Multi-mode packaging lens and multi-mode optical module

Abstract

The utility model relates to a kind of multi-mode packaging lenses, including top and the side portion at top edge, the upper surface of top is equipped with first light transmission structure, the lower surface of top is equipped with second light transmission structure and weak light structure, first light transmission structure is used to collimate light beam and reflect collimated light beam to the lower surface of top, second light transmission structure is used to gather and emit the light beam of reflection to cover-like structure outside, weak light structure is used to weaken the light energy of the second light transmission structure from outside back into the cover-like structure.Also provide a kind of multi-mode optical module.The utility model can realize collimation, reflection, convergence and weaken light energy function by integrating multiple functional structures on multi-mode packaging lens;The included angle between total reflection surface and the mounting surface of cover-like structure is between 50~54 degrees, which can optimize optical path return loss performance;Two groups of light receiving components are point symmetrical, which can still avoid the disadvantage that two TIA chips are difficult to place pad without mirror image version TIA.

Description

Technical Field

[0001] This utility model relates to the field of optical communication technology, specifically to a multimode packaged lens and a multimode optical module. Background Technology

[0002] For single-channel 50G optical module products, the 400G optical module receiver has eight channels. Two four-channel PD optical chip arrays and two TIA electrical chips are arranged within the COB area of ​​the PCBA. The PD chip arrays must ensure that their photosensitive surfaces are on the same straight line, and the distance between adjacent channels of two PD chips is constant. Some TIA models have original and mirror versions, where the PD and TIA chips are basically symmetrically distributed, and no bonding pads are needed in the area between the two TIA chips on the PCBA. However, for TIA models without mirror versions, if a symmetrical distribution is used, the gap between the two TIA chips is very small, leaving no space for gold wire bonding pads, making it difficult to place bonding pads between the two TIA chips.

[0003] Furthermore, the return loss performance of an optical module reflects the intensity of reflected light within the module's internal optical path. For high-speed optical modules, high return loss performance is crucial; generally, a higher return loss value is more beneficial to the module's performance. The inherent reflectivity of the PD photosensitive surface has a decisive impact on return loss performance. However, existing manufacturers have design flaws in reflectivity, leading to deviations in module return loss performance and affecting overall module performance. Utility Model Content

[0004] The purpose of this invention is to provide a multimode packaged lens and a multimode optical module, which can at least solve some of the defects in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multimode encapsulation lens, including a top and a side portion located at the edge of the top, the top and the side portion forming a cover-like structure for encapsulating a chip, a first light-giving structure being provided on the upper surface of the top, and a second light-giving structure and a light-weakening structure being provided on the lower surface of the top, the first light-giving structure being used to collimate a light beam and reflect the collimated light beam to the lower surface of the top, the second light-giving structure being used to converge the reflected light beam and emit it outside the cover-like structure, and the light-weakening structure being used to reduce the light energy returning to the cover-like structure from the second light-giving structure.

[0006] Furthermore, the upper surface of the top is recessed downward to form an air cavity, and the first light-giving structure is located on the side of the air cavity closer to the light source.

[0007] Furthermore, the first light-transmitting structure includes a first even-order aspherical surface for collimating a beam with a divergence angle into a collimated beam and a total reflection surface for reflecting the collimated beam to the lower surface of the top.

[0008] Furthermore, the angle between the total reflective surface and the mounting surface of the cover structure is between 50 and 54 degrees.

[0009] Furthermore, the second light-emitting structure includes a second even-order aspherical surface for converging the reflected light beam and projecting it out of the cap-like structure.

[0010] Furthermore, the low-light structure has a frosted surface, which is located on the side of the second light-giving structure.

[0011] Furthermore, there are multiple frosted surfaces, each of which is located on the side of the second light-transmitting structure.

[0012] This utility model embodiment provides another technical solution: a multimode optical module, including two sets of light receiving components, and also including the above-mentioned multimode encapsulated lens, wherein both sets of light receiving components are located in the encapsulation area of ​​the cover-like structure cover.

[0013] Furthermore, the two sets of optical receiving components are point-symmetric to each other.

[0014] Furthermore, each of the optical receiving components includes a PD chip and a TIA chip, and the two PD chips and / or the two TIA chips are point-symmetric to each other.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. By integrating multiple functional structures on a multimode packaged lens, functions such as collimation, reflection, focusing, and light energy reduction can be achieved, making the structure of the packaged lens more compact and improving the performance of the optical module.

[0017] 2. The angle between the total reflection surface and the mounting surface of the cover structure is between 50 and 54 degrees, which can optimize the optical path return loss performance and improve the module performance.

[0018] 3. The two sets of optical receiving components are point-symmetric to each other, which can avoid the disadvantage of difficulty in placing pads on two TIA chips even without a mirror version of TIA. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a multi-mode packaged lens disposed on a PCBA board according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of a multimode optical module with two sets of optical receiving components that are point-symmetric to each other, provided in an embodiment of the present invention.

[0021] Figure 3A top-view schematic diagram of a multimode optical module provided for an embodiment of this utility model;

[0022] Figure 4 A side view schematic diagram of a multimode optical module provided for an embodiment of this utility model;

[0023] In the attached figures: 1-Multimode encapsulated lens; 110-Air cavity; 111-Total reflection surface; 120-First even-order aspherical surface; 130-Second even-order aspherical surface; 140-First frosted surface; 150-Second frosted surface; 2-PCBA board; 210-PD chip placement area; 211-Symmetric point; 310-Upper surface of PD chip; 320-First PD chip; 330-Second PD chip; 4-First TIA chip; 410-Upper surface of first TIA chip; 5-Second TIA chip; 510-Upper surface of second TIA chip; 6-Multimode optical fiber; 7-MT ferrule; 8-Transmitter lens; 9-DSP chip; 10-Mimi-MT ferrule; A-Top; a1-Upper surface of top; a2-Lower surface of top; B-Side. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0025] Please see Figure 1 This utility model provides a multimode encapsulation lens, including a top A and a side B located at the edge of the top A. The top A and the side B enclose a cover-like structure for encapsulating a chip. The key feature is that a first light-giving structure is provided on the upper surface a1 of the top, and a second light-giving structure and a light-weakening structure are provided on the lower surface a2 of the top. The first light-giving structure collimates the light beam and reflects it to the lower surface a2 of the top. The second light-giving structure converges the reflected light beam and emits it outside the cover-like structure. The light-weakening structure reduces the light energy returning to the cover-like structure from the second light-giving structure. In this embodiment, by integrating multiple functional structures on the multimode encapsulation lens 1, the functions of collimation, reflection, convergence, and light energy reduction can be achieved, making the structure of the encapsulation lens more compact and improving the performance of the optical module. Specifically, the cover lens has a certain thickness, thus defining the upper surface a1 and the lower surface of the top. The side B surrounds the edge of the top A, forming a lid-like structure, such as... Figure 1The diagram shows how both the PD chip and the TIA chip can be encapsulated within the lens. This lens has multiple functions. On the top surface a1, it needs to collimate incoming light with a diverging angle into a collimated beam, and then reflect this collimated beam to the bottom surface a2. Therefore, a first light-giving structure is designed on the top surface a1. On the bottom surface a2, it needs to converge the reflected beam before projecting it out of the cover structure. Therefore, a second light-giving structure is designed on the bottom surface a2. Simultaneously, since light from outside the multimode packaged lens 1 will re-enter the multimode packaged lens 1 through the second light-giving structure, a light-weakening structure can be designed on the bottom surface a2 to reduce this light energy and avoid affecting device performance. Specifically, the light entering the multimode packaged lens 1 from the outside is the light reflected from the top surface 310 of the PD chip.

[0026] Please see Figure 1 The upper surface a1 of the top is recessed downward to form an air cavity 110, and the first light-giving structure is located on the side of the air cavity 110 closer to the light source. In this embodiment, the air cavity 110 is designed to facilitate the positioning of the first light-giving structure.

[0027] Please see Figure 1The first light-giving structure includes a first even-order aspherical surface 120 for collimating a beam with a divergence angle into a collimated beam, and a total reflection surface 111 for reflecting the collimated beam to the lower surface a2 of the top. In this embodiment, an even-order aspherical surface is used to collimate the beam, and a total reflection surface 111 is used to reflect the collimated light to the lower surface a2 of the top. Preferably, the angle between the total reflection surface 111 and the mounting surface of the cover structure is between 50 and 54 degrees, which can optimize the optical path return loss performance and improve the module performance. This angle is preferably 52°. Preferably, the second light-giving structure includes a second even-order aspherical surface 130 for converging the reflected beam and projecting it out of the cover structure. The weak light structure is a frosted surface, which is located on the side of the second light-giving structure. There are multiple frosted surfaces, each located on the side of the second light-giving structure. The upper surface a1 of the top protrudes upward to form a convex portion, and the side of the convex portion near the light source is the first even-order aspherical surface 120. Specifically, the multimode encapsulation lens 1 is made of PEI plastic, and there is a 52° total internal reflection surface 111 at the junction of the air cavity 110 and the multimode encapsulation lens 1. Light is emitted from the multimode fiber 6 and enters the multimode encapsulation lens 1. The light rays emitted from the multimode fiber 6 with a certain divergence angle are collimated by the first even-order aspherical surface 120 and propagate inside the multimode encapsulation lens 1. After total internal reflection by the total internal reflection surface 111, they continue to propagate inside the multimode encapsulation lens 1. After being converged by the second even-order aspherical surface 130, they are incident on the upper surface 310 of the PD chip. The upper surface 310 of the PD chip has a light reflectivity of 2%. If the tilt angle of the total reflection surface 111 is 45°, the light emitted from the multimode fiber 6 will reach the upper surface 310 of the PD chip, and a portion will be reflected. This reflected light will then enter the multimode packaging lens 1 through the second even-order aspherical surface 130, passing sequentially through the total reflection surface 111 and the first even-order aspherical surface 120 before entering the multimode fiber 6. The reflected light energy, measured by the return loss index, is 19.8 dB. Excessive reflected light entering the multimode fiber 6 via this path reduces module performance. If the tilt angle of the total reflection surface 111 is 52°, after reflection from the upper surface 310 of the PD chip, most of the reflected light will be reflected to the first frosted surface 140 and the second frosted surface 150 on the lower surface of the multimode packaging lens 1, with a small portion reflected to the second even-order aspherical surface 130 before entering the multimode packaging lens 1. The final reflected light energy entering the multimode fiber 6 is 30.32 dB. Since both the first frosted surface 140 and the second frosted surface 150 are frosted surfaces, the reflected light incident on these surfaces undergoes diffuse reflection. The reflected light is reflected by the first frosted surface 140 and the second frosted surface 150 and enters the upper surface 410 of the first TIA chip and the upper surface 510 of the second TIA chip, respectively. The reflected energy values ​​are 27.9dB and 37.57dB, respectively. This part of the light energy is relatively weak and will not affect the electrical performance of the TIA chip.As can be seen, when the total reflection surface 111 changes from 45° to 52°, the lens return loss increases from 19.8dB to 30.32dB. The 30.32dB reflected light has little impact on the module performance and complies with industry standards.

[0028] Please see Figures 1 to 4 This utility model embodiment provides a multimode optical module, including two sets of light receiving components and the aforementioned multimode encapsulated lens 1. Both sets of light receiving components are located within the encapsulation area of ​​the cover-like structure. In this embodiment, using the aforementioned multimode encapsulated lens 1 in the multimode optical module can improve the module's performance. The multimode encapsulated lens 1 is mounted on the PCBA board 2 and can be bonded with adhesive. The mounting surface of the multimode encapsulated lens 1 is the surface of the PCBA board 2. Therefore, the angle between the total reflection surface 111 and the mounting surface of the cover-like structure in the above embodiment is between 50 and 54 degrees, that is, the angle between the total reflection surface 111 and the upper surface of the PCBA board 2 is between 50 and 54 degrees. The PCBA board 2 has a PD chip placement area 210.

[0029] Please see Figure 2 The two sets of optical receiving components are point-symmetric to each other. In this embodiment, the point-symmetry of the two sets of optical receiving components avoids the disadvantage of difficulty in placing pads on the two TIA chips even without a mirrored version of the TIA. Specifically, each optical receiving component includes a PD chip and a TIA chip, and the two PD chips and / or the two TIA chips are point-symmetric to each other. The first TIA chip 4 and the second TIA chip 5 are point-symmetrically distributed based on the symmetry point 211, that is, a 180° rotational symmetry distribution, with the symmetry point 211 being a virtual point. The first PD chip 320 and the second PD chip 330 can also be point-symmetrically distributed based on the symmetry point 211. This distribution still avoids the disadvantage of difficulty in placing pads on the two TIA chips even without a mirrored version of the TIA.

[0030] Please see Figure 3 and Figure 4This multimode optical module also includes a PCBA board 2, a DSP chip 9, a transmitting lens 8, an MT ferrule 7, and a mini-MT ferrule 10. The multimode encapsulated lens 1, the transmitting lens 8, the first PD chip 320, the second PD chip 330, the first TIA chip 4, the second TIA chip 5, and the DSP chip 9 are all mounted on the PCBA board 2. There are two mini-MT ferrules 10 connected to the MT ferrule 7 via optical fibers. The bottom surface of the multimode encapsulated lens 1 is fixed to the PCBA board 2. The DSP chip 9 is located on the side of the multimode encapsulated lens 1 closest to the optical module's electrical port. A cavity is formed between the multimode encapsulated lens 1 and the PCBA board 2, and the first PD chip 320, the second PD chip 330, the first TIA chip 4, and the second TIA chip 5 are all encapsulated within this cavity. By adopting the above multimode packaged lens 1, the optical module can be adapted to a 180° rotationally symmetrical layout of PD chips and TIA chips while meeting the requirements of existing fiber optic patch cords; for the case of 2% reflectivity of PD chip photosensitive surface, the optical path return loss performance is excellent and the module performance meets the standards.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multimode packaged lens, comprising a top and a side portion located at the edge of the top, the top and the side portion forming a cap-like structure for encapsulating a chip, characterized in that: The top surface is provided with a first light-giving structure, and the bottom surface of the top is provided with a second light-giving structure and a dimming structure. The first light-giving structure is used to collimate the light beam and reflect the collimated light beam to the bottom surface of the top. The second light-giving structure is used to converge the reflected light beam and emit it outside the cover structure. The dimming structure is used to weaken the light energy that returns to the cover structure from the second light-giving structure.

2. The multimode packaged lens as described in claim 1, characterized in that: The upper surface of the top is recessed downward to form an air cavity, and the first light-giving structure is located on the side of the air cavity closer to the light source.

3. The multimode packaged lens as described in claim 1, characterized in that: The first light-transmitting structure includes a first even-order aspherical surface for collimating a beam with a divergence angle into a collimated beam and a total reflection surface for reflecting the collimated beam to the lower surface of the top.

4. The multimode packaged lens as described in claim 3, characterized in that: The angle between the total reflective surface and the mounting surface of the cover structure is between 50 and 54 degrees.

5. The multimode packaged lens as described in claim 1, characterized in that: The second light-emitting structure includes a second even-order aspherical surface for focusing the reflected light beam and projecting it out of the cap-like structure.

6. The multimode packaged lens as described in claim 1, characterized in that: The low-light structure has a frosted surface, which is located on the side of the second light-giving structure.

7. The multimode packaged lens as described in claim 6, characterized in that: There are multiple frosted surfaces, and each frosted surface is located on the side of the second light-transmitting structure.

8. A multimode optical module, comprising two sets of optical receiving components, characterized in that: It also includes a multimode packaged lens as described in any one of claims 1-7, wherein both sets of light receiving components are located within the packaged area of ​​the cover-like structure.

9. The multimode optical module as described in claim 8, characterized in that: The two sets of optical receiving components are point-symmetric to each other.

10. The multimode optical module as described in claim 8, characterized in that: Each of the optical receiving components includes a PD chip and a TIA chip, and the two PD chips and / or the two TIA chips are point-symmetric to each other.

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