Optical module with improved heat dissipation performance and optical communication system including the same

Abstract

To provide an optical module with improved heat dissipation performance.SOLUTION: This embodiment discloses an optical module including a substrate 210, an optical element 320 arranged on the substrate, for converting an electrical signal into an optical signal or converting an optical signal into an electrical signal, an electronic element 310 for driving the optical element, an optical fiber support portion for fixing an optical fiber 341 arranged at a distance from the optical element, an optical wire 330 for optically connecting the optical element and an end of the optical fiber, a container CA for accommodating the optical element, the electronic element, and the optical fiber and being isolated from the outside, and cooling water CW filled in the container. The electronic element, the optical element, and the optical wire are in contact with the cooling water. The embodiment also discloses an optical communication system including the optical module.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present embodiment relates to an optical module with improved heat dissipation performance, and an optical communication system including the same. [Background technology]

[0002] Global internet data traffic can be divided into data center internal traffic, data center-to-data center traffic, and data center-to-user traffic. Of these three types of data traffic, data center internal traffic accounts for the largest proportion. The majority of data generated worldwide originates from data production, processing, storage, and authentication within data centers. With the expansion of artificial intelligence (AI), machine learning (ML), and big data applications, data traffic generated within data centers is on the rise.

[0003] One way to efficiently handle the rapidly increasing traffic in data centers is through the expansion of data center optical interconnect solutions, i.e., optical modules. The application areas of optical modules are gradually expanding with the development of optical communication technology and the increase in data traffic.

[0004] With the trend toward higher speeds, larger capacities, and higher densities, the technical difficulty of optical modules is increasing, and the power consumption of optical modules is also increasing day by day.

[0005] The 200G optical modules most commonly used in artificial intelligence and machine learning clusters consume around 5W of power and operate at temperatures above 40°C in a typical data center environment.

[0006] Next-generation optical modules require higher power consumption, which generates more heat in proportion to the increased power consumption. High operating temperatures of optical modules not only degrade the optical signal transmission and reception performance of the optical module, but also may shorten the reliability and lifespan of the optical module.

[0007] Therefore, there is a demand for optical modules that have excellent thermal dissipation performance and can be mass-produced economically to improve reliability and lifespan as well as excellent performance. Summary of the Invention [Problem to be solved by the invention]

[0008] This embodiment provides an optical module with improved heat dissipation performance. [Means for solving the problem]

[0009] An optical module according to one aspect of the present invention includes a substrate, an optical element disposed on the substrate and converting an electrical signal into an optical signal or an optical signal into an electrical signal, an electronic element for driving the optical element, an optical fiber support for fixing an optical fiber disposed at a distance from the optical element, an optical wire for optically connecting the optical element and an end of the optical fiber, a container for accommodating the optical element, the electronic element, and the optical fiber and being insulated from the outside, and cooling water filled in the container, wherein the electronic element, the optical element, and the optical wire are in contact with the cooling water. [Effects of the Invention]

[0010] According to this embodiment, the heat generated by the electronic and optical elements disposed inside the optical module can be effectively dissipated, thereby improving the transmission and reception performance of optical signals and increasing the reliability and lifespan of the optical module. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a view of an optical module according to an embodiment of the present invention, viewed from one direction. [Figure 2] FIG. 10 is a view showing the optical module according to the embodiment of the present invention as viewed from another direction. [Figure 3] 1 is an exploded perspective view of an optical module according to an embodiment of the present invention; [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 3. [Figure 5] FIG. 5 is an enlarged view of part B in FIG. [Figure 6] FIG. 1 is a diagram showing a state in which an optical element and an optical fiber are optically connected by an optical wire. [Figure 7] FIG. 10 is a diagram showing a state in which cooling water is poured into the container. [Figure 8] 4A and 4B are diagrams showing partition walls and heat dissipation patterns formed on the first housing. [Figure 9] 10 is yet another embodiment of a container. [Figure 10] FIG. 10 is a diagram showing a state in which cooling water stored in a container is circulated to the outside. [Figure 11] FIG. 10 is a diagram showing a state in which cooling water is poured into a conventional optical module structure. [Figure 12] 10 is a simulation result showing the cooling performance of the optical module according to the embodiment of the present invention. [Figure 13] FIG. 10 is a diagram showing an optical module in which two optical couplers formed on the same substrate are connected by an optical wire. [Figure 14] FIG. 1 is a diagram showing an optical module in which two multi-channel optical elements formed on two different substrates are connected by a plurality of optical wires. [Figure 15]1 is a diagram illustrating an optical module in which a plurality of multi-channel optical elements are connected by a plurality of optical wires. [Figure 16] 1 is a diagram illustrating an optical communication system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1 and 2, an optical module according to an embodiment may include housings 110 and 120, a substrate 210 disposed inside the housings 110 and 120, and a holder 130 disposed on one side of the housings 110 and 120.

[0013] The optical module may be, but is not necessarily limited to, a QSFP (Quad Small Form-Factor Pluggable) or QSFP-DD (QSFP Double Density) / OSFP (Octal Small Form-Factor Pluggable) type, and may be any type of transceiver that meets an MSA (Multiple Source Agreement) agreement.

[0014] The housings 110 and 120 may extend to a predetermined length and have one side P1 and the other side P2, or may be manufactured by assembling the first housing 110 and the second housing 120. The first housing 110 may form one side of the housing, and the second housing 120 may form the other side of the housing. However, this is not necessarily limited, and the housings may be manufactured as a single unit. The housings may be made of a material that can easily dissipate heat, but is not necessarily limited to this. A plurality of heat dissipation fins 121 may be arranged on the outer surface of the second housing 120 or the first housing 110.

[0015] The holder 130 may include a coupling portion 131 coupled to one side of the housing, a pair of slide portions 132 extending to the other side P2 of the housing, and a handle 133 extending to the one side P1 of the housing.

[0016] The coupling part 131 is coupled to one side P1 of the housing, and the sliding part 132 can be moved in a first direction (Y-axis direction) by a handle 133. The handle 133 may be disposed on one side P1 of the coupling part. The handle 133 can transmit a force applied by a user to the holder 130. That is, when a user pulls the handle 133, the coupling part 131 and the sliding part 132 can move in that direction.

[0017] A user can insert an optical fiber module (not shown) into the other side P2 of the housing, and can separate the optical fiber module from the optical module after pulling the handle 133.

[0018] Fig. 3 is an exploded perspective view of an optical module according to one embodiment of the present invention. Fig. 4 is an enlarged view of part A in Fig. 3. Fig. 5 is an enlarged view of part B in Fig. 4. Fig. 6 is a diagram showing a state in which an optical element and an optical fiber are optically connected by an optical wire.

[0019] 3 to 5, at least one electronic element 310 may be disposed on a substrate 210, and a plurality of optical elements 320 may be disposed around the electronic element 310. The optical element 320 and the electronic element 310 may be electrically connected by a wire W1.

[0020] The electronic device 310 may drive the light emitting device in response to a signal transmitted from an external host, or convert an optical signal transmitted from the light receiving device into an electrical signal and transmit the electrical signal to the host. The electronic device 310 may be, but is not limited to, a semiconductor direct circuit that drives the optical device 320 at high speed.

[0021] In the embodiment, the first to fourth electronic elements 311, 312, 313, and 314 may be connected to optical elements 321, 322, 323, and 324, respectively. In the embodiment, one optical element is connected to one electronic element, but this is not necessarily limited to this, and multiple optical elements may be connected to one electronic element.

[0022] The optical element 320 may be various optical devices capable of transmitting or receiving light, such as a photonic integrated circuit chip (PIC), an optical coupler, a light-emitting diode, a light-receiving diode, etc. For example, the optical element 320 may include both a light-emitting diode that emits laser light in response to a drive signal output from the electronic element 310 and a light-receiving diode that receives external light.

[0023] The optical element 320 may be optically connected to an end of an optical fiber 341 exposed to the outside of the optical fiber support 340 via an optical wire 330. The optical fibers 341 may extend to the sockets 220 and 230 to which an external optical fiber module (not shown) is coupled. Therefore, when the external optical fiber module is inserted into the sockets 220 and 230, the external optical fiber module can be optically connected to the optical element 320. Therefore, a signal from the optical element 320 can be transmitted to the outside, and an external signal can be received by the optical element 320.

[0024] 6, the optical wire 330 connecting the optical element 320 and the optical fiber 341 can be made of a light-transmitting material and configured as a single wire with one end and the other end. As the material for the optical wire 330, various materials that can form a meniscus and are hardened by ultraviolet light can be selected.

[0025] As an example, the optical wire 330 may be made of polystyrene, polymethyl methacrylate, polycarbonate, or the like, or may be made of perfluorinated compounds (PFCs) such as CYTOP (amorphous fluoropolymer), polyimide, or epoxy such as SU-8.

[0026] Furthermore, organic conductive polymers (π-conjugated polymers) can be used as the material for the optical wire 330, which has the advantage that the electrical and optical properties can be freely adjusted by chemical doping.

[0027] As the solvent for the solution of the optical wire 330, a substance that evaporates easily (a volatile substance) can be used, and any substance used in the art can be selected without any limitation.

[0028] The optical wire 330 can be formed by first dispensing a solution of the optical wire 330 onto the optical element 320 using a micropipette, and then moving the micropipette to the end 341a of the optical fiber 341 to form the optical wire 330 that is continuously formed between the optical element 320 and the end 341a of the optical fiber 341. The optical wire 330 can then be hardened to maintain its shape. Therefore, a signal transmitted from the optical element 320 can be transmitted to the optical fiber 341 through the optical wire 330 without loss, and a signal transmitted from the optical fiber 341 can be transmitted to the optical element 320 through the optical wire 330 without loss.

[0029] The optical wire 330 may include a first convex portion 331 formed on the optical element 320, a second convex portion 333 formed on an end portion 341a of the optical fiber 341, and a channel portion 332 connecting the first convex portion 331 and the second convex portion 333. As an example, the first convex portion 331 and the second convex portion 333 may further include a layer having a refractive index different from that of the channel portion 332 for optical matching.

[0030] The shape of the optical wire 330 can be variously changed depending on the position of the element to be connected. The connection structure between various optical elements and the optical wire will be described later.

[0031] Fig. 7 is a view showing a state in which cooling water is poured into the container, Fig. 8 is a view showing a partition wall and a heat dissipation pattern formed in the first housing, and Fig. 9 is another embodiment of the container.

[0032] 7 and 8, a container CA for accommodating the electronic element 310, the optical element 320, the optical wire 330, and the ends of the optical fiber 341 may be provided on the substrate 210. The container CA may be a space that is isolated from the outside and accommodates cooling water CW.

[0033] The container CA may be formed by bonding partition walls 111 and 112 protruding from the first housing 110 onto the substrate 210 and the optical fiber support part 340. Therefore, the internal space of the container CA may be defined by the partition walls 111 and 112, the substrate 210, and the optical fiber support part 340. Adhesive layers 151 and 152 may be formed between the partition walls 111 and 112 and the substrate 210, thereby isolating the internal space of the container CA from the outside.

[0034] The partitions 111, 112 may be formed to surround the ends of the electronic element 310, the optical element 320, the optical wire 330, and the optical fiber 341, and may include a first partition 111 having a first length to adhere to the substrate 210, and a second partition 112 having a second length to be bonded to the upper surface of the optical fiber support portion 340.

[0035] Cooling water CW may be poured into the container CA. Any of various commonly used cooling fluids may be used as the cooling water CW. The cooling water CW may be in direct contact with the electronic element 310, the optical element 320, the optical wire 330, and the optical fiber 341 to exchange heat. In particular, the cooling water CW may be used to quickly release heat from the electronic element 310 and the optical element 320, which generate the most heat, thereby improving the cooling performance. This may prevent a performance degradation of the electronic element 310 and stabilize the output wavelength of the optical element 320.

[0036] The first housing 110 may include a plurality of heat dissipation patterns 113 disposed between the first partition wall 111 and the second partition wall 112. The second partition wall 112 may have a groove 112a formed therein so that the optical fiber support part 340 can be inserted therein.

[0037] The heat dissipation pattern 113 protrudes toward the substrate 210 and comes into direct contact with the cooling water CW, thereby dissipating the heat of the cooling water CW to the outside. A plurality of heat dissipation fins (not shown) are further arranged on the outer surface of the first housing 110, thereby enabling the heat to be quickly dissipated to the outside.

[0038] The first housing 110 or the second housing 120 may include an opening H1 through which cooling water CW can be poured into the container CA, and a plug (not shown) that covers the opening H1. Therefore, after assembling the first housing 110 and the second housing 120, the cooling water CW can be poured through the opening H1. Furthermore, if the cooling water CW evaporates, the plug may be opened and the cooling water CW may be poured again.

[0039] However, this is not necessarily limited to this, and cooling water CW may be poured into the container CA during initial assembly, without forming an opening or a stopper. As an example, the first housing 110 may be turned upside down so that the container CA faces upward, cooling water CW may be poured into the container CA, and the second housing 120 with the substrate 210 assembled thereto may be coupled to the first housing 110, and cooling water CW may be poured into the container CA.

[0040] The substrate 210 may have via holes 210a formed therein to dissipate heat from the electronic element 310. Therefore, heat from the upper part of the electronic element 310 is dissipated by the cooling water CW, and heat from the lower part of the electronic element 310 is dissipated to the second housing 120 through the via holes 210a, thereby further improving the heat dissipation performance of the electronic element 310. If necessary, a cooling element such as a Peltier module (not shown) may be further disposed below the electronic element 310.

[0041] The container CA may include a material or structure that allows it to withstand volumetric changes due to thermal expansion or contraction within it. By way of example, the container may be constructed of a material that can withstand thermal expansion or contraction, or may be constructed with multiple walls.

[0042] 9, a separate container CA may be formed on the substrate 210. That is, the container CA may be a structure separate from the first housing. The container CA may be assembled on the substrate 210 and have a rectangular shape with an open bottom. The container CA may be assembled on the substrate 210 after the substrate 210 is placed in the second housing 120. A separate hole (not shown) through which cooling water CW can be injected and a plug (not shown) to cover the hole may be arranged on the top surface of the container CA.

[0043] A cooling module such as a Peltier module PT1 may be disposed on top of the container CA. With this configuration, the heat of the cooling water CW can be quickly released.

[0044] In addition, a sensor 141 for detecting water leakage may be disposed on the outside of the container CA. Therefore, if the cooling water is exposed to the outside, the sensor 141 can detect this and generate an alarm signal.

[0045] 10, the container CA may be connected to a channel SC1 that circulates from inside the optical module to the outside. With this configuration, cooling water CW from the container CA circulates to the outside through the channel SC1 and comes into contact with the housing, thereby quickly dissipating heat. A separate cooling module PT2 may be disposed in the channel SC1.

[0046] FIG. 11 is a diagram showing a state in which cooling water is poured into a conventional optical module structure.

[0047] 11, a conventional optical module has a structure in which a prism lens OG or the like is used to change the direction of light emitted from a laser element OD and focus it onto an optical fiber OF. This optical coupling structure has a problem in that there is a space EP between the laser element OD and the prism lens OG, and a space EP between the prism lens OG and the optical fiber OF, and when cooling water CW is filled in these spaces, the refractive index changes, making optical coupling difficult. Therefore, in the optical coupling method using conventional lenses, it is difficult to adopt a structure in which cooling water CW directly contacts the optical element 320.

[0048] However, according to the embodiment, the optical element 320 and the optical fiber 341 are coupled by the optical wire 330, so even if the space between the optical element 320 and the optical fiber 341 is filled with cooling water CW, no problem occurs with optical coupling.

[0049] FIG. 12 shows a simulation result showing the cooling performance of the optical module according to the embodiment of the present invention.

[0050] Referring to FIG. 12, the optical module was placed in a duct in which a fan was installed, and hot air was blown onto it, and the cooling efficiency was measured using cooling water CW.

[0051] The experiment was conducted by installing eight 100G Retimers (power consumption 8W), two 4ch VCSEL Drivers (power consumption 3W), two 4ch TIAs (power consumption 3W), two Quad VCSEL Arrays (power consumption 0.05W), and two Quad PD Arrays (power consumption 0.01W) in the optical module.

[0052] As a result of the experiment, it was found that in the conventional structure, the temperature of the substrate 210 rose to 124.9°C as shown in Figure 12(a), but in the optical module according to the present invention, the temperature of the substrate 210 was reduced to 93.15°C as shown in Figure 12(b).

[0053] Fig. 13 is a diagram showing an optical module in which two optical couplers formed on the same substrate are connected by an optical wire. Fig. 14 is a diagram showing an optical module in which two multi-channel optical elements formed on two different substrates are connected by multiple optical wires. Fig. 15 is a diagram for explaining an optical module in which multiple multi-channel optical elements are connected by multiple optical wires.

[0054] Referring to FIG. 13, the optical module includes an optical interposer 41, an optical element 42, an optical waveguide 43, and an optical wire 20.

[0055] The optical interposer 41 refers to a platform formed including a plurality of electronic elements 310 and a plurality of optical elements 320 to support the transmission of electrical signals and optical signals. Here, the electronic elements 310 include various signal processing circuit elements, such as signal generators, amplifiers, modulators, demodulators, frequency converters, linearizers, and voltage converters, which can be manufactured using compound or silicon process technology.

[0056] The optical element 42 includes a semiconductor laser diode, a photodiode, an optical modulator, an optical demodulator, an optical multiplexer, an optical demultiplexer, a filter, a reflector, a lens, an optical waveguide, an optical coupler, and the like.

[0057] The first optical coupler 44 is a structure for transmitting the optical signal transmitted from the optical element 42 to the optical wire 20, and can be designed taking into consideration at least one selected from the geometrical characteristics and wave mechanical characteristics of the optical signal transmitted from the optical element 42.

[0058] The geometric characteristics of an optical signal include characteristics expressed in two or three dimensions, taking into consideration straightness, reflection, refraction, etc. For example, if the optical signal transmitted from the optical element 42 is diffused at a specific radiation angle, the diffused optical signal can be aligned or converted into an optical signal traveling in parallel before being transmitted to the optical wire 20.

[0059] The first optical coupler 44 may be designed in consideration of the wave dynamics of the optical signal. For example, the first optical coupler 44 may include a grating coupler for transmitting the optical signal transmitted from the optical element 42 to the optical wire 20.

[0060] The second optical coupler 45 is a structure for transmitting the optical signal transmitted through the optical wire 20 to the pre-installed optical element 320 or to the outside, and can be designed taking into consideration one or all of the geometrical and wave-mechanical characteristics of the optical signal transmitted through the optical wire 20.

[0061] The optical waveguide 43 is formed to include a core and a clad so as to transmit the optical signal received from the second optical coupler 45 to the outside without noise or loss. Here, the core and the clad of the optical waveguide 43 can be designed in consideration of the wavelength of the optical signal generated, emitted or transmitted from the optical element 42.

[0062] The optical waveguide 43 may be formed from the same material as the optical wire 20, and the end of the optical waveguide 43 that is in close contact with the second optical coupler 45 can be designed taking into account the characteristics of the optical signal transmitted from the second optical coupler 45.

[0063] Referring to FIG. 14, the optical module may include a first substrate 61, a second substrate 62, a first optical element group 11G, a second optical element group 12G, and an optical wire group 20G.

[0064] 15, the first optical element group 11G may be divided into a plurality of first unit groups 11G1, 11G2, 11Gn, and the second optical element group 12G may also be divided into a plurality of second unit groups. The optical wire group 20G may be divided into a plurality of sub-wire groups 20G1, 20G2, 20Gn according to the number of inputs and outputs of the unit groups of the first and second optical element groups 11G, 12G.

[0065] 16, the optical communication system can be defined as a system that performs optical communication using a plurality of optical modules, and as an example, a wavelength division multiplexing (WDM) transmission method can be used, but it is not necessarily limited to this, and various optical communication methods can be used.

[0066] Wavelength division multiplexing (WDM) is a method of converting multiple wavelength signals into a single multiplexed signal and transmitting it over a single optical fiber. WDM can be used not only in backbone networks but also in short-distance Ethernet transmission. For example, WDM can transmit large-capacity Ethernet signals over single-mode and multimode optical fibers.

[0067] The optical communication system may include a plurality of optical modules 10, a multiplexer (MUX) 20, and a demultiplexer 30. Each of the optical modules 10 can convert an electrical signal into an optical signal for transmission, or can convert an optical signal received via an optical fiber 40 into an electrical signal. The multiplexer 20 can convert wavelength signals output by the plurality of optical modules 10 into a single multiplexed signal for transmission to the optical fiber 40. The demultiplexer 30 can divide the optical signal received via the optical fiber 40 into wavelengths and transmit the divided signals to each optical module 10.

[0068] In this case, the optical modules 10 can all have the optical module configurations described in Figures 1 to 15. Therefore, since the optical elements and optical fibers are connected by optical wires, excellent heat dissipation performance can be achieved by cooling water.

Claims

1. A substrate; an optical element disposed on the substrate, which converts an electrical signal into an optical signal or converts an optical signal into an electrical signal; an electronic element that drives the optical element; an optical fiber support portion for fixing an optical fiber disposed apart from the optical element; an optical wire optically connecting the optical element and the end of the optical fiber; a container that accommodates the optical element, the electronic element, and the optical fiber and is isolated from the outside; cooling water filled in the container; The optical module, wherein the electronic element, the optical element, and the optical wire are in contact with the cooling water.

2. The optical module according to claim 1 , wherein one side surface of the optical fiber support part is in contact with the cooling water.

3. a housing that accommodates the substrate; the housing includes a second housing in which the substrate is disposed and a first housing that covers the substrate; The optical module of claim 1 , wherein the first housing is coupled to the substrate to form the container.

4. The optical module according to claim 3 , wherein the first housing includes a partition wall that protrudes toward the substrate and forms the container when coupled to an upper surface of the substrate.

5. The optical module according to claim 4 , further comprising an adhesive layer formed between the partition wall and the substrate.

6. 5. The optical module according to claim 4, wherein the partition walls include a first partition wall adhered to the substrate and a second partition wall adhered to the upper surface of the optical fiber support part.

7. The optical module according to claim 3 , further comprising a plurality of heat dissipation patterns disposed within the container and in contact with the cooling water.

8. The optical module according to claim 7 , further comprising a cooling element that absorbs heat from the heat dissipation pattern.

9. The optical module according to claim 7 , wherein the plurality of heat dissipation patterns are integrally formed on the housing.

10. 2. The optical module according to claim 1, wherein the container includes a structure that allows the container to withstand volume changes due to thermal expansion or contraction inside the container.

11. The container is connected to a channel through which the cooling water circulates to the outside of the container.

2. The optical module according to claim 1.

12. The optical module according to claim 3 , wherein the container is in physical contact with a part of the housing to release heat of the cooling water to the outside.

13. a plurality of optical modules; an optical fiber connecting the plurality of optical modules; Each of the plurality of optical modules comprises: A substrate; an optical element disposed on the substrate, which converts an electrical signal into an optical signal or converts an optical signal into an electrical signal; an electronic element that drives the optical element; an optical fiber support portion for fixing an optical fiber disposed apart from the optical element; an optical wire optically connecting the optical element and the end of the optical fiber; a container that accommodates the optical element, the electronic element, and the optical fiber and is isolated from the outside; cooling water filled in the container; The optical communication system, wherein the electronic element, the optical element, and the optical wire are in contact with the cooling water.

14. a housing that accommodates the substrate; the housing includes a second housing in which the substrate is disposed and a first housing that covers the substrate; The optical communication system of claim 13 , wherein the first housing is coupled to the substrate to form the container.

15. The optical communication system of claim 14 , wherein the first housing includes a partition wall that protrudes toward the substrate and is coupled to an upper surface of the substrate to form the container.

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