Optical circulator

Abstract

The utility model is suitable for the technical field of optical fiber communication, and provides an optical circulator which comprises a port assembly and a light guide assembly. A light beam input from the first port can be split into a first light beam and a second light beam by the first light splitting assembly, and the first light beam and the second light beam pass through the displacement crystal and the Faraday rotator and then are converged into one light beam by the second light splitting assembly to be emitted from the second port. A light beam input from the second port is divided into a third light beam and a fourth light beam by the second light splitting assembly, and the third light beam and the fourth light beam pass through the Faraday rotator and the displacement crystal and then are converged into one light beam by the first light splitting assembly to be emitted from the third port. Therefore, when the light beam is input at the first port, the first light splitting assembly splits the light beam, and when the third light beam and the fourth light beam are output towards the third port, the first light splitting assembly combines the two light beams, and a light splitting piece does not need to be additionally arranged between the first light splitting assembly and the third port for beam combination, so that the number of parts of the optical circulator is reduced, and the cost is reduced. And the size of the optical circulator is reduced.

Description

Technical Field

[0001] The present application belongs to the field of optical fiber communication technology, and more specifically, relates to an optical circulator. Background Art

[0002] An optical circulator is an optical device that uses multiple ports for non-reciprocal light transmission. Its primary function is to allow optical signals to sequentially pass through the circulator's multiple ports in one direction while preventing them from traveling in the opposite direction. For example, in a three-port optical circulator, light typically travels sequentially through the first, second, and third ports. This allows light to enter the circulator from the first port and exit from the second port, or it can enter from the second port and exit from the third port. However, light entering the circulator from the third port cannot exit from either the first or second port.

[0003] An optical circulator typically includes a housing and a first beam splitter, a Faraday rotator, a half-wave plate, and a second beam splitter disposed within the housing. The first beam splitter, the Faraday rotator, the half-wave plate, and the second beam splitter are sequentially arranged along the length of the housing. The housing is provided with a first port, a second port, and a third port. The first port is located on the side of the first beam splitter away from the Faraday rotator, the second port is located on the side of the second beam splitter away from the half-wave plate, and the third port is located on the side of the first beam splitter along the width of the housing. A third beam splitter is also disposed between the first beam splitter and the third port along the width of the housing. As a result, the housing needs to be designed to be relatively large in both width and length to accommodate the aforementioned components, resulting in a relatively large overall size of the optical circulator, which is not conducive to fiber optic coiling. Utility Model Content

[0004] One of the objectives of the embodiments of the present application is to provide an optical circulator, aiming to solve the technical problem of the large size of the optical circulator in the related art.

[0005] To solve the above technical problems, the technical solutions adopted in the embodiments of the present application are:

[0006] An optical circulator is provided, comprising:

[0007] A port assembly comprising a first port, a second port, and a third port arranged at intervals;

[0008] A light guide assembly comprising a first light splitting assembly, a displacement crystal, a Faraday rotator and a second light splitting assembly sequentially distributed along a first direction, wherein the Faraday rotator is used to change the polarization state of light;

[0009] The first beam splitter is used to split the light beam input from the first port into a first light beam and a second light beam, the displacement crystal is used to shift the optical path of the first light beam and the optical path of the second light beam, and the second beam splitter is used to merge the first light beam and the second light beam into a beam of light that can be output from the second port;

[0010] The second beam splitter component is further used to split the light beam input from the second port into a third light beam and a fourth light beam, the displacement crystal is further used to transmit the third light beam and the fourth light beam, and the first beam splitter component is further used to merge the third light beam and the fourth light beam into a beam of light that can be output from the third port.

[0011] In some embodiments, the optical circulator also includes a shell, and the first spectroscopic component, the displacement crystal, the Faraday rotator and the second spectroscopic component are distributed in sequence in the shell along the first direction; the first port and the third port are spaced apart and arranged on one side of the shell along the first direction, and are both arranged opposite to the first spectroscopic component along the first direction; the second port is arranged on the other side of the shell along the first direction, and is arranged opposite to the second spectroscopic component along the first direction.

[0012] In some embodiments, the optical circulator also includes a shell, and the first beam splitter component, the displacement crystal, the Faraday rotator and the second beam splitter component are distributed in sequence in the shell along the first direction; the optical circulator also includes a reflector, and the first port and the reflector are spaced apart and arranged on one side of the shell along the first direction, and are both arranged opposite to the first beam splitter component along the first direction; the second port is arranged on the other side of the shell along the first direction, and is arranged opposite to the second beam splitter component along the first direction; the third port is arranged on one side of the shell along the second direction, and is arranged opposite to the reflector along the second direction, and the reflector is used to reflect the light beam input from the third port onto the first beam splitter component; the first direction and the second direction are perpendicular.

[0013] In some embodiments, the first beam splitter assembly includes a first beam splitter, a first polarization converter, and a second polarization converter sequentially distributed along the first direction; the first beam splitter is used to split the light beam input from the first port into the first light beam and the second light beam spaced apart along a third direction, the first polarization converter and the shift crystal are used to sequentially input the first light beam output from the first beam splitter, and the shift crystal is used to input the second light beam output from the first beam splitter; the second beam splitter assembly is used to split the light beam input from the second port into the third light beam and the fourth light beam spaced apart along the third direction, the second polarization converter, the first polarization converter, and the first beam splitter are used to sequentially input the third light beam output from the shift crystal, the second polarization converter and the first beam splitter are used to input the fourth light beam output from the shift crystal, and the first beam splitter is used to merge the third light beam and the fourth light beam into one beam; the first direction is perpendicular to the third direction;

[0014] And / or, the second spectroscopic component includes a polarization conversion component and a second spectroscopic component distributed in sequence along the first direction, the first spectroscopic component is used to split the light beam input from the first port into the first light beam and the second light beam distributed along a third direction, the second spectroscopic component is used to merge the first light beam and the second light beam into one beam of light, and the second spectroscopic component is also used to split the light beam input from the second port into the third light beam and the fourth light beam distributed along the third direction; the polarization conversion component includes a third polarization conversion component and a fourth polarization conversion component distributed along the third direction, the third polarization conversion component is used to input the first light beam and the third light beam respectively, and the fourth polarization conversion component is used to input the second light beam and the fourth light beam respectively; the first direction is perpendicular to the third direction.

[0015] In some embodiments, in a rectangular coordinate system perpendicular to the first direction, the first port is located in the second quadrant, the third port is located in the first quadrant, the second port is located in the first quadrant, and the shift crystal and the Faraday rotator are located in four quadrants;

[0016] The first beam splitter is located in four quadrants, the first polarization conversion element is located in the first quadrant and the second quadrant, and the second polarization conversion element is located in the first quadrant and the fourth quadrant; and / or, the second beam splitter is located in four quadrants, the third polarization conversion element is located in the first quadrant and the second quadrant, and the fourth polarization conversion element is located in the third quadrant and the fourth quadrant.

[0017] In some embodiments, the first polarization converter abuts against the first beam splitter; and / or the second polarization converter abuts against the displacement crystal; and / or the third polarization converter abuts against the second beam splitter; and / or the fourth polarization converter abuts against the second beam splitter.

[0018] In some embodiments, the first polarization conversion element is a 45° half-wave plate, and the second polarization conversion element is a 45° half-wave plate;

[0019] And / or, the third polarization conversion element is a 22.5° half-wave plate, and the fourth polarization conversion element is a negative 22.5° half-wave plate.

[0020] In some embodiments, at least one of the first beam splitter and the shift crystal is a polarization beam splitter prism or a yttrium vanadate crystal;

[0021] And / or, at least one of the shift crystal and the second beam splitter is a polarization beam splitter prism or a yttrium vanadate crystal.

[0022] In some embodiments, the displacement crystal includes a first polarizing film and a second polarizing film spaced apart along a second direction, the first polarizing film being parallel to the second polarizing film, the first beam splitting component being used to split the light beam input from the first port into the first beam and the second beam spaced apart along a third direction, and the second beam splitting component being used to split the light beam input from the second port into the third beam and the fourth beam spaced apart along the third direction;

[0023] The first polarizing film is used to shift the first light beam and the second light beam along the second direction to the second polarizing film, and the second polarizing film is used to shift the first light beam and the second light beam along the first direction to the Faraday rotator; the second polarizing film is also used to transmit the third light beam and the fourth light beam along the first direction; the first direction, the second direction and the third direction are perpendicular to each other.

[0024] In some embodiments, the optical circulator further includes a first collimator, which is arranged between the first port and the first splitter component; and / or, the optical circulator further includes a second collimator, which is arranged between the second port and the second splitter component; and / or, the optical circulator further includes a third collimator, which is arranged between the third port and the first splitter component.

[0025] The optical circulator provided in the embodiment of the present application has the following beneficial effects:

[0026] The optical circulator provided by the embodiment of the present application, when in use, the light beam input from the first port can be divided into a first light beam and a second light beam by the first light splitting component, the first light beam and the second light beam are offset from the optical path by the displacement crystal, and then the polarization state is changed by the Faraday rotator, and finally the light beam is combined into a beam of light through the second light splitting component and emitted from the second port. The light input from the second port can be divided into a third light beam and a fourth light beam by the second light splitting component, the third light beam and the fourth light beam are changed from the polarization state by the Faraday rotator, and then the displacement crystal is transmitted, and finally the light beam is combined into a beam of light through the first light splitting component and emitted from the third port. Among them, the first light splitting component has the function of splitting and combining light. Specifically, when the light beam is input at the first port, the first light splitting component can split the light beam, and when the third light beam and the fourth light beam are output toward the third port, the first light splitting component can combine the third light beam and the fourth light beam. In this way, there is no need to set an additional light splitting component between the first light splitting component and the third port, which reduces the components of the optical circulator, so that the optical circulator can be designed to be smaller in size, which is convenient for fiber winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 A schematic diagram of a three-dimensional structure of a partial structure of an optical circulator provided in some embodiments of the present application;

[0029] Figure 2 for Figure 1 A schematic top view of a partial structure of an optical circulator is provided;

[0030] Figure 3 A schematic top view of the partial structure of the optical circulator provided in some embodiments of the present application Figure 1 ;

[0031] Figure 4 A schematic top view of the partial structure of the optical circulator provided in some embodiments of the present application Figure 2 ;

[0032] Figure 5 is a schematic diagram of the polarization state of the light beam when it is transmitted from the first port to the second port;

[0033] Figure 6 is a schematic diagram of the polarization state of the light beam when it propagates from the second port to the third port;

[0034] Figure 7Schematic diagram of the polarization state of the light beam when it is transmitted along the third port to the second port or the first port.

[0035] Among them, the reference numerals in the figures are:

[0036] 10-port assembly; 11-first port; 12-second port; 13-third port; 20-light-guiding assembly; 21-first spectrometer assembly; 211-first spectrometer element; 212-first polarization converter; 213-second polarization converter; 22-displacement crystal; 221-first polarization film; 222-second polarization film; 23-Faraday rotator; 24-second spectrometer assembly; 241-third polarization converter; 242-fourth polarization converter; 243-second spectrometer element; 30-reflector; 40-first collimator; 50-second collimator; 60-third collimator; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0037] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0038] Unless otherwise specified, all implementations and optional implementations of the embodiments of the present application can be combined with each other to form a new technical solution.

[0039] Unless otherwise specified, all technical features and optional technical features of the embodiments of the present application can be combined with each other to form a new technical solution.

[0040] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, 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 cannot be understood as a limitation on this application.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0042] In the description of this application, "a plurality of" means more than two, and unless otherwise specifically defined, "more than two" includes two. Accordingly, "a plurality of groups" means more than two groups, including two groups.

[0043] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0044] In this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, in this application, the character " / " generally indicates that the related objects are in an "or" relationship.

[0045] The following is a detailed description with reference to the accompanying drawings and embodiments:

[0046] See also Figure 1 and Figure 2 An embodiment of the present application provides an optical circulator, comprising a port assembly 10 and a light guide assembly 20. The port assembly 10 comprises a first port 11, a second port 12, and a third port 13, wherein the first port 11, the second port 12, and the third port 13 are spaced apart from each other. The light guide assembly 20 comprises a first beam splitter assembly 21, a displacement crystal 22, a Faraday rotator 23, and a second beam splitter assembly 24, which are sequentially arranged along a first direction X. The Faraday rotator 23 is used to change the polarization state of light. The first beam splitter assembly 21 is used to split a light beam input from the first port 11 into a first light beam and a second light beam. The displacement crystal 22 is used to shift the optical path of the first light beam and the optical path of the second light beam. The second beam splitter assembly 24 is used to merge the first light beam and the second light beam into a single beam, and to enable the merged light beam to be output from the second port 12. The second beam splitter assembly 24 is also used to split the light beam input from the second port 12 into a third light beam and a fourth light beam. The displacement crystal 22 is also used to transmit the third light beam and the fourth light beam. The first light splitting component 21 is further configured to combine the third light beam and the fourth light beam into one light beam, and enable the combined light beam to be output from the third port 13 .

[0047] It should be noted that the light beams input from the first port 11 and the second port 12 are parallel light beams, and the light beam output from the third port 13 is also parallel light beams. The first beam splitter 21 can split the parallel input light beam into two beams, namely the first and second beams, or combine the two separated light beams into a single beam for parallel output, namely combining the third and fourth beams into a single beam for parallel output. The second beam splitter 24 can split the parallel input light beam into two beams, namely the third and fourth beams, or combine the separated first and second beams into a single beam for parallel output.

[0048] The Faraday rotator 23 is a device that utilizes the Faraday effect to rotate the polarization of a light beam. It is typically constructed from a magneto-optical crystal or other device. This device is a non-reciprocal optical device. Specifically, the polarization of a light beam is rotated 45° in the same direction when it passes through the Faraday rotator 23 from the first beam splitter 21 toward the second beam splitter 24, and when it passes through the Faraday rotator 23 from the second beam splitter 24 toward the first beam splitter 21.

[0049] The displacement crystal 22 can reflect light beams with a polarization state of 90° and transmit light beams with a polarization state of 0°, with the polarization state of the light beams remaining unchanged during reflection and transmission. Leveraging this optical property, the user designs the first beam splitter component 21 so that the light beam input at the first port 11 is split into a first light beam and a second light beam after being split by the first beam splitter component 21. Both the first and second light beams have polarization states of 90°, allowing the first and second light beams to be reflected after entering the displacement crystal 22. The user also designs the second beam splitter component 24 so that the light beam input at the second port 12 is split into a third light beam and a fourth light beam after being split by the second beam splitter component 24. Both the third and fourth light beams have polarization states of 45°, allowing the third and fourth light beams to have polarization states of 0° after being rotated by the Faraday rotator 23, allowing them to be transmitted by the displacement crystal 22.

[0050] It should be noted that the light beams input from the first port 11 and the second port 12 are natural light, and the light beam output from the third port 13 is also natural light. After being split, the light beam is split into two beams, and the polarization states of the two beams are perpendicular to each other. When the two beams are combined, the two beams of light with mutually perpendicular polarization states can be combined into a single beam of natural light. Therefore, the first and second beam-splitting components 21 and 24 can also change the polarization state of the light during the splitting and combining process, so that the light beams passing through the first and second beam-splitting components 21 and 24 can be smoothly split and combined.

[0051] In the optical circulator provided in the embodiments of the present application, when in use, a light beam input from the first port 11 can be split into a first light beam and a second light beam by the first beam splitter component 21. After the first and second light beams are deflected by the displacement crystal 22, their polarization states are changed by the Faraday rotator 23, and finally, they are combined into a single light beam by the second beam splitter component 24 and emitted from the second port 12. Light input from the second port 12 can be split into a third light beam and a fourth light beam by the second beam splitter component 24. After the third and fourth light beams have their polarization states changed by the Faraday rotator 23, they are transmitted by the displacement crystal 22, and finally, they are combined into a single light beam by the first beam splitter component 21 and emitted from the third port 13. The first beam splitter component 21 has the functions of both splitting and combining light beams. Specifically, when a light beam is input at the first port 11, the first beam splitter component 21 can split the light beam. When the third and fourth light beams are output toward the third port 13, the first beam splitter component 21 can combine the third and fourth light beams. In this way, there is no need to arrange an additional light splitter between the first light splitting component 21 and the third port 13, which reduces the components of the optical circulator and enables the optical circulator to be designed with a smaller size, which is beneficial for optical circulator fiber winding.

[0052] In some embodiments, see Figure 1 and Figure 2 The optical circulator also includes a housing. A first beam splitter assembly 21, a displacement crystal 22, a Faraday rotator 23, and a second beam splitter assembly 24 are sequentially arranged within the housing along a first direction X. A first port 11 and a third port 13 are spaced apart and disposed on one side of the housing along the first direction X. Both the first port 11 and the third port 13 are disposed opposite the first beam splitter assembly 21 along the first direction X. The second port 12 is disposed on the other side of the housing along the first direction X. The second port 12 is disposed opposite the second beam splitter assembly 24 along the first direction X.

[0053] The housing may be a tubular or box-shaped structure and is used to accommodate and protect components such as the first light splitting component 21 , the shift crystal 22 , the Faraday rotator 23 and the second light splitting component 24 .

[0054] In one possible design, the optical path shifting operation of the optical circulator is performed solely through the displacement crystal 22. Along the first direction X, the second port 12 is staggered with the first port 11, such that the optical paths of the first and second optical beams, after being shifted by the displacement crystal 22, are aligned with the second port 12, and are output from the second port 12. Along the first direction X, the second port 12 and the third port 13 are positioned relative to each other, such that the third and fourth optical beams input from the second port 12, after being transmitted through the displacement crystal 22, are aligned with the third port 13, and are output from the third port 13. Of course, in some other possible designs, the relative positions of the first port 11, the second port 12, and the third port 13 along the first direction X can also be designed in other forms, which are not limited here.

[0055] In actual optical circulator products, the first direction X is roughly the length direction of the shell. The first beam splitter component 21, the displacement crystal 22, the Faraday rotator 23, and the second beam splitter component 24 are distributed in sequence within the shell along the length direction of the shell. In this way, the first port 11 and the third port 13 are arranged on the same side of the shell along the first direction X. Compared with the existing solution in which the third port 13 is arranged on one side of the first beam splitter 211 along the width direction of the shell, and an additional beam splitter is arranged between the first beam splitter 211 and the third port 13 along the width direction of the shell, the width dimension of the shell of the present application can be designed to be smaller, thereby making the overall size of the optical circulator smaller and easier to coil.

[0056] In some embodiments, see Figures 1 to 3 The optical circulator also includes a housing. The first beam splitter component 21, the displacement crystal 22, the Faraday rotator 23, and the second beam splitter component 24 are sequentially distributed in the housing along the first direction X. The optical circulator also includes a reflector 30. The first port 11 and the reflector 30 are spaced apart and arranged on one side of the housing along the first direction X. The first port 11 and the reflector 30 are both arranged opposite to the first beam splitter component 21 along the first direction X. The second port 12 is arranged on the other side of the housing along the first direction X. The second port 12 is arranged opposite to the second beam splitter component 24 along the first direction X. The third port 13 is arranged on one side of the housing along the second direction Y. The third port 13 is arranged opposite to the reflector 30 along the second direction Y. In this way, the reflector 30 can reflect the light beam input from the third port 13 onto the first beam splitter component 21. The first direction X and the second direction Y are perpendicular.

[0057] The reflector 30 may be a structure such as a prism or a plane mirror that can deflect the optical path of a light beam.

[0058] When in use, a beam of light converged at the first light splitting component 21 is irradiated onto the reflector 30 along the first direction X, and is reflected by the reflector 30, causing the optical path of the beam to be deflected, and then emitted along a second direction Y perpendicular to the first direction X to be output from the third port 13.

[0059] Wherein, the first direction X is as follows Figure 3 The direction X shown in the figure, the second direction Y is as follows Figure 3 The direction Y shown in FIG. 1 is a direction X and a direction Y are directions of two coordinate axes in a rectangular coordinate system, that is, the direction X is perpendicular to the direction Y.

[0060] In this way, the third port 13 can be located on one side of the housing along the second direction Y, and the light beam output by the first beam splitter assembly 21 is reflected to the third port 13 via the reflector 30. This prevents the first port 11 and the third port 13 from being located on the same side of the housing, thereby reducing the likelihood of interference on the housing. Furthermore, since the reflector 30 and the first port 11 are located on the same side of the housing along the first direction X, there is no need to locate a beam splitter on the side of the housing along the second direction Y to mate with the third port 13. This allows the optical circulator housing to be designed to be smaller, making fiber winding easier.

[0061] In some embodiments, see Figures 1 to 6 The first beam splitter assembly 21 includes a first beam splitter 211, a first polarization converter 212, and a second polarization converter 213. The first beam splitter 211, the first polarization converter 212, and the second polarization converter 213 are sequentially arranged along the first direction X. The first beam splitter 211 is used to split the light beam input from the first port 11 into a first light beam and a second light beam, and the first light beam and the second light beam are spaced apart along the third direction Z. The first polarization converter 212 and the shift crystal 22 are used to sequentially input the first light beam output from the first beam splitter 211. The shift crystal 22 is used to input the second light beam output from the first beam splitter 211. The second beam splitter assembly 24 is used to split the light beam input from the second port 12 into a third light beam and a fourth light beam, and the third light beam and the fourth light beam are spaced apart along the third direction Z. The second polarization converter 213, the first polarization converter 212, and the first beam splitter 211 are used to sequentially input the third light beam output from the shift crystal 22. The second polarization converter 213 and the first beam splitter 211 are used to input the fourth light beam output from the shift crystal 22. The first beam splitter 211 is used to combine the third light beam and the fourth light beam into one beam of light.

[0062] The first beam splitter 211 is used to split a beam of light into two beams of light with different polarization states. For example, the first beam splitter 211 can split natural light into a first beam and a second beam of light with mutually perpendicular polarization states. As an example, the polarization state of the first beam is 0°, i.e., P light, and the polarization state of the second beam is 90°, i.e., S light.

[0063] The first polarization converter 212 and the second polarization converter 213 may be, but are not limited to, optical rotation crystals, and are used to rotate the polarization state of the light beam.

[0064] Along the third direction Z, the first beam splitter 211 has two regions, one of which faces the first polarization converter 212, and the other directly faces the shift crystal 22. Along the second direction Y, the first beam splitter 211 has two regions, one of which faces the second polarization converter 213, and the other directly faces the shift crystal 22. Simultaneously, along the third direction Z, the shift crystal 22 has two regions, one of which faces the first polarization converter 212, and the other directly faces the first beam splitter 211. Along the second direction Y, the shift crystal 22 has two regions, one of which faces the second polarization converter 213, and the other directly faces the first beam splitter 211.

[0065] Wherein, the first direction X is as follows Figure 1 The direction X shown in the figure, the third direction Z is as follows Figure 1 The direction Z is shown in the figure. Figure 1 Direction Y is also shown in the figure. Direction X, direction Y and direction Z are the directions of the three coordinate axes in the spatial coordinate system, that is, direction X is perpendicular to direction Y, direction X is perpendicular to direction Z, and direction Y is perpendicular to direction Z.

[0066] When a light beam is transmitted from the first port 11 to the second port 12, it first passes through the first beam splitter 211, which splits the natural light beam into a first beam and a second beam with mutually perpendicular polarization states. The first beam output by the first beam splitter 211 enters the first polarization converter 212, while the second beam is offset from the first polarization converter 212, causing the polarization state of the first beam to be altered. It is understood that at this point, the polarization states of the first and second beams are both 90°. When the first and second beams pass through the shifting crystal 22, they are reflected without changing their polarization states, meaning that the polarization states of the two beams remain at 90°. The shifting crystal 22 shifts the optical paths of the first and second beams, causing them to correspond to the second port 12 along the first direction X. The first and second beams then pass through the Faraday rotator 23, rotating their polarization states by 45° clockwise, resulting in a 45° polarization state. They then pass through the second beam splitter 24, where they are combined into a single beam and output from the second port 12.

[0067] When a light beam is transmitted from the second port 12 to the third port 13, it is first split by the second beam splitter 24 into a third and fourth beams with mutually perpendicular polarization states. The polarization states of the third and fourth beams are 45°. The third and fourth beams are then input into the Faraday rotator 23, which rotates the polarization states of the two beams by 45°, resulting in a polarization state of 0° for both beams. The shift crystal 22 then transmits the third and fourth beams with polarization states of 0° without changing their polarization states. The third and fourth beams then pass through the second polarization converter 213. The third beam enters the first polarization converter 212, while the fourth beam is offset from the first polarization converter 212, causing the polarization state of the third beam to rotate while the polarization state of the fourth beam remains unchanged. Finally, the polarization states of the two beams are 0° and 90°, respectively, and are perpendicular to each other. The third and fourth beams can then be combined into a single beam through the first beam splitter 211 and output from the third port 13.

[0068] Alternatively, in another embodiment, the second beam splitter component 24 includes a polarization conversion component and a second beam splitter 243 sequentially distributed along the first direction X. The first beam splitter component 21 is used to split the light beam input from the first port 11 into a first light beam and a second light beam, and the first light beam and the second light beam are distributed along the third direction Z. The second beam splitter 243 is used to merge the first light beam and the second light beam into a single beam of light. The second beam splitter 243 is also used to split the light beam input from the second port 12 into a third light beam and a fourth light beam, and the third light beam and the fourth light beam are distributed along the third direction Z. The polarization conversion component includes a third polarization conversion component 241 and a fourth polarization conversion component 242. The third polarization conversion component 241 and the fourth polarization conversion component 242 are distributed along the third direction Z. The third polarization conversion component 241 is used to input the first light beam and the third light beam, respectively. The fourth polarization conversion component 242 is used to input the second light beam and the fourth light beam, respectively. The first direction X and the third direction Z are perpendicular.

[0069] Along the third direction Z, the second beam splitter 243 has two regions, one of which faces the third polarization converter 241, and the other faces the fourth polarization converter 242. Simultaneously, along the third direction Z, the Faraday rotator 23 has two regions, one of which faces the third polarization converter 241, and the other faces the fourth polarization converter 242.

[0070] When a light beam is transmitted from the first port 11 toward the second port 12, the natural light beam input to the first port 11 is split into a first beam and a second beam by the first beam splitter 21. It is understood that the polarization states of the first and second beams are both 90° at this point. When the first and second beams pass through the shifting crystal 22, they are reflected without changing their polarization states, that is, their polarization states remain at 90°. The shifting crystal 22 shifts the optical paths of the first and second beams, causing them to correspond to the second port 12 along the first direction X. Next, the first and second beams pass through the Faraday rotator 23, rotating their polarization states by 45° clockwise. At this point, the polarization states of the first and second beams are 45°. The first beam then passes through the third polarization converter 241, and the second beam passes through the fourth polarization converter 242. After these polarization rotations, the polarization states of the first and second beams become perpendicular to each other. Finally, after passing through the second beam splitter 243, the first and second beams are combined into a single beam and output from the second port 12.

[0071] When the light beam is transmitted from the second port 12 to the third port 13, the natural light beam input from the second port 12 first passes through the second beam splitter 243 and is split into a third light beam and a fourth light beam with mutually perpendicular polarization states. The third light beam then passes through the third polarization converter 241, and the fourth light beam passes through the fourth polarization converter 242. After undergoing polarization rotation, they are converted into light beams with polarization states of 45°. The third and fourth light beams are then input into the Faraday rotator 23, which rotates the polarization state by 45°, rotating the polarization state to 0° for both beams. The shift crystal 22 then directly transmits the third and fourth light beams with a polarization state of 0°, without shifting the optical path. That is, the polarization states of the third and fourth light beams remain at 0°. Finally, the third and fourth light beams are input into the first beam splitter 21 and can be combined into a beam of natural light and output from the third port 13.

[0072] Alternatively, in another embodiment, the first beam splitter assembly 21 includes a first beam splitter 211, a first polarization converter 212, and a second polarization converter 213. The first beam splitter 211, the first polarization converter 212, and the second polarization converter 213 are sequentially arranged along a first direction X. The second beam splitter assembly 24 includes a polarization converter assembly and a second beam splitter 243, which are sequentially arranged along the first direction X. The polarization converter assembly includes a third polarization converter 241 and a fourth polarization converter 242. The third polarization converter 241 and the fourth polarization converter 242 are arranged along a third direction Z. The first direction X and the third direction Z are perpendicular.

[0073] When the light beam is transmitted from the first port 11 toward the second port 12, the natural light beam input from the first port 11 is first input into the first beam splitter 211. Then, the light beam passes through the first beam splitter 211, which can split the natural light beam into a first light beam and a second light beam whose polarization states are perpendicular to each other. The first light beam output from the first beam splitter 211 will be input into the first polarization conversion element 212, and the second light beam will be offset from the first polarization conversion element 212, so that the polarization state of the first light beam is rotated. It can be understood that at this time, the polarization states of the first light beam and the second light beam are both 90°, so that the first light beam and the second light beam can be reflected when passing through the displacement crystal 22, and the polarization state remains unchanged. The displacement crystal 22 offsets the optical path position of the first light beam and the second light beam. Then, the first light beam and the second light beam pass through the Faraday rotator 23, so that the polarization state of the two beams rotates 45° clockwise. At this time, the polarization state of the first light beam and the second light beam is 45°. Next, the first beam enters the third polarization converter 241, and the second beam enters the fourth polarization converter 242. After polarization rotation, the polarization states of the first and second beams become perpendicular to each other. Finally, the first and second beams pass through the second beam splitter 243, where they are combined into a single beam that is output from the second port 12.

[0074] When the light beam is transmitted from the second port 12 to the third port 13, the light beam input from the second port 12 is first split by the second beam splitter 243 into a third light beam and a fourth light beam with mutually perpendicular polarization states. At this time, the polarization states of the third and fourth light beams are mutually perpendicular. The third light beam is then input into the third polarization converter 241, and the fourth light beam is input into the fourth polarization converter 242. After the polarization states are respectively rotated, the polarization states of both are 45°. Next, the third and fourth light beams are both input into the Faraday rotator 23, which rotates the polarization states by 45°, so that the polarization states of the third and fourth light beams are both 0°. The displacement crystal 22 can directly transmit the third and fourth light beams with a polarization state of 0°, and the optical path is not offset. The polarization states of the third and fourth light beams remain at 0°. Then, the third light beam and the fourth light beam pass through the second polarization converter 213. The third light beam is deflected by the second polarization converter 213 and input into the first polarization converter 212. The fourth light beam is deflected by the second polarization converter 213 and offset from the first polarization converter 212, so that the polarization state of the third light beam rotates while the polarization state of the fourth light beam remains unchanged. Finally, the polarization states of the two light beams are perpendicular to each other and are combined into one beam through the first beam splitter 211 to be output from the third port 13.

[0075] When a light beam is input from the third port 13, it first enters the first beam splitter 211. The first beam splitter 211 then splits the light beam into a fifth light beam and a sixth light beam with mutually perpendicular polarization states. The fifth light beam enters the first polarization converter 212, while the sixth light beam is offset from the first polarization converter 212. Next, both the fifth and sixth light beams enter the second polarization converter 213, where the polarization states of the two beams are rotated, and the polarization states of the fifth and second light beams are both rotated to 0°, allowing them to be transmitted through the shift crystal 22 without changing their polarization states. Next, the fifth and sixth light beams pass through the Faraday rotator 23, causing the polarization states of the two beams to rotate 45° clockwise. At this point, the polarization states of the first and second light beams are both negative 45°. Next, the fifth light beam enters the third polarization converter 241, and the sixth light beam enters the fourth polarization converter 242. After the polarization rotation, the polarization states of the two beams are 90° and 0°, respectively. Finally, the fifth and sixth light beams are input to the second beam splitter 243, which outputs the fifth and sixth light beams in two mutually perpendicular directions. Therefore, the two light beams cannot be combined into a single beam to be output from the second port 12. Therefore, the light beam input to the third port 13 cannot be output from the first port 11 or the second port 12.

[0076] like Figures 5 to 7 The winning bid numbers 001-011 are Figure 2 Schematic diagram of the polarization state of the light beam at the corresponding labeled position in . Figure 5 The figure shows the change of the polarization state of the light beam after it passes through different components in the optical circulator when transmitting from the first port 11 to the second port 12. Figure 6 The figure shows the change of the polarization state of the light beam after it passes through different components in the optical circulator when the light beam is transmitted from the second port 12 to the third port 13. Figure 7 The figure shows the change of the polarization state of the light beam after it passes through different components in the optical circulator when the light beam is transmitted from the third port 13 toward the first port 11 or the second port 12. Figure 7 The number 013 in the figure represents the polarization state of the fifth light beam and the sixth light beam when they are output from the second port 12 .

[0077] In this way, the light beam can enter the optical circulator from the first port 11 and then output from the second port 12, or enter the optical circulator from the second port 12 and then output from the third port 13. However, the light input from the third port 13 cannot be output from the first port 11 or the second port 12, thereby achieving sequential transmission of the light beams in one direction at the three ports of the optical circulator, and is less likely to cause signal crosstalk.

[0078] In some embodiments, see Figure 1 and Figure 2In a plane rectangular coordinate system perpendicular to the first direction X, the first port 11 is located in the second quadrant. The third port 13 is located in the first quadrant. The second port 12 is located in the first quadrant. The shift crystal 22 and the Faraday rotator 23 are located in four quadrants.

[0079] In one embodiment, the first beam splitter 211 is located in four quadrants, the first polarization converter 212 is located in the first and second quadrants, and the second polarization converter 213 is located in the first and fourth quadrants.

[0080] Alternatively, in another embodiment, the second beam splitter 243 is located in four quadrants, the third polarization converter 241 is located in the first and second quadrants, and the fourth polarization converter 242 is located in the third and fourth quadrants.

[0081] Alternatively, in yet another embodiment, the first beam splitter 211 is positioned in four quadrants. The first polarization converter 212 is positioned in the first and second quadrants. The second polarization converter 213 is positioned in the first and fourth quadrants. The second beam splitter 243 is positioned in four quadrants, the third polarization converter 241 is positioned in the first and second quadrants, and the fourth polarization converter 242 is positioned in the third and fourth quadrants.

[0082] like Figure 1 As shown, the first quadrant refers to the area between the positive X-axis and the positive Z-axis. The second quadrant refers to the area between the negative X-axis and the positive Z-axis. The third quadrant refers to the area between the negative X-axis and the negative Z-axis. The fourth quadrant refers to the area between the positive X-axis and the negative Z-axis. The X-axis, Y-axis, and Z-axis are the three coordinate axes in the spatial coordinate system, that is, the X direction is perpendicular to the Y direction, the X direction is perpendicular to the Z direction, and the Y direction is perpendicular to the Z direction.

[0083] The light beam input from the first port 11 passes through the first beam splitter 211 to form a first beam and a second beam. The first beam is located in the second quadrant, and the second beam is located in the fourth quadrant. This allows the first beam to enter the portion of the first polarization converter 212 located in the second quadrant, while the second beam is offset from the first polarization converter 212. This facilitates adjusting the polarization states of the first and second beams to 90°, facilitating reflection by the shift crystal 22. After reflection, the first and second beams pass through the portion of the third polarization converter 241 located in the second quadrant and the portion of the fourth polarization converter 242 located in the fourth quadrant, respectively, to achieve polarization state conversion, facilitating beam combining by the second beam splitter 243.

[0084] The light beam input from the second port 12 passes through the second beam splitter 243 to form a third beam and a fourth beam. The third beam is located in the first quadrant, and the fourth beam is located in the fourth quadrant. This allows the third beam to be input into the portion of the third polarization converter 241 located in the first quadrant, while the fourth beam can be input into the portion of the fourth polarization converter 242 located in the fourth quadrant. This allows both beams to be converted to a 0° polarization state, allowing for smooth transmission through the shift crystal 22. The third beam then passes through the portion of the second polarization converter 213 located in the first quadrant, and the portion of the first polarization converter 212 located in the first quadrant. The fourth beam passes through the portion of the second polarization converter 213 located in the fourth quadrant, and through polarization rotation, allows for smooth beam combination upon input into the first beam splitter 211.

[0085] In this way, it is beneficial for the first light beam and the second light beam to align with the optical devices in the corresponding quadrants, and it is also beneficial for the third light beam and the fourth light beam to align with the optical devices in the corresponding quadrants, thereby improving the accuracy of the polarization rotation of the light beams input from the first port 11 and the second port 12, and making it less likely for optical signal crosstalk to occur.

[0086] In some embodiments, see Figure 1 , the first polarization converter 212 abuts against the first beam splitter 211. Alternatively, in another embodiment, the second polarization converter 213 abuts against the shift crystal 22. Alternatively, in yet another embodiment, the third polarization converter 241 abuts against the second beam splitter 243. Alternatively, in yet another embodiment, the fourth polarization converter 242 abuts against the second beam splitter 243.

[0087] As an example, the first polarization converter 212 and the first beam splitter 211 can be bonded together, that is, the first polarization converter 212 and the first beam splitter 211 can be adhered together using a heat-curing adhesive, a UV-curing adhesive, or the like. Similarly, the second polarization converter 213 and the shift crystal 22 can be bonded together, the third polarization converter 241 and the second beam splitter 243 can be bonded together, and the fourth polarization converter 242 and the second beam splitter 243 can also be bonded together. Of course, in other embodiments, the aforementioned components can also be bonded together using other methods.

[0088] It is understandable that only the first polarization converter 212 may be arranged to abut against the first beam splitter 211, only the second polarization converter 213 may be arranged to abut against the shift crystal 22, only the third polarization converter 241 may be arranged to abut against the second beam splitter 243, or only the fourth polarization converter 242 may be arranged to abut against the second beam splitter 243. Alternatively, at least two of the above-mentioned embodiments may be arranged to exist simultaneously.

[0089] In this way, the components of the optical circulator are more compactly distributed, so that the optical circulator can be processed into a smaller size during packaging, thereby facilitating the fiber coiling operation of the optical circulator.

[0090] In some embodiments, the first polarization converter 212 is a 45° half-wave plate, and the second polarization converter 213 is a 45° half-wave plate.

[0091] After passing through the first polarization converter 212, the polarization state of the first light beam rotates 90°, while the polarization state of the second light beam remains unchanged after passing through the second polarization converter. As a result, both the first light beam and the second light beam are input into the displacement crystal 22 with a 90° polarization state, thereby enabling the first light beam and the second light beam to be reflected to shift the optical path.

[0092] After the third light beam passes through the second polarization conversion element 213, its polarization state is rotated 90° to 90°, and then after passing through the first polarization conversion element 212, its polarization state is rotated 90° to 0°. After the fourth light beam passes through the second polarization conversion element 213, its polarization state is rotated 90° and staggered with the first polarization conversion element 212, so that the polarization states of the third light beam and the fourth light beam can be perpendicular to each other.

[0093] In this way, it is ensured that the first light beam and the second light beam can be reflected to offset the optical path, and it is also ensured that the polarization states of the third light beam and the fourth light beam can be perpendicular to each other when input from the first light splitter 211, so that the third light beam and the fourth light beam can be smoothly merged into one light beam after passing through the first light splitter 211. In this way, the light beam input from the second port 12 can be smoothly output from the third port 13.

[0094] Alternatively, in another embodiment, the third polarization conversion element 241 is a 22.5° half-wave plate, and the fourth polarization conversion element 242 is a negative 22.5° half-wave plate.

[0095] After passing through the third polarization converter 241 , the polarization state of the first light beam rotates 45° clockwise, and after passing through the fourth polarization converter 242 , the polarization state of the second light beam rotates 45° counterclockwise, so that the polarization states of the first light beam and the second light beam are 0° and 90° respectively when inputting the second beam splitter 243 .

[0096] The polarization state of the third light beam is rotated 45° clockwise after passing through the third polarization converter 241 , and the polarization state of the fourth light beam is rotated 45° counterclockwise after passing through the fourth polarization converter 242 , so that the polarization states of the third and fourth light beams are both 45° when input into the Faraday rotator 23 .

[0097] In this way, it is ensured that after passing through the Faraday rotator 23, the third light beam and the fourth light beam can be converted into a 0° polarization state, thereby facilitating the transmission of the third light beam and the fourth light beam from the displacement crystal 22; it is also ensured that the polarization states of the first light beam and the second light beam are perpendicular to each other when input from the second light splitter 243, so that after passing through the second light splitter 243, the first light beam and the second light beam can be merged into one light beam and smoothly output from the second port 12.

[0098] Alternatively, in another embodiment, the first polarization converter 212 is a 45° half-wave plate, the second polarization converter 213 is a 45° half-wave plate, the third polarization converter 241 is a 22.5° half-wave plate, and the fourth polarization converter 242 is a negative 22.5° half-wave plate.

[0099] This ensures that after passing through the Faraday rotator 23, the third and fourth light beams can be converted to a 0° polarization state, thereby facilitating the transmission of the third and fourth light beams through the displacement crystal 22. At the same time, it also ensures that the polarization states of the third and fourth light beams are perpendicular to each other when input from the first beam splitter 211, so that after passing through the first beam splitter 211, the third and fourth light beams can be combined into a single beam. Thus, the light beam input from the second port 12 can be smoothly output from the third port 13. At the same time, it ensures that the first and second light beams can be reflected to smoothly shift the optical path. When input from the second beam splitter 243, the polarization states of the first and second light beams are perpendicular to each other, so that after passing through the second beam splitter 243, the first and second light beams can be combined into a single beam and smoothly output from the second port 12.

[0100] In some embodiments, at least one of the first beam splitter 211 and the shift crystal 22 is a polarization beam splitter prism or a yttrium vanadate crystal.

[0101] Polarization beam splitters or yttrium vanadate crystals can decompose a beam of natural light into two beams polarized in different directions, and can also combine two beams polarized in different directions into one beam of natural light.

[0102] like Figure 4 , which is a light path diagram of a light beam when the first beam splitter 211 and the shift crystal 22 are yttrium vanadate crystals.

[0103] When the first beam splitter assembly 21 includes a first beam splitter 211, a first polarization converter 212, and a second polarization converter 213, and the first beam splitter 211, the first polarization converter 212, and the second polarization converter 213 are sequentially arranged along the first direction X, at least one of the first beam splitter 211 and the shift crystal 22 is a polarization beam splitter prism. When both the first beam splitter 211 and the shift crystal 22 are polarization beam splitters, the first beam splitter 211 and the shift crystal 22 can be made of the same polarization beam splitter prism, and the effect of the light beam passing through the polarization beam splitter prism can be modified by changing the placement direction of the polarization beam splitter prism. Similarly, when both the first beam splitter 211 and the shift crystal 22 are made of yttrium vanadate crystal, the first beam splitter 211 and the shift crystal 22 can be made of the same yttrium vanadate crystal, and the effect of the light beam passing through the yttrium vanadate crystal can be modified by changing the placement direction of the yttrium vanadate crystal.

[0104] In this way, the same polarization beam splitter prism or yttrium vanadate crystal can achieve different operations on the light beam by changing the placement direction, reducing the types of components in the optical circulator, thereby reducing the processing difficulty and cost of the optical circulator.

[0105] Alternatively, in another embodiment, at least one of the shift crystal 22 and the second beam splitter 243 is a polarization beam splitter prism or a yttrium vanadate crystal.

[0106] When the second beam splitter assembly 24 includes a polarization conversion assembly and a second beam splitter 243 sequentially distributed along the first direction X, at least one of the second beam splitter 243 and the polarization beam splitter assembly is a polarization beam splitter prism. Specifically, when both the second beam splitter 243 and the polarization beam splitter assembly are polarization beam splitter prisms, the second beam splitter 243 and the polarization beam splitter assembly utilize the same polarization beam splitter prism, and the effect of the light beam passing through the polarization beam splitter prism can be modified by changing the placement direction of the polarization beam splitter prism. Similarly, when both the second beam splitter 243 and the polarization beam splitter assembly are yttrium vanadate crystals, the second beam splitter 243 and the polarization beam splitter assembly utilize the same yttrium vanadate crystals, and the effect of the light beam passing through the yttrium vanadate crystals can be modified by changing the placement direction of the yttrium vanadate crystals.

[0107] In this way, the same polarization beam splitter prism or yttrium vanadate crystal can achieve different operations on the light beam by changing the placement direction, reducing the types of components in the optical circulator, thereby reducing the processing difficulty and cost of the optical circulator.

[0108] Alternatively, in another embodiment, the first beam splitter component 21 includes a first beam splitter 211, a first polarization conversion component 212 and a second polarization conversion component 213, and the second beam splitter component 24 includes a polarization conversion component and a second beam splitter 243 distributed in sequence along the first direction X, at least one of the first beam splitter 211, the displacement crystal 22 and the second beam splitter 243 is a polarization beam splitter prism or an yttrium vanadate crystal.

[0109] In this way, users can convert the same polarization beam splitter prism or yttrium vanadate crystal into different angles to form the first beam splitter 211, the displacement crystal 22, or the second beam splitter 243. The processing and installation are relatively convenient, and the polarization beam splitter prism or yttrium vanadate crystal has different optical effects after the angle is converted, thereby reducing the types of components in the optical circulator, thereby reducing the processing difficulty and processing cost of the optical circulator.

[0110] In some embodiments, see Figure 1 and Figure 2 The shift crystal 22 includes a first polarizing film 221 and a second polarizing film 222, which are spaced apart along the second direction Y. The first polarizing film 221 is parallel to the second polarizing film 222. The first beam splitter 211 is used to split the light beam input from the first port 11 into a first light beam and a second light beam spaced apart along the third direction Z. The second beam splitter 24 is used to split the light beam input from the second port 12 into a third light beam and a fourth light beam spaced apart along the third direction Z. The first polarizing film 221 is used to shift the first light beam and the second light beam along the second direction Y onto the second polarizing film 222. The second polarizing film 222 is used to shift the first light beam and the second light beam along the first direction X onto the Faraday rotator 23. The second polarizing film 222 is also used to transmit the third light beam and the fourth light beam along the first direction X. The first direction X is perpendicular to the second direction Y, the second direction Y is perpendicular to the third direction Z, and the first direction X is perpendicular to the third direction Z.

[0111] When incident on the shift crystal 22, the first and second light beams both have a polarization state of 90°. They are reflected by the first polarizing film 221 and then by the second polarizing film. It is understood that light beams with a polarization state of 90° can be reflected after passing through the polarizing film without changing their polarization state. In this way, after being reflected by the parallel first and second polarizing films 221 and 222, the first and second light beams can be emitted from the shift crystal 22 in the same direction as their incident direction, causing the shift crystal 22 to shift the optical paths of the first and second light beams along the second direction Y.

[0112] A light beam with a polarization state of 0° can be transmitted directly after passing through the polarizing film, and the polarization state does not change.

[0113] In this way, through the polarization film and the polarization characteristics of the light beam, the second port 12 can receive the light beam input from the first port 11, and the third port 13 can receive the light beam input from the second port 12, and the light beam input from the third port 13 toward the second port 12 and the first port 11 cannot be output from the first port 11 or the second port 12, thereby achieving reverse isolation of the light beam and stable transmission of the optical signal, reducing crosstalk.

[0114] In some embodiments, see Figure 2 The optical circulator further includes a first collimator 40 . The first collimator 40 is provided between the first port 11 and the first light splitting component 21 .

[0115] Specifically, after passing through the first collimator 40 , the light beam can be transformed into parallel light and input from the first port 11 , and then irradiated on the first light splitting component 21 in parallel.

[0116] Alternatively, in another embodiment, the optical circulator further includes a second collimator 50 . The second collimator 50 is disposed between the second port 12 and the second light splitting component 24 .

[0117] Specifically, after passing through the second collimator 50 , the light beam can be transformed into parallel light and input from the second port 12 , and then irradiated on the second light splitting component 24 in parallel.

[0118] Alternatively, in another embodiment, the optical circulator further includes a third collimator 60 . The third collimator 60 is disposed between the third port 13 and the first light splitting component 21 .

[0119] Specifically, the light beam emitted from the first light splitting component 21 can be transformed into parallel light after passing through the third collimator 60 , and then emitted in parallel from the third port 13 .

[0120] It can be understood that only the first collimator 40 , only the second collimator 50 , only the third collimator 60 , or at least two of the first collimator 40 , the second collimator 50 , and the third collimator 60 may be provided.

[0121] In this way, by providing at least one of the first collimator 40, the second collimator 50, and the third collimator 60, the light beam can be coupled into the optical device inside the optical circulator with maximum efficiency, thereby increasing the transmission efficiency of the light beam in the optical circulator, thereby optimizing the optical signal transmission effect of the optical circulator.

[0122] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An optical circulator, characterized in that: include: A port assembly comprising a first port, a second port, and a third port arranged at intervals; A light guide assembly comprising a first light splitting assembly, a displacement crystal, a Faraday rotator and a second light splitting assembly sequentially distributed along a first direction, wherein the Faraday rotator is used to change the polarization state of light; The first beam splitter is used to split the light beam input from the first port into a first light beam and a second light beam, the displacement crystal is used to shift the optical path of the first light beam and the optical path of the second light beam, and the second beam splitter is used to merge the first light beam and the second light beam into a beam of light that can be output from the second port; The second beam splitter component is further used to split the light beam input from the second port into a third light beam and a fourth light beam, the displacement crystal is further used to transmit the third light beam and the fourth light beam, and the first beam splitter component is further used to merge the third light beam and the fourth light beam into a beam of light that can be output from the third port.

2. The optical circulator according to claim 1, wherein: The optical circulator also includes a housing, wherein the first beam splitter component, the displacement crystal, the Faraday rotator and the second beam splitter component are sequentially distributed in the housing along the first direction; the first port and the third port are spaced apart and arranged on one side of the housing along the first direction, and are both arranged opposite to the first beam splitter component along the first direction; the second port is arranged on the other side of the housing along the first direction, and is arranged opposite to the second beam splitter component along the first direction.

3. The optical circulator according to claim 1, wherein: The optical circulator also includes a shell, and the first beam splitter component, the displacement crystal, the Faraday rotator and the second beam splitter component are distributed in sequence in the shell along the first direction; the optical circulator also includes a reflector, the first port and the reflector are arranged at intervals on one side of the shell along the first direction, and are both arranged opposite to the first beam splitter component along the first direction; the second port is arranged on the other side of the shell along the first direction, and is arranged opposite to the second beam splitter component along the first direction; the third port is arranged on one side of the shell along the second direction, and is arranged opposite to the reflector along the second direction, and the reflector is used to reflect the light beam input from the third port onto the first beam splitter component; the first direction and the second direction are perpendicular.

4. The optical circulator according to claim 1, wherein: The first beam splitter assembly includes a first beam splitter, a first polarization converter, and a second polarization converter sequentially distributed along the first direction; the first beam splitter is used to split the light beam input from the first port into the first light beam and the second light beam spaced apart along a third direction; the first polarization converter and the shift crystal are used to sequentially input the first light beam output from the first beam splitter, and the shift crystal is used to input the second light beam output from the first beam splitter; the second beam splitter assembly is used to split the light beam input from the second port into the third light beam and the fourth light beam spaced apart along the third direction; the second polarization converter, the first polarization converter, and the first beam splitter are used to sequentially input the third light beam output from the shift crystal, and the second polarization converter and the first beam splitter are used to input the fourth light beam output from the shift crystal, and the first beam splitter is used to merge the third light beam and the fourth light beam into one beam; the first direction is perpendicular to the third direction; And / or, the second spectroscopic component includes a polarization conversion component and a second spectroscopic component distributed in sequence along the first direction, the first spectroscopic component is used to split the light beam input from the first port into the first light beam and the second light beam distributed along a third direction, the second spectroscopic component is used to merge the first light beam and the second light beam into one beam of light, and the second spectroscopic component is also used to split the light beam input from the second port into the third light beam and the fourth light beam distributed along the third direction; the polarization conversion component includes a third polarization conversion component and a fourth polarization conversion component distributed along the third direction, the third polarization conversion component is used to input the first light beam and the third light beam respectively, and the fourth polarization conversion component is used to input the second light beam and the fourth light beam respectively; the first direction is perpendicular to the third direction.

5. The optical circulator according to claim 4, wherein: In a rectangular coordinate system perpendicular to the first direction, the first port is located in the second quadrant, the third port is located in the first quadrant, the second port is located in the first quadrant, and the shift crystal and the Faraday rotator are located in four quadrants; The first beam splitter is located in four quadrants, the first polarization conversion element is located in the first quadrant and the second quadrant, and the second polarization conversion element is located in the first quadrant and the fourth quadrant; and / or, the second beam splitter is located in four quadrants, the third polarization conversion element is located in the first quadrant and the second quadrant, and the fourth polarization conversion element is located in the third quadrant and the fourth quadrant.

6. The optical circulator according to claim 4, wherein: The first polarization converter rests on the first beam splitter; and / or the second polarization converter rests on the displacement crystal; and / or the third polarization converter rests on the second beam splitter; and / or the fourth polarization converter rests on the second beam splitter.

7. The optical circulator according to claim 4, wherein: The first polarization conversion element is a 45° half-wave plate, and the second polarization conversion element is a 45° half-wave plate; And / or, the third polarization conversion element is a 22.5° half-wave plate, and the fourth polarization conversion element is a negative 22.5° half-wave plate.

8. The optical circulator according to claim 4, wherein: At least one of the first beam splitter and the shift crystal is a polarization beam splitter prism or a yttrium vanadate crystal; And / or, at least one of the shift crystal and the second beam splitter is a polarization beam splitter prism or a yttrium vanadate crystal.

9. The optical circulator according to any one of claims 1 to 8, wherein: The shift crystal includes a first polarizing film and a second polarizing film spaced apart along a second direction, the first polarizing film being parallel to the second polarizing film, the first beam splitting component being used to split the light beam input from the first port into the first beam and the second beam spaced apart along a third direction, and the second beam splitting component being used to split the light beam input from the second port into the third beam and the fourth beam spaced apart along the third direction; The first polarizing film is used to shift the first light beam and the second light beam along the second direction to the second polarizing film, and the second polarizing film is used to shift the first light beam and the second light beam along the first direction to the Faraday rotator; the second polarizing film is also used to transmit the third light beam and the fourth light beam along the first direction; the first direction, the second direction and the third direction are perpendicular to each other.

10. The optical circulator according to any one of claims 1 to 8, wherein: The optical circulator further includes a first collimator, which is arranged between the first port and the first spectroscopic component; and / or, the optical circulator further includes a second collimator, which is arranged between the second port and the second spectroscopic component; and / or, the optical circulator further includes a third collimator, which is arranged between the third port and the first spectroscopic component.

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