Optical passive module and device with same

Abstract

The embodiment of the invention provides an optical passive module and a device with the optical passive module, relates to the technical field of optical communication equipment, and aims to solve the problem that the transmission distance of an optical module adopting a multi-mode light source is limited. The optical passive module comprises at least one coupling element and a diffractive optical element. Wherein a coupling element in the optical passive module is used for adjusting a larger light spot of an optical signal into a smaller light spot matched with a target optical fiber, and the target optical fiber is a single-mode optical fiber or a multimode optical fiber; the diffractive optical element is of a micro-nano structure arranged on at least one coupling element. The optical passive module can be applied to an optical transmitting assembly, an optical module and communication equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical communication equipment, and in particular to an optical passive module and a device having the same. BACKGROUND

[0002] An optical module is a signal transmission device capable of realizing photoelectric and electro-optical conversion, which can convert an electrical signal into an optical signal at the sending end and convert an input optical signal into an electrical signal at the receiving end.

[0003] In some optical modules, a multimode light source such as a vertical-cavity surface-emitting laser (VCSEL) or a light emitting diode (LED) is used at the sending end. The multimode light source can generate a plurality of transverse mode optical signals, and therefore a multimode optical fiber is usually used to couple with the multimode light source. In the multimode optical fiber, dozens or even hundreds of transverse mode modes can be supported for simultaneous transmission.

[0004] However, different transverse mode optical signals have different transmission speeds in the multimode optical fiber, and when reaching the end of the multimode optical fiber, they need to pass through different time lengths, thereby forming intermodal dispersion. The intermodal dispersion will affect the quality of the transmitted signal, and the higher the communication rate and the longer the transmission distance, the greater the influence of the intermodal dispersion on the signal quality. Therefore, the transmission distance of the optical module using the multimode light source is very limited. SUMMARY

[0005] Embodiments of the present application provide an optical passive module and a device having the same, which are used to solve the problem of limited transmission distance of the optical module using the multimode light source.

[0006] To achieve the above-mentioned purpose, embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an optical passive module is provided, which includes at least one coupling element and a diffractive optical element; wherein the coupling element in the optical passive module is used to adjust a larger light spot of an optical signal into a smaller light spot matched with a target optical fiber, and the target optical fiber is a single-mode optical fiber or a multimode optical fiber; and the diffractive optical element is a micro-nano structure arranged on the at least one coupling element.

[0008] This design offers several advantages. First, it allows for phase modulation of the optical signal using diffractive optical elements, achieving mode transfer. This mode transfer improves intermodal dispersion when the passive optical module is used for coupling a multimode light source to the target fiber, thus extending the transmission distance of optical modules employing multimode light sources. Second, by integrating the diffractive optical elements onto the coupling element, the original coupling element is combined into a single component. This design offers advantages such as simple structure, ease of implementation, and minimal impact on the shape and size of the passive optical module.

[0009] In some embodiments, the diffractive optical element is used to convert at least a portion of the optical signals of higher-order transverse modes into fundamental mode spots with different offsets relative to the center of the optical path; wherein, the higher-order transverse modes include the transverse mode of the fundamental mode.

[0010] Fundamental mode spots with different offsets relative to the optical path center can be coupled to low-order modules (such as LP01 mode, LP11a mode and LP11b mode) supported by the target optical fiber for transmission. This can reduce the number of high-order transverse modes through mode transfer, thereby improving the intermodal dispersion problem and facilitating the expansion of the transmission distance of optical modules using multimode light sources.

[0011] In some embodiments, the diffractive optical element is used to maintain the mode of any transverse mode optical signal in the first module and to convert any transverse mode optical signal in the second module into a fundamental mode light spot with different offsets relative to the optical path center; wherein, the fundamental mode light spot is a light spot of LP01 mode, the first module includes LP01 mode, LP11a mode and LP11b mode, and the second module includes transverse mode modes outside the first module.

[0012] In the passive optical module provided in this application embodiment, diffractive optical elements can couple optical signals of different transverse modes into the LP01, LP11a, and LP11b modes of the target optical fiber for transmission. This design reduces the number of modes in the target optical fiber, and because the intermodal dispersion between the LP01, LP11a, and LP11b modes is relatively small, it significantly improves the intermodal dispersion problem, which is beneficial for significantly extending the transmission distance of optical modules using multimode light sources. Furthermore, it is applicable to scenarios where the target optical fiber is both single-mode and multimode, demonstrating good adaptability.

[0013] In some embodiments, the diffractive optical element is used to maintain the mode of the optical signal in the LP01 mode and to convert optical signals of different higher-order transverse modes into fundamental mode spots with different offsets relative to the center of the optical path; wherein the fundamental mode spot is the LP01 mode spot and the higher-order transverse modes include transverse mode modes other than the LP01 mode.

[0014] In the passive optical module provided in this application embodiment, diffractive optical elements can couple optical signals of different transverse modes into the LP01, LP11a, and LP11b modes of the target optical fiber for transmission. This design reduces the number of modes in the target optical fiber, and because the intermodal dispersion between the LP01, LP11a, and LP11b modes is relatively small, it significantly improves the intermodal dispersion problem, which is beneficial for significantly extending the transmission distance of optical modules using multimode light sources. Furthermore, it is applicable to scenarios where the target optical fiber is both single-mode and multimode, demonstrating good adaptability.

[0015] In some embodiments, the target optical fiber is a multimode optical fiber; the diffractive optical element is used to maintain the mode of any transverse mode optical signal in the third module and to convert any transverse mode optical signal in the fourth module into a fundamental mode spot with different offsets relative to the optical path center; wherein, the fundamental mode spot is an LP01 mode spot, the third module includes the LP31 mode and transverse mode modes lower than the LP31 mode; the fourth module includes transverse mode modes other than the third module.

[0016] In the passive optical module provided in this application embodiment, diffractive optical elements can couple optical signals of different transverse modes into lower-order modes of the multimode fiber for transmission. This design reduces the number of modes in the multimode fiber, ensuring that all are lower-order modes, significantly reducing intermodal dispersion compared to multimode fibers in related technologies. This substantially improves intermodal dispersion and facilitates a significant increase in the transmission distance of optical modules using multimode light sources. Furthermore, it is applicable to scenarios where the target fiber is either single-mode or multimode fiber, demonstrating good adaptability.

[0017] In some embodiments, the target fiber is a single-mode fiber, with the fundamental mode spot offset from the optical path center by less than 4.5 micrometers; or, the target fiber is a multimode fiber, with the fundamental mode spot offset from the optical path center by less than 10 micrometers. This design ensures efficient coupling between the fundamental mode spot offset from the optical path center and the target fiber. Furthermore, when the target fiber is a multimode fiber, it facilitates coupling the fundamental mode spot offset from the optical path center into lower-order modes within the multimode fiber for transmission, thereby mitigating intermodal dispersion.

[0018] In some embodiments, the diffractive optical element includes: a micro / nano structure integrally formed with the coupling element; or a micro / nano structure fabricated on the coupling element; or a micro / nano structure mounted on the coupling element.

[0019] In the passive optical module provided in this application embodiment, diffractive optical elements and coupling elements can be integrated together in a variety of different ways, with a simple structure, flexible implementation, and the ability to adapt to different process scenarios.

[0020] In some embodiments, the diffractive optical element includes a plurality of stepped or sawtooth structures of different heights; or, the diffractive optical element includes a microstructure array, which includes a plurality of microstructures arranged in an array.

[0021] In the passive optical module provided in this application embodiment, the diffractive optical element can be formed using a variety of different structures. The structure is simple, the implementation is flexible, and it can adapt to different process scenarios.

[0022] In some embodiments, the microstructures include cylindrical, conical, frustum-shaped, prism-shaped, frustum-shaped, pyramidal, or hemispherical protrusions or grooves; at different locations of the coupling element, the multiple microstructures in the microstructure array have different arrangement rules; the arrangement rules include the shape, size, and arrangement density of the microstructures.

[0023] In the passive optical module provided in this application embodiment, the diffractive optical element can adopt a variety of different microstructure arrays, which are simple in structure, flexible in implementation, and can adapt to different process scenarios.

[0024] In some embodiments, the passive optical module includes two coupling elements, a collimating lens and a focusing lens, with a diffractive optical element disposed on at least one of the collimating lens and the focusing lens. This design allows for the adaptation of passive optical modules with collimating and focusing lenses, achieving the aforementioned technical effects in such passive optical modules.

[0025] In some embodiments, the passive optical module includes three coupling elements: a collimating lens, a reflecting structure, and a focusing lens, with a diffractive optical element disposed on at least one of the collimating lens, reflecting structure, and focusing lens. This design allows for adaptation to passive optical modules with collimating lenses, reflecting structures, and focusing lenses, achieving the aforementioned technical effects in such passive optical modules. Furthermore, the reflecting structure allows for changing the transmission direction of the optical signal in the passive optical module, thus enabling its application in different scenarios; for example, it can be used in scenarios where the emission direction of the multimode light source differs from the coupling direction of the target optical fiber.

[0026] Secondly, embodiments of this application also provide a passive optical module, which includes at least one coupling element and a diffractive optical element; wherein, the coupling element in the passive optical module is used to adjust a larger spot of the optical signal into a smaller spot that matches the target optical fiber, and the target optical fiber is a single-mode optical fiber or a multimode optical fiber.

[0027] A diffractive optical element, which is a device disposed separately from any of the coupling elements, is used to convert at least a portion of the optical signals of higher-order transverse modes into fundamental mode spots with different offsets relative to the center of the optical path; wherein, higher-order transverse modes include transverse modes other than the fundamental mode.

[0028] This design offers several advantages. First, it allows for phase modulation of the optical signal using diffractive optical elements, achieving mode transfer. This enables the passive optical module to improve intermodal dispersion when used for coupling multimode light sources to target optical fibers, thus extending the transmission distance of optical modules employing multimode light sources. Second, the diffractive optical elements are discrete devices, offering greater flexibility in implementation and avoiding interference with coupling elements, while also reducing the complexity of integrating them into the coupling elements.

[0029] In some embodiments, the diffractive optical element includes a plurality of stepped or sawtooth structures of different heights; or, the diffractive optical element includes a microstructure array, which includes a plurality of microstructures arranged in an array.

[0030] In the passive optical module provided in this application embodiment, the diffractive optical element can be formed using a variety of different structures. The structure is simple, the implementation is flexible, and it can adapt to different process scenarios.

[0031] Thirdly, embodiments of this application also provide an optical emitting component, which includes a multimode light source and a passive optical module as described in the first or second aspect embodiments: wherein the multimode light source is a vertical cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals.

[0032] The passive optical module is located on the light-emitting side of the multimode light source and is used to couple the optical signal to the target optical fiber; wherein the target optical fiber is a single-mode optical fiber or a multimode optical fiber.

[0033] Fourthly, this application also provides an optical module, which includes a first circuit board, an optical fiber interface, and an optical emitting component as described in the third aspect embodiment; wherein, the first circuit board is provided with an electrical interface; the optical emitting component is electrically connected to the first circuit board and connected to the optical fiber interface.

[0034] Fifthly, embodiments of this application also provide an optical module, which includes a first circuit board, a multimode light source, an optical fiber interface, and a passive optical module as described in the first or second aspect embodiments; wherein, an electrical interface is provided on the first circuit board; the multimode light source is a vertical cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals; the multimode light source is electrically connected to the first circuit board; and the passive optical module is disposed between the multimode light source and the optical fiber interface.

[0035] In a sixth aspect, embodiments of this application also provide an active optical module, which includes a first circuit board and an optical emitting component as described in the third aspect embodiment; wherein the optical emitting component is electrically connected to the first circuit board.

[0036] In a seventh aspect, embodiments of this application also provide an active optical module, which includes a first circuit board, a multimode light source, and a passive optical module as described in the first or second aspect embodiments; wherein, the multimode light source is a vertical cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals; the multimode light source is electrically connected to the first circuit board; and the passive optical module is disposed on the light-emitting side of the multimode light source.

[0037] Eighthly, embodiments of this application also provide a communication device, which includes a second circuit board and an active optical module as described in the sixth or seventh aspect embodiments; wherein the active optical module is located inside the communication device and is electrically connected to the second circuit board.

[0038] In a ninth aspect, embodiments of this application also provide a communication device, which includes a second circuit board, a pluggable interface, and an optical module as described in the fourth or fifth aspect embodiments; wherein the pluggable interface is electrically connected to the second circuit board and exposed to the outside of the communication device; and the optical module is connected to the pluggable interface.

[0039] The technical effects achievable by the optical emitting components, optical modules, active optical modules, and communication devices provided in this application are the same as those achievable by the passive optical modules in any of the above embodiments, and will not be repeated here. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of an optical module provided in an embodiment of this application;

[0041] Figure 2 for Figure 1 Schematic diagram of the structure of the optical emission component;

[0042] Figure 3 This is a schematic diagram of another optical module provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the structure of a passive optical module provided in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the structure of a diffractive optical element provided in an embodiment of this application;

[0045] Figure 6 This is a schematic diagram of another diffractive optical element provided in an embodiment of this application;

[0046] Figure 7 A schematic diagram of mode transfer for a diffractive optical element provided in an embodiment of this application;

[0047] Figure 8A schematic diagram of mode transfer for another diffractive optical element provided in an embodiment of this application;

[0048] Figure 9 This is a schematic diagram of another passive optical module provided in an embodiment of this application;

[0049] Figure 10 This is a schematic diagram of the structure of another passive optical module provided in the embodiments of this application;

[0050] Figure 11 This is a schematic diagram of the structure of another passive optical module provided in the embodiments of this application;

[0051] Figure 12 A diagram illustrating an optical communication architecture for a data center or AI cluster, provided as an embodiment of this application;

[0052] Figure 13 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0053] Figure 14 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0054] In short-range (SR) optical communication scenarios such as data centers or AI (Artificial Intelligence) clusters, optical modules (hereinafter referred to as VCSEL optical modules) using vertical-cavity surface-emitting lasers (VCSELs) as light sources are typically used to achieve short-range interconnection.

[0055] VCSELs are multimode light sources capable of generating multiple transverse mode optical signals. Therefore, multimode fiber is typically used to connect VCSEL optical modules. Multimode fiber can support the simultaneous transmission of dozens or even hundreds of transverse mode modes. However, different transverse mode optical signals have different transmission speeds within multimode fiber, requiring varying transit times to reach the fiber end, resulting in intermodal dispersion. Intermodal dispersion affects the quality of the transmitted signal, and the higher the communication rate and the greater the transmission distance, the greater the impact of intermodal dispersion on signal quality. Consequently, the transmission distance of VCSEL optical modules is very limited; for example, the transmission distance of a 400G SR8 optical module is typically limited to only 100m.

[0056] Based on this, embodiments of this application provide a passive optical module and an apparatus having the passive optical module to improve the above-mentioned problems.

[0057] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0058] In the following embodiments of this application, the terms "first," "second," etc., are used for descriptive convenience only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0059] In the embodiments of this application, "upper", "lower", "left" and "right" are not limited to the orientation of the components in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0060] In the embodiments of this application, unless the context otherwise requires, the term "comprising" is interpreted as open and encompassing throughout the specification and claims, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "exemplarily," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0061] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0062] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0063] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0064] Exemplary embodiments are described in this application with reference to cross-sectional views and / or plan views and / or equivalent circuit diagrams, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0065] This application provides an optical module, which is a signal transmission device capable of photoelectric and electro-optic conversion. At the transmitting end, it can convert electrical signals into optical signals and output them, and at the receiving end, it can convert input optical signals into electrical signals.

[0066] Figure 1 This is a schematic diagram of the structure of an optical module 100 provided in an embodiment of this application, as shown below. Figure 1 As shown, the optical module 100 includes a first circuit board, a Transmitter Optical Subassembly (TOSA) 110, a Receiver Optical Subassembly (ROSA) 120, and an optical fiber interface 140. The transmitter optical subassembly 110 converts electrical signals into optical signals, and the Receiver optical subassembly 120 converts optical signals into electrical signals.

[0067] Both the optical transmitting component 110 and the optical receiving component 120 are connected to the optical fiber interface 140 via connecting optical fibers, and the optical fiber interface 140 is used to connect to an external optical fiber. The optical transmitting component 110 can transmit the generated optical signal to the external optical fiber through the connecting optical fiber and the optical fiber interface 140, and the optical receiving component 120 can receive the optical signal input from the external optical fiber through the connecting optical fiber and the optical fiber interface 140.

[0068] Both the optical emitting component 110 and the optical receiving component 120 are electrically connected to a first circuit board, which integrates a signal processing circuit 130. During the signal transmission phase, the signal processing circuit 130 can output a driving signal to the optical emitting component 110 based on an electrical signal, and the optical emitting component 110 generates an optical signal corresponding to the electrical signal under the control of the driving signal. During the signal receiving phase, the signal processing circuit 130 can also convert the photodetector signal generated by the optical receiving component 120 based on the optical signal into an electrical signal and output it.

[0069] The first circuit board is also equipped with an electrical interface, which is exposed on the outside of the optical module 100 and is used to realize the input and output of electrical signals in the optical module 100.

[0070] Figure 2 for Figure 1 A schematic diagram of the structure of the optical emission component 110 is shown below. Figure 2 As shown, the optical emitting component 110 includes a multimode light source 111 and a passive optical module 1. The multimode light source 111 can be a vertical-cavity surface-emitting laser (VCSEL) or a light-emitting diode (LED). The multimode light source 111 can generate multiple transverse mode optical signals.

[0071] In this paper, the transverse mode of an optical signal is characterized by linearly polarized (LP) modes. The optical signal generated by the multimode source 111 can be, for example, the LP01 mode (fundamental mode), LP11a mode, LP11b mode, LP21a mode, LP21b mode, LP31a mode, and LP31b mode. For ease of description, the LP01 mode is referred to as the fundamental mode in this paper. Other transverse modes besides the LP01 mode (fundamental mode) are collectively referred to as higher-order transverse modes, such as the LP11a mode, LP11b mode, LP21a mode, LP21b mode, LP31a mode, and LP31b mode.

[0072] The passive optical module 1 is located on the light-emitting side of the multimode light source 111 and is used to couple the optical signal generated by the multimode light source 111 to the connecting optical fiber. The optical signal is then transmitted to the external optical fiber through the connecting optical fiber and the optical fiber interface 140. In this case, the connecting optical fiber is the target optical fiber 2 of the passive optical module 1.

[0073] In some embodiments, the connecting optical fiber is connected to the optical emitting assembly 110 in the form of a pigtail. In this case, the optical emitting assembly 110 includes a multimode light source 111, a passive optical module 1, and a pigtail (connecting optical fiber).

[0074] In some other embodiments, there may be no connecting optical fiber between the optical transmitting component 110 and the optical fiber interface 140. The passive optical module 1 in the optical transmitting component 110 directly couples the optical signal generated by the multimode light source 111 to the external optical fiber in the optical fiber interface 140. In this case, the external optical fiber in the optical fiber interface 140 is the target optical fiber 2 of the passive optical module 1.

[0075] This application also provides another optical module 100, which differs from the optical module 100 in the above embodiments in that, in the optical module 100 provided in the above embodiments, the light emitting component 110 is disposed on the first circuit board in the form of a packaged device. In this embodiment, the multimode light source 111 and the passive optical module 1 in the light emitting component 110 are disposed in the optical module 100 in the form of discrete devices (structures).

[0076] For example, such as Figure 3 As shown, the optical module 100 includes a first circuit board, a multimode light source 111, a passive optical module 1, connecting optical fibers, and an optical fiber interface 140. The multimode light source 111 can be a vertical-cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals.

[0077] The multimode light source 111 is electrically connected to the first circuit board, which integrates a signal processing circuit 130. During the signal transmission phase, the signal processing circuit 130 outputs a driving signal to the multimode light source 111 based on the electrical signal. Under the control of the driving signal, the multimode light source 111 generates an optical signal corresponding to the electrical signal. The first circuit board also has an electrical interface exposed on the outside of the optical module 100, used for inputting and outputting electrical signals within the optical module 100.

[0078] The passive optical module 1 is positioned on the light-emitting side of the multimode light source 111, between the multimode light source 111 and the connecting optical fiber. The other end of the connecting optical fiber is connected to an optical fiber interface 140, which is used to connect to an external optical fiber. The passive optical module 1 couples the optical signal generated by the multimode light source 111 to the connecting optical fiber, and the optical signal is transmitted to the external optical fiber through the connecting optical fiber and the optical fiber interface 140. In this case, the connecting optical fiber is the target optical fiber 2 of the passive optical module 1.

[0079] In some embodiments, the connecting optical fiber is connected to the passive optical module 1 in the form of a pigtail.

[0080] In some other embodiments, the passive optical module 1 and the fiber optic interface 140 may not be connected by a connecting fiber. The passive optical module 1 directly couples the optical signal generated by the multimode light source 111 to the external fiber in the fiber optic interface 140. In this case, the external fiber in the fiber optic interface 140 is the target fiber 2 of the passive optical module 1.

[0081] The optical module 100 also includes an optical receiving component 120, which can be disposed on the first circuit board in the form of a packaged device, or disposed in the optical module 100 in the form of a discrete device (structure), similar to the optical emitting component 110.

[0082] This application also provides an active optical module, which functions identically to the optical module 100. Both are signal transmission devices capable of photoelectric and electro-optical conversion, converting electrical signals into optical signals at the transmitting end and converting input optical signals back into electrical signals at the receiving end. Therefore, the active optical module can have the same components (structure) as the optical module 100 at both the transmitting and receiving ends. However, the difference lies in the structural dimensions, electrical interface, and fiber optic interface 140 manufactured according to protocol standards. In use, the external optical fiber is connected to the fiber optic interface 140 of the optical module 100, and the optical module 100 is connected to a specially designed pluggable interface in the communication equipment, with a pluggable fit. The active optical module, on the other hand, is typically fixedly installed inside the communication equipment, offering more flexible and diverse electrical and optical fiber connections, adaptable to various application scenarios.

[0083] For example, when electrically connected to communication equipment (see below for information on communication equipment and...) Figure 14 (As described above), the optical active module can be connected to the circuit board of the communication device through electrical connection structures such as metal pins, connecting wires or flexible printed circuit (FPC). The connection method can be soldering or connection through electrical connectors.

[0084] For example, when connecting to an external fiber optic cable (see below for information on communication equipment and...) Figure 14 (As described), the active optical module can be connected to the fiber optic connector on the panel of the communication device via a connecting optical fiber. The fiber optic connector is used to connect to an external optical fiber.

[0085] For further descriptions of the active optical module, please refer to the description of optical module 100 in this article, which will not be repeated here.

[0086] This application also provides a passive optical module 1, which can be used in the aforementioned optical module 100 and active optical module to couple multiple transverse mode optical signals generated by the multimode light source 111 into the target optical fiber 2. Here, the target optical fiber 2 can be a single-mode fiber or a multimode fiber. The single-mode fiber can be a conventional commercially available single-mode fiber, such as G.652 fiber; the multimode fiber can be a conventional commercially available multimode fiber, such as OM3 fiber.

[0087] This article first takes the target fiber 2 as a single-mode fiber as an example to illustrate the scheme.

[0088] like Figure 4 As shown, the passive optical module 1 includes two coupling elements 10: a collimating lens 11 and a focusing lens 12. The collimating lens 11 is located on the light-inlet side of the passive optical module 1 and is used to collimate the optical signal incident on the passive optical module 1. Here, the optical signal incident on the passive optical module 1 can be multiple transverse mode optical signals generated by a multimode light source 111. The focusing lens 12 is used to focus the optical signal collimated by the collimating lens 11.

[0089] Collimating lens 11 and focusing lens 12 can adjust the large spot of the optical signal incident on the passive optical module 1 into a smaller spot that matches the single-mode fiber 21. For example, when the optical signal incident on the passive optical module 1 is in LP01 mode (fundamental mode), the waist size of the adjusted spot needs to match the waist size of the fundamental mode of the single-mode fiber 21 to achieve better coupling efficiency. When the optical signal incident on the passive optical module 1 is a higher-order transverse mode, collimating lens 11 and focusing lens 12 produce the same or essentially the same scaling factor for the higher-order transverse mode optical signal as for the LP01 mode (fundamental mode) optical signal.

[0090] Please refer to Figures 4 to 6 The passive optical module 1 also includes a diffractive optical element (DOE) 13, which can be a micro- or nano-structure disposed on the collimating lens 11 and the focusing lens 12.

[0091] like Figure 5As shown in parts (a) and (b), the micro / nano structure may include multiple sawtooth structures 131 or stepped structures 132 with different heights. The sawtooth structures 131 or stepped structures 132 at different positions and with different heights can generate different phase delays for the optical signal, thereby achieving the purpose of phase modulation.

[0092] like Figure 6 As shown, the micro / nano structure can also be a microstructure array 133, which includes multiple microstructures arranged in an array. These microstructures can be protrusions or grooves in shapes such as cylinders, cones, frustums, prisms, pyramids, or hemispheres. The microstructure array 133 has different arrangement rules at different positions. These rules include the shape, size, and density of the microstructures at that position. Different arrangement rules refer to differences in at least one of the microstructure shape, size, and density. The microstructure array 133, with its different positions and arrangement rules, can produce different phase delays in the optical signal, thereby achieving phase modulation.

[0093] The diffractive optical element 13 can be disposed on the lens surface of the collimating lens 11 and the focusing lens 12. When the collimating lens 11 or the focusing lens 12 is a Fresnel lens, the micro-nano structure contained in the diffractive optical element 13 can be embedded in the concentric rings of the Fresnel lens.

[0094] The diffractive optical element 13 and the collimating lens 11, as well as the diffractive optical element 13 and the focusing lens 12, can be an integral structure. In this case, the collimating lens 11 and the focusing lens 12 can also be referred to as DOE lenses. DOE lenses can be formed integrally, for example, the diffractive optical element 13 and the collimating lens 11, as well as the diffractive optical element 13 and the focusing lens 12, can be integrally formed by injection molding, compression molding, or laser direct writing. DOE lenses can also be formed by fabricating the diffractive optical element 13 on a pre-formed lens, for example, after the collimating lens 11 and the focusing lens 12 are formed, the diffractive optical element 13 can be fabricated on the lens surface by nanoimprinting or laser direct writing.

[0095] The diffractive optical element 13 can also be an independent structure that is fixedly connected to the collimating lens 11 and the focusing lens 12. For example, after the diffractive optical element 13 is manufactured separately by injection molding, nanoimprinting, molding or laser direct writing, it can be mounted on the lens surface of the collimating lens 11 and the focusing lens 12.

[0096] As can be seen from the above description, after the collimating lens 11 and focusing lens 12 are equipped with the diffractive optical element 13, they not only possess collimation and focusing functions but also phase modulation functions. Through phase modulation of the diffractive optical element 13, the intensity and phase distribution of the light field can be changed, thereby achieving the purpose of controlling the mode transfer of the optical signal. Utilizing mode transfer, the diffractive optical element 13 can be used to convert at least a portion of the higher-order transverse mode optical signals into modes supported by the single-mode fiber 21, thus enabling the transmission of higher-order transverse mode optical signals through the single-mode fiber 21.

[0097] For example, such as Figure 7 As shown, in scenarios where the single-mode fiber 21 can support the transmission of optical signals in LP01 mode (fundamental mode), LP11a, and LP11b modes, for example, when the single-mode fiber 21 is G.652 fiber and the wavelength of the optical signal is 850nm, the G.652 fiber can support the transmission of optical signals with a wavelength of 850nm in LP01 mode (fundamental mode), LP11a, and LP11b modes. The function of the diffractive optical element 13 includes allowing optical signals of any transverse mode in the first module to pass through normally without changing the transverse mode of the optical signal. The first module includes LP01 mode (fundamental mode), LP11a mode, and LP11b mode. That is, when optical signals in LP01 mode (fundamental mode), LP11a mode, and LP11b mode pass through the diffractive optical element 13, the mode remains LP01, LP11a, and LP11b, respectively.

[0098] It should be noted that in the passive optical module 1 provided in this application embodiment, although the transverse mode of a certain transverse mode optical signal does not change after passing through the diffractive optical element 13, a small amount of stray light may be generated due to factors such as the processing precision of the diffractive optical element 13. However, this small amount of stray light does not affect the technical effect that this solution can achieve.

[0099] Please continue to refer to this. Figure 7 The diffractive optical element 13 also functions by converting any transverse mode optical signal in the second module into a fundamental mode spot with different offsets relative to the optical path center through mode transfer. The second module includes other transverse mode modes besides the first module, such as LP21a, LP21b, LP31a, and LP31b modes. The fundamental mode spot refers to the spot of the LP01 mode, and the optical path center is the optical path center of the passive optical module 1 at the optical signal emission position; in this embodiment, the optical path center is the optical axis of the focusing lens 12.

[0100] Offset relative to the optical path center refers to the fact that the center of the fundamental mode spot does not coincide with the center of the optical path. The offset of the fundamental mode spot can be characterized by the offset distance and offset angle relative to the optical path center. In the second module, different modes of optical signals, after being converted into the fundamental mode spot, have different offsets relative to the optical path center; these different offsets can be different offset distances, different offset angles, or both different offset distances and offset angles.

[0101] Furthermore, in order for the offset fundamental mode spot to couple into the single-mode fiber 21, the diffractive optical element 13 should be designed so that when any transverse mode optical signal in the second module is converted into a fundamental mode spot with different offsets relative to the optical path center, the maximum offset distance relative to the optical path center is less than half the core diameter of the single-mode fiber 21. For example, when the core diameter of the single-mode fiber 21 is 9 micrometers, the maximum offset distance of the fundamental mode spot relative to the optical path center is less than 4.5 micrometers.

[0102] When the multimode light source 111 is coupled to the single-mode fiber 21 through the passive optical module 1 designed above, any transverse mode optical signal in the first module can be coupled to the corresponding mode of the single-mode fiber 21 for transmission. For example, the LP01 mode optical signal can be coupled to the LP01 mode in the single-mode fiber 21 for transmission, the LP11a mode optical signal can be coupled to the LP11a mode in the single-mode fiber 21 for transmission, and the LP11b mode optical signal can be coupled to the LP11b mode in the single-mode fiber 21 for transmission. Any transverse mode optical signal in the second module can be converted into a fundamental mode spot with different offsets relative to the optical path center. The fundamental mode spot with offsets relative to the optical path center can be coupled to the LP01 (fundamental mode) and LP11a modes in the single-mode fiber 21 for transmission, or coupled to the LP01 (fundamental mode) and LP11b modes in the single-mode fiber 21 for transmission, or coupled to the LP01 (fundamental mode), LP11a mode, and LP11b mode in the single-mode fiber 21 for transmission. In other words, any transverse mode optical signal in the second module can be coupled to the LP01 (fundamental mode), LP11a mode and LP11b mode of the single-mode fiber 21 for transmission under the action of the passive optical module 1. As described above, the LP01 (fundamental mode), LP11a mode and LP11b mode are the transmission modes that the single-mode fiber 21 can support.

[0103] Another example, such as Figure 8As shown, the diffractive optical element 13 allows the LP01 mode (fundamental mode) optical signal to pass through normally without changing the transverse mode of the optical signal. The diffractive optical element 13 also converts optical signals of different higher-order transverse modes into fundamental mode spots with different offsets relative to the optical path center through mode transfer. As mentioned above, higher-order transverse modes refer to other transverse mode modes besides the LP01 mode (fundamental mode), such as LP11a, LP11b, LP21a, LP21b, LP31a, and LP31b modes. The maximum offset of the fundamental mode spot relative to the optical path center is less than 4.5 micrometers.

[0104] When the multimode light source 111 is coupled to the single-mode fiber 21 through the optical passive module 1 designed above, the LP01 mode (fundamental mode) optical signal can be coupled into the LP01 mode of the single-mode fiber 21 for transmission. Different higher-order transverse mode optical signals can be converted into fundamental mode spots with different offsets relative to the optical path center. These fundamental mode spots can be coupled into the LP01 (fundamental mode) and LP11a modes in the single-mode fiber 21 for transmission, or into the LP01 (fundamental mode) and LP11b modes in the single-mode fiber 21 for transmission, or into the LP01 (fundamental mode), LP11a mode, and LP11b mode in the single-mode fiber 21 for transmission. In other words, under the action of the optical passive module 1, different higher-order transverse mode optical signals can be coupled into the LP01 (fundamental mode), LP11a mode, and LP11b mode of the single-mode fiber 21 for transmission. As described above, LP01 (fundamental mode), LP11a mode, and LP11b mode are the transmission modes that single-mode fiber 21 can support.

[0105] In some embodiments, the diffractive optical element 13 can be disposed only on the focusing lens 12 or the collimating lens 11, and the above functions can be achieved in the same way.

[0106] As described above, the passive optical module 1 with the above design can couple high-order transverse mode optical signals into the single-mode fiber 21 with low loss, and transmit them in the modes supported by the single-mode fiber 21. This design has two advantages: firstly, since the single-mode fiber 21 supports fewer modes (e.g., the three in the above embodiment), the intermodal dispersion is much smaller than that in the multimode fiber 22 in related technologies, thus significantly improving the signal quality degradation caused by intermodal dispersion and supporting longer transmission distances (e.g., hundreds or thousands of meters). Secondly, it avoids the loss of high-order transverse mode optical signals, improving the signal integrity of high-speed optoelectronic links.

[0107] In addition, the passive optical module 1 designed above can be adapted to the optical emitting component 110, optical module 100 and active optical module formed by the multimode light source 111. Compared with the use of single-mode light source, the use of multimode light source 111 has advantages in terms of cost, yield and reliability in the optical emitting component 110, optical module 100 and active optical module.

[0108] Furthermore, the passive optical module 1 designed above can simply have its diffractive optical devices mounted on the existing coupling element 10, which has advantages such as simple structure, easy implementation, and minimal impact on structural shape and volume.

[0109] This application also provides a passive optical module 1, such as... Figure 9 As shown, the passive optical module 1 is used for coupling with the multimode fiber 22. The passive optical module 1 includes two coupling elements 10: a collimating lens 11 and a focusing lens 12. The collimating lens 11 is located on the light-input side of the passive optical module 1 and is used to collimate the optical signal incident on the passive optical module 1. The focusing lens 12 is used to focus the optical signal collimated by the collimating lens 11.

[0110] Collimating lens 11 and focusing lens 12 can adjust the large spot of the optical signal incident on the passive optical module 1 into a smaller spot that matches the multimode fiber 22. For example, when the optical signal incident on the passive optical module 1 is in LP01 mode (fundamental mode), the waist size of the adjusted spot needs to match the waist size of the multimode fiber 22 to achieve better coupling efficiency. When the optical signal incident on the passive optical module 1 is a higher-order transverse mode, collimating lens 11 and focusing lens 12 produce the same or essentially the same scaling factor for the higher-order transverse mode optical signal as for the LP01 mode (fundamental mode) optical signal.

[0111] At least one of the collimating lens 11 and the focusing lens 12 is provided with a diffractive optical element 13, for example, in Figure 9 In the illustrated scheme, both the collimating lens 11 and the focusing lens 12 are equipped with diffractive optical elements 13. The diffractive optical elements 13 can form a specific light intensity distribution by modulating the phase of the incident light field, thereby achieving the purpose of controlling mode transfer.

[0112] In this embodiment, the diffractive optical element 13 allows the LP01 mode (fundamental mode) optical signal to pass through normally without changing the transverse mode of the optical signal. The diffractive optical element 13 also converts optical signals of different higher-order transverse modes into fundamental mode spots with different offsets relative to the center of the optical path through mode transfer.

[0113] Furthermore, in order for the offset fundamental mode spot to couple into the multimode fiber 22, the diffractive optical element 13 should be designed so that when optical signals of different higher-order transverse modes are converted into fundamental mode spots with different offsets relative to the optical path center, the maximum offset distance relative to the optical path center is less than half the core diameter of the multimode fiber 22. For example, when the core diameter of the multimode fiber 22 is 50 micrometers, the maximum offset distance of the fundamental mode spot relative to the optical path center is less than 25 micrometers.

[0114] In some embodiments, the maximum offset distance of the fundamental mode spot relative to the center of the optical path is less than 10 micrometers. This design enables the offset fundamental mode spot to be coupled into a lower-order mode in the multimode fiber 22 for transmission, thereby helping to further improve the problem of intermodal dispersion.

[0115] When the multimode light source 111 is coupled to the multimode fiber 22 via the passive optical module 1 designed above, the LP01 mode (fundamental mode) optical signal can be coupled into the LP01 mode of the multimode fiber 22 for transmission. Different higher-order transverse mode optical signals can be converted into fundamental mode spots with different offsets relative to the optical path center. These fundamental mode spots can be coupled into the LP01 (fundamental mode) and LP11a modes in the multimode fiber 22 for transmission, or into the LP01 (fundamental mode) and LP11b modes in the multimode fiber 22 for transmission, or into the LP01 (fundamental mode), LP11a mode, and LP11b mode in the multimode fiber 22 for transmission. In other words, under the action of the passive optical module 1, different higher-order transverse mode optical signals can be coupled into the LP01 (fundamental mode), LP11a mode, and LP11b mode of the multimode fiber 22 for transmission. LP01 (fundamental mode), LP11a mode and LP11b mode are the transmission modes that multimode fiber 22 can support.

[0116] In other embodiments, the diffractive optical element 13 allows optical signals of any transverse mode in the first module to pass through normally without changing the transverse mode of the optical signal. The first module includes the LP01 mode (fundamental mode), LP11a mode, and LP11b mode. That is, when optical signals of the LP01 mode (fundamental mode), LP11a mode, and LP11b mode pass through the diffractive optical element 13, the mode remains LP01, LP11a, and LP11b, respectively.

[0117] The diffractive optical element 13 also functions to convert optical signals of any transverse mode in the second module into fundamental mode spots with different offsets relative to the optical path center through mode transfer. The second module includes other transverse mode modes besides those in the first module, such as LP21a, LP21b, LP31a, and LP31b modes. The maximum offset of the fundamental mode spot relative to the optical path center is less than 10 micrometers.

[0118] When the multimode light source 111 is coupled to the multimode fiber 22 through the passive optical module 1 designed above, any transverse mode optical signal in the first module can be coupled to the corresponding mode of the multimode fiber 22 for transmission. For example, the LP01 mode optical signal can be coupled to the LP01 mode in the multimode fiber 22 for transmission, the LP11a mode optical signal can be coupled to the LP11a mode in the multimode fiber 22 for transmission, and the LP11b mode optical signal can be coupled to the LP11b mode in the multimode fiber 22 for transmission. Any transverse mode optical signal in the second module can be converted into a fundamental mode spot with different offsets relative to the optical path center. The fundamental mode spot with offsets relative to the optical path center can be coupled to the LP01 (fundamental mode) and LP11a modes in the multimode fiber 22 for transmission, or coupled to the LP01 (fundamental mode) and LP11b modes in the multimode fiber 22 for transmission, or coupled to the LP01 (fundamental mode), LP11a mode, and LP11b mode in the multimode fiber 22 for transmission. In other words, any transverse mode optical signal in the second module can be coupled to the LP01 (fundamental mode), LP11a mode, and LP11b mode of the multimode fiber 22 for transmission under the action of the passive optical module 1. LP01 (fundamental mode), LP11a mode, and LP11b mode are the transmission modes that the multimode fiber 22 can support.

[0119] In other embodiments, the diffractive optical element 13 functions to allow any transverse mode of optical signal in the third module to pass through normally without altering the transverse mode of the optical signal. The third module includes the LP31 mode and transverse modes below the LP31 mode.

[0120] The diffractive optical element 13 also functions to convert optical signals of any transverse mode in the fourth module into fundamental mode spots with different offsets relative to the optical path center through mode transfer. The fourth module includes transverse modes other than those in the third module.

[0121] When the multimode light source 111 is coupled to the multimode fiber 22 through the passive optical module 1 designed above, the optical signal of any transverse mode in the third module can be coupled into the corresponding mode of the multimode fiber 22 for transmission. The optical signal of any transverse mode in the fourth module can be converted into a fundamental mode spot with different offsets relative to the center of the optical path. The fundamental mode spot with offsets relative to the center of the optical path can be coupled into the LP01 (fundamental mode), LP11 mode, LP21 mode and LP31 mode in the multimode fiber 22 for transmission.

[0122] As can be seen from the above description, the passive optical module 1 designed above can couple high-order mode optical signals into the multimode fiber 22 with low loss, and transmit them in a lower-order mode within the multimode fiber 22. This design, due to the reduced number of modes in the multimode fiber 22, and the fact that all modes are lower-order, results in significantly less intermodal dispersion than in related technologies (e.g., the intermodal dispersion of LP01, LP11, LP91, and LP82 modes). This greatly improves the signal quality degradation caused by intermodal dispersion and enables transmission over longer distances (e.g., hundreds or thousands of meters).

[0123] In addition, the passive optical module 1 designed above can be adapted to the optical emitting component 110, optical module 100 and active optical module formed by the multimode light source 111. Compared with the use of single-mode light source, the use of multimode light source 111 has advantages in terms of cost, yield and reliability in the optical emitting component 110, optical module 100 and active optical module.

[0124] Furthermore, the passive optical module 1 designed above can be adapted to multimode fiber 22. Compared with single-mode fiber 21, using multimode fiber 22 reduces the difficulty of coupling alignment.

[0125] Furthermore, the passive optical module 1 designed above can simply have its diffractive optical devices mounted on the existing coupling element 10, which has advantages such as simple structure, easy implementation, and minimal impact on structural shape and volume.

[0126] This application also provides another passive optical module 1, such as... Figure 10 As shown, the optical axes of the collimating lens 11 and the focusing lens 12 are set at a certain angle, for example, 90 degrees. A reflecting structure 14 is also provided between the collimating lens 11 and the focusing lens 12. The reflecting structure 14 is used to change the propagation direction of the light signal, thereby reflecting the light signal emitted from the collimating lens 11 into the focusing lens 12. In this embodiment, the passive optical module 1 includes three coupling elements 10, namely the collimating lens 11, the focusing lens 12, and the reflecting structure 14. The diffractive optical element 13 can be provided in at least one of the collimating lens 11, the focusing lens 12, and the reflecting structure 14. For example, in Figure 10 In the illustrated scheme, diffractive optical elements 13 are provided in the collimating lens 11, the focusing lens 12, and the reflecting structure 14.

[0127] The working principle and the effects that the diffractive optical element 13 can achieve in this embodiment are the same as those in the diffractive optical element 13 in the above embodiments, and will not be repeated here.

[0128] In this embodiment, the passive optical module 1, by setting the reflection structure 14, can adapt to scenarios where the light emission direction of the multimode light source 111 and the coupling direction of the target optical fiber 2 are not parallel. For example, in a VCSEL optical module, the light emission direction of the VCSEL is perpendicular to the coupling direction of the target optical fiber, so the passive optical module 1 in this embodiment can be used to achieve the coupling between the VCSEL and the target optical fiber.

[0129] This application also provides another passive optical module 1, such as... Figure 11 As shown, the passive optical module 1 includes a mounting structure 15, and a collimating lens 11, a focusing lens 12, and a reflecting structure 14 are all fixedly mounted on the mounting structure 15. The mounting structure 15, the collimating lens 11, the focusing lens 12, and the reflecting structure 14 can be integrally formed. For example, the mounting structure 15, the collimating lens 11, and the focusing lens 12 can be integrally formed by injection molding or compression molding, and the reflecting structure 14 can be formed from the structural surface of the mounting structure 15.

[0130] The diffractive optical element 13 in the passive optical module 1 can also be integrally formed with the mounting structure 15, collimating lens 11, focusing lens 12, and reflecting structure 14 by injection molding or molding processes. Alternatively, after the mounting structure 15, collimating lens 11, focusing lens 12, and reflecting structure 14 are integrally formed, they can be disposed on the corresponding coupling elements 10 (e.g., collimating lens 11, focusing lens 12, and reflecting structure 14) by nanoimprinting, molding, or laser direct writing. When the diffractive optical element 13 is disposed on the collimating lens 11 and the focusing lens 12, and the passive optical module 1 is manufactured in the above manner, the diffractive optical element 13 is located on the light-inlet side of the collimating lens 11 and on the light-outlet side of the focusing lens 12.

[0131] In some embodiments, the collimating lens 11, the focusing lens 12, and the reflecting structure 14 are individually molded and then mounted on the mounting structure 15 by means of snap-fitting, adhesive bonding, or other methods.

[0132] The mounting structure 15 may also be provided with a first connecting structure 151 and a second connecting structure 152. The first connecting structure 151 is used to connect to the target optical fiber, and the second connecting structure 152 is used to connect to the first circuit board on which the multimode light source is located. After the mounting structure 15 is connected to the first circuit board through the second connecting structure 152, the collimating lens 11 faces the multimode light source, and the light signal generated by the multimode light source can be incident on the collimating lens 11. After the target optical fiber is connected to the mounting structure 15 through the first connecting structure 151, the light signal emitted from the focusing lens 12 can be incident on the target optical fiber.

[0133] This application also provides another passive optical module, which includes a mounting structure, a collimating lens, and a focusing lens, wherein the optical axes of the collimating lens and the focusing lens are aligned. The structural relationship and manufacturing method of the diffractive optical element, the collimating lens, the focusing lens, and the mounting structure can be referred to above, and will not be repeated here.

[0134] In some embodiments, the mounting structure may also be provided with a first connection structure and a second connection structure, wherein the first connection structure is used to connect to the target optical fiber, and the second connection structure is used to connect to a first circuit board provided with a multimode light source.

[0135] This application also provides another passive optical module, which includes a focusing lens, i.e., only one coupling element, on which a diffractive optical element is disposed. The working principle and the effects achieved by this diffractive optical element are the same as those in the above embodiments, and will not be described again here.

[0136] This application also provides another passive optical module, which includes at least one coupling element and a diffractive optical element. That is, the difference between the passive optical module in this embodiment and the passive optical module in the above embodiment is that the diffractive optical element is a separate device from the coupling element, but the function and working principle of the diffractive optical element are the same as those of the diffractive optical element in the above embodiment.

[0137] In addition, diffractive optical elements can be a single discrete device or two or more discrete devices.

[0138] It should be noted that although the transverse mode of an optical signal is represented by LP mode in this paper, the transverse mode of an optical signal generated by a multimode source may have different representations depending on the multimode source. For example, some VCSELs may use Gaussian mode to represent the transverse mode of their generated optical signals. In the above cases, the passive optical module provided in this application can convert optical signals of different transverse modes into modes that can be coupled into the target optical fiber for transmission based on the same working principle, and achieve the same technical effect.

[0139] This application also provides a communication device, which may be, for example, a communication device... Figure 12 The server 4 or switch 3 is shown in the optical communication architecture of the data center or AI cluster.

[0140] like Figure 13As shown, the communication device 1000 includes a second circuit board 200, a pluggable interface 300, and the optical module 100 described in the above embodiment. The pluggable interface 300 is electrically connected to the second circuit board 200 and is exposed to the outside of the communication device 1000. The optical module 100 is pluggably connected to the pluggable interface 300, and when the optical module 100 is connected to the pluggable interface 300, it can be electrically connected to the second circuit board 200 through the pluggable interface 300.

[0141] In some embodiments, such as Figure 14 As shown, the communication device 1000 includes a second circuit board 200 and the active optical module 400 described in the above embodiment. The active optical module 400 is located inside the communication device 1000 and is directly electrically connected to the second circuit board 200 by soldering metal pins. The active optical module 400 is also connected to a fiber optic connector 500 on the panel of the communication device 1000 via a connecting optical fiber 600. The fiber optic connector 500 is used to connect to an external optical fiber.

[0142] The technical effects achievable by the optical emitting component 110, optical module 100, active optical module 400, and communication device 1000 provided in this application embodiment are the same as those achievable by the passive optical module 1 in any of the above embodiments, and will not be repeated here.

[0143] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A passive optical module, characterized in that, The passive optical module includes: At least one coupling element, said at least one coupling element being used to adjust a larger spot of an optical signal to a smaller spot matching a target optical fiber, said target optical fiber being a single-mode fiber or a multimode fiber; and A diffractive optical element, the diffractive optical element comprising a micro / nano structure disposed on at least one of the coupling elements.

2. The passive optical module according to claim 1, characterized in that, The diffractive optical element is used to convert at least a portion of the higher-order transverse mode optical signals into fundamental mode light spots with different offsets relative to the center of the optical path. The higher-order transverse mode includes the transverse mode of the basic mode.

3. The passive optical module according to claim 1 or 2, characterized in that, The diffractive optical element is used to maintain the mode of any transverse mode optical signal in the first module and to convert any transverse mode optical signal in the second module into a fundamental mode light spot with different offsets relative to the optical path center. The fundamental mode spot is an LP01 mode spot, the first module includes LP01 mode, LP11a mode and LP11b mode, and the second module includes transverse mode other than the first module.

4. The passive optical module according to claim 1 or 2, characterized in that, The diffractive optical element is used to maintain the mode of the LP01 mode optical signal and to convert different higher-order transverse mode optical signals into fundamental mode light spots with different offsets relative to the optical path center. The fundamental mode spot is the LP01 mode spot, and the higher-order transverse modes include transverse modes other than the LP01 mode.

5. The passive optical module according to claim 1 or 2, characterized in that, The target optical fiber is a multimode optical fiber; The diffractive optical element is used to maintain the mode of any transverse mode optical signal in the third module and to convert any transverse mode optical signal in the fourth module into a fundamental mode light spot with different offsets relative to the optical path center. The fundamental mode spot is an LP01 mode spot, the third module includes the LP31 mode and a transverse mode below the LP31 mode, and the fourth module includes transverse modes other than the third module.

6. The passive optical module according to claim 2, characterized in that, The target optical fiber is a single-mode optical fiber, and the offset of the fundamental mode spot relative to the center of the optical path is less than 4.5 micrometers; Alternatively, the target optical fiber is a multimode optical fiber, and the offset of the fundamental mode spot relative to the center of the optical path is less than 10 micrometers.

7. The passive optical module according to any one of claims 1 to 6, characterized in that, The diffractive optical element includes: A micro / nano structure integrally formed with the coupling element; Alternatively, micro / nano structures can be fabricated on the coupling element; Alternatively, micro / nano structures can be mounted on the coupling element.

8. The passive optical module according to any one of claims 1 to 7, characterized in that, The passive optical module also includes a mounting structure, and the coupling element is disposed on the mounting structure; The mounting structure and the coupling element are either integrally formed or relatively fixed separate structures.

9. The passive optical module according to any one of claims 1 to 8, characterized in that, The diffractive optical element includes multiple stepped or sawtooth structures of different heights; Alternatively, the diffractive optical element may include a microstructure array comprising multiple microstructures arranged in an array.

10. The passive optical module according to claim 9, characterized in that, The microstructure includes cylindrical, conical, frustum-shaped, prismatic, frustum-shaped, pyramidal, or hemispherical protrusions or grooves. At different locations of the coupling element, the multiple microstructures in the microstructure array have different arrangement rules; the arrangement rules include the shape, size and arrangement density of the microstructures.

11. The passive optical module according to any one of claims 1 to 9, characterized in that, The passive optical module includes two coupling elements, namely a collimating lens and a focusing lens; Alternatively, the passive optical module may include three coupling elements: a collimating lens, a reflecting structure, and a focusing lens.

12. A passive optical module, characterized in that, The passive optical module includes: At least one coupling element, said at least one coupling element being used to adjust a larger spot of an optical signal to a smaller spot matching a target optical fiber, said target optical fiber being a single-mode fiber or a multimode fiber; and A diffractive optical element, wherein the diffractive optical element is a device disposed separately from any of the coupling elements, for converting at least a portion of the optical signals of higher-order transverse modes into fundamental mode light spots with different offsets relative to the center of the optical path; The higher-order transverse mode includes transverse mode modes other than the basic mode.

13. The passive optical module according to claim 12, characterized in that, The diffractive optical element includes multiple stepped or sawtooth structures of different heights; Alternatively, the diffractive optical element may include a microstructure array comprising multiple microstructures arranged in an array.

14. A light-emitting component, characterized in that, The optical emitting component includes: A multimode light source, wherein the multimode light source is a vertical-cavity surface-emitting laser or a light-emitting diode, is used to generate multiple transverse mode optical signals; and The passive optical module as described in any one of claims 1 to 13 is disposed on the light-emitting side of the multimode light source and is used to couple the optical signal to the target optical fiber; The target optical fiber is either a single-mode optical fiber or a multimode optical fiber.

15. An optical module, characterized in that, The optical module includes a first circuit board, an optical fiber interface, and an optical emitting component as described in claim 14; The first circuit board is provided with an electrical interface; The optical emitting component is electrically connected to the first circuit board and is connected to the optical fiber interface; Alternatively, the optical module may include a first circuit board, a multimode light source, an optical fiber interface, and a passive optical module as described in any one of claims 1 to 13; wherein, an electrical interface is provided on the first circuit board; The multimode light source is a vertical cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals; the multimode light source is electrically connected to the first circuit board; The passive optical module is disposed between the multimode light source and the optical fiber interface.

16. An active optical module, characterized in that, The active optical module includes a first circuit board and the optical emitting component as described in claim 14; The light emitting component is electrically connected to the first circuit board; Alternatively, the active optical module includes a first circuit board, a multimode light source, and a passive optical module as described in any one of claims 1 to 13; wherein the multimode light source is a vertical cavity surface-emitting laser or a light-emitting diode, used to generate multiple transverse mode optical signals; the multimode light source is electrically connected to the first circuit board; The passive optical module is located on the light-emitting side of the multimode light source.

17. A communication device, characterized in that, The communication device includes a second circuit board and an active optical module as described in claim 16; The active optical module is located inside the communication device and is electrically connected to the second circuit board. Alternatively, the communication device may include a second circuit board, a pluggable interface, and an optical module as described in claim 15; The pluggable interface is electrically connected to the second circuit board and exposed to the outside of the communication device; the optical module is connected to the pluggable interface.

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