Transmission-type multichannel optical circulator

Abstract

The utility model provides a transmission-type multichannel optical circulator, which comprises a first collimator array and a second collimator array, the first collimator array comprises a plurality of first collimators, and the second collimator array comprises a plurality of second collimators; a first light splitting device, a first wave plate group, a first Faraday rotation sheet, a second light splitting device, a second Faraday rotation sheet, a second wave plate group and a third light splitting device are sequentially arranged between the first collimator array and the second collimator array; wherein the first wave plate group is provided with two first wave plates, the two first wave plates cover different light paths of the first light splitting device, and the optical axes of the two first wave plates are different; the second wave plate group is provided with two second wave plates, the two second wave plates cover different light paths of the third light splitting device, and the optical axes of the two second wave plates are different. The transmission-type multichannel optical circulator is compact in structure and low in production cost.

Description

Technical Field

[0001] This utility model relates to the technical field of optical communication devices, specifically, a transmissive multi-channel optical circulator. Background Technology

[0002] An optical circulator is a common optical device with multiple ports. A light beam entering through one port can only exit through the next adjacent port, and the optical path is fixed and irreversible. It is often used to control the propagation path of a light beam. Common circulators include three-port circulators and four-port circulators.

[0003] Existing optical circulators include reflective and transmissive types. For example, utility model patent CN219641965U discloses an open-loop four-port optical circulator. This circulator includes a base and a housing, with four ports on the housing. Each port has a collimator, four polarization beam splitters, and multiple Faraday rotators. This type of optical circulator has a very complex structure, uses many optical components, which is not conducive to miniaturization and results in high production costs. Utility Model Content

[0004] The purpose of this invention is to provide a simple, low-cost, transmission-type multi-channel optical circulator.

[0005] To achieve the above objectives, the transmissive multichannel optical circulator provided by this utility model includes a first collimator array and a second collimator array. The first collimator array includes multiple first collimators, and the second collimator array includes multiple second collimators. A first beam splitter, a first waveplate group, a first Faraday rotator, a second beam splitter, a second Faraday rotator, a second waveplate group, and a third beam splitter are sequentially arranged between the first and second collimator arrays. The first waveplate group has two first waveplates, which cover different optical paths of the first beam splitter, and the optical axes of the two first waveplates are different. The second waveplate group has two second waveplates, which cover different optical paths of the second beam splitter, and the optical axes of the two second waveplates are different.

[0006] As can be seen from the above scheme, the beam emitted from the first collimator is split into two beams with mutually perpendicular polarization states after passing through the first beam splitter. After passing through the first waveplate group, the two beams have the same polarization state. After passing through the first Faraday rotator, they form ordinary light, allowing the beam to propagate in the second beam splitter along the ordinary light path. After passing through the second beam splitter, the beam then passes through the second Faraday rotator, the second waveplate group, and the third beam splitter before being combined and finally emitted from the second collimator.

[0007] The light beam incident from the second collimator is split into two beams with mutually perpendicular polarization states after passing through the third beam splitter. After passing through the second waveplate group, the polarization states of the two beams are the same. After passing through the second Faraday rotator, they form unusual light, whose propagation path is different from that of ordinary light. As a result, the light path is deflected in the second beam splitter and cannot exit from the corresponding first collimator, thus realizing unidirectional transmission of the light path.

[0008] Because this invention uses a small number of optical components, and each optical component can be arranged compactly, the transmissive multichannel optical circulator is small in size and has a low production cost.

[0009] A preferred embodiment is that the first collimator array and the second collimator array are positioned opposite each other at both ends of the transmissive multichannel optical circulator.

[0010] As can be seen, since the optical circulator is transmissive, the first collimator array and the second collimator array can be distributed at both ends of the transmissive multichannel optical circulator, making the structure of the transmissive multichannel optical circulator more compact.

[0011] A further approach is to arrange multiple first collimators in the first collimator array along a one-dimensional direction; and to arrange multiple second collimators in the second collimator array along the same one-dimensional direction.

[0012] It can be seen that the arrangement of multiple first collimators and second collimators in the two collimator arrays of this transmissive multichannel optical circulator is in the same direction, which is beneficial for connecting with external optical fibers.

[0013] A further approach is to have the same number of first collimators as the number of second collimators.

[0014] A further alternative is that the first and third beam-splitting devices have the same structure. Preferably, the first beam-splitting device is a first birefringent crystal, and the third beam-splitting device is a third birefringent crystal.

[0015] Since birefringent crystals are common optical devices with simple structures and low costs, they can reduce the production cost of transmission-type multichannel optical circulators.

[0016] A further proposed solution is to use a second birefringent crystal or a polarizing beam splitter as the second beam splitter.

[0017] A further approach is to make the length of the second beam splitter directly proportional to the distance between two adjacent first collimators in the first collimator array.

[0018] This arrangement allows for a more reasonable length setting for the second beam splitter, facilitating a compact arrangement of all optical components and thus reducing the size of the transmissive multichannel optical circulator.

[0019] A further proposed solution is to symmetrically arrange two first waveplates and two second waveplates on both sides of the second beam splitter. Attached Figure Description

[0020] Figure 1 This is a structural diagram from a first-view perspective of an embodiment of this utility model.

[0021] Figure 2 This is a structural diagram from a second perspective of an embodiment of this utility model.

[0022] Figure 3 This is a schematic diagram of the structure of the first waveplate group in an embodiment of this utility model.

[0023] Figure 4 This is an optical path diagram of an embodiment of the present invention.

[0024] Figure 5 This is the optical path diagram of the first direction in an embodiment of this utility model.

[0025] Figure 6 This is the optical path diagram of the second direction in an embodiment of this utility model.

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0027] The transmissive multichannel optical circulator of this invention has two collimator arrays, which are located at both ends of the transmissive multichannel optical circulator and serve as the input and output ports of the light beam, respectively.

[0028] See Figure 1 and Figure 2 The transmissive multichannel optical circulator of this embodiment has a first collimator array 10 and a second collimator array 90. The first collimator array 10 has a plurality of first collimators, such as first collimators 11, 12, 13, 14, 15, 16, and 17. The second collimator array 90 has a plurality of second collimators, such as second collimators 91, 92, 93, 94, 95, 96, and 97. It can be seen that the number of the plurality of first collimators in the first collimator array 10 is equal to the number of the plurality of second collimators in the second collimator array 90. Furthermore, the plurality of first collimators 11, 12, 13, 14, 15, 16, and 17 are arranged along a one-dimensional direction, specifically, sequentially along the Y-axis. Similarly, the plurality of second collimators 91, 92, 93, 94, 95, 96, and 97 are also arranged in a one-dimensional direction, and are also sequentially arranged along the Y-axis. In the X-axis direction, the first collimator array 10 and the second collimator array 90 are located at the two ends of the transmissive multichannel optical circulator, respectively.

[0029] Between the first collimator array 10 and the second collimator array 90, a first beam splitter 20, a first waveplate group 30, a first Faraday rotator 40, a second beam splitter 50, a second Faraday rotator 60, a second waveplate group 70, and a third beam splitter 80 are sequentially arranged. The first beam splitter 20 and the third beam splitter 80 have identical structures, shapes, and optical characteristics. For example, the first beam splitter 20 is a first birefringent crystal, and the third beam splitter 80 is a third birefringent crystal. After the light beam passes through the first or third birefringent crystal, it will be split into two beams with mutually perpendicular polarization states, i.e., ordinary ray and extraordinary ray, respectively. Of course, if the ordinary ray and extraordinary ray pass through the first or third birefringent crystal, they can also be combined to form a single beam.

[0030] The first wave plate group 30 has two first wave plates, namely first wave plate 31 and first wave plate 32, from Figure 2 As can be seen, the first waveplates 31 and 32 are arranged along the Z-axis and cover different optical paths of the first beam splitter 20. See [link / reference] Figure 3 The optical axis of the first waveplate 31 is not the same as that of the first waveplate 32. Figure 3 The arrow inside the first waveplate 31 indicates the optical axis direction of the first waveplate 31, while the arrow inside the first waveplate 32 indicates the optical axis direction of the first waveplate 32. Preferably, the optical axis angle of the first waveplate 31 is 22.5°, pointing towards the positive Z-axis, while the optical axis angle of the first waveplate 32 is 22.5°, pointing towards the negative Z-axis.

[0031] With the central axis of the second beam splitter 50 as the axis of symmetry, the second waveplate group 70 is arranged symmetrically with the first waveplate group 30. Furthermore, the second waveplate group 70 also has two second waveplates, namely second waveplate 71 and second waveplate 72. Figure 2 As can be seen, the second waveplates 71 and 72 are arranged along the Z-axis and cover different optical paths of the second beam splitter 80. Furthermore, the optical axes of the second waveplates 71 and 72 are not the same. It is evident that the two first waveplates 31 and 32 and the two second waveplates 71 and 72 are symmetrically arranged on both sides of the second beam splitter 50.

[0032] The second beam splitter 50 can be a second birefringent crystal or a polarizing beam splitter prism. Furthermore, the length of the second beam splitter 50 is directly related to the distance between two adjacent first collimators in the first collimator array 10. That is, the greater the distance between two adjacent first collimators in the first collimator array 10, the longer the length of the second beam splitter 50.

[0033] The following is combined Figures 4 to 6The optical path of this embodiment is described below. Taking the optical path exiting from the first collimator 11 as an example, after the light beam exiting from the first collimator 11 enters the first beam splitter 20, it forms two beams with mutually perpendicular polarization states under the birefringence effect of the first beam splitter 20, for example, beam L11 and beam L21. For example, beam L11 is ordinary light and beam L21 is extraordinary light. Then, beams L11 and L21 pass through the first waveplate 31 and the first waveplate 32 of the first waveplate group 30, respectively. Since the optical axis directions of the first waveplate 31 and the first waveplate 32 are different, that is, the fast and slow axis directions of the first waveplate 31 and the first waveplate 32 are different, the polarization states of beams L11 and L21 will rotate along different directions and become polarized light with the same polarization state.

[0034] Next, beams L11 and L21 are incident on the first Faraday rotator 40. A certain magnetic field is applied outside the first Faraday rotator 40, causing the polarization states of beams L11 and L21 to deflect by a certain angle along the same direction. Then, beams L11 and L21 are both incident on the second beam splitter 50, forming beams L12 and L22 respectively. Since the polarization states of beams L12 and L22 have been adjusted before they are incident on the second beam splitter 50, under the birefringence effect of the second beam splitter, the polarization states of beams L12 and L22 correspond to the ordinary light of the second beam splitter 50. Therefore, beams L12 and L22 pass through the second beam splitter 50 along the ordinary light path. Then, after exiting the second beam splitter 50, beams L12 and L22 pass through the second Faraday rotator 60, and the polarization states of beams L12 and L22 are rotated by the same angle again.

[0035] Then, the beams L12 and L22 passing through the second Faraday rotator 60 pass through the second waveplate 71 and the second waveplate 72 of the second waveplate group 70, respectively. Since the optical axes of the second waveplate 71 and the second waveplate 72 are different, the beams L12 after passing through the second waveplate 71 and L22 after passing through the second waveplate 72 have different polarization states, becoming two beams of polarized light with mutually perpendicular polarization states.

[0036] Next, beams L12 and L22, after passing through the second waveplate group 70, are incident on the third beam splitter 80, forming beams L13 and L23 respectively. Due to the birefringence effect of the third beam splitter 80, beams L13 and L23 will combine. Therefore, beam L14 exiting the third beam splitter 80 is formed by the combination of two beams with mutually perpendicular polarization states, and ultimately enters the second collimator 91. It can be seen that the beam exiting the first collimator 11 will enter the second collimator 91. Similarly, the beam exiting the first collimator 12 will enter the second collimator 92, the beam exiting the first collimator 13 will enter the second collimator 93, and so on.

[0037] The following is combined with Figure 4 and Figure 6 The optical path incident from the second collimator 92 is described. The beam L30 exiting the second collimator 92 is incident on the third beam splitter 80. Under the birefringence effect of the third beam splitter 80, it forms two beams with mutually perpendicular polarization states, for example, beam L31 and beam L41. For example, beam L31 is ordinary light, and beam L41 is extraordinary light. Then, beams L31 and L41 pass through the second waveplate 71 and the second waveplate 72 of the second waveplate group 70, respectively. Since the optical axis directions of the second waveplate 71 and the second waveplate 72 are different, the polarization states of beams L31 and L41 will rotate along different directions, becoming polarized light with the same polarization state.

[0038] Next, beams L31 and L41 are incident on the second Faraday rotator 60. A certain magnetic field is applied outside the second Faraday rotator 60, causing the polarization states of beams L31 and L41 to deflect by a certain angle along the same direction. Then, beams L31 and L41 are both incident on the second beam splitter 50, forming beams L32 and L42 respectively. Since the polarization states of beams L32 and L42 have been adjusted before they are incident on the second beam splitter 50, under the birefringence effect of the second beam splitter, the polarization states of beams L32 and L42 correspond to the unusual light of the second beam splitter 50. Therefore, beams L32 and L42 pass through the second beam splitter 50 along the optical path of the unusual light. From Figure 4 It can be seen that the propagation directions of beams L32 and L42 are offset along the Y-axis, that is, offset towards the direction of the first collimator 13.

[0039] Next, after beams L32 and L42 exit from the second beam splitter 50, they pass through the first Faraday rotator 40, and their polarization states rotate by the same angle again. Then, beams L32 and L42 passing through the first Faraday rotator 40 pass through the first waveplate 31 and the first waveplate 32 of the first waveplate group 30, respectively. Since the optical axes of the first waveplate 31 and the first waveplate 32 are different, the polarization states of beam L32 after passing through the first waveplate 31 and beam L42 after passing through the first waveplate 32 are different, becoming two polarized beams with mutually perpendicular polarization states.

[0040] Next, beams L32 and L42, after passing through the first waveplate group 30, are incident on the first beam splitter 20, forming beams L33 and L43 respectively. Due to the birefringence effect of the first beam splitter 20, beams L33 and L43 will combine. Therefore, beam L44 exiting the first beam splitter 20 is formed by the combination of two beams with mutually perpendicular polarization states, and ultimately enters the first collimator 13. It can be seen that the beam exiting the second collimator 92 will enter the first collimator 13. Similarly, the beam exiting the second collimator 91 will enter the first collimator 12, the beam exiting the second collimator 93 will enter the first collimator 14, and so on.

[0041] As can be seen, the light beam incident from the first collimator 11 eventually exits from the second collimator 91, the light beam incident from the second collimator 91 exits from the first collimator 12, the light beam incident from the first collimator 12 eventually exits from the second collimator 92, and the light beam exiting from the second collimator 92 will be incident on the first collimator 13, and so on, thereby realizing the function of a multi-channel optical circulator.

[0042] Because this invention uses fewer optical components, employing only three beam splitters and two Faraday rotators, along with two sets of waveplates, the overall structure is simple, which is beneficial for miniaturizing the size of the transmissive multichannel optical circulator and reducing the production cost of the multichannel optical circulator.

[0043] Finally, it should be emphasized that the above are only preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1.A transmissive multi-channel optical circulator, comprising a first collimator array and a second collimator array, the first collimator array comprising a plurality of first collimators, and the second collimator array comprising a plurality of second collimators; a first light splitting device, a first wave plate set, a first Faraday rotator, a second light splitting device, a second Faraday rotator, a second wave plate set and a third light splitting device are sequentially arranged between the first collimator array and the second collimator array; wherein the first wave plate set comprises two first wave plates, the two first wave plates are arranged on different optical paths of the first light splitting device, and optical axes of the two first wave plates are different; the second wave plate set comprises two second wave plates, the two second wave plates are arranged on different optical paths of the third light splitting device, and optical axes of the two second wave plates are different. characterized in that ； 2.The transmissive multi-channel optical circulator of claim 1, wherein: the first collimator array and the second collimator array are oppositely arranged at two ends of the transmissive multi-channel optical circulator. 3.The transmissive multi-channel optical circulator of claim 2, wherein: the plurality of first collimators in the first collimator array are arranged in a one-dimensional direction; and the plurality of second collimators in the second collimator array are arranged in the same one-dimensional direction. 4.The transmissive multi-channel optical circulator of any one of claims 1 to 3, wherein: a number of the first collimators is equal to a number of the second collimators. 5.The transmissive multi-channel optical circulator of any one of claims 1 to 3, wherein: the first light splitting device and the third light splitting device have the same structure. 6.The transmissive multi-channel optical circulator of claim 5, wherein: the first light splitting device is a first birefringent crystal, and the third light splitting device is a third birefringent crystal. 7.The transmissive multi-channel optical circulator of any one of claims 1 to 3, wherein: the second light splitting device is a second birefringent crystal or a polarization splitting prism. 8.The transmissive multi-channel optical circulator of any one of claims 1 to 3, wherein: a length of the second light splitting device is in positive correlation with a distance between two adjacent first collimators in the first collimator array. 9.The transmissive multi-channel optical circulator of claim 8, wherein: the two first wave plates and the two second wave plates are symmetrically arranged on two sides of the second light splitting device. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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