Light engine for coupling array light sources with array optical fibers

Abstract

The light engine of this invention primarily provides an aperture plate positioned between the array light sources and the array optical fibers. By calculating and setting the distance between the array light sources and the aperture plate, the divergence angle of the array light sources can cover the core diameter of the array optical fibers. This design not only improves passive coupling efficiency but also enhances assembly convenience and efficiency. Additionally, the emission surface of the array light sources is covered with a high-refractive-index encapsulant to adjust the divergence angle of the light, concentrating it within the core diameter range of the array optical fibers. This reduces light reflection from the array light sources, minimizes noise, lowers coupling loss, and enhances optical communication performance.

Description

[Technical Field]

[0001] This invention relates to an optical engine that couples an array of light sources and an array of optical fibers, and more particularly to an optical engine that uses a beam of light carrying optical signals to perform high-speed signal transmission, which not only reduces insertion loss, but also reduces light reflection and noise, thereby improving the optical communication effect. [Previous Technology]

[0002] Note: Network data volume continues to grow exponentially with the development of the technology industry. Applications such as 5G, AI, self-driving cars, and AR / VR will continue to generate more digital data, and network traffic growth has no end. The demand for bandwidth expansion for transmission network systems, which play a fundamental backbone role, is becoming increasingly urgent. In the next few years, 400G fiber optic networks will gradually become the main backbone network, replacing the current architecture dominated by 100G. In particular, the accelerated growth of hyperscale data centers and supercomputing will continue to expand the demand for bandwidth.

[0003] As data centers move towards hyperscale development, the reason is that the amount of data in future network applications will continue to grow, and the demand for data interconnection will greatly increase. Centralizing servers and data allows for more effective management. In the past, a data center had only a few hundred servers, but a hyperscale data center may have more than 100,000 servers. The number of interconnecting such a large number of servers is considerable. According to statistics, three-quarters of the total data transmission volume of a data center is internal data interconnection, and only one-quarter is used for external transmission. The number of connections increases more than linearly with the number of servers.

[0004] Because optical signals transmitted in optical fibers can travel longer distances and have lower distortion compared to electrical signals transmitted in cables, and because optical communication has characteristics such as low transmission loss, high data security, excellent anti-interference ability, and ultra-high bandwidth, it has become the main information communication method in modern times and has been developing rapidly in recent years. Furthermore, because the bandwidth of optical signals is much higher than that of electrical signals, most servers in data centers currently use optical signals for communication.

[0005] However, optical communication systems must handle optical signal splitting, combining, switching, and modulation. Therefore, in addition to optical fibers, other electronic chips capable of processing optical signals are still needed, which we call "optical waveguide elements" or integrated optical circuits (OICs). Among them, silicon photonic integrated circuits (SPICs) refer to the integration of numerous optical components into one using silicon manufacturing processes, enabling the conversion of electrical signals into optical signals and copper into optical fibers, thus overcoming the speed, bandwidth, and heat problems of traditional electrical signal transmission. Silicon photonics and its related high-speed optical transmission modules have advantages such as high bandwidth, high speed, and no electromagnetic interference, aiming to replace copper or metal electrical signal conductors, and can simultaneously solve issues such as increased transmission distance, rapid growth in data bandwidth, and power consumption cooling. Silicon photonic integrated circuits are considered a very important emerging technology with no other alternatives at present, suitable for applications in data centers, high-performance computing, etc. Co-Package Optics (CPO) refers to the technology of "packaging optical chips / modules and electronic chip modules together". CPO products are mostly used in AI servers, cloud servers, and high-speed transmission servers.

[0006] The aforementioned optical communication systems all require converting electrical signals into optical signals via optical emitting elements, and then coupling the optical signals into the optical fiber that transmits the optical signals. In the prior art, optical emitting elements can utilize light sources such as vertical cavity surface-emitting lasers (VCSELs) or laser diodes (LDs) to emit beams carrying optical signals. Laser diode 15 has a resonant cavity, causing the beam to be emitted along the direction of the reflector, resulting in a smaller divergence angle, as shown in Figure 1. If a light-emitting diode array is used to provide a beam carrying optical signals, and light-emitting diode 61 is a scattering and omnidirectional light source, its light diffusion is a divergence angle. Whether it is laser diode 62 or light-emitting diode 61, its light is in a divergent form. In collimation applications, lenses are usually further used to collimate the divergent beam into a parallel beam, and lenses are used to convert the divergent beam into a slightly converged beam for transmission to the optical fiber.

[0007] However, in the manufacturing process, the multiple lenses must undergo a positional calibration procedure with the light-emitting sub-module. During calibration, optical correction instruments are required to ensure that the multiple lenses are accurately aligned and coupled to the light source. Since these optical correction instruments are very expensive and time-consuming, and general assembly plants do not possess the technology to calibrate the light-directing device and the coupling, it is inconvenient for mass production and division of labor assembly. Furthermore, the use of more lenses and other optical devices increases the overall manufacturing cost of the optical communication module. Moreover, the limitation of this type of optical fiber and lens array in the prior art is that since the lens and optical fiber are separate components, it is difficult to optimally align the core region of the optical fiber with the lens, which results in insertion loss, increases the loss of optical signal energy, and affects the performance of optical communication. [Summary of the Invention]

[0008] This invention relates to an optical engine coupled to an array of light sources and an array of optical fibers, and more particularly to an optical engine that uses a beam of light carrying optical signals to be applied to high-speed parallel signal transmission, which not only reduces insertion loss, but also reduces light reflection and noise, thereby improving the optical communication effect.

[0009] To achieve the above-mentioned objective, the optical engine coupling the array light source and the array optical fiber in this invention includes at least: an array light source having a first carrier plate and a plurality of point light sources, the first carrier plate having adjacent first and second surfaces and a plurality of first conductive components, the first conductive components being formed on the second surface, the plurality of point light sources being arranged in an array in a local area of ​​the first surface and electrically coupled to the first conductive components, the emitting surface of the plurality of point light sources being covered with a high-reflectivity encapsulating adhesive; and an array optical fiber having a plurality of fiber cores, wherein... The multiple fiber cores are arranged in an array; and a perforated plate is disposed between the array light source and the array optical fiber. The perforated plate has a body and multiple through holes penetrating the opposite sides of the body. One end of each of the multiple through holes is used for the insertion and positioning of the multiple fiber cores, and the other end of each of the multiple through holes corresponds to the high reflectivity encapsulant of the multiple point light sources. The array light source and the perforated plate have a predetermined distance, which is the diameter of the fiber core divided by tan(θ / 2), where θ is the light divergence angle of the point light source.

[0010] In a preferred embodiment, the core diameter is 30µm to 70µm, the point light source is a vertical cavity surface emitting laser (VCSEL), and the light divergence angle is 20 degrees to 40 degrees.

[0011] In a preferred embodiment, the core diameter is 30um to 70um, the point light source is a micro LED, and the light divergence angle is 120 degrees to 150 degrees.

[0012] In a preferred embodiment, the array light source is disposed on a second carrier plate and electrically connected to a silicon photonic integrated circuit by a plurality of second conductive components. The distance between adjacent point light sources is 10 μm to 250 μm. The plurality of point light sources are axially aligned with a portion of the plurality of fiber cores, and the plurality of point light sources and the plurality of fiber cores are close to each other.

[0013] In a preferred embodiment, the plurality of first conductive components may be metal-plated wires and extend to cover the space between the first and second surfaces.

[0014] In a preferred embodiment, the plurality of first conductive components have solder pads, internal wires, and metal plating lines formed on the second surface.

[0015] In a preferred embodiment, the high-reflectivity encapsulant is inserted into the perforation by the fiber core, and the high-reflectivity encapsulant pre-filled in the perforation is extruded from the perforation to cover the light-emitting surface of the point light source.

[0016] In a preferred embodiment, the shape of the high-reflectivity encapsulant corresponds to the configuration of the perforation.

[0017] In a preferred embodiment, the first carrier plate is made of heat dissipation material.

[0018] In a preferred embodiment, the body extends a stepped portion toward one side of the array optical fiber, and the surface of the stepped portion is recessed with a plurality of grooves, which can respectively accommodate the plurality of fiber cores for positioning.

Implementation Method

[0019] Unless otherwise stated, the following terms used in this specification and claims have the definitions given below. Please note that the singular form of the term "a" used in this specification and claims is intended to encompass one or more items contained herein, such as at least one, at least two, or at least three, and not to imply only a single item contained herein. Furthermore, the open-ended conjunctions such as "comprising," "including," and "having" used in the claims indicate that the combination of elements or components described in the claim does not exclude other components or components not specified in the claim. It should also be noted that the term "or" generally includes "and / or" in its meaning, unless otherwise clearly stated. The terms "about" or "substantially" used in this specification and claims are used to modify any slight variations that do not alter the essence of the claim.

[0020] As shown in Figure 2, which is a schematic diagram of the structure of the optical engine in this invention, and Figure 3, which is an enlarged perspective view of the structure of the coupling device in this invention, the coupling device of this invention includes at least: an array light source 10, an array optical fiber 20, and a aperture plate 30.

[0021] The array light source 10 has a first carrier plate 11 and a plurality of point light sources 12. Please refer to Figure 4. The first carrier plate 11 has adjacent first and second surfaces 111 and 112 and a plurality of first conductive components 113. The first conductive components 113 are formed on the second surface 112 and the first surface 111. The plurality of point light sources 12 are arranged in an array in a local area of ​​the first surface 111 and are electrically coupled to the first conductive components 113. The light-emitting surface of the plurality of point light sources 12 is covered with a high-reflectivity encapsulant 13. In the embodiment shown in the figure, the first carrier plate 11 is a cuboid and can be made of a heat dissipation material such as aluminum nitride (AlN). The first and second surfaces 111 and 112 are two roughly perpendicularly adjacent sides of a cuboid. The plurality of first conductive components 113 may include solder pads 113a, internal wires 113b, and metal-plated wires 113c formed on the second surface 112. The plurality of point light sources 12 are electrically connected to the solder pads 113a by wire bonding, and the internal wires 113b and the metal-plated wires 113c connected to them are used to guide the electrical contacts of the plurality of point light sources 12 and the external circuit to the second surface 112. The distance between adjacent point light sources 12 is 10μm to 250μm. Of course, the plurality of first conductive components may also be metal-plated lines that extend and cover between the first and second surfaces. These micro-light-emitting diodes are electrically connected by the metal-plated lines, and the metal-plated lines on the second surface are electrically connected to the external circuit.

[0022] The array fiber 20 has a plurality of fiber cores 21, which are arrayed and can be located together at a fiber bundle connector 22.

[0023] The aperture plate 30 is disposed between the array light source 10 and the array optical fiber 20. The aperture plate 30 has a body 31 and a plurality of through holes 32 penetrating opposite sides of the body 31. One end of each of the plurality of through holes 32 is used for the insertion and positioning of the plurality of fiber cores 21, and the other end of each of the plurality of through holes 32 corresponds to the high-reflectivity encapsulant 13 of the plurality of point light sources 12. In addition, a stepped portion 33 extends from the side of the body 31 facing the array optical fiber 20, and a plurality of grooves 34 are recessed on the surface of the stepped portion 33 to accommodate the plurality of fiber cores 21 for positioning.

[0024] Wherein, the array light source 10 and the aperture 30 have a predetermined distance H, the predetermined distance H is the diameter of the fiber core 21 divided by tan(θ / 2), where θ is the light divergence angle of the point light source 12; wherein, the array fiber of the present invention can be a multimode array fiber, the fiber core diameter is 30um to 70um, the point light source is a micro light-emitting diode (Micro LED), and the light divergence angle is 120 degrees to 150 degrees; in another preferred embodiment, a vertical cavity surface emitting laser (VCSEL) can be used as the array light source, and the light divergence angle is 20 degrees to 40 degrees.

[0025] The present invention can calculate the distance H between the array light source 10 and the aperture 30 according to the above formula based on the use of different array light sources and array optical fibers, so that the light divergence angle of the array light source can cover the core diameter of the array optical fiber, thereby achieving passive optical coupling and automatic light alignment to reduce the cost of optical coupling. Furthermore, each of the point light sources 12 is axially aligned with a portion of the fiber core 21. This axial alignment refers to linear optical coupling or linear projection onto the light-incident surface (end face) of the fiber core 21, without needing to project onto the light-incident surface (end face) of the fiber core 21 via a reflecting mirror. That is, the optical axis of each point light source 12 passes precisely through the extended axial direction of any of the aforementioned fiber cores 21.

[0026] Furthermore, please refer to Figure 5. During manufacturing, the high-reflectivity encapsulant 13 is inserted into the perforation 22 by the fiber core 21, and the high-reflectivity encapsulant pre-filled in the perforation 22 is extruded from the perforation 22 and covers the light-emitting surface of the point light source 12. Adhesive 41 is applied between the array light source 10, the array optical fiber 20, and the aperture plate 30 to fix them together. Because the high-reflectivity encapsulant 13 is formed on the light-emitting surface of the point light source 12 by extruding from the perforation 22, the shape of the high-reflectivity encapsulant 13 corresponds to the configuration of the perforation 22. Different shapes of the high-reflectivity encapsulant 13 can be designed according to requirements, such as the arc-convex shape shown in Figure 6, or the conical shape shown in Figure 7. Of course, multiple microstructures can also be formed on the surface of the high-reflectivity encapsulant 13.

[0027] Furthermore, the configuration of the optical engine in this invention is also as shown in the embodiment of Figure 8. The array light source is coupled to the array optical fiber, allowing the array light source to perform high-speed parallel signal transmission through the array optical fiber. The aforementioned optical engine can also be further applied to silicon photonic communication systems, as shown in the embodiment of Figure 9. The silicon photonic communication system includes at least: a second carrier board 51, a silicon photonic integrated circuit 52, and an array light source 10. The second carrier board 51 is provided with a plurality of second conductive components. In the embodiment shown, the plurality of second conductive components may include solder pads 53 and metal traces 54, which can be used to set and electrically connect the silicon photonic integrated circuit 52 and the array light source 10. The array light source 10 is electrically connected to the solder pads 53 by the metal plating lines 113c of its second surface 112 to form an electrical circuit. Furthermore, this invention utilizes co-packaged optics. Optics (CPO) integrates the silicon photonics integrated circuit 52 and the array light source 10 directly into a single advanced package, also known as "silicon photonics technology." This allows the silicon photonics integrated circuit 52 to simultaneously process electrical signals and transmit optical signals. Previously, electrons would travel from the chip through metal traces to the optical transceiver at the server's end before being converted into light. With this silicon photonics technology, electrons are converted into photons as soon as they leave the chip, eliminating the need to wait until the server's end for conversion. This reduces the distance electrons travel through metal traces, and the entire subsequent transmission is done by photons. This allows for further upgrades in chip performance and power consumption, while also enabling smaller component sizes, reduced power consumption, lower costs, and faster speeds.

[0028] In this invention, the light from the array light source can be directly refracted by the encapsulating colloid and enter the fiber core. This not only reduces the refraction loss caused by light transmission between different media, but also utilizes the high refractive index material and shape of the encapsulating colloid to adjust the light divergence angle of the array light source to form a focusing effect. This makes the array light source more concentrated within the diameter range of the fiber core entering the array optical fiber, thereby reducing light reflection and noise, effectively reducing insertion loss by approximately 3dB to 4dB, and improving the optical communication effect.

[0029] The above embodiments are only for illustrating the present invention and are not intended to limit the present invention. Various modifications or changes made by those skilled in the art without departing from the technical scope of the present invention should also fall within the protection scope of the present invention. [Simplified Explanation of the Diagram]

[0030] Figure 1 is a schematic diagram of the light source scattering angle of a laser diode and a light-emitting diode. Figure 2 is a schematic diagram of the structure of the optical engine in this invention. Figure 3 is an exploded perspective view of the structure of the optical engine in this invention. Figure 4 is a schematic diagram of the structure of the array light source in this invention. Figure 5 is a schematic diagram of the structure of the high-reflectivity encapsulant molding in this invention. Figure 6 is an enlarged schematic diagram of the structure of the high-reflectivity encapsulant in this invention. Figure 7 is another enlarged schematic diagram of the structure of the high-reflectivity encapsulant in this invention. Figure 8 is another exploded perspective view of the structure of the optical engine in this invention. Figure 9 is a schematic diagram of the structure of the optical engine in this invention applied to a silicon photonics communication system.

Claims

1. An optical engine coupled to an array of light sources and an array of optical fibers, comprising at least: an array of light sources having a first carrier plate and a plurality of point light sources, the first carrier plate having adjacent first and second surfaces and a plurality of first conductive components, the first conductive components being formed on the second surface, the plurality of point light sources being arranged in an array in a local area of ​​the first surface and electrically coupled to the first conductive components, the light-emitting surface of the plurality of point light sources being covered with a high-reflectivity encapsulating adhesive; An arrayed optical fiber has a plurality of fiber cores arranged in an array; and a perforated plate is disposed between the arrayed light source and the arrayed optical fiber. The perforated plate has a body and a plurality of through holes penetrating opposite sides of the body. One end of each of the multiple through holes is used for the insertion and positioning of the plurality of fiber cores, and the other end of each of the multiple through holes corresponds to the high-reflectivity encapsulant of the plurality of point light sources. The arrayed light source and the perforated plate have a predetermined distance, which is the diameter of the fiber core divided by tan(θ / 2), where θ is the light divergence angle of the point light source. The high-reflectivity encapsulant is inserted into the through holes by the fiber cores, and the high-reflectivity encapsulant pre-filled in the through holes is squeezed out of the through holes and covers the light-emitting surface of the point light source.

2. The optical engine that couples the array light source and the array fiber optic cable as described in claim 1, wherein, The fiber core diameter is 30µm to 70µm, the point light source is a vertical cavity surface emitting laser (VCSEL), and the light divergence angle is 20 degrees to 40 degrees.

3. The optical engine that couples the array light source and the array fiber optic cable as described in claim 1, wherein, The core diameter is 30µm to 70µm, the point light source is a micro LED, and the light divergence angle is 120 degrees to 150 degrees.

4. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The array light source is disposed on a second carrier plate and electrically connected to a silicon photonic integrated circuit by a plurality of second conductive components. The distance between adjacent point light sources is 10μm to 250μm. The plurality of point light sources are axially aligned with a portion of the plurality of fiber cores, and the plurality of point light sources and the plurality of fiber cores are close to each other.

5. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The plurality of first conductive components may be metal-plated wires and extend to cover the space between the first and second surfaces.

6. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The plurality of first conductive components have solder pads, internal wires, and metal plating lines formed on the second surface.

7. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The shape of the high-reflectivity encapsulant corresponds to the configuration of the perforation.

8. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The first carrier board is made of heat dissipation material.

9. An optical engine coupled to an array of optical fibers as described in any one of claims 1 to 3, wherein, The main body extends a stepped portion toward one side of the array optical fiber, and the surface of the stepped portion is recessed with a plurality of grooves, which can respectively accommodate the plurality of fiber cores for positioning.

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