Using free-space optics to interconnect multiple computing nodes

Abstract

A system for using free-space optics to interconnect multiple computing nodes may include a plurality of node optical transceivers electrically coupled to at least some of the plurality of computing nodes. The system may further include a plurality of router optical transceivers facilitating free-space optical communications with the plurality of node optical transceivers. Each node optical transceiver in the plurality of node optical transceivers may have a corresponding router optical transceiver optically coupled to the node optical transceiver. The system may further include a router coupled to the plurality of router optical transceivers. The router may be configured to route free-space optical communications among the plurality of computing nodes.

Description

Technical Field

[0001] The present disclosure relates to using free space optics to interconnect multiple computing nodes.

Background Art

[0002]

[0001] A data center is a physical facility used to house computer systems and associated components. A data center typically includes a number of servers that can be stacked in the form of racks installed in rows.

[0003]

[0002] One relatively recent development in data center technology involves disaggregation. Currently, most data centers include multiple servers, each of which includes one or more central processing units (CPUs) and a specific amount of memory. Disaggregation involves separating the servers into their processing and memory resources so that these resources can be allocated as needed according to the needs of each workload.

[0004]

[0003] Separating servers into resource components can provide additional flexibility. Workloads can be highly diverse, especially in commercial data centers. One of the main goals of data center operation is to have enough resources to cover peak demand, yet still ensure that the same resources are not underutilized during non-peak conditions. Disaggregation increases the opportunity to supply sufficient resources during periods of high demand and even ensure an optimal utilization rate.

Summary of the Invention

Problems to be Solved by the Invention

[0005]

[0004] To achieve disaggregation, the interconnection between computing resources should provide high bandwidth and low latency, similar to the high bandwidth and low latency provided by the communication interfaces inside traditional servers. This can be a challenge for data centers that have a large number of computing nodes to be interconnected.

Means for Solving the Problem

[0006]

[0005] According to one aspect of the present disclosure, a system for using free space optics to interconnect a plurality of computing nodes is disclosed. The system includes a plurality of node optical transceivers electrically coupled to at least a portion of the plurality of computing nodes. The system further includes a router configured to communicate with the plurality of computing nodes by free space optical communication. The system further includes a plurality of router optical transceivers coupled to the router. The plurality of router optical transceivers are separate from the plurality of node optical transceivers. Optical transmission between the plurality of router optical transceivers and the plurality of node optical transceivers enables free space optical communication between the router and the plurality of computing nodes. The system further includes a plurality of light sources. The plurality of light sources include at least one separate light source for each node optical transceiver among the plurality of node optical transceivers and for each router optical transceiver among the plurality of router optical transceivers. The system further includes a plurality of photodetectors. The plurality of photodetectors include at least one separate photodetector for each node optical transceiver among the plurality of node optical transceivers and for each router optical transceiver among the plurality of router optical transceivers.

[0007]

[0006] A plurality of node optical transceivers, a plurality of router optical transceivers, and a router can interconnect a plurality of computing nodes to form a network fabric. The plurality of computing nodes may be accessible to each other via the network fabric.

[0008]

[0007] The plurality of computing nodes may include a plurality of processing nodes and a plurality of memory nodes. The plurality of processing nodes may not be electrically coupled to all of the plurality of memory nodes. All of the plurality of memory nodes may be accessible to all of the plurality of processing nodes via the network fabric.

[0009]

[0008] The plurality of node optical transceivers may not be electrically coupled to the router. The plurality of router optical transceivers may not be electrically coupled to the plurality of computing nodes.

[0010]

[0009] A first computing node may be electrically coupled to a first node optical transceiver. A first router optical transceiver may be optically coupled to the first node optical transceiver. A second computing node may be electrically coupled to a second node optical transceiver. A second router optical transceiver may be optically coupled to the second node optical transceiver. The first router optical transceiver may be configured to receive a first modulated optical beam from the first node optical transceiver and demodulate the first modulated optical beam to extract data. The router may be configured to route data to the second router optical transceiver. The second router optical transceiver may be configured to transmit a second modulated optical beam to the second node optical transceiver. The second modulated optical beam may include data.

[0011]

[0010] The router may include at least one of an electrical crossbar switch that performs a routing operation, a microelectromechanical system (MEMS) device that performs a routing operation, and a prism that performs a routing operation.

[0012]

[0011] According to another aspect of the present disclosure, a system for using free space optics to interconnect a plurality of computing nodes is disclosed. The system includes a router configured to communicate with a plurality of computing nodes by free space optical communication. The system further includes a plurality of optical modules electrically coupled to at least a portion of the plurality of computing nodes. The system further includes a plurality of optical transceivers coupled to the router. The plurality of optical transceivers assist in free space optical communication with the plurality of optical modules. Each optical module among the plurality of optical modules has a corresponding optical transceiver optically coupled to the optical module. The system further includes a first plurality of light sources separate from the plurality of optical modules and enabling free space optical communication from the router to the plurality of optical modules. The system further includes a second plurality of light sources separate from the plurality of optical modules and enabling free space optical communication from the plurality of optical modules to the router.

[0013]

[0012] Each optical module among the plurality of optical modules may include a modulator and an optical system. The modulator within a particular optical module may be configured to modulate an optical beam received from one of the second plurality of light sources to generate a modulated optical beam. The optical system within a particular optical module may be configured to direct the modulated optical beam toward the router. In some embodiments, the plurality of optical modules do not include any light sources.

[0014]

[0013] A plurality of optical modules, a plurality of optical transceivers, and a router can interconnect a plurality of computing nodes to form a network fabric. The plurality of computing nodes can include a plurality of processing nodes and a plurality of memory nodes. The plurality of processing nodes may not be electrically coupled to all of the plurality of memory nodes. All of the plurality of memory nodes may be accessible to all of the plurality of processing nodes via the network fabric.

[0015]

[0014] A first computing node can be electrically coupled to a first optical module. A first optical transceiver can be optically coupled to the first optical module. A second computing node can be electrically coupled to a second optical module. A second optical transceiver can be optically coupled to the second optical module. The first optical transceiver can be configured to receive a first modulated optical beam from the first optical module and demodulate the first modulated optical beam to extract data. The router can be configured to route data to the second optical transceiver. The second optical transceiver can be configured to transmit a second modulated optical beam to the second optical module. The second modulated optical beam can include data.

[0016]

[0015] According to another aspect of the present disclosure, a system for using free space optics to interconnect a plurality of computing nodes placed within an enclosure is disclosed. The system includes a router configured to route free space optical communications among the plurality of computing nodes. The system further includes a plurality of processing nodes in a first zone of the enclosure. The system further includes a plurality of optical modules electrically coupled to at least a portion of the plurality of computing nodes. The system further includes a plurality of memory nodes in a second zone of the enclosure. Each memory node among the plurality of memory nodes may be electrically coupled to at least one processing node among the plurality of processing nodes. The system further includes a plurality of optical transceivers coupled to the router. The plurality of optical transceivers assist in free space optical communication with the plurality of optical modules. Each optical module among the plurality of optical modules has a corresponding optical transceiver optically coupled to the optical module. The system further includes at least one light source disposed outside the first zone of the enclosure and configured to transmit an optical beam towards the plurality of optical modules.

[0017]

[0016] The first temperature of the first zone of the enclosure may be lower than the second temperature of the second zone of the enclosure.

[0018]

[0017] The plurality of optical modules may be placed in the first zone of the enclosure.

[0019]

[0018] The plurality of optical modules may be placed in the third zone of the enclosure.

[0020]

[0019] The first temperature of the first zone of the enclosure may be lower than the second temperature of the second zone of the enclosure. The second temperature may be lower than the third temperature of the third zone of the enclosure.

[0021]

[0020] A plurality of optical modules, a plurality of optical transceivers, and a router can interconnect a plurality of computing nodes to form a network fabric. The plurality of computing nodes can be accessible to each other through the network fabric.

[0022]

[0021] The plurality of processing nodes may not be electrically coupled to all of the plurality of memory nodes. All of the plurality of memory nodes may be accessible to all of the plurality of processing nodes through the network fabric.

[0023]

[0022] Each optical module among the plurality of optical modules may include a modulator and an optical system. The modulator within a particular optical module may be configured to modulate an optical beam received from at least one light source to generate a modulated optical beam. The optical system within a particular optical module may be configured to direct the modulated optical beam toward an optical transceiver among the plurality of optical transceivers.

[0024]

[0023] A first computing node may be electrically coupled to a first optical module. A first optical transceiver may be optically coupled to the first optical module. A second computing node may be electrically coupled to a second optical module. A second optical transceiver may be optically coupled to the second optical module. The first optical transceiver may be configured to receive a first modulated optical beam from the first optical module and demodulate the first modulated optical beam to extract data. The router may be configured to route data to the second optical transceiver. The second optical transceiver may be configured to transmit a second modulated optical beam to the second optical module. The second modulated optical beam may include data.

[0025]

[0024] This summary is provided to introduce selected parts of the concepts in a simple form that will be further explained below in the detailed description. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0026]

[0025] Additional features and advantages will be described in the subsequent description. The features and advantages of the present disclosure can be realized and obtained by the systems and methods particularly shown in the appended claims. The features of the present disclosure will become more fully apparent from the subsequent description and the appended claims, or may be known from the practice of the disclosed subject matter as hereinafter described in this specification.

[0027]

[0026] To explain the manner in which the features of the present disclosure, detailed above and others, can be obtained, a more detailed description will be given by reference to specific embodiments of the present disclosure shown in the accompanying drawings. For better understanding, like elements are designated by like reference numerals throughout the various accompanying figures. It is to be understood that the drawings depict some example embodiments, and that the embodiments will be explained and illustrated by additional specificity and detail through the use of the accompanying drawings.

Brief Description of the Drawings

[0028]

Figure 1

[0027] FIG. is a diagram showing an example of a system for using free space optics to interconnect a plurality of computing nodes in accordance with the present disclosure.

Figure 2

[0028] FIG. is a diagram showing an example of how free space optical communication can occur between a first processing node and a second processing node in a system configured similar to the system shown in FIG. 1.

Figure 3

[0029] FIG. is a diagram showing another example of a system for using free space optics to interconnect a plurality of computing nodes, where different types of computing nodes are placed in different sections of an enclosure and a light source is placed outside the enclosure to minimize the amount of heat generated within the enclosure.

Figure 4

[0030] FIG. is a diagram showing an example of how free space optical communication can occur between a first processing node and a second processing node in a system configured similar to the system shown in FIG.

Figure 5

[0031] FIG. is a diagram showing another example of a system for using free space optics to interconnect a plurality of computing nodes, where different types of computing nodes are placed in different sections of an enclosure and a light source is placed within a section of the enclosure maintained at room temperature. DETAILED DESCRIPTION

[0029]

[0032] The present disclosure is generally related to interconnecting a plurality of computing resources in a way that provides high bandwidth and low latency. This can be useful in various types of computing systems, including disaggregated computing systems.

[0030]

[0033] One type of network topology that can be used to provide high bandwidth and low latency interconnectivity between computing resources is sometimes referred to as a network fabric. In this type of architecture, computing resources can be deployed in a relatively small number of highly interconnected layers. Unlike traditional multi-layer architectures, a network fabric effectively flattens the network architecture, thereby reducing the distance between endpoints.

[0031]

[0034] In theory, a network fabric that provides high bandwidth and low latency can be achieved using wired connections. However, in a data center that includes a large number of computing nodes, a large number of wired connections would be required to provide this type of network topology. Therefore, in terms of means for providing high bandwidth and low latency, using wired connections to interconnect a large number of computing nodes is impractical.

[0032]

[0035] The present disclosure proposes the use of free space optics to create a network fabric that interconnects a large number of computing nodes. Free space optics is an optical communication technology that uses light propagating in free space to transmit data between two points. Free space optical communication is typically performed by two systems each including an optical transceiver. The optical transceiver may include an optical transmitter and an optical receiver to provide full duplex (bidirectional) capability. The optical transmitter may include a light source (e.g., a laser, a light emitting diode, an infrared light emitting diode) and a modulator. The modulator may be configured to vary one or more properties of the optical beam generated by the light source with a modulation signal including the data to be transmitted. The modulated optical beam may be transmitted through the atmosphere to the optical receiver. The optical receiver may include a photodetector and a demodulator. The photodetector may be configured to convert the modulated optical beam into an electrical signal, and the demodulator may be configured to demodulate the electrical signal to extract the transmitted data.

[0033]

[0036] In some embodiments, to interconnect a plurality of computing nodes using free space optics, at least some of the computing nodes may be electrically coupled to an optical transceiver. Additionally, a router may be provided. The router may be coupled to a plurality of optical transceivers.

[0034]

[0037] Free-space optical communication can occur between an optical transceiver electrically coupled to a computing node and an optical transceiver coupled to a router. In some embodiments, for each optical transceiver coupled to a particular computing node, there is a corresponding optical transceiver in the router. Free-space optical communication sent by an optical transceiver at a computing node can be received by the corresponding optical transceiver at the router, and vice versa.

[0035]

[0038] The router can be configured to route free-space optical communication among the computing nodes in the system. That is, different computing nodes can communicate with each other through the router. Thus, the router, the optical transceivers coupled to the router, and the optical transceivers coupled to the computing nodes can all function together to interconnect the computing nodes so as to form a network fabric.

[0036]

[0039] Advantageously, the use of free-space optics enables the network fabric to have high bandwidth and low latency. In some embodiments, the bandwidth and latency of a network fabric that utilizes free-space optics according to the techniques disclosed herein can be similar to the high bandwidth and low latency provided by the interconnection between the CPU and memory in a conventional server. At the same time, the use of free-space optics eliminates the need to utilize a large number of wired connections to achieve the desired high bandwidth and low latency, which (as noted above) is impractical.

[0037]

[0040] In some embodiments, the techniques disclosed herein may be utilized in a disaggregated computing system. In a disaggregated computing system, computing resources may be separated into dedicated nodes such as processing nodes, memory nodes, storage nodes, and the like. The various types of nodes utilized in a computing system may generally be referred to herein as computing nodes. In a disaggregated system, the term "computing node" may refer to a processing node, a memory node, a storage node, and / or another type of node utilized by a computing system.

[0038]

[0041] FIG. 1 shows an example of a system 100 in which the techniques disclosed herein may be utilized. System 100 is a disaggregated computing system that includes a plurality of computing nodes. In particular, system 100 is shown with a plurality of processing nodes 102 and a plurality of memory nodes 104.

[0039]

[0042] System 100 further includes a plurality of optical transceivers. At least some of the computing nodes may be electrically coupled to an optical transceiver. System 100 further includes a router 106 configured to route free space optical communications among the plurality of computing nodes. Router 106 may be coupled to a plurality of optical transceivers corresponding to at least some of the computing nodes.

[0040]

[0043] To distinguish the optical transceiver coupled to router 106 from the optical transceiver coupled to the computing node, the optical transceiver coupled to the router may be referred to herein as router optical transceiver 108, and the optical transceiver coupled to the computing node may be referred to herein as node optical transceiver 110. Router optical transceiver 108 and node optical transceiver 110 are abbreviated as "OT" in FIG. 1.

[0041]

[0044] Node optical transceiver 110, router optical transceiver 108, and router 106 can all function together to interconnect computing nodes so as to form a network fabric. The network fabric enables all of the computing nodes to be accessible to each other.

[0042]

[0045] As discussed above, the use of free space optics to construct the network fabric eliminates the need to provide wired connections between computing nodes. This is highly beneficial because, as noted above, providing wired connections between computing nodes can be impractical when there are a large number of computing nodes in system 100. The use of free space optics to construct the network fabric also enables the network fabric to have a high bandwidth and low latency similar to that provided by the interconnection between the CPU and memory in a conventional server.

[0043]

[0046] Free-space optical communication can occur between the node optical transceiver 110 and the router optical transceiver 108. In some embodiments, the system 100 can be configured such that for each node optical transceiver 110, there is a corresponding router optical transceiver 108 in the router 106 that is optically coupled to the node optical transceiver 110. Free-space optical communication sent by a particular node optical transceiver 110 can be received by the corresponding router optical transceiver 108, and vice versa.

[0044]

[0047] The router 106 can be coupled to the router optical transceiver 108. In some embodiments, the router 106 can be electrically coupled to the router optical transceiver 108. In some embodiments, the router 106 can be optically coupled to the router optical transceiver 108. In FIG. 1, the router optical transceiver 108 is shown as being part of the router 106. However, in some alternative embodiments, the router optical transceiver 108 can be separate from (and still coupled to) the router 106.

[0045]

[0048] The router 106 can be configured to route free-space optical communication among the computing nodes in the system 100. That is, different computing nodes (e.g., the processing node 102, the memory node 104) can communicate with each other through the router 106.

[0046]

[0049] For example, consider a scenario where a first processing node 102a sends some type of communication to a second processing node 102b. In some embodiments, a first node optical transceiver 110a electrically coupled to the first processing node 102a may generate a modulated optical beam that includes information to be conveyed to the second processing node 102b. The first node optical transceiver 110a may transmit the modulated optical beam to a router optical transceiver 110 corresponding to the first node optical transceiver 110a. The router 106 may determine (e.g., based on information included in the modulated optical beam) that the information should be delivered to the second processing node 102b. The router 106 may then cause the router optical transceiver 110 corresponding to the second node optical transceiver 110b to transmit the information to the second node optical transceiver 110b. An example of how this communication may occur will be described below with respect to FIGS. 2A and 2B.

[0047]

[0050] As shown above, the network fabric formed by the node optical transceivers 110, the router optical transceivers 108, and the router 106 enables all of the computing nodes to be accessible to each other. For example, all of the memory nodes 104 may be accessible to all of the processing nodes 102 by the network fabric.

[0048]

[0051] More specifically, in the system 100 shown in FIG. 1, each processing node 102 is electrically coupled to a memory node 104 by a direct electrical connection 112. The direct electrical connection 112 between the processing node 102 and the memory node 104 can be, for example, a wired connection. The processing node 102 can access the memory node 104 to which the processing node 102 is electrically coupled by this direct electrical connection 112. For example, the first processing node 102a can access the first memory node 104a by a direct electrical connection 112a between the first processing node 102a and the first memory node 104a. Similarly, the second processing node 102b can access the second memory node 104b by a direct electrical connection 112b between the second processing node 102b and the second memory node 104b.

[0049]

[0052] However, in the depicted system 100, the processing nodes 102 are not all electrically coupled to the memory nodes 104. That is, in the system 100, there is no direct electrical connection (e.g., wired connection) between each processing node 102 and all of the memory nodes 104. For example, it is not possible for the first processing node 102a to access the second memory node 104b by a direct electrical connection. Similarly, it is not possible for the second processing node 102b to access the first memory node 104a by a direct electrical connection.

[0050]

[0053] There is no direct electrical connection between each processing node 102 and all of the memory nodes 104, but the network fabric formed by the node optical transceivers 110, the router optical transceivers 108, and the routers 106 makes all of the memory nodes 104 accessible to all of the processing nodes 102. For example, the first processing node 102a can access the second memory node 104b (and all of the other memory nodes 104 in the system 100) via the network fabric. Similarly, the second processing node 102b can access the first memory node 104a (and all of the other memory nodes 104 in the system 100) via the network fabric. Thus, even though the processing nodes 102 are not electrically coupled to all of the memory nodes 104 in the system 100, the processing nodes 102 are either electrically coupled or optically coupled to all of the memory nodes 104 in the system 100. Further, as discussed above, the use of free-space optics to construct the network fabric enables the network fabric to have a high bandwidth and low latency similar to that provided by the interconnection between the CPU and memory in a conventional server.

[0051]

[0054] The system 100 shown in FIG. 1 is provided for illustrative purposes only, and the specific characteristics of the system 100 should not be construed as limiting the scope of the present disclosure. The techniques disclosed herein may be utilized in other systems with characteristics different from those of the depicted system 100.

[0052]

[0055] For example, in the depicted system 100, one node optical transceiver 110 is coupled to each processing node 102. However, in some embodiments, two or more node optical transceivers 110 may be coupled to each processing node 102. Similarly, there may be two or more router optical transceivers 108 corresponding to each processing node 102 (or other types of computing nodes).

[0053]

[0056] As another example, only processing node 102 and memory node 104 are shown in the depicted system 100. However, in alternative embodiments, other types of computing nodes (e.g., storage nodes) may be utilized.

[0054]

[0057] As another example, in the depicted system 100, each processing node 102 is electrically coupled to only one memory node 104 (e.g., has a direct electrical connection 112 to only one memory node 104). However, in alternative embodiments, at least some processing nodes may be electrically coupled to two or more memory nodes and / or may not be electrically coupled to any separate memory nodes.

[0055]

[0058] As another example, in the depicted system 100, each processing node 102 is electrically coupled to a node optical transceiver 110, and each node optical transceiver 110 may include a light source for generating an optical beam that can be transmitted to a modulated router optical transceiver 108. However, in some alternative embodiments, a processing node may not be electrically coupled to an optical transceiver that includes a light source. This will be discussed in more detail below.

[0056]

[0059] As another example, the depicted system 100 is a disaggregated computing system in which computing resources are separated into dedicated nodes (e.g., processing node 102, memory node 104). However, the scope of the present disclosure is not limited to disaggregated computing systems. The techniques disclosed herein for utilizing free space optics to interconnect computing nodes may be implemented in a system that includes a plurality of conventional servers.

[0057]

[0060] Figure 2 shows an example illustrating how free-space optical communication can occur among multiple computing nodes. The example will be described with respect to a system configured similarly to system 100 shown in Figure 1. The various components shown in Figure 2 are examples of possible implementations of corresponding components in system 100 shown in Figure 1.

[0058]

[0061] For simplicity, the depicted example will be communication between a first processing node 202a and a second processing node 202b. The first processing node 202a is coupled to a first node optical transceiver 210a, and the second processing node 202b is coupled to a second node optical transceiver 210b. The router 206 includes multiple router optical transceivers, including a first router optical transceiver 208a and a second router optical transceiver 208b. For purposes of this example, it will be assumed that the first router optical transceiver 208a is optically coupled to the first node optical transceiver 210a, and the second router optical transceiver 208b is optically coupled to the second node optical transceiver 210b.

[0059]

[0062] The first node optical transceiver 210a and the second node optical transceiver 210b may both include a receiver module configured to receive free-space optical communications from the router 206. In particular, the first node optical transceiver 210a may include a receiver module 282a, and the second node optical transceiver 210b may include a receiver module 282b. The receiver module 282a in the first node optical transceiver 210a may include a photodetector 270a and a demodulator 272a. The receiver module 282b in the second node optical transceiver 210b may include a photodetector 270b and a demodulator 272b.

[0060]

[0063] The first router optical transceiver 208a and the second router optical transceiver 208b may each include a transmission module configured to transmit free-space optical communications to the first node optical transceiver 210a and the second node optical transceiver 210b, respectively. In particular, the first router optical transceiver 208a may include a transmission module 284a, and the second router optical transceiver 208b may include a transmission module 284b. The transmission module 284a in the first router optical transceiver 208a may include a light source 220a and a modulator 266a. The transmission module 284b in the second router optical transceiver 208b may include a light source 220b and a modulator 266b.

[0061]

[0064] The transmission module 284a in the first router optical transceiver 208a and the reception module 282a in the first node optical transceiver 210a may enable the router 206 to send data to the first processing node 202a. More specifically, the light source 220a in the first router optical transceiver 208a may generate an optical beam directed towards the photodetector 270a in the first node optical transceiver 210a. The optical beam may be modulated by the modulator 266a based on a modulation signal including the data to be transmitted. The photodetector 270a in the first node optical transceiver 210a may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 272a in the first node optical transceiver 210a may be configured to extract data from the electrical signal generated by the photodetector 270a. This data may then be provided to the first processing node 202a.

[0062]

[0065] In a similar manner, a transmission module 284b in the second router optical transceiver 208b and a reception module 282b in the second node optical transceiver 210b may enable the router 206 to send data to the second processing node 202b. More specifically, a light source 220b in the second router optical transceiver 208b may generate an optical beam directed towards a photodetector 270b in the second node optical transceiver 210b. The optical beam may be modulated by a modulator 266b based on a modulation signal including data to be transmitted. The photodetector 270b in the second node optical transceiver 210b may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. A demodulator 272b in the second node optical transceiver 210b may be configured to extract data from the electrical signal generated by the photodetector 270b. This data may then be provided to the second processing node 202b.

[0063]

[0066] The first node optical transceiver 210a and the second node optical transceiver 210b may both include a transmission module configured to send free space optical communication to the router 206. In particular, the first node optical transceiver 210a may include a transmission module 286a, and the second node optical transceiver 210b may include a transmission module 286b. The transmission module 286a in the first node optical transceiver 210a may include a light source 222a and a modulator 274a. Similarly, the transmission module 286b in the second node optical transceiver 210b may include a light source 222b and a modulator 274b.

[0064]

[0067] The first router optical transceiver 208a and the second router optical transceiver 208b may each include a receiving module configured to receive free-space optical communications from the first node optical transceiver 210a and the second node optical transceiver 210b, respectively. In particular, the first router optical transceiver 208a may include a receiving module 288a, and the second router optical transceiver 208b may include a receiving module 288b. The receiving module 288a in the first router optical transceiver 208a may include a photodetector 268a and a demodulator 276a. The receiving module 288b in the second router optical transceiver 208b may include a photodetector 268b and a demodulator 276b.

[0065]

[0068] The transmission module 286a in the first node optical transceiver 210a and the receiving module 288a in the first router optical transceiver 208a may enable the first processing node 202a to send data to the router 206. More specifically, the light source 222a in the first node optical transceiver 210a may generate an optical beam directed towards the photodetector 268a in the first router optical transceiver 208a. The optical beam may be modulated by a modulator 274a based on a modulation signal containing the data to be transmitted. The photodetector 268a in the first router optical transceiver 208a may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 276a in the first router optical transceiver 208a may be configured to extract data from the electrical signal generated by the photodetector 268a. This data may then be provided to a routing module 230 within the router 206.

[0066]

[0069] The transmission module 286b in the second node optical transceiver 210b and the receiving module 288b in the second router optical transceiver 208b may enable the second processing node 202b to send data to the router 206. More specifically, the light source 222b in the second node optical transceiver 210b may generate an optical beam directed towards the photodetector 268b in the second router optical transceiver 208b. The optical beam may be modulated by the modulator 274b based on a modulation signal including the data to be transmitted. The photodetector 268b in the second router optical transceiver 208b may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 276b in the second router optical transceiver 208b may be configured to extract data from the electrical signal generated by the photodetector 268b. This data may then be provided to the routing module 230 within the router 206.

[0067]

[0070] An example including communication from the first processing node 202a to the second processing node 202b will be described here. In this example, it is assumed that the first processing node 202a has data to send to the second processing node 202b.

[0068]

[0071] When the first processing node 202a has data to send to the second processing node 202b, the transmission module 286a in the first node optical transceiver 210a can send the data to the reception module 288a in the first router optical transceiver 208a in the manner described above. Along with the data, the transmission module 286a can further send, in this example to the second processing node 202b, an indication of the destination for the data to the reception module 288a. The reception module 288a can provide the data, and the indication of the destination for the data, to the routing module 230. The routing module 230 can then provide the data to the optical transceiver corresponding to the destination for the data, which in this example is the second router optical transceiver 208b. The transmission module 284b in the second router optical transceiver 208b can send the data to the reception module 282b in the second node optical transceiver 210b in the manner described above. The second node optical transceiver 210b can then provide the data to the second processing node 202b.

[0069]

[0072] The second processing node 202b can further send data to the first processing node 202a in a similar manner. When the second processing node 202b has data to send to the first processing node 202a, the transmission module 286b in the second node optical transceiver 210b can send the data to the reception module 288b in the second router optical transceiver 208b in the manner described above. Along with the data, the transmission module 286b can further send an indication of the destination for the data, which in this example is the first processing node 202a, to the reception module 288b. The reception module 288b can provide the data and the indication of the destination for the data to the routing module 230. The routing module 230 can then provide the data to the optical transceiver corresponding to the destination for the data, which in this example is the first router optical transceiver 208a. The transmission module 284a in the first router optical transceiver 208a can send the data to the reception module 282a in the first node optical transceiver 210a in the manner described above. The first node optical transceiver 210a can then provide the data to the first processing node 202a.

[0070]

[0073] In the example shown in FIG. 2, there is two-way communication between router 206 and each processing node. Communication from router 206 to the first processing node 202a occurs from the transmission module 284a in the first router optical transceiver 208a to the reception module 282a in the first node optical transceiver 210a. Communication from the first processing node 202a to router 206 occurs from the transmission module 286a in the first node optical transceiver 210a to the reception module 288a in the first router optical transceiver 208a. Communication from router 206 to the second processing node 202b occurs from the transmission module 284b in the second router optical transceiver 208b to the reception module 282b in the second node optical transceiver 210b. Communication from the second processing node 202b to router 206 occurs from the transmission module 286b in the second node optical transceiver 210b to the reception module 288b in the second router optical transceiver 208b.

[0071]

[0074] In some embodiments, the transmission module in a particular optical transceiver is optically aligned with the reception module in the corresponding optical transceiver. In the example shown in FIG. 2, the transmission module 284a in the first router optical transceiver 208a is optically aligned with the reception module 282a in the first node optical transceiver 210a. The transmission module 286a in the first node optical transceiver 210a is optically aligned with the reception module 288a in the first router optical transceiver 208a. The transmission module 284b in the second router optical transceiver 208b is optically aligned with the reception module 282b in the second node optical transceiver 210b. The transmission module 286b in the second node optical transceiver 210b is optically aligned with the reception module 288b in the second router optical transceiver 208b.

[0072]

[0075] In some embodiments, the light sources 220a - b, 222a - b may remain powered on at all times (or substantially at all times). The modulators 266a - b, 274a - b may be activated when there is data to send. When a particular processing node has data to send to another processing node, the processing node having the data to send may initiate communication with the router 206 (if the processing node has not yet been communicating with the router 206). The processing node having the data to send may request access to send the data through the router 206.

[0073]

[0076] In some embodiments, the node optical transceivers 210a - b shown in FIG. 2 may be representative of the node optical transceiver 110 shown in FIG. 1. That is, the node optical transceiver 110 shown in FIG. 1 may be configured similarly to the node optical transceivers 210a - b shown in FIG. 2. Similarly, the router optical transceivers 208a - b shown in FIG. 2 may be representative of the router optical transceiver 108 shown in FIG. 1. That is, the router optical transceiver 108 in the system 100 shown in FIG. 1 may be configured similarly to the router optical transceivers 208a - b in the system 200 shown in FIG. 2. In some embodiments, any two processing nodes 102 in the system 100 shown in FIG. 1 may communicate with each other in a manner similar to the means by which the first processing node 202a and the second processing node 202b communicate with each other.

[0074]

[0077] Of course, the particular configurations of the router optical transceivers 208a - b and the node optical transceivers 210a - b are provided for illustrative purposes only and should not be construed as limiting the scope of the present disclosure. The optical transceivers may be configured in many different ways in accordance with the present disclosure.

[0075]

[0078] The light sources 220a - b, 222a - b shown in FIG. 2 can be any device that emits electromagnetic radiation in a form that can be used for optical communication. For example, the light sources 220a - b, 222a - b can be configured to emit an optical beam that can be modulated to transmit information. Some examples of light sources 220a - b, 222a - b that can be used include lasers, light emitting diodes (LEDs), and infrared light emitting diodes (IREDs).

[0076]

[0079] The photodetectors 268a - b, 270a - b can be any device configured to convert light into an electrical signal. Some examples of photodetectors 268a - b, 270a - b include photodiodes and phototransistors.

[0077]

[0080] The router optical transceivers 208a - b and the node optical transceivers 210a - b can further include one or more communication interfaces for one or more other devices. The router optical transceivers 208a - b can include one or more communication interfaces for a routing module 230 within the router 206. The node optical transceivers 210a - b can include one or more communication interfaces for a processing node. For example, the first node optical transceiver 210a can include a communication interface for the first processing node 202a, and the second node optical transceiver 210b can include a communication interface for the second processing node 202b.

[0078]

[0081] As described above, when the routing module 230 receives data from a specific processing node, the routing module 230 can determine the destination for the data. In some embodiments, the routing module 230 can determine the destination for the data based on information (e.g., an address) contained within the data itself. Alternatively, the routing module 230 can determine the destination for the data based on information sent to the routing module 230 in another signal.

[0079]

[0082] The routing module 230 can be implemented in a variety of different ways. For example, in some embodiments, the routing module 230 can be implemented using one or more electrical crossbar switches. As another example, in some embodiments, the routing module 230 can be implemented by one or more microelectromechanical systems (MEMS) devices configured to perform routing operations. As yet another example, in some embodiments, the routing module 230 can be implemented using one or more prisms configured to perform routing operations.

[0080]

[0083] In the above discussion, it was assumed that the routing module 230 is electrically coupled to the router optical transceivers 208a - b. Alternatively, in some embodiments, the routing module 230 can be optically coupled to the router optical transceivers 208a - b. For example, in embodiments where the routing module 230 is implemented by one or more MEMS devices and / or one or more prisms, the routing module 230 can be optically coupled to the router optical transceivers 208a - b. In such embodiments, it is not necessary for the modulated optical beam to be converted to an electrical signal before being provided to the routing module 230. Instead, in such embodiments, the routing module 230 can receive a modulated optical beam from one node optical transceiver (e.g., the first node optical transceiver 210a) and simply redirect the modulated optical beam to another node optical transceiver (e.g., the second node optical transceiver 210b) without converting the modulated optical beam to an electrical signal.

[0081]

[0084] In the example discussed above with respect to FIGS. 1 and 2, each node optical transceiver includes a light source. Thus, when a particular processing node sends data to a router, the light source in the node optical transceiver coupled to the processing node generates an optical beam, which can then be modulated based on the data to be transmitted.

[0082]

[0085] In the types of implementations described so far, there are a plurality of light sources very close to the computing nodes. However, in some embodiments, this type of architecture may not necessarily be desirable. In some situations, it may be advantageous for the light sources to be placed elsewhere.

[0083]

[0086] FIG. 3 shows another example of a system 300 in which the techniques disclosed herein may be utilized. More specifically, FIG. 3 shows another example of a system 300 for using free space optics to interconnect a plurality of computing nodes in accordance with the present disclosure. In the system 300 depicted, the light source is placed separately from the computing nodes in order to minimize the amount of heat generated near the computing nodes. Some potential benefits of this system architecture will be discussed below.

[0084]

[0087] The system 300 shown in FIG. 3 is similar to the system 100 shown in FIG. 1 in several respects. For example, the system 300 includes a plurality of computing nodes. In particular, the system 300 is shown with a plurality of processing nodes 302 and a plurality of memory nodes 304. In addition, the system 300 includes a router 306 coupled to a plurality of optical transceivers 308.

[0085]

[0088] However, in the system being depicted, the light source for generating the optical beam to send free-space optical communication from processing node 302 to router 306 is placed at a distance from processing node 302. That is, unlike the system 100 shown in FIG. 1, processing node 302 is not coupled to the optical transceiver that includes the light source. Instead, processing node 302 is coupled to an optical module 350 that does not include a light source. Some of the potential benefits of this will be explained below. Optical module 350 is abbreviated as "OM" in FIG. 3.

[0086]

[0089] Free-space optical communication can occur between an optical transceiver 308 coupled to router 306 and an optical module 350 coupled to processing node 302. However, since optical module 350 does not include a light source, the procedure by which free-space optical communication occurs in the depicted system 300 is somewhat different from the procedure by which free-space optical communication occurs in the system 100 shown in FIG. 1.

[0087]

[0090] More specifically, optical module 350 can receive free-space optical communication from router 306 in the same way that node optical transceiver 110 receives free-space optical communication from router 106 in the system 100 shown in FIG. 1. However, since optical module 350 does not include a light source, the procedure by which optical module 350 sends free-space optical communication to router 306 can be different from the procedure by which node optical transceiver 110 sends free-space optical communication to router 106 in the system 100 shown in FIG. 1.

[0088]

[0091] In order for the optical module 350 to be able to send free - space optical communication to the router 306 in the depicted system 300, the router 306 itself may include one or more light sources 336 that generate an optical beam and direct the optical beam towards the optical module 350. Each optical module 350 may include a modulator configured to modulate the optical beam received from the router 306, and an optical system for reflecting the modulated optical beam back towards the router 306. Examples of the optical module 350 will be discussed in more detail below.

[0089]

[0092] In FIG. 3, the light source 336 is shown within the router 306. Alternatively, the light source 336 can be separate from the router 306. In some embodiments, the light source 336 is separate from the router 306 and may be coupled to the router 306. In some embodiments, the light source 336 is separate from the router 306 and may not be coupled to the router 306.

[0090]

[0093] In some embodiments, the system 300 can be configured such that for each optical module 350, there is a corresponding optical transceiver 308 that is coupled to the router 306 and optically coupled to the optical module 350. The router 306, the optical transceiver 308 coupled to the router 306, and the optical module 350 can all function together to interconnect computing nodes in order to form a network fabric. Similar to the network fabric in the system 100 shown in FIG. 1, the network fabric in the depicted system 300 enables all computing nodes to be accessible to each other. For example, all of the memory nodes 304 can be accessible to all of the processing nodes 302 by the network fabric.

[0091]

[0094] In the system 300 being described, the computing nodes are placed within an enclosure 338. In some embodiments, the enclosure 338 can be a tank such as a tank that can be utilized in a cryogenic computing system (which may be referred to herein as a cryogenic tank).

[0092]

[0095] In general terms, cryogenics is related to the production and behavior of materials at extremely low temperatures. The impact of cryogenics on various aspects of computing systems is currently being studied. Some researchers have concluded that chips developed for operation at extremely low temperatures have significant advantages over their conventional counterparts (e.g., are significantly faster than their conventional counterparts). Due to the increasing challenges in conventional approaches to improving the performance of computing systems, some researchers are convinced that significant changes in the operating temperature of computing components (e.g., processors, memory) that use cryogenic techniques can be important for the future development of computing systems. Since cryogenic computing systems are designed to operate at extremely low temperatures, the computing nodes operating within a cryogenic computing system can be placed within a tank that is cooled to the desired temperature.

[0093]

[0096] Of course, in some embodiments, the enclosure 338 shown in FIG. 3 can be implemented as something other than a cryogenic tank. For example, in some embodiments, the enclosure 338 can be a rack such as a server rack commonly used in a data center. In other embodiments, the enclosure 338 can be another type of container such as a barrel, vat, or the like.

[0094]

[0097] As described above, computing nodes developed for a low-temperature computing system can be designed to operate at extremely low temperatures. However, in a low-temperature computing system, some types of computing nodes may be able to operate at lower temperatures than other types of computing nodes. For example, the processing node 302 in a low-temperature computing system can be designed to operate at extremely low temperatures, while the memory node 304 in a low-temperature computing system can be designed to operate at a slightly higher temperature.

[0095]

[0098] In an embodiment where the enclosure 338 is a cryogenic tank designed for use in a low-temperature computing system, the enclosure 338 can include different zones for different types of computing nodes. For example, in some embodiments, the enclosure 338 can include a first zone 340 and a second zone 342. In FIG. 3, the processing node 302 is shown in the first zone 340 of the enclosure 338, and the memory node 304 is shown in the second zone 342 of the enclosure 338. The first zone 340 can be designed for extremely low temperatures, such as the temperature suitable for the processing node 302. The second zone 342 can be designed for a slightly higher temperature, such as the temperature suitable for the memory node 304. As a specific example, in some embodiments, the first zone 340 of the enclosure 338 can be designed for a temperature of about 4K, and the second zone 342 of the enclosure 338 can be designed for a temperature of about 77K.

[0096]

[0099] The light source can generate a significant amount of heat. Therefore, having the processing node 302 coupled to the light module 350 that does not include the light source makes it easier to maintain the first zone 340 of the enclosure 338 at a very low temperature, which is suitable for the processing node 302 in a low-temperature computing system. If the light module 350 includes a light source (similar to the node optical transceiver 110 in the system 100 shown in FIG. 1), this will add a significant amount of heat to the first zone 340 of the enclosure 338, and thus increase the cost of cooling the first zone 340 of the enclosure to the desired temperature.

[0097]

[0100] The above discussion focused on one potential benefit of having the processing node 302 coupled to the light module 350 that does not include the light source, and this benefit is specifically associated with a low-temperature computing system. However, this type of architecture can be utilized in embodiments that do not include a low-temperature computing system. For example, even if the system 300 is designed such that all of the computing nodes (e.g., the processing node 302 and the memory node 304) operate at the same temperature (e.g., room temperature), having the processing node 302 coupled to the light module 350 that does not include the light source and instead using an external light source 336 can still be beneficial. For example, the reduction in heat resulting from using the light module 350 instead of the node optical transceiver 110 can improve the performance of the processing node 302.

[0098]

[0101] FIG. 4 shows an example of how free-space optical communication can occur among multiple computing nodes. The example will be described with respect to a system configured similar to the system 300 shown in FIG. 3. The various components shown in FIG. 4 are examples of possible implementations of the corresponding components in the system 300 shown in FIG. 3.

[0099]

[0102] For simplicity, the example depicted is assumed to communicate between a first processing node 402a and a second processing node 402b. The first processing node 402a is coupled to a first optical module 450a, and the second processing node 402b is coupled to a second optical module 450b. The router 406 includes a plurality of optical transceivers, including a first optical transceiver 408a and a second optical transceiver 408b. For the purposes of this example, it is assumed that the first optical transceiver 408a is optically coupled to the first optical module 450a and the second optical transceiver 408b is optically coupled to the second optical module 450b.

[0100]

[0103] The first optical module 450a and the second optical module 450b may both include a receiving module configured to receive free space optical communication from the router 406. In particular, the first optical module 450a may include a receiving module 482a, and the second optical module 450b may include a receiving module 482b. The receiving module 482a in the first optical module 450a may include a photodetector 470a and a demodulator 472a. The receiving module 482b in the second optical module 450b may include a photodetector 470b and a demodulator 472b.

[0101]

[0104] The first optical transceiver 408a and the second optical transceiver 408b may both include a transmitting module configured to transmit free space optical communication to the first optical module 450a and the second optical module 450b, respectively. In particular, the first optical transceiver 408a may include a transmitting module 484a, and the second optical transceiver 408b may include a transmitting module 484b. The transmitting module 484a in the first optical transceiver 408a may include a light source 420a and a modulator 466a. The transmitting module 484b in the second optical transceiver 408b may include a light source 420b and a modulator 466b.

[0102]

[0105] The transmission module 484a in the first optical transceiver 408a and the receiving module 482a in the first optical module 450a may enable the router 406 to send data to the first processing node 402a. More specifically, the light source 420a in the first optical transceiver 408a may generate an optical beam directed towards the photodetector 470a in the first optical module 450a. The optical beam may be modulated by the modulator 466a based on a modulation signal including the data to be transmitted. The photodetector 470a in the first optical module 450a may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 472a in the first optical module 450a may be configured to extract data from the electrical signal generated by the photodetector 470a. This data may then be provided to the first processing node 402a.

[0103]

[0106] In a similar manner, the transmission module 484b in the second optical transceiver 408b and the receiving module 482b in the second optical module 450b may enable the router 406 to send data to the second processing node 402b. More specifically, the light source 420b in the second optical transceiver 408b may generate an optical beam directed towards the photodetector 470b in the second optical module 450b. The optical beam may be modulated by the modulator 466b based on a modulation signal including the data to be transmitted. The photodetector 470b in the second optical module 450b may detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 472b in the second optical module 450b may be configured to extract data from the electrical signal generated by the photodetector 470b. This data may then be provided to the second processing node 402b.

[0104]

[0107] The first optical module 450a and the second optical module 450b may both include a transmission module configured to send free-space optical communication to the router 406. In particular, the first optical module 450a may include a transmission module 486a, and the second optical module 450b may include a transmission module 486b. The transmission module 486a in the first optical module 450a may include a modulator 474a and a mirror 478 1a , 478 1b and an optical system that may include the same. Similarly, the transmission module 486b in the second optical module 450b may include a modulator 474b and a mirror 478 2a , 478 2b and an optical system that may include the same.

[0105]

[0108] The first optical transceiver 408a and the second optical transceiver 408b may both include a reception module configured to receive free-space optical communication from the first optical module 450a and the second optical module 450b, respectively. In particular, the first optical transceiver 408a may include a reception module 488a, and the second optical transceiver 408b may include a reception module 488b. The reception module 488a in the first optical transceiver 408a may include a light source 436a, a photodetector 468a, and a demodulator 476a. The reception module 488b in the second optical transceiver 408b may include a light source 436b, a photodetector 468b, and a demodulator 476b.

[0106]

[0109] The transmission module 486a in the first optical module 450a and the reception module 488a in the first optical transceiver 408a may enable the first processing node 402a to send data to the router 406. More specifically, the light source 436a in the reception module 488a may direct an optical beam towards the first optical module 450a. The optical system in the transmission module 486a may direct the optical beam towards the modulator 474a. In the example depicted, the mirror 478 1areflects the optical beam in the direction of the modulator 474a. The modulator 474a can modulate the optical beam based on a modulation signal including data to be transmitted, thereby generating a modulated optical beam. The optical system in the transmission module 486a can direct the modulated optical beam toward the first optical transceiver 408a in the router 406, which is optically coupled to the first optical module 450a in this example (as described above). In the example depicted, the mirror 478 1b reflects the modulated optical beam in the direction of the photodetector 468a in the receiving module 488a. The photodetector 468a in the receiving module 488a can detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 476a in the receiving module 488a can extract data from the electrical signal generated by the photodetector 468a. This data can then be provided to the routing module 430 within the router 406.

[0107]

[0110] Similarly, the transmission module 486b in the second optical module 450b and the receiving module 488b in the second optical transceiver 408b can enable the second processing node 402b to send data to the router 406. More specifically, the light source 436b in the receiving module 488b can direct an optical beam toward the second optical module 450b. The optical system in the transmission module 486b can direct the optical beam toward the modulator 474b. In the example depicted, the mirror 478 2a reflects the optical beam in the direction of the modulator 474b. The modulator 474b can modulate the optical beam based on a modulation signal including data to be transmitted, thereby generating a modulated optical beam. The optical system in the transmission module 486b can direct the modulated optical beam toward the second optical transceiver 408b in the router 406, which is optically coupled to the second optical module 450b in this example (as described above). In the example depicted, the mirror 478 2breflects the modulated optical beam in the direction of the photodetector 468b in the receiving module 488b. The photodetector 468b in the receiving module 488b can detect the modulated optical beam and convert the modulated optical beam into an electrical signal. The demodulator 476b in the receiving module 488b can extract data from the electrical signal generated by the photodetector 468b. This data can then be provided to the routing module 430 within the router 406.

[0108]

[0111] An example including communication from the first processing node 402a to the second processing node 402b will be described here. In this example, it is assumed that the first processing node 402a has data to send to the second processing node 402b.

[0109]

[0112] When the first processing node 402a has data to send to the second processing node 402b, the transmission module 486a in the first optical module 450a can send the data to the receiving module 488a in the first optical transceiver 408a in the manner described above. Along with the data, the transmission module 486a can further send an indication of the destination for the data, which is the second processing node 402b in this example, to the receiving module 488a. The receiving module 488a can provide the data and the indication of the destination for the data to the routing module 430. The routing module 430 can then provide the data to the optical transceiver corresponding to the destination for the data, which is the second optical transceiver 408b in this example. The transmission module 484b in the second optical transceiver 408b can send the data to the receiving module 482b in the second optical module 450b in the manner described above. The second optical module 450b can then provide the data to the second processing node 402b.

[0110]

[0113] The second processing node 402b can further send data to the first processing node 402a in a similar manner. When the second processing node 402b has data to send to the first processing node 402a, the transmission module 486b in the second optical module 450b can send the data to the receiving module 488b in the second optical transceiver 408b in the manner described above. Along with the data, the transmission module 486b can further send an indication of the destination for the data, which is the first processing node 402a in this example, to the receiving module 488b. The receiving module 488b can provide the data and the indication of the destination for the data to the routing module 430. The routing module 430 can then provide the data to the optical transceiver corresponding to the destination for the data, which is the first optical transceiver 408a in this example. The transmission module 484a in the first optical transceiver 408a can send the data to the receiving module 482a in the first optical module 450a in the manner described above. The first optical module 450a can then provide the data to the first processing node 402a.

[0111]

[0114] In some embodiments, the optical modules 450a - b shown in FIG. 4 can be representative of the optical module 350 shown in FIG. 3. That is, the optical module 350 in the system 300 shown in FIG. 3 can be configured similarly to the optical modules 450a - b shown in FIG. 4. Similarly, the optical transceivers 408a - b shown in FIG. 4 can be representative of the optical transceiver 308 shown in FIG. 3. That is, the optical transceiver 308 in the system 30 exhibited in FIG. 3 can be configured similarly to the optical transceivers 408a - b in the system 400 shown in FIG. 4. In some embodiments, any two processing nodes 302 in the system 300 shown in FIG. 3 can communicate with each other in a manner similar to the means by which the first processing node 402a and the second processing node 402b communicate with each other.

[0112]

[0115] In the system 300 shown in FIG. 3, the light source 336 is shown separately from the optical transceiver 308. However, in some embodiments, the light source 336 may be included within the optical transceiver 308. For example, in the example shown in FIG. 4, the light sources 436a-b are shown as parts of the optical transceivers 408a-b.

[0113]

[0116] Of course, the specific configurations of the first optical module 450a, the second optical module 450b, the first optical transceiver 408a, and the second optical transceiver 408b are provided for illustrative purposes only and should not be construed as limiting the scope of the present disclosure. The optical modules and optical transceivers can be configured in many different ways in accordance with the present disclosure.

[0114]

[0117] In the described embodiments, the transmission modules 486a-b in the optical modules 450a-b each include an optical system, and each optical system includes a mirror. More specifically, the optical system in the transmission module 486a includes the mirrors 478 1a 、478 1b and the optical system in the transmission module 486b includes the mirrors 478 2a 、478 2b However, in alternative embodiments, other types of optical components (e.g., lenses, gratings) may be used in the optical system. These other optical components can be used in addition to or instead of the mirrors.

[0115]

[0118] The routing module 430 can be implemented in the same manner as the routing module 230 discussed above with respect to FIG. 2. For example, the routing module 430 can be implemented using one or more electrical crossbar switches, one or more MEMS devices, one or more prisms, and the like. In embodiments where the routing module 430 is implemented by one or more MEMS devices and / or by one or more prisms, it is not necessary for the modulated optical beam detected by the photodetectors 468a-b to be converted into an electrical signal.

[0116]

[0119] FIG. 3 discussed above represents one example of a system 300 in which the light source is placed separately from the computing node. However, there are many other possible ways in which such a system can be designed. FIG. 5 shows another example of a system 500 for using free space optics to interconnect a plurality of computing nodes where the light source is placed separately from the computing node.

[0117]

[0120] System 500 is similar to system 300 shown in FIG. 3 in several respects. For example, system 500 includes a plurality of computing nodes. In particular, system 500 is shown with a plurality of processing nodes 502 and a plurality of memory nodes 504. In addition, system 500 includes a router 506 coupled to a plurality of optical transceivers 508. The processing nodes 502 are electrically coupled to an optical module 550 that does not include a light source in the depicted embodiment. The router 506 includes one or more light sources 536 that generate an optical beam and direct the optical beam towards the optical module 550 to enable the optical module 550 to send free space optical communications to the router 506. The computing nodes are placed within an enclosure 538. The enclosure can include different zones for different types of computing nodes.

[0118]

[0121] In the example described, the enclosure includes three different zones: a first zone 540, a second zone 542, and a third zone 544. The processing node 502 is displayed in the first zone 540 of the enclosure 538. The memory node 504 is displayed in the second zone 542 of the enclosure 538. The router 506, which includes the light source 536 and the optical transceiver 508, is displayed in the third zone 544 of the enclosure 538. Most of the optical module 550 is in the third zone 544 of the enclosure 538, but some portions of the optical module 550 are placed in the second zone 542.

[0119]

[0122] In some embodiments, the enclosure 538 can be a cryogenic tank designed for use in a cryogenic computing system. As discussed above, in a cryogenic computing system, some types of computing nodes can operate at lower temperatures than other types of computing nodes. In some embodiments, the first zone 540 can be designed for extremely low temperatures, such as the temperature suitable for the processing node 502. The second zone 542 can be designed for slightly higher temperatures, such as the temperature suitable for the memory node 504. The third zone 544 can be designed for room temperature. As a specific example, in some embodiments, the first zone 540 of the enclosure 538 can be designed for a temperature of about 4K, the second zone 542 of the enclosure 538 can be designed for a temperature of about 77K, and the third zone 544 of the enclosure 538 can be designed for a temperature of about 300K.

[0120]

[0123] Since the third zone 544 of the enclosure 538 can be designed for room temperature, the router 506 can be placed inside the third zone 544. In the system 300 shown in FIG. 3, the router 306 is arranged outside the enclosure 338 because the router 306 includes light sources (the light source 336 that directs a light beam to the modulator in the optical module 350 and the light sources in the optical transceiver 308) that generate a significant amount of heat. In the embodiment shown in FIG. 3, the entire enclosure 338 is maintained below room temperature. As explained above, if the router 306 (including the light sources of the router 306) is placed inside the enclosure 338, this will increase the cost of cooling the enclosure 338. Therefore, in the system 300 shown in FIG. 3, it may be beneficial to place the router 306 outside the enclosure 338. In contrast, in the system 500 shown in FIG. 5, the third zone 544 of the enclosure 538 can be maintained at room temperature. Since the third zone 544 of the enclosure 538 is not cooled, the router 506 (including the light sources of the router 506) can be placed inside the enclosure 538.

[0121]

[0124] In some embodiments, a "network fabric" refers to a computer network architecture in which multiple computing systems or computing nodes are interconnected. In some embodiments, the computing systems or computing nodes in the network fabric may be interconnected using routers, switches, and other types of network components. In some embodiments, the computing systems or computing nodes in the network fabric may be interconnected in a manner that provides low latency and / or high bandwidth interconnectivity between different computing systems or computing nodes. In some embodiments, the computing systems or computing nodes in the network fabric may be interconnected using a relatively small number of layers (e.g., two or three layers). This essentially flattens the network architecture, thereby reducing the distance between endpoints.

[0122]

[0125] In some embodiments, two components are "coupled" when they are electrically coupled, optically coupled, or mechanically coupled.

[0123]

[0126] In some embodiments, two components are "electrically coupled" when current can flow from one component to another. In some embodiments, two electrically coupled components may be in direct contact with each other such that current flows directly from one component to the other. However, this is not required. In some embodiments, two electrically coupled components may not be in direct contact with each other. There may be any number of other conductive materials and components disposed electrically between the two components, and the two components are electrically coupled as long as current can flow between them.

[0124]

[0127] In some embodiments, two optical components are "optically coupled" if there is an optical path between the two optical components. Thus, in such embodiments, a first optical component (e.g., node optical transceiver 110) may be considered to be optically coupled to a second optical component (e.g., router optical transceiver 108) when optical transmission sent by the first component is received by the second optical component.

[0125]

[0128] In some embodiments, two optical components are "optically aligned" if there is a direct optical path between the two optical components without any intervening optical element redirecting the path of optical transmission between the two optical components. In some embodiments, a first optical component (e.g., transmission module 284a in router optical transceiver 208a) may be considered to be optically aligned with a second optical component (e.g., receiving module 282a in node optical transceiver 210a) when optical transmission sent by the first optical component is received by the second optical component without any intervening optical component between the first and second optical components.

[0126]

[0129] The term "determine" (and grammatical variants thereof) encompasses a wide variety of actions, and thus "determine" can include compute, calculate, process, derive, inquire, search (e.g., search in a table, database, or other data structure), verify, and the like. Further, "determine" can include receive (e.g., receive information), access (e.g., access data in a memory), and the like. Further, "determine" can include resolve, select, choose, establish, and the like.

[0127]

[0130] The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. Further, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be construed as excluding the existence of additional embodiments that further incorporate the described features. For example, any element or feature described herein with respect to one embodiment can be combined with any element or feature of any other embodiment described herein, if compatible.

(0128)

[0131] The described embodiments should be considered exemplary and not restrictive, and the present disclosure can be implemented in other forms than those specifically described herein. Accordingly, the scope of the present disclosure is indicated by the appended claims rather than by the foregoing description. Modifications within the meaning and scope of equivalency of the claims are to be included within the scope of those claims.

Claims

1. A system for using free space optics to interconnect a plurality of computing nodes, wherein the plurality of computing nodes comprise a plurality of processing nodes and a plurality of memory nodes, and the plurality of processing nodes and the plurality of memory nodes are arranged such that the plurality of processing nodes are not all electrically coupled to all of the plurality of memory nodes, the system comprising: a plurality of node optical transceivers electrically coupled to at least a portion of the plurality of computing nodes; a router configured to communicate with the plurality of computing nodes by free space optical communication; a plurality of router optical transceivers coupled to the router, distinct from the plurality of node optical transceivers, wherein optical transmission between the plurality of router optical transceivers and the plurality of node optical transceivers enables the free space optical communication between the router and the plurality of computing nodes; a network fabric that interconnects the plurality of computing nodes such that the plurality of computing nodes are accessible to each other by the network fabric, the network fabric comprising the plurality of node optical transceivers, the plurality of router optical transceivers, and the router, and the network fabric being configured such that all of the plurality of memory nodes are accessible to all of the plurality of processing nodes by the network fabric; a plurality of light sources, each node optical transceiver of the plurality of node optical transceivers and each router optical transceiver of the plurality of router optical transceivers having at least one separate light source; a plurality of photodetectors, each node optical transceiver of the plurality of node optical transceivers and each router optical transceiver of the plurality of router optical transceivers having at least one separate photodetector; A system comprising the above.

2. The system according to claim 1, wherein: The plurality of node optical transceivers are not electrically coupled to the router, The plurality of router optical transceivers are not electrically coupled to the plurality of computing nodes, System.

3. The system according to claim 1, A first computing node is electrically coupled to a first node optical transceiver, A first router optical transceiver is optically coupled to the first node optical transceiver, A second computing node is electrically coupled to a second node optical transceiver, A second router optical transceiver is optically coupled to the second node optical transceiver, The first router optical transceiver is configured to receive a first modulated optical beam from the first node optical transceiver and demodulate the first modulated optical beam to extract data, The router is configured to route the data to the second router optical transceiver, The second router optical transceiver is configured to transmit a second modulated optical beam to the second node optical transceiver, the second modulated optical beam comprising the data, System.

4. The system according to claim 1, wherein the router comprises An electrical crossbar switch for performing a routing operation, A microelectromechanical system (MEMS) device for performing the routing operation, A prism for performing the routing operation And at least one of them. System.

5. A system for using free space optics to interconnect a plurality of computing nodes, A router configured to communicate with the plurality of computing nodes by free space optical communication, A plurality of optical modules, the plurality of optical modules do not include a light source, are electrically coupled to at least a part of the plurality of computing nodes, and each optical module among the plurality of optical modules comprises a modulator and an optical system. A plurality of optical modules A plurality of optical transceivers coupled to the router, wherein the plurality of optical transceivers assist in the free space optical communication with the plurality of optical modules, and each optical module among the plurality of optical modules has a corresponding optical transceiver optically coupled to the optical module, the plurality of optical transceivers; A first plurality of light sources, wherein the first plurality of light sources are separate from the plurality of optical modules and enable the free space optical communication from the router to the plurality of optical modules, the first plurality of light sources; A second plurality of light sources, wherein the second plurality of light sources are separate from the plurality of optical modules and enable the free space optical communication from the plurality of optical modules to the router, and the modulator in a specific optical module is configured to modulate a light beam received from one of the second plurality of light sources to generate a modulated light beam, and the optical system in the specific optical module is configured to direct the modulated light beam towards the router, the second plurality of light sources A system comprising.

6. The system according to claim 5, wherein The plurality of optical modules, the plurality of optical transceivers, and the router interconnect the plurality of computing nodes to form a network fabric, The plurality of computing nodes comprise a plurality of processing nodes and a plurality of memory nodes, The plurality of processing nodes are not electrically coupled to all of the plurality of memory nodes, All of the plurality of memory nodes are accessible to all of the plurality of processing nodes by the network fabric, A system.

7. The system according to claim 5, wherein A first computing node is electrically coupled to a first optical module, A first optical transceiver is optically coupled to the first optical module, A second computing node is electrically coupled to a second optical module, A second optical transceiver is optically coupled to the second optical module, The first optical transceiver is configured to receive a first modulated light beam from the first optical module and demodulate the first modulated light beam to extract data, The router is configured to route the data to the second optical transceiver. The second optical transceiver is configured to transmit a second modulated optical beam to the second optical module, and the second modulated optical beam comprises the data. System. **Claim 8** A system for using free space optics to interconnect a plurality of computing nodes disposed within an enclosure, a router configured to route free space optical communications among the plurality of computing nodes, a plurality of processing nodes in a first zone of the enclosure, a plurality of optical modules electrically coupled to at least a portion of the plurality of computing nodes, a plurality of memory nodes in a second zone of the enclosure, wherein each memory node among the plurality of memory nodes is electrically coupled to at least one processing node among the plurality of processing nodes, a plurality of optical transceivers coupled to the router, the plurality of optical transceivers facilitating free space optical communications with the plurality of optical modules, and each optical module among the plurality of optical modules having a corresponding optical transceiver optically coupled thereto, and at least one light source disposed outside the first zone of the enclosure and configured to transmit an optical beam toward the plurality of optical modules. System. **Claim 9** The system according to claim 8, wherein a first temperature of the first zone of the enclosure is lower than a second temperature of the second zone of the enclosure. **Claim 10** The system according to claim 8, wherein the plurality of optical modules are disposed in the first zone of the enclosure. **Claim 11** The system according to claim 8, wherein the plurality of optical modules are disposed in a third zone of the enclosure. **Claim 12** The system according to claim 11, wherein a first temperature of the first zone of the enclosure is lower than a second temperature of the second zone of the enclosure, and the second temperature is lower than a third temperature of the third zone of the enclosure. System.

13. The system according to claim 8, wherein the plurality of optical modules, the plurality of optical transceivers, and the router interconnect the plurality of computing nodes to form a network fabric, the plurality of computing nodes are accessible to each other by the network fabric, a system.

14. The system according to claim 13, wherein the plurality of processing nodes are not all electrically coupled to all of the plurality of memory nodes, all of the plurality of memory nodes are accessible to all of the plurality of processing nodes by the network fabric, a system.

15. The system according to claim 8, wherein each optical module among the plurality of optical modules includes a modulator and an optical system, the modulator in a particular optical module is configured to modulate an optical beam received from the at least one light source to generate a modulated optical beam, the optical system in the particular optical module is configured to direct the modulated optical beam to an optical transceiver among the plurality of optical transceivers, a system.

16. The system according to claim 8, wherein a first computing node is electrically coupled to a first optical module, a first optical transceiver is optically coupled to the first optical module, a second computing node is electrically coupled to a second optical module, a second optical transceiver is optically coupled to the second optical module, the first optical transceiver is configured to receive a first modulated optical beam from the first optical module and demodulate the first modulated optical beam to extract data, the router is configured to route the data to the second optical transceiver, the second optical transceiver is configured to transmit a second modulated optical beam to the second optical module, the second modulated optical beam comprising the data, a system.

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