Packaging structure, optical module, and optical communication system

Abstract

A packaging structure, an optical module, and an optical communication system. The packaging structure comprises: a ferrule (110) which comprises an optical fiber (111), the optical fiber (111) being used for transmitting signal light; a cap (120) which comprises a lens (121), the lens (121) being used for focusing the signal light; and a header (130) which cooperates with the cap (120) to form an accommodating cavity, an optical receiving chip (140) being provided in the accommodating cavity, and the optical receiving chip (140) being used for receiving the focused signal light. The included angle between a normal line (141) of a plane where the optical receiving chip (140) is located and a main optical axis (122) of the lens (121) is greater than 0 degree. The focused signal light received by the optical receiving chip (140) undergoes wide-angle reflection at the optical receiving chip (140), so that most of the signal light reflected at the optical receiving chip (140) exits from the edge of the lens (121) and cannot converge at the optical fiber (111), thereby improving the return loss capability of the packaging structure.

Description

Packaging structure, optical module and optical communication system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 27, 2023, with application number 202311820649.3, and the priority of the Chinese patent application entitled "A packaging structure, optical module and optical communication system". Technical Field

[0002] The present application relates to the field of optical communications, and in particular to a packaging structure, an optical module, and an optical communication system. Background Art

[0003] Radio-over-fiber (RoF) is a wireless access technology that combines fiber-optic communication and wireless communication. RoF uses optical fiber as the transmission link between the base station and the central station, modulates the electrical signal onto the signal light, and transmits it through the optical fiber link. Finally, the signal light is demodulated into the electrical signal at the base station. Compared with cables, optical fiber has the advantages of small size, low loss, wide bandwidth, long transmission distance, and resistance to electromagnetic interference. In addition, since the exchange and control of signal light are concentrated in the central station, multiple base stations can share the same central station, thereby reducing the overall power consumption and cost of the RoF system. Therefore, RoF has been widely studied as an important signal transmission technology and can be used as a favorable solution for indoor fifth-generation mobile communication technology (5G) wireless base stations.

[0004] In RoF systems, since the optical carrier carries analog RF signals, compared to traditional digital fiber transmission links, inherent dispersion and nonlinear effects can affect the analog and digital links. Therefore, the optical return loss requirements for the device are extremely high. Optical loss can interfere with the transmitted signal, resulting in measured insertion loss and reduced available optical power at the far end. This directly impacts RoF uplink and downlink links, as well as clock synchronization. In severe cases, it can even cause the fiber link to become inoperable. Therefore, achieving a high optical return loss solution at the receiving end of wireless over fiber communication is an urgent problem to be solved.

[0005] Summary of the Invention

[0006] The present application provides a packaging structure, an optical module and an optical communication system, which adopt an inclined mounting scheme for an optical receiving chip, thereby forming a large-angle reflection at the reflection surface of the optical receiving chip, increasing the aberration of the reflected light beam, and improving the return loss capability.

[0007] In the first aspect, a packaging structure is provided, comprising: a core, comprising an optical fiber, the optical fiber being used to transmit signal light; a tube cap, comprising a lens, the lens being used to focus the signal light; a tube seat, cooperating with the tube cap to form a receiving cavity, a light receiving chip being provided in the receiving cavity, the light receiving chip being used to receive the focused signal light, wherein the angle between the normal of the plane where the light receiving chip is located and the main optical axis of the lens is greater than 0 degrees. In the packaging structure of the present application, the signal light emitted through the optical fiber directly enters the lens, and is emitted after being focused by the lens, and the focused signal light is directly received by the light receiving chip. Since the light receiving chip is tilted in the receiving cavity, the focused signal light received by the light receiving chip will be reflected at a large angle at the light receiving chip, so that most of the signal light reflected from the light receiving chip is emitted from the edge of the lens and cannot be converged at the optical fiber, thereby improving the return loss capability of the packaging structure.

[0008] In conjunction with the first aspect, in certain implementations of the first aspect, the angle between the normal and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 25 degrees. This ensures that the size of the receiving spot on the optical receiving chip is large enough so that the optical receiving chip can correctly identify the focused signal light. It also ensures that a large-angle reflection is formed at the reflective surface of the optical receiving chip, thereby increasing the aberration of the reflected light beam and improving return loss capability.

[0009] In some implementations, when the lens is aspherical, the angle between the normal and the principal optical axis is greater than or equal to 6 degrees and less than or equal to 10 degrees. The object distance and phase distance of the aspherical lens are similar, and the relationship between the angle and return loss is consistent. At this angle, the return loss capability of the package structure is guaranteed, and the responsivity of the optical receiver chip can be guaranteed.

[0010] In some implementations, when the lens is spherical, the angle between the normal and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 8 degrees. Spherical lenses have a large phase difference, and the angular return loss relationship has a different relationship. At this angle, the return loss capability of the package structure is guaranteed, and the responsivity of the optical receiver chip can also be guaranteed.

[0011] In conjunction with the first aspect, in certain implementations of the first aspect, a filter film is affixed to the edge of the lens, and the filter is used to absorb signal light reflected from the optical receiving chip. This reduces the intensity of the signal light reflected from the optical receiving chip, further improving the return loss capability of the packaging structure. In some implementations, a filter is provided between the lens and the optical receiving chip, and the filter is located in the reflection path of the signal light from the optical receiving chip. The affixed filter film can reduce the intensity of the signal light reflected from the optical receiving chip to the edge of the lens, further improving the return loss capability of the packaging structure.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the light receiving chip is mounted on a carrier module having an inclined surface, thereby achieving inclined mounting of the light receiving chip.

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, the height of the carrier module is adjustable. The carrier module is used to adjust the distance between the light receiving chip and the lens. The distance between the light receiving chip and the lens is determined by the focal length of the lens, thereby determining the size of the received light spot on the light receiving chip, ensuring that the light receiving chip can correctly identify the focused signal light. The carrier module can be a gasket, a groove, a boss, or a column.

[0014] In conjunction with the first aspect, in certain implementations of the first aspect, the optical fiber is located on the principal optical axis, so that the incident path of the signal light on the lens coincides with the principal optical axis, thereby improving the coupling efficiency between the optical fiber and the lens and reducing the difficulty of the coupled light search process.

[0015] In conjunction with the first aspect, in certain implementations of the first aspect, a beam splitter is disposed between the ferrule and the lens, with the center of the beam splitter located on the principal optical axis. The angle between the optical fiber and the beam splitter is equal to the angle between the beam splitter and the principal optical axis. This ensures that the incident path of the signal light on the lens coincides with the principal optical axis, thereby improving the coupling efficiency between the optical fiber and the lens and reducing the difficulty of the coupled light search process.

[0016] In conjunction with the first aspect, certain implementations of the first aspect further include a light emitting chip, wherein the light emitting chip is disposed in the accommodating cavity; or the packaging structure further includes another tube base and another tube cap, wherein the other tube base and the other tube cap cooperate to form another accommodating cavity, and the light emitting chip is disposed in the other accommodating cavity. In this case, the packaging structure can be in the form of an optical transceiver assembly.

[0017] In a second aspect, an optical module is provided, comprising a processor and the first aspect and any possible packaging structure, wherein the packaging structure is configured to receive signal light and convert the signal light into an electrical signal, and the processor is configured to receive the electrical signal and obtain data.

[0018] In combination with the second aspect, in some implementations of the second aspect, the optical module further includes a light source and a driver.

[0019] In a third aspect, an optical communication system is provided, comprising an electronic device and the optical module of the second aspect or any possible implementation, wherein the electronic device is connected to the optical module, and the electronic device is any one of a switch, a fiber optic router, and a fiber optic network card. The electronic device may include multiple ports, each of the multiple ports corresponding to an optical transmission channel, and the ports of the multiple ports are connected to the optical module to achieve multi-channel, high-speed data transmission.

[0020] In a fourth aspect, an optical module is provided, comprising a light source, a driver, a processor, and the optical transceiver package structure of the first aspect. The light source is configured to emit a light beam. The driver is configured to transmit an electrical signal carrying data. The driver is connected to a light emitting chip, which modulates a light beam according to the electrical signal to transmit signal light. The driver can be in the form of a driver chip. The light receiving chip is configured to receive another signal light and convert it into another electrical signal. The processor is configured to receive the electrical signal and obtain data. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic diagram of a packaging structure provided in an embodiment of the present application.

[0022] FIG2 is a schematic diagram of another packaging structure provided in an embodiment of the present application.

[0023] FIG3 is a schematic diagram of an optical path in a packaging structure provided in an embodiment of the present application.

[0024] FIG4 is a schematic diagram of mounting a light receiving chip provided in an embodiment of the present application.

[0025] FIG5 is a schematic diagram of a method for determining the distance between a light receiving chip and a lens provided in an embodiment of the present application.

[0026] FIG6 is a schematic diagram of an optical coupling and optical return loss structure of a packaging structure provided in an embodiment of the present application.

[0027] FIG7 is a schematic diagram of an optical coupling and optical return loss structure of a packaging structure provided in an embodiment of the present application.

[0028] FIG8 is a schematic diagram of the light path in another packaging structure provided in an embodiment of the present application.

[0029] FIG9 is an optical module provided in an embodiment of the present application.

[0030] FIG10 is another optical module provided in an embodiment of the present application.

[0031] FIG11 is a schematic diagram of an optical communication system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The technical solution in this application will be described below with reference to the accompanying drawings.

[0033] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0034] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0035] In the description of the embodiments of the present application, the terms "upper", "lower", "vertical", "horizontal", etc. indicate orientations or positional relationships that are defined relative to the orientations or positions of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative descriptions and clarifications, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They may change accordingly according to changes in the orientation of the components placed in the drawings, and therefore cannot be understood as limitations on the present application.

[0036] The terms "including" and "having" and any variations thereof in the embodiments of the present application shown below are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, products or apparatus.

[0037] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. An embodiment or design described as "exemplary" or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. The use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete manner to facilitate understanding.

[0038] In the embodiments of the present application, the same reference numerals are used to represent the same component or the same part. In addition, the various parts in the drawings are not drawn to scale, and the sizes and dimensions of the parts shown in the drawings are only exemplary and should not be understood as limiting the present application.

[0039] Radio-over-fiber (RoF) is a wireless access technology that combines fiber-optic communication and wireless communication. RoF uses optical fiber as the transmission link between the base station and the central station, modulates the electrical signal onto the signal light, and transmits it through the optical fiber link. Finally, the signal light is demodulated into the electrical signal at the base station. Compared with cables, optical fiber has the advantages of small size, low loss, wide bandwidth, long transmission distance, and resistance to electromagnetic interference. In addition, since the exchange and control of signal light are concentrated in the central station, multiple base stations can share the same central station, thereby reducing the overall power consumption and cost of the RoF system. Therefore, RoF has been widely studied as an important signal transmission technology and can be used as a favorable solution for indoor fifth-generation mobile communication technology (5G) wireless base stations.

[0040] In RoF systems, since the optical carrier carries analog RF signals, compared to traditional digital fiber transmission links, inherent dispersion and nonlinear effects can affect the analog-digital link. Therefore, the optical return loss (ORL) requirements for the device are extremely high. Optical return loss, also known as optical return loss or optical reflection loss, refers to the loss caused by reflections between fiber interfaces, connections, and channels during optical fiber transmission. Optical loss can interfere with the transmitted signal, resulting in measured insertion loss and reduced available optical power at the far end. This directly impacts RoF uplink and downlink links, as well as clock synchronization. In severe cases, it can even cause the fiber link to become inoperable. Therefore, achieving a high ORL receiving solution at the receiving end of wireless over fiber communication is a pressing issue.

[0041] In view of this, the present application provides a packaging structure, an optical module and an optical communication system, which adopts a tilted mounting scheme for the optical receiving chip, thereby forming a large-angle reflection at the reflection surface of the optical receiving chip, increasing the aberration of the reflected light beam, and improving the return loss capability.

[0042] FIG1 is a schematic diagram of a packaging structure provided by an embodiment of the present application. As shown in FIG1 , the packaging structure may include a ferrule 110, an optical fiber 111, a cap 120, a lens 121, a base 130, and a light receiving chip 140.

[0043] The ferrule 110 includes an optical fiber 111, which is used to transmit signal light. The ferrule 110 shown in Figure 1 is a cylindrical structure with a microhole in the center for fixing the position of the optical fiber 111 to achieve precise alignment of the optical fiber with other devices, such as the lens 121, the light receiving chip 140, etc. In addition, the ferrule can also be called a fiber optic connector. The mechanical firmware for fixing the ferrule, the ferrule and the lens can also be called a fiber optic adapter. The ferrule can also be a structure other than a cylinder, and this application does not limit this. In addition, the optical fiber 111 can also specifically refer to a fiber optic pigtail.

[0044] The tube cap 120 includes a lens 121, which is used to focus the signal light. The lens 121 can be a spherical lens or an aspherical lens, etc., which is determined according to actual conditions. The main optical axis 122 of the lens 121 can be perpendicular to the bearing surface of the tube seat 130. The main optical axis 122 of the lens 121 can be a straight line passing through the center of the lens 121 (or it can also be understood as the optical center) and perpendicular to the lens. Alternatively, the main optical axis 122 can also be understood as a straight line passing through the center of the upper surface of the lens 121 and the center of the lower surface of the lens 122. In the case where the upper surface or the lower surface of the lens 121 is a spherical surface, the center can refer to the center of the sphere. The main optical axis of the lens can also be simply referred to as the main axis of the lens.

[0045] The tube base 130 cooperates with the tube cap 120 to form a receiving cavity. A light receiving chip 140 is provided in the receiving cavity. The light receiving chip 140 is used to receive the focused signal light and convert the signal light into an electrical signal. The normal 141 of the plane where the light receiving chip 140 is located and the main optical axis 122 of the lens 121 have an angle greater than 0 degrees. Alternatively, it can be understood that the plane where the light receiving chip 140 is located intersects with the bearing surface of the tube base 130, the light receiving chip 140 is not parallel to the bearing surface of the tube base 130, and the light receiving chip 140 is tilted in the receiving cavity. The center of the light receiving chip 140 can be located on the main optical axis 122.

[0046] In the package structure shown in Figure 1 , the signal light transmitted through the optical fiber 111 directly enters the lens 121, is focused by the lens 121, and then is directly received by the optical receiver chip 140. Because the optical receiver chip 140 is arranged at an angle within the accommodating cavity, the focused signal light received by the optical receiver chip 140 is reflected at a large angle at the optical receiver chip 140. As a result, most of the signal light reflected from the optical receiver chip is emitted from the edge of the lens 121 and cannot be converged at the optical fiber 111, thereby improving the return loss capability of the package structure.

[0047] FIG2 is a schematic diagram of another packaging structure provided by an embodiment of the present application. As shown in FIG2 , the packaging structure may include a ferrule 210 , an optical fiber 211 , a cap 220 , a lens 221 , a socket 230 , a light receiving chip 240 , and a beam splitter 250 .

[0048] Ferrule 210, optical fiber 211, cap 220, lens 221, socket 230, and optical receiver chip 240 are similar to ferrule 110, optical fiber 111, cap 120, lens 121, socket 130, and optical receiver chip 140 in FIG1 , and are not further described here. Similarly to FIG1 , a normal 241 to the plane on which optical receiver chip 240 lies forms an angle greater than 0 degrees with the principal optical axis 222 of lens 221.

[0049] The beam splitter 250 is disposed between the optical fiber 211 and the lens 221 included in the tube cap 220. The beam splitter 250 is used to reflect the signal light emitted by the optical fiber 111, allowing the signal light to enter the lens 221, be focused by the lens 221, and then be emitted. The focused signal light is directly received by the optical receiver chip 240. Because the optical receiver chip 240 is disposed at an angle within the accommodating cavity, the focused signal light received by the optical receiver chip 240 is reflected at a large angle at the optical receiver chip 240. As a result, most of the signal light reflected from the optical receiver chip is emitted from the edge of the lens 221, and only a small amount of the signal light is reflected back to the optical fiber 211 by the beam splitter 250. Therefore, the signal light reflected from the optical receiver chip 240 cannot be re-converged at the optical fiber 211, thereby improving the return loss capability of the packaging structure.

[0050] Figure 3 is a schematic diagram of the optical path in a package structure provided by an embodiment of the present application. In the package structures shown in Figures 1 and 2, the incident path of the signal light on the lens coincides with the principal optical axis. This improves the coupling efficiency between the optical fiber and the lens, reduces the difficulty of the coupled light search process, and further improves the coupling efficiency of the signal light incident on the lens in the package structure while ensuring high return loss of the signal light reflected from the optical receiving chip in the package structure.

[0051] As an implementation, as shown in Figure 3(a), optical fiber 310, lens 320, and light receiving chip 330 are arranged sequentially along the principal optical axis of lens 320. Optical fiber 310 is located on the principal optical axis, and the light outlet of optical fiber 310 is aligned with the center of lens 320. This improves the coupling efficiency between the optical fiber and the lens and reduces the difficulty of coupling and light tracking. The optical path shown in Figure 3(a) can be applied to the package structure shown in Figure 1.

[0052] As another implementation, as shown in Figure 3(b), optical fiber 310, beamsplitter 340, lens 320, and optical receiver chip 330 are arranged sequentially along the signal light transmission path. The angle between the line containing optical fiber 310 and beamsplitter 340 is equal to the angle between the beamsplitter 340 and the principal optical axis of lens 320, so that the incident path of the signal light on the lens coincides with the principal optical axis. This improves the coupling efficiency between the optical fiber and the lens and reduces the difficulty of coupling and light tracking. The optical path shown in Figure 3(b) can be applied to the package structure shown in Figure 2. In the case shown in Figure 3(b), the center of optical fiber 310 is aligned with the center of beamsplitter 340, the center of lens 320 is aligned with the center of beamsplitter 340, the angle between the line containing optical fiber 310 and beamsplitter 340 is 45 degrees, and the angle between the principal optical axis of beamsplitter 340 and lens 320 is also 45 degrees. Furthermore, depending on the specific design of the package structure, the specific angles can be other degrees. In addition, the same angle referred to in this application can also be understood as the difference between the two angles being less than 1 degree.

[0053] In addition, in the packaging structure provided in the present application, one or more prisms, or multiple optical elements such as beam splitters can be arranged between the optical fiber and the lens so that the incident path of the signal light on the lens coincides with the main optical axis. The present application does not impose any restrictions on this.

[0054] Figure 4 is a schematic diagram of the mounting of a light receiving chip provided in an embodiment of the present application. In some implementations, the light receiving chip is mounted on a carrier module having an inclined surface, and the carrier module can specifically refer to a gasket, a groove, a boss or a column. As shown in Figure 4 (a), the light receiving chip 410 can be mounted on a gasket 420 having an inclined surface. As shown in Figure 4 (b), the light receiving chip 410 can be mounted in a groove 430 having an inclined surface. In addition, the light receiving chip can also be mounted on a boss or a column having an inclined surface, and this application does not limit this.

[0055] In some implementations, the height of the carrier module is adjustable, and the carrier module is used to adjust the distance between the light receiving chip and the lens. The distance between the light receiving chip and the lens is determined according to the focal length of the lens, thereby determining the size of the receiving light spot on the light receiving chip, ensuring that the light receiving chip can correctly identify the focused signal light.

[0056] Figure 5 is a schematic diagram of a method for determining the distance between a light receiving chip and a lens provided in an embodiment of the present application. According to the geometric optics lens imaging formula: 1 / f = 1 / u + 1 / v. Wherein, f is the focal length, u is the object distance, and v is the image distance. The focal length f can be determined according to the specific model of the lens. The object distance u can be determined according to the position of the light exit point of the signal light. For example, the position of the light exit point in Figure 1 can be understood as the light exit position of the optical fiber, or the position of the light exit point in Figure 2 can be understood as the reflection position of the signal light in the spectrometer. After the signal light is emitted from the light exit point, it has a certain divergence. After determining the object distance f and the object distance u, the distance v can be determined according to the incident direction of the signal light on the lens. Thus, the distance between the light receiving chip and the lens is determined according to the distance v, a corresponding carrier module is set on the tube seat, and the light receiving chip is tilted and mounted on the carrier module, and the tube cap including the lens is welded to the tube seat.

[0057] In some implementations, in the packaging structure of the present application, the angle between the normal of the plane where the optical receiver chip resides and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 25 degrees. This ensures that the size of the received light spot on the optical receiver chip is large enough to enable the optical receiver chip to correctly identify the focused signal light. It also ensures that a large-angle reflection is formed at the reflective surface of the optical receiver chip, increasing the aberration of the reflected light beam and improving the return loss capability. The following describes the lens configurations for both non-spherical and spherical lens configurations in conjunction with Figures 6 and 7.

[0058] Figure 6 is a schematic diagram of the optical coupling and optical return loss structure of a package structure provided in an embodiment of the present application. As shown in Figure 6(a), an optical fiber (simplified as a dot in the figure), a lens 610, and a light receiving chip 620 are arranged in sequence along the principal optical axis of lens 610, wherein lens 610 is an aspherical lens. As the angle θ between the normal of the plane on which light receiving chip 620 resides and the principal optical axis of lens 610 varies, the corresponding return loss of the package structure is shown in Table 1.

[0059] Table 1

[0060] As shown in Table 1, when the angle θ is between 6 and 10 degrees, the package structure's return loss exceeds 30 dB, meeting the high-return-loss package structure requirements of RoF systems. When the angle θ is between 8 and 10 degrees, the package structure's return loss exceeds 45 dB, significantly improving the package's return loss capability.

[0061] Figure 6(b) shows the focused signal light spot received by the optical receiver chip when the angle θ is 10 degrees and the signal light energy emitted from the optical fiber is 1 W. As shown in Figure 6(a), the received light power on the circular photosensitive surface with a diameter of 20 μm in the optical receiver chip is approximately 0.93 W, and the optical coupling efficiency of the package structure is approximately 93%.

[0062] Figure 6(c) shows the energy distribution of the light reflected from the optical receiving chip back to the optical fiber outlet when θ is 10 and the signal light energy emitted from the optical fiber is 1W. The optical fiber outlet is a 9μm circular port, and the energy at the outlet is about 7×10 -5 W, the return loss of the package structure reaches -41.5dB.

[0063] When the lens is non-spherical, the object distance and phase distance are close, and the angle and return loss relationship are consistent. When the angle between the normal of the lens and the main optical axis is greater than or equal to 6 degrees and less than or equal to 10 degrees, it can not only ensure the return loss capability of the packaging structure, but also ensure that the optical receiving chip meets the response index.

[0064] Figure 7 is a schematic diagram of the optical coupling and optical return loss structure of a package structure provided in an embodiment of the present application. As shown in Figure 7(a), an optical fiber (simplified as a dot in the figure), a lens 710, and a light receiving chip 720 are arranged in sequence along the principal optical axis of lens 710, wherein lens 710 is a spherical lens. As the angle θ between the normal of the plane on which light receiving chip 720 resides and the principal optical axis of lens 710 varies, the corresponding return loss of the package structure is shown in Table 2.

[0065] Table 2

[0066] As shown in Table 2, when the θ angle is 2 to 4 degrees, the package structure's return loss exceeds 30 dB, meeting the high-return-loss package structure requirements of RoF systems. When the θ angle is 4 to 6 degrees, the package structure's return loss exceeds 45 dB, significantly improving return loss. When the θ angle is 6 to 8 degrees, the package structure's return loss exceeds 55 dB.

[0067] Figure 7(b) shows the focused signal light spot received by the optical receiving chip, and Figure 7(c) shows the energy distribution of the light reflected from the optical receiving chip back to the light outlet of the optical fiber.

[0068] Spherical lenses have large phase differences and different angular return loss relationships. When the angle between the normal of the lens and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 8 degrees, it can ensure both the return loss capability of the packaging structure and the response index of the optical receiving chip.

[0069] FIG8 is a schematic diagram of the optical path in another packaging structure provided in an embodiment of the present application. As shown in FIG8 , an optical filter 840 may be provided between the lens 820 and the optical receiving chip 830, and the optical filter 840 may be located on the reflection path of the signal light on the optical receiving chip 830. Alternatively, the optical filter 840 may be located on the normal line of the plane where the optical receiving chip 830 is located. The optical filter is used to absorb the signal light reflected from the optical receiving chip. This reduces the intensity of the signal light reflected from the optical receiving chip, further improving the return loss capability of the packaging structure. The optical filter may specifically be filter glass, an optical filter, etc., and this application does not impose any restrictions on this.

[0070] In some implementations, a filter film may also be attached to the edge of the lens 820. The attached filter film can reduce the intensity of the signal light reflected from the optical receiving chip 830 to the edge of the lens, further improving the return loss capability of the packaging structure. The filter film attached to the edge of the lens can specifically refer to the edge of the side of the lens 820 adjacent to the optical fiber 810 being attached to the filter film, and / or the edge of the side of the lens adjacent to the optical receiving chip 830 being attached to the filter film. The filter film material can be Cr2O3, etc., determined according to actual conditions, and this application does not impose any restrictions on this.

[0071] The package structure shown in FIG1 or FIG2 may also include a light emitting chip. In some implementations, the light emitting chip and the light receiving chip may be disposed in the same housing. In some implementations, the package structure further includes another tube base and another tube cap, the other tube base and the other tube cap cooperating to form another housing cavity, and the light emitting chip is disposed in the other housing cavity.

[0072] In some implementations, the package structure may include only one optical receiving chip, and the package structure is a single-receiver mode optical receiving device.

[0073] In some implementations, the package structure further includes one or more optical receiving chips, and the package structure is an optical receiving device in a one-transmitter-one-receiver mode or a multi-receiver mode.

[0074] In some implementations, the package structure includes not only one or more optical receiving chips, but also a multi-receiving mode optical receiving device.

[0075] In some implementations, the packaging structure further includes one or more optical transmitter chips and one or more optical receiver chips, and the packaging structure is an optical transceiver device in a multi-transmitter and multi-receiver mode.

[0076] Among them, the light receiving chip referred to in this application can be any chip that receives signal light and converts the signal light into an electrical signal. For example, the light receiving chip can be a photodiode (PD) chip, a photomultiplier tube chip, an avalanche photodiode (APD) chip, etc., and this application does not limit this. The light emitting chip referred to in this application can be any chip that receives an electrical signal and converts the electrical signal into signal light and sends it. For example, the light emitting chip can be a vertical cavity surface emitting laser chip, a Fabry-Perot laser chip, a horizontal cavity surface emitting laser chip, an electro-absorption modulation chip, a distributed feedback chip, etc., and this application does not limit this.

[0077] In addition, the package structure may also include an amplifier chip, which can be disposed in the same housing as the optical receiver chip. The amplifier chip is used to amplify the electrical signal converted by the optical receiver chip. The amplifier chip can be a transimpedance amplifier chip, a limiting amplifier chip, an automatic gain amplifier chip, etc., and this application does not impose any restrictions on this.

[0078] Among them, the mounting methods of the optical transmitter chip and the optical receiver chip can be active mounting or passive mounting. Active mounting can be understood as a packaging structure that includes optical components with active functions, such as optical modulators, etc. Through active coupling, multiple light beams can be combined in different dimensions, that is, the overall package appears to the outside as a single-beam optical path component containing different optical signals. Passive mounting can be understood as a packaging structure that only includes optical components with passive functions, such as optical isolators, splitters, optical switches, etc. Through passive mounting, multiple light beams can be combined in different dimensions, that is, the overall package appears to the outside as a single-beam optical path component containing different optical signals.

[0079] It should be understood that the packaging structure shown in Figure 1 and the packaging structure shown in Figure 2 only illustrate the form of a transmitter optical subassembly (TOSA) and a bidirectional optical sub-assembly (BOSA). In addition, the packaging structure provided in this application is also applicable to, for example, a triplexer optical transceiver assembly and a quad-optical sub-assembly (Quad-OSA), and this application does not limit the specific packaging form.

[0080] FIG9 illustrates an optical module provided in an embodiment of the present application. As shown in FIG9 , the optical module includes a packaging structure 910 and a processor 920. The packaging structure 910 may be the packaging structure shown in FIG1 through FIG7 . The packaging structure is configured to receive signal light and convert it into an electrical signal, and the processor 920 is configured to receive the electrical signal and obtain data. The processor 920 may be in the form of a processing chip.

[0081] FIG10 is another optical module provided in an embodiment of the present application. As shown in FIG10 , the optical module includes a light source 1010, a driver 1020, a processor 1030, and a packaging structure 1040. The packaging structure 1010 may be the packaging structure shown in FIG1 to FIG7 , and the packaging structure 1010 includes a light emitting chip 1041 and a light receiving chip 1042.

[0082] The light source 1010 is used to emit a light beam. The driver 1020 is used to send an electrical signal that carries data. The driver 1020 is connected to the light emitting chip 1041. The light emitting chip 1041 modulates the light beam according to the electrical signal to transmit the signal light. The driver 1020 can be in the form of a driver chip.

[0083] The optical receiving chip 1042 is used to receive another signal light and convert the signal light into another electrical signal, and the processor 1030 is used to receive the electrical signal and obtain data. The processor 1030 can be in the form of a processing chip.

[0084] Figure 11 is a schematic diagram of an optical communication system provided in an embodiment of the present application. As shown in Figure 11, the optical communication system may include an electronic device 1110 and an optical module as shown in Figure 9 or Figure 10. Electronic device 1110 may be any one of a switch, a fiber optic router, and a fiber optic network card, and the electronic device is connected to the optical module.

[0085] The electronic device 1110 may include multiple ports, each corresponding to an optical transmission channel. The ports are connected to optical modules, thereby enabling multi-channel, high-speed data transmission. A switch may be used to exchange data between multiple transmission channels. A fiber optic router may be used to convert optical signals into data signals and forward and route the data signals. A fiber optic network card may be used in an Ethernet network to connect computers to optical fibers.

[0086] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An encapsulation structure, characterized in that, Comprising: An optical ferrule, including an optical fiber for transmitting signal light; A ferrule cap, including a lens for focusing the signal light; A ferrule base, which cooperates with the ferrule cap to form a receiving cavity, and a photoreceiving chip is disposed in the receiving cavity for receiving the focused signal light. Wherein, the included angle between the normal line of the plane where the photoreceiving chip is located and the principal optical axis of the lens is greater than 0 degrees.

2. The encapsulation structure according to claim 1, wherein The included angle between the normal line and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 25 degrees.

3. The encapsulation structure according to claim 2, wherein When the lens is non-spherical, the included angle between the normal line and the principal optical axis is greater than or equal to 6 degrees and less than or equal to 10 degrees.

4. The encapsulation structure according to claim 2, wherein When the lens is spherical, the included angle between the normal line and the principal optical axis is greater than or equal to 2 degrees and less than or equal to 8 degrees.

5. The encapsulation structure according to any one of claims 1 to 4, characterized in that, Wherein: A filter film is attached to the edge of the lens; and / or A filter is disposed between the lens and the photoreceiving chip, and the filter is located on the reflection path of the signal light on the photoreceiving chip.

6. The encapsulation structure according to any one of claims 1 to 5, characterized in that, The photoreceiving chip is mounted on a carrier module having an inclined surface.

7. The encapsulation structure according to claim 6, wherein The height of the carrier module is adjustable.

8. The encapsulation structure according to any one of claims 1 to 7, characterized in that, The optical fiber is located on the principal optical axis.

9. The encapsulation structure according to any one of claims 1 to 8, characterized in that, A beam splitter is disposed between the optical ferrule and the lens. The center of the beam splitter is located on the principal optical axis, and the included angle between the straight line where the optical fiber is located and the beam splitter is equal to the included angle between the beam splitter and the principal optical axis.

10. The encapsulation structure according to any one of claims 1 to 9, characterized in that It further includes a light emitting chip, wherein: The light emitting chip is disposed in the receiving cavity; or The packaging structure further includes another ferrule base and another ferrule cap. The another ferrule base and the another ferrule cap cooperate to form another receiving cavity, and the light emitting chip is disposed in the another receiving cavity.

11. An optical module, characterized in that, Comprising a processor and the packaging structure according to any one of claims 1 to 10.

12. The optical module according to claim 11, wherein The optical module further includes a light source and a driver.

13. An optical communication system, characterized in that, Comprising an electronic device and the optical module according to claim 11 or 12. Wherein, the electronic device is connected to the optical module, and the electronic device is any one of a switch, an optical fiber router, and an optical fiber network card.

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