Two-dimensional array multi-channel multi-port optical circulator

Abstract

The present invention provides a two-dimensional array multi-channel, multi-port optical circulator, comprising two or more collimator arrays, each collimator array comprising three or more collimators, with the collimators in the same collimator array being located on the same side of the optical circulator; a first birefringent crystal disposed on one side of the collimator array, through which optical signals from the multiple collimator arrays all pass; a half-wave plate assembly disposed on a side of the first birefringent crystal away from the collimator array, the half-wave plate assembly comprising two or more half-wave plates; an optical rotator disposed on a side of the half-wave plate assembly away from the first birefringent crystal, a light combining and splitting device disposed on the side of the optical rotator assembly away from the half-wave plate assembly; a polarization state converter disposed on a side of the optical rotator assembly away from the light combining and splitting devices; and a reflector disposed on a side of the polarization state converter away from the optical rotator assembly. The present invention can integrate a multi-channel, multi-port optical circulator, facilitating miniaturization of the optical circulator.

Description

Technical Field

[0001] This invention relates to an optical device, and more particularly to a small-sized two-dimensional array-type multi-port optical circulator. Background Art

[0002] Various optical devices are widely used in current fiber optic communication systems, among which optical circulators are common. An optical circulator is a multi-port non-reciprocal optical device whose function is to ensure that optical signals are transmitted sequentially along designated ports, thereby achieving bidirectional optical signal transmission over a single optical fiber. Typically, optical circulators have three or more ports, such as... Figure 1 As shown, the optical circulator has four ports, namely ports 11, 12, 13, and 14. When the optical signal enters the optical circulator from port 11, the optical signal is output from port 12 with almost no loss, and the other ports have almost no optical output; when the optical signal enters the optical circulator from port 12, the optical signal is output from port 13 with almost no loss, and the other ports have almost no optical output, and so on.

[0003] Optical circulators, due to their non-reciprocity, are crucial components in bidirectional communication, enabling the separation of forward and reverse-transmitting light. They can be used in single-fiber bidirectional communication, fiber Bragg grating (FBG) combinations, erbium-doped fiber amplifiers (EDFAs), wavelength division multiplexing (WDM), dispersion compensation, and as couplers in optical time domain reflectometers (OTDRs) and fiber optic gyroscopes (Sagnac interferometers), effectively improving the performance of fiber optic communication systems.

[0004] The most widely used optical circulators at present are single-channel three-port optical circulators, such as... Figure 2 As shown, this optical circulator adopts a transmission structure, with ports 21 and 23 on the first side and port 22 on the second side. A series of optical elements 34 are arranged in the middle of the optical circulator to change the transmission direction of the light beam. However, in some scenarios where optical circulators are used, it is necessary to use two or more optical circulators simultaneously. If a traditional single-channel three-port optical circulator is used, the space required to arrange the optical circulators increases with the increase in the number of optical circulators used, which is not conducive to the miniaturization of devices used in optical fiber communication systems.

[0005] Some existing optical circulators have multiple ports, and these ports are located on the same side of the circulator. For example, Chinese invention patent application CN103955026A discloses a single-path multi-port reflective optical circulator, which sequentially includes an optical fiber array, a lens array, a first displacement plate, a first waveplate, a rotation plate, a second waveplate, a second displacement plate, a quarter-waveplate, and a mirror in the optical path. However, in this design, the first displacement plate is a PBS polarized beam splitter array, which consists of multiple polarized beam splitters. Not all optical signals pass through a single polarized beam splitter, resulting in an excessively large optical circulator size.

[0006] Furthermore, since the optical circulator uses three waveplates—a first waveplate, a second waveplate, and a quarter waveplate—it requires a large number of optical components, which is not conducive to miniaturization of the optical circulator. This not only increases the production cost of the optical circulator but also increases the assembly difficulty, resulting in low production efficiency.

[0007] In addition, the multiple ports of this scheme are only extended in one dimension, that is, multiple ports are arranged on the same straight line. If the ports are expanded, more ports will only be set on the same straight line, resulting in a larger width of the optical circulator, which is not conducive to the miniaturization of the optical circulator. Summary of the Invention

[0008] The purpose of this invention is to provide a small-sized, two-dimensional array-type multi-port optical circulator that extends in two-dimensional space.

[0009] To achieve the above objectives, the two-dimensional array-type multi-channel multi-port optical circulator provided by the present invention includes two or more collimator arrays, each collimator array including three collimators, and multiple collimators in the same collimator array located on the same side of the optical circulator; a first birefringent crystal disposed on one side of the collimator array, through which the optical signals of multiple collimator arrays pass; a half-wave plate group disposed on the side of the first birefringent crystal away from the collimator array, the half-wave plate group having two or more half-wave plates; an optical rotator disposed on the side of the half-wave plate group away from the first birefringent crystal, the side of the optical rotator away from the half-wave plate group having a beam combining and splitting device; a polarization state conversion device disposed on the side of the optical rotator away from the beam combining and splitting device; and a reflection device disposed on the side of the polarization state conversion device away from the optical rotator.

[0010] As can be seen from the above scheme, the present invention uses a reflective structure to form an optical circulator. All ports of the optical circulator are located on the same side of the circulator, which is beneficial for the arrangement of the optical circulator, reduces the wiring space of the optical fiber, and facilitates the miniaturization of the optical fiber communication system. Furthermore, the first birefringent crystal used in the optical circulator is a single crystal. The optical signals of all collimator arrays pass through the first birefringent crystal, that is, multiple collimator arrays share a single first birefringent crystal, thereby avoiding the problem of excessively large optical circulator size due to the excessive size of the first birefringent crystal.

[0011] On the other hand, since the optical circulator only has two waveplates, namely a half-waveplate group and a polarization state conversion device, the structure of the entire optical circulator is more compact and uses fewer optical components, which is conducive to the miniaturization of the optical circulator.

[0012] Optionally, the beam combining and splitting device can be a second birefringent crystal or a polarizing beam splitter prism.

[0013] A preferred embodiment is that the optical axis of at least one half-wave plate is different from that of the other half-wave plate.

[0014] Since this invention uses half-wave plates to change the polarization state of ordinary light and unusual light, by setting half-wave plates with different optical axes, ordinary light and unusual light can be made to have the same polarization state after passing through the half-wave plate group, so that the optical signal can propagate according to the preset polarization state.

[0015] A further approach is to arrange multiple collimators in the same collimator array in parallel and side-by-side; or to arrange multiple collimator arrays in two or more rows.

[0016] Therefore, arranging multiple collimator arrays in two rows to achieve two-dimensional expansion of multiple collimator arrays is beneficial to reducing the width of the optical circulator and making the structure of the optical circulator more compact.

[0017] A further approach is to set up a half-wave plate group with multiple half-wave plates. The number of half-wave plates is one more than the number of rows of collimators arranged side by side in the collimator array. The multiple half-wave plates are stacked, and the optical axes of two adjacent half-wave plates are flipped in the horizontal direction.

[0018] In this way, the half-wave plate in the middle will be used by the optical signals output from the two collimator arrays, resulting in higher utilization of optical components and a more compact structure for the optical circulator.

[0019] A further proposed solution is to have the optical signal propagation direction of the multiple collimators in the first row be opposite to that of the multiple collimators in the second row.

[0020] This avoids interference between the optical signals from the first row of collimators and the optical signals from the second row of collimators, thus improving the accuracy of optical communication.

[0021] A further approach is to have a row of collimators consisting of multiple collimators in an array of two or more collimators.

[0022] As can be seen, four or more collimator arrays can be set inside the optical circulator, thereby realizing the function of multiple single multi-port optical circulators.

[0023] An alternative approach is to arrange multiple collimators in the same collimator array in parallel and side by side; or to arrange multiple collimator arrays in a row.

[0024] Therefore, this approach can also realize the function of multiple single multi-port optical circulators within a single optical circulator. In confined spaces, this approach can facilitate the miniaturization of optical circulators.

[0025] A further approach is to have a half-wave plate assembly consisting of two half-wave plates, with the optical axes of the two half-wave plates flipped horizontally.

[0026] A further approach is to use a quarter-wave plate or a Faraday rotator as the polarization state conversion device. Since both quarter-wave plates and Faraday rotators have the characteristic of converting linearly polarized light into circularly polarized light, using them as polarization state conversion devices can achieve changes in the polarization state of optical signals.

[0027] A further approach is to use a beam splitter as the reflector, with a photodetector array positioned on the side of the beam splitter furthest from the polarization state conversion device.

[0028] By setting a photodetector array on one side of the reflector, the optical power of the optical signal entering the optical circulator can be detected, thereby improving the function of the optical circulator.

[0029] A further approach is that the collimator array consists of multiple individual collimators, each of which includes a single lens and a single optical fiber; or the collimator array consists of an optical fiber array containing multiple optical fibers and a lens array containing multiple lenses.

[0030] Therefore, it can be seen that there are many ways to compose a collimator array, and different collimator array structures can be adopted according to the needs of different application scenarios.

[0031] A further approach is to provide a filter group between the reflective device and the polarization state conversion device, wherein the filter group has one or more filters, and each filter is positioned on the optical path corresponding to a single circulator.

[0032] Therefore, it can be seen that a filter can filter light beams, allowing only specific wavelengths of light to pass through the filter, thus enabling the filtering of optical signals incident on an optical circulator.

[0033] A further approach is to use multiple filters with the same or different filtering wavelengths. This allows for the filtering of the light beam entering the optical circulator at a specific wavelength, depending on the actual application requirements. For example, if multiple filters have different filtering wavelengths, the light beams incident from different ports will have different filtered wavelengths, which can meet the needs of special environments.

[0034] An alternative approach is to use a reflective device that includes a mirror and a filter. This allows for filtering of the optical signals entering all channels of the optical circulator, ensuring that only specific wavelengths of light are reflected while other wavelengths are transmitted.

[0035] A further approach is that each collimator array contains two collimators, one as the input and the other as the output. In this way, the optical device only allows unidirectional light transmission, and the present invention can be used as an array-type isolator. Attached Figure Description

[0036] Figure 1 This is a functional diagram of an optical circulator.

[0037] Figure 2 This is a schematic diagram of an existing transmissive single-channel three-port optical circulator.

[0038] Figure 3 This is the front view of the first embodiment of the present invention.

[0039] Figure 4 This is a top view of the first embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the collimator array according to the first embodiment of the present invention.

[0041] Figure 6 This is a schematic diagram of the structure of the half-wave plate group according to the first embodiment of the present invention.

[0042] Figure 7 This is a unidirectional transmission optical path diagram from the first collimator to the second collimator in the first embodiment of the present invention.

[0043] Figure 8 This is a unidirectional transmission optical path diagram of the fourth to fifth collimators in the first embodiment of the present invention.

[0044] Figure 9 This is the front view of the second embodiment of the present invention.

[0045] Figure 10 This is a top view of the second embodiment of the present invention.

[0046] Figure 11 This is a schematic diagram of the collimator array according to the second embodiment of the present invention.

[0047] Figure 12 This is a schematic diagram of the structure of the half-wave plate group according to the second embodiment of the present invention.

[0048] Figure 13 This is the front view of the third embodiment of the present invention.

[0049] Figure 14 This is a top view of the third embodiment of the present invention.

[0050] Figure 15 This is a schematic diagram of the collimator array according to the third embodiment of the present invention.

[0051] Figure 16 This is a schematic diagram of the structure of the half-wave plate group according to the third embodiment of the present invention.

[0052] Figure 17 This is the front view of the fourth embodiment of the present invention.

[0053] Figure 18 This is a top view of the fourth embodiment of the present invention.

[0054] Figure 19 This is the front view of the fifth embodiment of the present invention.

[0055] Figure 20 This is a top view of the fifth embodiment of the present invention.

[0056] Figure 21 This is the front view of the sixth embodiment of the present invention.

[0057] Figure 22 This is a top view of the sixth embodiment of the present invention.

[0058] Figure 23 This is the front view of the seventh embodiment of the present invention.

[0059] Figure 24 This is a top view of the seventh embodiment of the present invention.

[0060] Figure 25 This is a schematic diagram of the filter group in the seventh embodiment of the present invention.

[0061] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0062] The two-dimensional array-type multi-port optical circulator of the present invention can realize the functions of multiple single multiport optical circulators. Using the optical circulator of the present invention can replace two or more single-port circulators, making the structure of the optical fiber communication system more compact.

[0063] First embodiment:

[0064] See Figure 3 and Figure 4 The two-dimensional array-type multi-port optical circulator in this embodiment is a dual-channel three-port optical circulator, comprising a collimator array 110, a first birefringent crystal 120, a half-wave plate group 130, a Faraday rotator 140, a second birefringent crystal 150, a quarter-wave plate 160, and a reflector 170. The quarter-wave plate 160 is the polarization state transformation device in this embodiment. In other embodiments, the polarization state transformation device can also be a Faraday rotator, the reflector 170 is the reflector in this embodiment, and the second birefringent crystal 150 serves as the beam combining and splitting device. Of course, in practical applications, a polarizing beam splitter prism can be used instead of the second birefringent crystal as the beam combining and splitting device.

[0065] Collimator array 110 includes two collimator arrays, each containing three collimators, thus forming a three-port single optical circulator. See also Figure 5 The first collimator array includes collimators 111, 112, and 113, and the second collimator array includes collimators 114, 115, and 116. For the first collimator array, the optical signal can only be transmitted unidirectionally from collimator 111 to collimator 112, and from collimator 112 to collimator 113, thus forming the function of one optical circulator. For the second collimator array, the optical signal can only be transmitted unidirectionally from collimator 114 to collimator 115, and from collimator 115 to collimator 116, thus forming the function of another optical circulator. Therefore, this embodiment can realize the function of two single optical circulators.

[0066] In this embodiment, all collimators 111, 112, 113, 114, 115, and 116 are located on the same side of the optical circulator, i.e., on the side with the negative Z-axis, and all collimators are arranged parallel to each other. Furthermore, for the first collimator array, the three collimators 111, 112, and 113 are arranged side-by-side, meaning their axes are aligned on the same straight line in the X-axis direction. For the second collimator array, the three collimators 114, 115, and 116 are arranged side-by-side, meaning their axes are aligned on the same straight line in the X-axis direction. Furthermore, the straight lines containing the axes of the three collimators in the first collimator array are parallel to but do not overlap with the straight lines containing the axes of the three collimators in the first collimator array. Therefore, the multiple collimators in the same collimator array are parallel to each other and arranged side by side, and the two collimator arrays are arranged in two rows. In this way, the multiple collimators extend in two directions in the two-dimensional direction, that is, there are more than two collimators along the X-axis and Y-axis.

[0067] In this embodiment, the collimator array 110 consists of a plurality of individual collimators. Specifically, each individual collimator includes a single lens and a single optical fiber. In other embodiments, the collimator array consists of an optical fiber array and a lens array, wherein the optical fiber array contains multiple optical fibers and the lens array contains multiple lenses.

[0068] For the first optical circulator, the optical signal propagates unidirectionally from collimator 111 to collimator 112, and then unidirectionally from collimator 112 to collimator 113, i.e., along the negative X-axis. For the second optical circulator, the optical signal propagates unidirectionally from collimator 114 to collimator 115, and then unidirectionally from collimator 115 to collimator 116, i.e., along the positive X-axis. Therefore, the optical signal propagation directions of multiple collimators in the two collimator arrays are opposite, or conversely, the optical signal propagation directions of multiple collimators in the two rows of collimator arrays are opposite.

[0069] The first birefringent crystal 120 is disposed on one side of the collimator array, specifically on the side of the collimator array along the positive Z-axis in this embodiment. All optical signals emitted from the collimators of the collimator array are transmitted to subsequent optical elements via the first birefringent crystal 120, and the optical signals passing through the first birefringent crystal 120 can be emitted to multiple collimators in the collimator array. In this embodiment, two individual optical circulators share one first birefringent crystal 120.

[0070] The half-wave plate group 130 is positioned on the side of the first birefringent crystal 120 away from the collimator array, specifically on the side of the first birefringent crystal 120 along the positive Z-axis. The half-wave plate group 130 comprises three half-wave plates 131, 132, and 133. (See attached diagram.) Figure 6 Three half-wave plates are stacked along the Y-axis, and the optical axes of the three half-wave plates 131, 132, and 133 are not exactly the same. Specifically, the optical axes of two adjacent half-wave plates are flipped in the horizontal direction. Therefore, the optical axes of half-wave plates 131 and 133 are the same, but the optical axis of half-wave plate 132 is flipped in the horizontal direction relative to the optical axes of half-wave plates 131 and 133.

[0071] It should be noted that the number of half-wave plates in the half-wave plate group 130 is related to the number of collimators arranged side by side in the collimator array 110. Assuming that the number of collimators arranged side by side is X rows, the number of half-wave plates is X+1, that is, the number of half-wave plates is the number of rows of collimators arranged side by side in the collimator array 110 plus 1.

[0072] A Faraday rotator 140, serving as an optical rotator, is disposed on the side of the half-wave plate group 130 away from the first birefringent crystal 120. A second birefringent crystal 150 is disposed on the side of the Faraday rotator 140 away from the half-wave plate group 130. A quarter-wave plate 160 is disposed on the side of the second birefringent crystal 150 away from the Faraday rotator 140. A reflector 170 is disposed on the side of the quarter-wave plate 160 away from the second birefringent crystal 150. It can be seen that the collimator array 110, the first birefringent crystal 120, the half-wave plate group 130, the Faraday rotator 140, the second birefringent crystal 150, the quarter-wave plate 160, and the reflector 170 are arranged sequentially in the optical path.

[0073] The following is combined Figure 7 The optical path of the transmitted optical signal after it enters port 111 is described. After the optical signal enters collimator 111, the resulting beam L10 is incident on the first birefringent crystal 120, forming two beams L11 and L12. Beam L11 is the ordinary ray (o-ray) in the first birefringent crystal 120, with its polarization direction parallel to the X-axis. Beam L12 is the extraordinary ray (e-ray) in the first birefringent crystal 120, with its polarization direction parallel to the Y-axis. After passing through the first birefringent crystal 120, beams L11 and L12 are separated by a certain distance along the Y-axis. Therefore, beams L11 and L12 pass through different positions of the half-wave plate group 130, from... Figure 7 As can be seen, beam L11 passes through half-wave plate 132, while beam L12 passes through half-wave plate 131. Since the optical axis directions of half-wave plates 131 and 132 are different, the polarization direction of beam L11 rotates counterclockwise by 45° after passing through half-wave plate 132, and the polarization direction of beam L12 rotates clockwise by 45° after passing through half-wave plate 131. At this time, the polarization directions of beams L11 and L12 are the same.

[0074] After passing through the half-wave plate group 130, beams L11 and L12 are incident on the Faraday rotator plate 140, where their polarization directions rotate 45° clockwise and become parallel to the X-axis. Next, beams L11 and L12 are incident on the second birefringent crystal 150, forming beams L13 and L14 respectively. Beams L13 and L14 are e-rays in the second birefringent crystal 150, with their propagation direction shifted towards the negative X-axis, but their polarization direction remains unchanged. After passing through the quarter-wave plate 160, beams L13 and L14 change from linearly polarized to circularly polarized light. Then, after passing through the quarter-wave plate 160, beams L13 and L14 are incident on the reflecting mirror 170 and reflected. Since beams L13 and L14 are incident perpendicularly on the reflecting mirror 170, they are reflected back to the quarter-wave plate 160 along their original path.

[0075] When the beams are incident on the quarter-wave plate 160 again, beams L13 and L14 form beams L15 and L16 respectively. Beams L15 and L16 change from circularly polarized light to linearly polarized light, with their polarization direction parallel to the Y-axis. At this time, beams L15 and L16 are o-light in the second birefringent crystal 150, with almost no shift in their propagation direction and no change in their polarization direction. After exiting the second birefringent crystal 150, beams L15 and L16 pass through the Faraday rotator plate 140 again, and their polarization direction rotates 45° clockwise. Then they pass through the half-wave plate group 130 again. At this time, beam L15 passes through half-wave plate 132, and its polarization direction rotates 45° clockwise, becoming parallel to the X-axis; beam L16 passes through half-wave plate 131, and its polarization direction rotates 45° counterclockwise, becoming parallel to the Y-axis.

[0076] After exiting the half-wave plate group 130, light beams L15 and L16 re-enter the first birefringent crystal 120 and form light beams L17 and L18 respectively. In the first birefringent crystal 120, L17 is the o-ray and L18 is the e-ray. After passing through the first birefringent crystal 120 again, L17 and L18 merge back into a single beam L19, which is received by the collimator 112, thereby realizing unidirectional transmission of the optical signal.

[0077] The optical path from collimator 112 to collimator 113 is the same as the optical path from collimator 111 to collimator 112. The optical signals also pass through half-wave plates 131 and 132 respectively. Therefore, for the first collimator array, the optical signals only use half-wave plates 131 and 132.

[0078] The following is combined Figure 8 The optical path of the transmitted optical signal after it enters through port 114 is described. After the optical signal enters through collimator 114, the resulting beam L20 is incident on the first birefringent crystal 120, forming two beams L21 and L22. Beam L21 is the ordinary ray (o-ray) in the first birefringent crystal 120, with its polarization direction parallel to the X-axis. Beam L22 is the extraordinary ray (e-ray) in the first birefringent crystal 120, with its polarization direction parallel to the Y-axis. After passing through the first birefringent crystal 120, beams L21 and L22 are separated by a certain distance along the Y-axis. Therefore, beams L21 and L22 pass through different positions of the half-wave plate group 130, from... Figure 8 As can be seen, beam L21 passes through half-wave plate 133, while beam L22 passes through half-wave plate 132. Since the optical axis directions of half-wave plates 132 and 133 are different, after beam L21 passes through half-wave plate 133, its polarization direction rotates 45° clockwise, and after beam L22 passes through half-wave plate 132, its polarization direction rotates 45° counterclockwise. At this time, the polarization directions of beams L21 and L22 are the same.

[0079] After passing through the half-wave plate group 130, beams L21 and L22 are incident on the Faraday rotator plate 140, where their polarization directions rotate 45° clockwise and become parallel to the Y-axis. Next, beams L21 and L22 are incident on the second birefringent crystal 150, forming beams L23 and L24 respectively. Beams L23 and L24 are o-beams in the second birefringent crystal 150, with almost no shift in their propagation direction and no change in their polarization direction. After passing through the quarter-wave plate 160, beams L23 and L24 change from linearly polarized to circularly polarized light. Then, after passing through the quarter-wave plate 160, beams L23 and L24 are incident on the reflector 170 and reflected. Since beams L23 and L24 are incident perpendicularly on the reflector 170, they are reflected back to the quarter-wave plate 160 along their original path.

[0080] When the beams are incident on the quarter-wave plate 160 again, beams L23 and L24 form beams L25 and L26 respectively. Beams L25 and L26 change from circularly polarized light to linearly polarized light, with their polarization direction parallel to the X-axis. At this time, beams L25 and L26 are e-rays in the second birefringent crystal 150, with their propagation direction shifted towards the positive X-axis, but their polarization direction remains unchanged. After exiting the second birefringent crystal 150, beams L25 and L26 pass through the Faraday rotator plate 140 again, and their polarization direction rotates 45° clockwise. Then they pass through the half-wave plate group 130 again. At this time, beam L25 passes through half-wave plate 133, and its polarization direction rotates 45° counterclockwise, becoming parallel to the X-axis; beam L26 passes through half-wave plate 132, and its polarization direction rotates 45° clockwise, becoming parallel to the Y-axis.

[0081] After exiting the half-wave plate group 130, light beams L25 and L26 are incident again on the first birefringent crystal 120 and form light beams L27 and L28 respectively. In the first birefringent crystal 120, L27 is the o-ray and L28 is the e-ray. After passing through the first birefringent crystal 120 again, L27 and L28 are combined again into a single beam L29, which is received by the collimator 115, thereby realizing the unidirectional transmission of the optical signal.

[0082] The optical path from collimator 115 to collimator 116 is the same as the optical path from collimator 114 to collimator 115. The optical signals also pass through half-wave plates 132 and 133 respectively. Therefore, for the second collimator array, the optical signals only use half-wave plates 132 and 133.

[0083] As can be seen, both the beam transmitted by the first collimator array and the beam transmitted by the second collimator array pass through the half-wave plate 132. Therefore, the two collimator arrays share the half-wave plate 132, which can reduce the volume of the optical circulator.

[0084] Second embodiment:

[0085] See Figure 9 and Figure 10 The two-dimensional array multi-port optical circulator in this embodiment is a dual-channel three-port optical circulator. A collimator array 210, a first birefringent crystal 220, a half-wave plate group 230, a Faraday rotator 240, a second birefringent crystal 250, a quarter-wave plate 260, and a reflector 270 are arranged sequentially on the optical path.

[0086] The collimator array 210 includes two sets of collimator arrays, each set comprising three collimators, forming a three-port single optical circulator. See also Figure 11 The first collimator array includes collimators 211, 212, and 213, and the second collimator array includes collimators 214, 215, and 216. For the first collimator array, the optical signal can only be transmitted unidirectionally from collimator 211 to collimator 212, and from collimator 212 to collimator 213, thus forming the function of one optical circulator. For the second collimator array, the optical signal can only be transmitted unidirectionally from collimator 214 to collimator 215, and from collimator 215 to collimator 216, thus forming the function of another optical circulator. Therefore, this embodiment can realize the function of two single optical circulators.

[0087] Unlike the first embodiment, in this embodiment, the six collimators 211, 212, 213, 214, 215, and 216 of the collimator array 210 are arranged in a straight line, as shown below. Figure 11 As shown, the central axes of the six collimators 211, 212, 213, 214, 215, and 216 are arranged in a straight line along the X-axis, and the six collimators 211, 212, 213, 214, 215, and 216 are arranged parallel to each other. Correspondingly, the half-wave plate group 230 is provided with two half-wave plates 231 and 232, as shown... Figure 12 As shown, two half-wave plates 231 and 232 are stacked along the Y-axis, and the optical axes of the two half-wave plates 231 and 232 are flipped along the horizontal direction.

[0088] The optical path of the light signal emitted from collimator 211 being unidirectionally transmitted to collimator 212 is the same as that of the light signal emitted from collimator 111 being unidirectionally transmitted to collimator 112 in the first embodiment, and will not be described again. The optical paths of the light signals incident from other collimators are also transmitted along the same optical path.

[0089] Furthermore, this embodiment can also be used as an array-type three-way optical isolator. The collimator array 210 includes three sets of collimator arrays, each set including two collimators, forming a unidirectional optical isolator. The first set of collimator arrays includes collimators 211 and 212, the second set includes collimators 213 and 214, and the third set includes collimators 215 and 216. For the first set of collimator arrays, the optical signal can only be transmitted unidirectionally from collimator 211 to collimator 212, forming the function of the first optical isolator; for the second set of collimator arrays, the optical signal can only be transmitted unidirectionally from collimator 213 to collimator 214, forming the function of the second optical isolator; for the third set of collimator arrays, the optical signal can only be transmitted unidirectionally from collimator 215 to collimator 216, forming the function of the third optical isolator. Therefore, this embodiment can realize the function of three single optical isolators, which is equivalent to integrating three devices with the function of a single optical isolator onto one optical device.

[0090] Third embodiment:

[0091] See Figure 13 and Figure 14 The two-dimensional array multi-port optical circulator in this embodiment is a four-way three-port optical circulator. A collimator array 310, a first birefringent crystal 320, a half-wave plate group 330, a Faraday rotator 340, a second birefringent crystal 350, a quarter-wave plate 360, and a reflector 370 are arranged sequentially on the optical path.

[0092] The collimator array 310 includes four collimator arrays, each containing three collimators, forming a three-port single optical circulator. See also Figure 15The first collimator array includes collimators 311, 312, and 313; the second collimator array includes collimators 314, 315, and 316; the third collimator array includes collimators 317, 318, and 319; and the fourth collimator array includes collimators 321, 322, and 323. For the first collimator array, the optical signal can only be transmitted unidirectionally from collimator 311 to collimator 312, and from collimator 312 to collimator 313, thus forming the function of an optical circulator. For the second collimator array, the optical signal can only be transmitted unidirectionally from collimator 314 to collimator 315, and from collimator 315 to collimator 316, thus forming the function of another optical circulator. For the third collimator array, the optical signal can only be transmitted unidirectionally from collimator 317 to collimator 318, and from collimator 319 to collimator 319, thus forming the function of an optical circulator. For the fourth collimator array, the optical signal can only be transmitted unidirectionally from collimator 321 to collimator 322, and from collimator 322 to collimator 323, thus forming the function of another optical circulator. Therefore, this embodiment can realize the function of four individual optical circulators.

[0093] Compared to the first embodiment, in this embodiment, the twelve collimators of the collimator array 310 are arranged in two straight lines, such as... Figure 15 As shown, the twelve collimators are arranged in parallel, and their central axes are aligned in two straight lines along the X-axis. In this embodiment, the half-wave plate group 330 is provided with three half-wave plates 331, 332, and 333, as shown... Figure 16 As shown, three half-wave plates 331, 332 and 333 are stacked along the Y-axis, and the optical axes of two adjacent half-wave plates are horizontally flipped. Therefore, the optical axes of half-wave plates 331 and 333 are the same.

[0094] The optical path from which the light signal emitted from collimator 311 is unidirectionally transmitted to collimator 312 is the same as the optical path from which the light signal emitted from collimator 111 is unidirectionally transmitted to collimator 112 in the first embodiment. The optical path from which the light signal emitted from collimator 317 is unidirectionally transmitted to collimator 318 is the same as the optical path from which the light signal emitted from collimator 114 is unidirectionally transmitted to collimator 115 in the first embodiment, and will not be described again.

[0095] Fourth embodiment:

[0096] See Figure 17 and Figure 18This embodiment of the two-dimensional array-type multi-channel multi-port optical circulator is a dual-channel three-port optical circulator. Along the optical path, a collimator array 410, a first birefringent crystal 420, a half-wave plate group 430, a Faraday rotator 440, a second birefringent crystal 450, a quarter-wave plate 460, a beam splitter 470, and a photodetector array 480 are sequentially arranged. Compared to the first embodiment, this embodiment does not include a reflector, but instead uses a beam splitter 470 and a photodetector array 480. The beam splitter 470 reflects most of the optical signal and transmits a small portion. The transmitted optical signal passes through the beam splitter 470 and enters the photodetector array 480. The photodetector array 480 is equipped with multiple photodetectors 481 and 482. Preferably, the number of photodetectors is four, arranged in a 2×2 matrix.

[0097] The collimator array 410 includes six collimators, namely collimators 411, 412, 413, and 416. The arrangement of these collimators is the same as in the first embodiment, i.e., a 3×2 arrangement. Collimators 411, 412, and 413 form the three ports of a three-port optical circulator, while the other three collimators form the three ports of another three-port optical circulator. Furthermore, the half-wave plate group 430 includes three half-wave plates 431, 432, and 433, arranged in the same manner as in the first embodiment.

[0098] The optical path from collimator 411 to collimator 412 is basically the same as that in the first embodiment, the optical signal from collimator 111 to collimator 112 is transmitted unidirectionally. The difference is that in this embodiment, after the optical signal is incident on the beam splitter 470, most of the optical signal is reflected back to the quarter-wave plate 460, and a small portion of the optical signal is transmitted and passes through the beam splitter 470 and is incident on the photodetector array 480. One of the photodetectors in the photodetector array 480 detects the optical power of the optical signal passing through the beam splitter 470, thereby realizing the function of the optical circulator and the photodetector combination.

[0099] Fifth embodiment:

[0100] See Figure 19 and Figure 20This embodiment of the two-dimensional array-type multi-port optical circulator is a single-channel six-port optical circulator. Along the optical path, a collimator array 510, a first birefringent crystal 520, a half-wave plate group 530, a Faraday rotator 540, a second birefringent crystal 550, a quarter-wave plate 560, a beam splitter 570, and a photodetector array 580 are sequentially arranged. Compared to the second embodiment, this embodiment does not use a reflector, but instead uses a beam splitter 570 and a photodetector array 580. The beam splitter 570 reflects most of the optical signal and transmits a small portion. The transmitted optical signal passes through the beam splitter 570 and enters the photodetector array 580. The photodetector array 580 is equipped with multiple photodetectors; preferably, there are four photodetectors arranged side-by-side along the X-axis.

[0101] The collimator array 510 is provided with six collimators, including collimators 511, 512, 513, 514, 515, and 516, arranged in the same manner as in the second embodiment. Collimators 511, 512, and 513 form the three ports of a three-port optical circulator, while the other three collimators 514, 515, and 516 form the three ports of another three-port optical circulator. Furthermore, the half-wave plate group 530 includes two half-wave plates.

[0102] The optical path from collimator 511 to collimator 512 is basically the same as that in the second embodiment, the optical path from collimator 211 to collimator 212 is also basically the same. The difference is that after the optical signal is incident on the beam splitter 570, most of the optical signal is reflected back to the quarter-wave plate 560, and a small portion of the optical signal is transmitted and passes through the beam splitter 570 and is incident on the photodetector array 580. The photodetector in the photodetector array 580 detects the optical power of the optical signal passing through the beam splitter 570, thereby realizing the function of the optical circulator and the photodetector combination.

[0103] Sixth embodiment:

[0104] See Figure 21 and Figure 22This embodiment of the two-dimensional array-type multi-port optical circulator is a four-way three-port optical circulator. Along the optical path, a collimator array 610, a first birefringent crystal 620, a half-wave plate group 630, a Faraday rotator 640, a second birefringent crystal 650, a quarter-wave plate 660, a beam splitter 670, and a photodetector array 680 are sequentially arranged. Compared to the third embodiment, this embodiment does not use a reflector, but instead uses a beam splitter 670 and a photodetector array 680. The beam splitter 670 reflects most of the optical signal and transmits a small portion. The transmitted optical signal passes through the beam splitter 670 and enters the photodetector array 680. The photodetector array 680 has multiple photodetectors; preferably, there are eight photodetectors arranged in a 4×2 matrix.

[0105] The collimator array 610 has twelve collimators, with three collimators forming the three ports of a single optical circulator. The arrangement of the collimators is the same as in the third embodiment. Furthermore, the half-wave plate group 630 includes three half-wave plates, arranged in the same way as in the third embodiment.

[0106] The optical path from collimator 611 to collimator 612 is basically the same as that in the third embodiment, the optical path from collimator 311 to collimator 312 is also basically the same. The difference is that after the optical signal is incident on the beam splitter 670, most of the optical signal is reflected back to the quarter-wave plate 660, and a small portion of the optical signal passes through the beam splitter 670 and is incident on the photodetector array 680. The photodetector in the photodetector array 680 detects the optical power of the optical signal passing through the beam splitter 670, thereby realizing the function of the optical circulator and the photodetector combination.

[0107] Seventh embodiment:

[0108] See Figure 23 and Figure 24 This embodiment is a single-path three-port optical circulator, in which a collimator array 710, a first birefringent crystal 720, a half-wave plate group 730, a Faraday rotator 740, a second birefringent crystal 750, a quarter-wave plate 760, a filter group 770, and a reflector 780 are sequentially arranged along the optical path. The structure of the filter group is as follows: Figure 25 The filter group 770 of this embodiment includes two adjacent filters 771 and 772, wherein filter 771 can only pass light signals with wavelength λ1, while filter 772 can only pass light signals with wavelength λ2.

[0109] Furthermore, each filter 771 and 772 is positioned on an optical path corresponding to a single circulator. Specifically, filter 771 is positioned on the optical path of the single circulator that exits from collimator 711 and is transmitted to collimator 712, while filter 772 is positioned on the optical path of the single circulator that exits from collimator 712 and is transmitted to collimator 713. In this way, the two filters 771 and 772 filter the optical signals on different optical paths respectively.

[0110] The optical path from collimator 711 to collimator 712 is essentially the same as that in the third embodiment, where the optical signal from collimator 311 is unidirectionally transmitted to collimator 312. The difference is that in this embodiment, after the optical signal is incident on filter 771, only the optical signal with wavelength λ1 can pass through. The optical signal passing through filter 771 continues to be transmitted after passing through mirror 780. Thus, the optical signal emitted from collimator 712 contains only the optical signal with wavelength λ1, achieving the filtering function.

[0111] Similarly, the optical signal emitted from collimator 712 is unidirectionally transmitted into the optical path of collimator 713. After the optical signal enters the filter 772, only the optical signal with wavelength λ2 can pass through. The optical signal passing through filter 772 continues to be transmitted after passing through mirror 780. The optical signal emitted from collimator 713 contains only the optical signal with wavelength λ2. It can be seen that this embodiment can not only realize the function of an optical circulator, that is, realize the unidirectional transmission of optical signals, but also realize the function of filtering, that is, realize the function of a filterable optical circulator.

[0112] Of course, in other embodiments, the wavelengths filtered by the two filters can also be the same, for example, both of which only allow light signals with a wavelength of λ1 to pass through.

[0113] The optical circulator of the present invention can be configured with a collimator array in a two-dimensional direction, making the structure of the optical circulator more compact. Furthermore, the use of the same first birefringent crystal and other devices for multiple collimators facilitates the miniaturization of the optical circulator. In addition, the present invention only requires one set of half-wave plates and polarization state transformation devices, such as a quarter-wave plate, resulting in a smaller number of wave plates and further reducing the size of the optical circulator.

[0114] In practical applications, this invention has many other implementations. For example, a quarter-wave plate can be equivalently replaced by a wave plate of order (2n+1)×(1 / 4), where n is a positive integer. Alternatively, the optical circulator can be configured as a three-, four-, six-, or any number of multi-port circulators. Furthermore, the number of ports of the optical circulator is not limited to three ports; it can be four-port, six-port, etc.

[0115] Of course, the above-described scheme is only a preferred embodiment of the present invention. In actual application, there are many more changes, such as changes in the arrangement of each collimator array in the optical circulator. Such changes should also be included within the scope of protection of the claims of the present invention.

Claims

1. A two-dimensional array-type multi-channel multi-port optical circulator, characterized in that: include Two or more collimator arrays, each of which includes three collimators, with multiple collimators in the same group located on the same side of the optical circulator, the multiple collimators in the same group arranged parallel to each other and side by side, and the multiple collimator arrays arranged in two or more rows. A first birefringent crystal is disposed on one side of the collimator array, and the optical signals of multiple collimator arrays all pass through the first birefringent crystal; A half-wave plate group is disposed on the side of the first birefringent crystal away from the collimator array, and the half-wave plate group is provided with two or more half-wave plates; An optical rotator is disposed on the side of the half-wave plate group away from the first birefringent crystal, and a beam combining and splitting device is disposed on the side of the optical rotator away from the half-wave plate group. A polarization state conversion device is disposed on the side of the beam combining and splitting device away from the beam rotating device; A reflective device is disposed on the side of the polarization state conversion device away from the optical rotator; The half-wave plate group is provided with multiple half-wave plates. The number of half-wave plates is the number of rows of collimators arranged side by side in the collimator array plus 1. Multiple half-wave plates are stacked. The optical axes of two adjacent half-wave plates are flipped in the horizontal direction, and the optical signal propagation direction of multiple collimators in the first row is opposite to the optical signal propagation direction of multiple collimators in the second row.

2. The two-dimensional array type multi-channel multi-port optical circulator according to claim 1, characterized in that: The reflective device is a beam splitter, and a photodetector array is disposed on the side of the beam splitter away from the polarization state conversion device.

3. The two-dimensional array-type multi-channel multi-port optical circulator according to claim 1, characterized in that: A filter group is provided between the reflective device and the polarization state conversion device. The filter group has one or more filters, and each filter is arranged on the optical path corresponding to a single circulator.

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