Device for improving crosstalk of polarization dependent circulator

Abstract

The utility model relates to the technical field of circulator bodies, in particular to a device for improving crosstalk of a polarization dependent circulator, which comprises a circulator body, the outer side of the circulator body is connected with three ports which are respectively a port I, a port II and a port III, an inner cavity is formed in the circulator body, the inner cavity is polygonal, and the outer side of the circulator body is connected with the port II. A first polarization beam splitter, a Faraday rotation piece, a half-wave plate and a second polarization beam splitter are sequentially arranged in the inner cavity in the direction from the first port to the second port, and an inclined face is arranged on the side wall in the inner cavity. According to the device for improving crosstalk of the polarization dependent circulator, the black coating opposite to the second polarization beam splitter and the first polarization beam splitter is arranged at the inclined plane in the inner cavity, so that fast-axis optical signal interference of an input signal can be effectively inhibited, and fast-axis light from the second polarization beam splitter can be prevented from returning to a port III again; by suppressing and isolating unnecessary optical signals, mutual interference between ports can be reduced, and the stability and reliability of the whole optical system can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of circulator body, concretely is a kind of polarization dependent circulator promotes the device of disturbance string. BACKGROUND

[0002] Polarization dependent circulator body is a device that can guide optical signals from one optical fiber to another. It can transmit signals on optical fibers while ensuring that signals are not distorted due to loss, interference or attenuation.

[0003] During optical signal transmission, signals are often affected by some noise and interference. These disturbances can cause signal attenuation and also affect the quality of optical signals. Traditional polarization dependent circulators are very sensitive to the polarization state of input light. If the polarization state of input light changes, it may cause signal loss or increase insertion loss. Although polarization dependent circulators help manage signal paths, they cannot completely eliminate all types of noise and interference, such as shot noise, thermal noise, phase noise, etc. which can still affect signal quality. Even if PBS and other components are used to separate light of different polarization states, there may still be some degree of crosstalk. SUMMARY

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a kind of polarization dependent circulator promotes the device of disturbance string, including circulator body, the outside of circulator body is connected with three ports, respectively port one, port two and port three, and the inner cavity is formed in the inside of circulator body, the inner cavity is polygon, and first polarization beam splitter, Faraday rotator, half-wave plate and second polarization beam splitter are sequentially arranged in the direction from port one to port two inside, and the inner cavity has inclined surface in side wall, and black paint is coated on inclined surface, and the inner cavity has inclined surface in side wall, and black paint is coated on inclined surface.

[0005] Further, the black paint is coated on the three inclined surfaces of the inner cavity side wall and located in the non-light path area, and opposite to the corresponding first polarization beam splitter and second polarization beam splitter.

[0006] Further, the two side walls opposite to the second polarization beam splitter and the side wall opposite to the first polarization beam splitter and different from port three in the inner cavity are the inclined surface.

[0007] Further, the inner cavity center of the circulator body is formed with a protrusion, the center of the protrusion is a semicircular groove, and the Faraday rotator is installed in the semicircular groove.

[0008] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0009] The polarization related circulator promotes the device of the crosstalk, through the port one input light passes through the first polarization beam splitter, Faraday rotator, half wave plate and second polarization beam splitter to port two, port two separates the fast axis and slow axis light transmission input to port three output;

[0010] Wherein the inner cavity is provided with black paint opposite to the second polarization beam splitter and the first polarization beam splitter at the slope, therefore the fast axis light signal interference of input signal can be effectively suppressed, the fast axis light from the second polarization beam splitter can be prevented from returning to port three, by suppressing and isolating unnecessary optical signal, the mutual interference between ports can be reduced, the stability and reliability of the whole optical system can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 It is the structure schematic view of the utility model;

[0012] Fig. 2 It is the three-dimensional schematic view of the section structure of the utility model

[0013] Fig. 3 It is the principle schematic view of the utility model.

[0014] In the drawing: 1, circulator body;21, optical fiber collimator one;22, optical fiber collimator two;23, optical fiber collimator three;201, port one;202, port two;203, port three;3, inner cavity;4, lug;5, Faraday rotator;61, second polarization beam splitter;62, first polarization beam splitter;7, half wave plate;8, black paint. DETAILED DESCRIPTION

[0015] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments, based on the embodiments in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the range of protection of the utility model.

[0016] Please refer to Figs. 1-3The device for improving crosstalk of the polarization-dependent circulator in the embodiment comprises a circulator body 1, three ports connected outside the circulator body 1, and an inner cavity 3 formed inside the circulator body 1. The three ports are a port one 201 on the right side of the circulator body 1, a port two 202 on the left side of the circulator body 1, and a port three 203 at the bottom. The outer sides of the port one 201, the port two 202, and the port three 203 are respectively connected with a fiber collimator two 22, a fiber collimator one 21, and a fiber collimator three 23. The inner cavity 3 is a heptagon, and a first polarization beam splitter 62, a Faraday rotator 5, a half-wave plate 7, and a second polarization beam splitter 61 are sequentially installed inside the inner cavity 3 from the port one 201 to the port two 202. Three groups of inclined surfaces are formed on the side wall of the inner cavity 3. The second polarization beam splitter 61 is located between two groups of oppositely distributed inclined surfaces, and the first polarization beam splitter 62 is located between another inclined surface and the port three 203. The inclined surfaces are coated with black paint 8.

[0017] In the above structure, the second polarization beam splitter, the Faraday rotator, the half-wave plate, and the first polarization beam splitter are first installed and adjusted to the appropriate positions. Then the port one input light is transmitted through the first polarization beam splitter to separate the fast-axis and slow-axis light. The slow-axis light is transmitted through the Faraday rotator to rotate the optical axis by 45° in the positive direction, then through the half-wave plate to rotate by 45° in the reverse direction to output slow-axis light. The slow-axis light is output to the port two through the second polarization beam splitter.

[0018] The port two input slow-axis light is output through the second polarization beam splitter slow-axis, rotated by 45° in the reverse direction by the half-wave plate, and then rotated by 45° in the direction by the Faraday rotator to output 90° fast-axis light. The fast-axis light is refracted by 90° through the first polarization beam splitter and output from the port three.

[0019] By using black paint to absorb the fast-axis light output by the first polarization beam splitter, the light can be prevented from returning to the port three, thereby reducing crosstalk between ports and improving the signal-to-noise ratio of the system. The inclined surface design is to change the path of the light that may cause interference, so that it no longer propagates in the original direction, but deviates at a certain angle. This can avoid the light directly entering the sensitive area and thus reduce interference.

[0020] The outer sides of the port one 201, the port two 202, and the port three 203 are sequentially connected with the fiber collimator two 22, the fiber collimator one 21, and the fiber collimator three 23. The fiber collimator can convert this divergent light into a parallel light beam, which helps to improve the efficiency and quality of subsequent optical components in processing or transmitting light signals.

[0021] The inner side of the circulator body 1 is formed with a protrusion 4, the protrusion 4 is longitudinally located at the center of the inner cavity 3, the center of the protrusion 4 is a semicircular groove, a Faraday rotating plate 5 is installed in the semicircular groove, the semicircular groove is matched with the Faraday rotating plate, so that the Faraday rotating plate can be limited and rotated to adjust the appropriate position in the semicircular groove.

[0022] In addition, three mounting hole plates are mounted on the outer side of the circulator body 1, so that the circulator body can be positioned through the mounting hole plates.

[0023] The whole work flow is ended, and the contents not described in detail in the specification all belong to the prior art known by the professional technical personnel in the art.

[0024] It should be noted that the relational terms herein such as first and second and the like are used only to differentiate one entity or operation from another, and do not necessarily require or imply that these entities or operations exist in any such actual relationship or order. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed or inherent to such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus including the element.

[0025] Although the embodiments of the present application have been shown and described, it should be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A device for improving crosstalk of a polarization-dependent circulator, comprising a circulator body (1), the outer side of the circulator body (1) is connected with three ports, respectively, port one (201), port two (202) and port three (203), and an inner cavity (3) is formed in the circulator body (1), characterized in that: the inner cavity (3) is a polygon, and a first polarization beam splitter (62), a Faraday rotator (5), a half-wave plate (7) and a second polarization beam splitter (61) are sequentially arranged in the inner cavity (3) from the direction of port one (201) to port two (202), and the inner cavity (3) has inclined surfaces on the side walls, and the inclined surfaces are coated with black paint (8). The black paint (8) is coated on the three inclined surfaces of the side walls of the inner cavity (3) and is located in a non-optical path area and opposite to the corresponding first polarization beam splitter (62) and second polarization beam splitter (61).

2. The apparatus of claim 1, wherein: The two side walls opposite to the second polarization beam splitter (61) and the side wall opposite to the first polarization beam splitter (62) and different from port three (203) in the inner cavity (3) are the inclined surfaces.

3. The apparatus of claim 2, wherein: A protrusion (4) is formed at the center of the inner cavity (3) of the circulator body (1), the center of the protrusion (4) is a semicircular groove, and the Faraday rotator (5) is installed in the semicircular groove.

4. The apparatus of claim 1, wherein: the polarization dependent circulator is a fiber circulator; and the fiber circulator is a fiber circulator with a fiber length of 1.5 meters or less. ​

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