10 and located in the optical path between the incident fiber 11 and the outgoing fiber 12. The phase delay mirror group 20 is used to modulate the phase of the light beam. The polarization rotation mirror group 30 is disposed on the side of the phase delay mirror group 20 away from the dual-fiber assembly 10 and is located in the optical path between the incident fiber 11 and the outgoing fiber 12. The polarization rotation mirror group 30 is used to control the polarization angle of the light beam. The reflector 40 is located on the side of the polarization rotation mirror group 30 away from the phase delay mirror group 20, so that the incident light can be reflected back to the outgoing fiber 12 sequentially through the polarization rotation mirror group 30 and the phase delay mirror group 20. This application can solve the problems of poor depolarization effect and large size of the existing depolarizer 1000. The depolarizer 1000 not only has excellent depolarization performance, but also has a smaller size.

[0021] Specifically, on the one hand, the phase delay mirror group 20 first randomly modulates the polarization state of the beam, introducing a phase difference that changes rapidly with wavelength. The polarization rotation mirror group 30 then applies rotation to the polarization state of the returning beam. The two work together to break the coherence of the beam's polarization state and avoid interference between the polarization states of the reflected and incident light. At the same time, because the polarization rotation mirror group 30 applies rotation to the light, the reflected light path is misaligned with the incident light path, so even if the reflected light path forms a backlight, it cannot interfere with the incident light path, thereby improving the depolarization performance and the stability of the output light. On the other hand, the depolarizer 1000 adopts a folded optical path design, that is, the optical path is folded back at the reflector 40, which greatly improves the space utilization and reduces the size of the depolarizer 1000.

[0022] The optical path operation of the above embodiment is as follows: the light beam emitted by the incident fiber 11 passes through the phase delay mirror group 20 and the polarization rotation mirror group 30 in sequence, and is reflected by the reflector 40 along the original path; the reflected light passes through the polarization rotation mirror group 30 and the phase delay mirror group 20 again in reverse direction, and finally outputs the optical signal outward into the exiting fiber 12.

[0023] In this application, the reflector 40 includes a reflective surface 41 facing the polarization rotation mirror assembly 30. The reflective surface 41 is used to reflect incident light to form reflected light. The reflective surface 41 can be designed to have a preset tilt angle. This tilting arrangement allows the reflective surface 41 to reflect the incident light in a non-perpendicular manner, thereby creating a certain separation angle between the optical axes of the reflected light and the incident light, thus causing the reflected light path to be offset from the incident light path. Combined with the polarization rotation mirror assembly 30, this provides dual protection, enhancing the stability of the system and the reliability of the depolarization effect.

[0024] In one embodiment, the phase retardation mirror assembly 20 includes multiple polarizing glass plates 21 arranged sequentially along the optical path. Thus, the polarizing glass plates 21 allow the polarization state of the output beam to change rapidly and randomly over time, causing light of different wavelengths to lose polarization, achieving a "depolarization" effect. Furthermore, the combination of multiple polarizing glass plates 21 creates a superposition of multiple levels of phase retardation, making it more effective at maintaining a stable polarization direction over a wider wavelength range. The polarization states of different wavelengths become more random, making the output beam closer to completely unpolarized light, thereby achieving a more comprehensive depolarization effect.

[0025] The number of polarizing glass slides 21 can be freely adjusted according to design requirements and is not limited here. (Refer to...) Figure 2 In this embodiment, two polarizing glass plates 21 are provided; further, the polarizing glass plate 21 has a fast axis, wherein the fast axis of the polarizing glass plate 21 closest to the dual-fiber assembly 10 (e.g., Figure 2The outgoing beam (shown in the X1 direction) is parallel to the incident fiber 11 and is far from the fast axis of the polarizing glass plate 21 of the dual-fiber assembly 10 (as shown in the X1 direction). Figure 2 The angle between the X2 direction (as shown in the figure) and the fast axis of the polarizing glass plate 21 near the dual-fiber assembly 10 (as shown in the figure) is (e.g., Figure 2 (As shown in O) is greater than or equal to 30° and less than or equal to 60°. Thus, the polarizing glass 21 near the dual-fiber assembly 10 converts the input beam into elliptically polarized light, and because the fast axis of the polarizing glass 21 is perpendicular to the incident direction of the incident light (as shown in O), the polarization angle is greater than or equal to 30° and less than or equal to 60°. Figure 2 The two polarizing glass plates 21 are parallel (as shown in the X direction), so that the beam energy does not need to be split on the fast axis of the polarizing glass plate 21, which can effectively reduce energy loss. By reasonably controlling the angle between the fast axes of the two polarizing glass plates 21 to be greater than or equal to 30° and less than or equal to 60°, the polarization state of the output beam can be made fast and uniform, so that the beam output through the phase retardation mirror group 20 approaches completely unpolarized light, thereby achieving a better depolarization effect. In this embodiment, the angle between the fast axes of the two polarizing glass plates 21 is 45°.

[0026] Preferably, the ratio of the thickness of one polarizing glass plate 21 farther from the dual-fiber assembly 10 to the thickness of the other polarizing glass plate 21 closer to the dual-fiber assembly 10 is greater than or equal to 1.5 and less than or equal to 2.5. Thus, the thickness of the polarizing glass plates 21 determines the phase difference of the modulated beam. By setting the thickness of the polarizing glass plate 21 farther from the dual-fiber assembly 10 to be greater than the thickness of the polarizing glass plate 21 closer to the dual-fiber assembly 10, the range of beam delay phase can be increased, thereby making the phase difference of different wavelengths in the output beam more pronounced, thus improving the depolarization effect. In this embodiment, the thickness of the polarizing glass plate 21 farther from the dual-fiber assembly 10 is twice the thickness of the polarizing glass plate 21 closer to the dual-fiber assembly 10.

[0027] In one embodiment, the polarization rotating mirror assembly 30 includes a Faraday rotator 31 and a magnetic ring 32. The Faraday rotator 31 is disposed at the center of the magnetic ring 32 and is located on the optical path between the incident fiber 11 and the outgoing fiber 12. Thus, according to Faraday's principle, the polarization rotating mirror assembly 30 utilizes the axial, uniform, and strong magnetic field generated by the magnetic ring 32 to drive the Faraday rotator 31 to perform precise and stable polarization rotation on the polarization state of the light beam passing through it. Furthermore, the incident light beam undergoes a first polarization rotation when it first passes through the polarization rotating mirror assembly 30. After returning via the reflector 40, the light passes back through the same polarization rotating mirror assembly 30 along the original path. Due to the non-reciprocity of the Faraday effect, the reflected light undergoes a second polarization rotation at the same angle in the same direction. This ensures that the polarization state of the reflected light does not interfere with the polarization state of the incident light when it returns, reducing interference signal fluctuations and thus lowering the resulting polarization noise, making the output optical signal more stable.

[0028] In one embodiment, the polarization rotation angle of the Faraday rotator 31 is greater than or equal to 8° and less than or equal to 14°. Controlling the polarization rotation angle of the Faraday rotator 31 within this range effectively reduces polarization noise and makes the output optical signal more stable. Preferably, in this embodiment, the polarization rotation angle of the Faraday rotator 31 is 12.25°. Based on the non-reciprocity of the Faraday effect, when the beam passes through the rotator and rotates 11.25°, then returns via reflection and passes through the same Faraday rotator 31 again, its polarization direction will rotate another 11.25° in the same direction. Therefore, the total polarization rotation angle of the beam after one round trip is 22.5°.

[0029] In one embodiment, the depolarizer 1000 further includes a tube 50, on which a dual-fiber assembly 10, a phase retardation mirror assembly 20, a polarization rotation mirror assembly 30, and a reflector 40 are sequentially arranged along the length of the tube 50. In this way, the tube 50 can fix each component while maintaining a small volume, ensuring the relative positions of each component and reducing the overall size of the depolarizer 1000. Specifically, the tube 50 can be a glass sleeve, with the dual-fiber assembly 10 fitted at one end and the reflector 40 fitted at the other end. The phase retardation mirror assembly 20 and the polarization rotation mirror assembly 30 are installed inside the glass sleeve. Preferably, the dual-fiber assembly 10, the phase retardation mirror assembly 20, the polarization rotation mirror assembly 30, and the reflector 40 are connected to the tube 50 with sealant to improve the strength of the connection.

[0030] In one embodiment, the dual-fiber assembly 10 is a dual-fiber collimator, which also includes a collimating lens located between the incident fiber 11, the exit fiber 12, and the phase delay mirror group 20. Thus, the dual-fiber collimator integrates the collimating lens and is positioned in the optical path between the incident fiber 11, the exit fiber 12, and the phase delay mirror group 20, eliminating the need for additional installation and calibration of the collimating lens, and avoiding the complex optical alignment steps between the incident fiber 11, the exit fiber 12, and the lens. This not only ensures the stability and consistency of the optical path output but also reduces installation steps, improving overall assembly efficiency and reliability. Preferably, the collimating lens can be a short focal length lens to shorten the optical path, thereby further reducing the size of the depolarizer 1000.

[0031] In one embodiment, the reflector 40 is positioned at the waist of the optical path of the dual-fiber collimator. Thus, the core function of the dual-fiber collimator is to convert the diverging light emitted from the optical fiber into a nearly parallel beam through a collimating lens. This conversion process does not produce ideal, perfectly parallel light, but rather forms a Gaussian beam with a waist at a specific location. This "specific location" is the waist position, optically referred to as the working distance of the dual-fiber collimator. By positioning the reflector 40 at the waist position, it is ensured that the reflected beam returns along its original path with reduced loss. Furthermore, the spot size at the waist is minimized, meaning that the reflector 40 can be used in a smaller size, which is beneficial for device miniaturization and integration. Specifically, the reflector 40 is a reflecting column.

[0032] In one embodiment, the distance between the incident fiber 11 and the output fiber 12 is greater than or equal to 125 μm and less than or equal to 131 μm. Thus, the standard cladding diameter of the dual-fiber assembly 10 is 125 μm. Controlling the center-to-center distance between the incident fiber 11 and the output fiber 12 within the range of greater than or equal to 125 μm and less than or equal to 131 μm means that the outer surfaces of the incident fiber 11 and the output fiber 12 are closer to the outer wall of the cladding, avoiding an increase in the size of the dual-fiber assembly 10, thereby reducing the volume of the depolarizer 1000.

[0033] It should be understood that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of this utility model.

Claims

1. A depolarizer, characterized in that, include: A dual-fiber assembly comprising an incident fiber and an outgoing fiber spaced apart; A phase delay mirror assembly is disposed on one side of the dual-fiber assembly and located on the optical path between the incident fiber and the outgoing fiber. The phase delay mirror assembly is used to modulate the phase of the light beam. A polarization rotating mirror group is disposed on the side of the phase delay mirror group away from the dual-fiber assembly and located on the optical path between the incident fiber and the outgoing fiber. The polarization rotating mirror group is used to control the polarization angle of the light beam. A reflector is located on the side of the polarization rotating mirror group away from the phase delay mirror group, so that the incident light can be reflected back to the outgoing optical fiber in sequence via the polarization rotating mirror group and the phase delay mirror group.

2. The depolarizer according to claim 1, characterized in that, The phase delay mirror assembly includes multiple polarizing glass plates, which are arranged sequentially along the optical path.

3. The depolarizer according to claim 2, characterized in that, The polarizing glass slide has a fast axis, and there are two polarizing glass slides, wherein the fast axis of the polarizing glass slide closer to the dual-fiber assembly is parallel to the outgoing beam of the incident fiber, and the included angle between the fast axes of the two polarizing glass slides is greater than or equal to 30° and less than or equal to 60°.

4. The depolarizer according to claim 3, characterized in that, The ratio of the thickness of one polarizing glass plate farther from the dual-fiber assembly to the thickness of the other polarizing glass plate closer to the dual-fiber assembly is greater than or equal to 1.5 and less than or equal to 2.

5.

5. The depolarizer according to claim 1, characterized in that, The polarization rotating mirror assembly includes a Faraday rotator and a magnetic ring. The Faraday rotator is disposed at the center of the magnetic ring and is located on the optical path between the incident optical fiber and the outgoing optical fiber.

6. The depolarizer according to claim 5, characterized in that, The polarization rotation angle of the Faraday rotator is greater than or equal to 8° and less than or equal to 14°.

7. The depolarizer according to any one of claims 1-6, characterized in that, It also includes a tube body, and the dual-fiber assembly, the phase delay mirror group, the polarization rotation mirror group, and the reflector are sequentially arranged on the tube body along the length direction of the tube body.

8. The depolarizer according to any one of claims 1-6, characterized in that, The dual-fiber assembly is a dual-fiber collimator, which further includes a collimating lens located between the incident fiber, the outgoing fiber, and the phase delay mirror group.

9. The depolarizer according to claim 8, characterized in that, The reflector is positioned at the waist of the optical path of the dual-fiber collimator.

10. The depolarizer according to any one of claims 1-6, characterized in that, The distance between the incident optical fiber and the outgoing optical fiber is greater than or equal to 125 μm and less than or equal to 131 μm.

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