Method and system for intersatellite communications

Abstract

An optical router configured to facilitate communication between a satellite constellation and a plurality of satellite nodes is provided, the optical router comprising: an upstream interface configured to facilitate communication via an upstream communication link to the satellite constellation, a downstream interface configured to simultaneously communicate with the satellite node via a single optical aperture via multiple downstream optical communication links in different directions, the downstream interface through which the multiple optical communication links are established, and a controller for directing operation of the optical router.

Description

[Technical Field]

[0001] The subject matter disclosed herein relates to satellite communication systems, and more particularly to satellite communication systems configured to establish and maintain optical communication links. [Background technology]

[0002] For example, satellites in low Earth orbit are deployed for a variety of purposes. To facilitate communication therewith, several entities have established networks of high-bandwidth optical communication satellites that provide global data transmission. According to some designs, the networks comprise a constellation of communication satellites that operate using free-space optical communication links (sometimes referred to as "laser communications").

[0003] This solution could provide global availability of high-speed network access to satellites in low Earth orbit, however this requires that the satellites be able to maintain optical communication links with the constellation at distances greater than, for example, 5000 km, which small satellites may not be equipped to achieve. Summary of the Invention

[0004] According to an aspect of the subject matter disclosed herein, there is provided an optical router configured to facilitate communication between a satellite constellation and a plurality of satellite nodes, the optical router comprising: an upstream interface configured to facilitate communication over an upstream communication link to the satellite communication constellation, which may be, for example, an optical or radio frequency communication link; a downstream interface configured to simultaneously communicate with a satellite node via multiple downstream optical communication links in different directions, the multiple optical communication links being established through a single optical aperture; and A controller to instruct the operation of the optical router. Equipped with.

[0005] The optical router may be configured to define hot spots where downstream optical communication links are established.

[0006] The optical router may further be configured to define two or more zones within the hotspot, wherein the wavelength of each of the downstream optical communication links is unique in each of the zones, i.e., none of the zones includes downstream optical communication links having the same wavelength of the carrier signal.

[0007] The optical router may be further configured to define two or more zones within the hotspot, the downstream optical communication links in each of the zones being time division multiplexed.

[0008] Each of the downstream optical communication links comprises a modulated beam, and the downstream interface comprises a transmit array comprising a plurality of transmit assemblies each configured to generate one of the outgoing beams for transmission over a respective optical communication link, and an aperture assembly defining an optical aperture.

[0009] Each of the transmit assemblies may include a laser configured to generate one of the output beams along an output beam path and a transmit lens assembly configured to adjust parameters of the output beam.

[0010] The transmit lens assembly may include a focusing lens configured to adjust the divergence of the output beam, and / or one or more positioning lenses each configured to adjust the direction of the output beam.

[0011] The focusing lens and / or the positioning lens may be liquid lenses, and the controller is configured to adjust respective parameters of the output beam by applying electrical signals to selectively change the shape of one or more of the lenses of the transmit lens assembly.

[0012] The focusing lens and / or the positioning lens may be solid lenses, and the controller is configured to adjust respective parameters of the output beam by operating the actuators to selectively adjust the position and / or orientation of one or more of the lenses of the transmit lens assembly.

[0013] The downstream interface may further include a transmit steering arrangement configured to facilitate determining the positions of the output beams, and the controller is configured to operate one or more of the transmit assemblies to adjust the positions of the respective output beams based on information provided by the transmit steering arrangement.

[0014] The transmit steering arrangement may include a transmit steering camera and an output beam splitter configured to split each output beam into a first portion emitted toward the transmit steering camera and a second portion emitted toward the optical aperture.

[0015] The exit beam splitter may be an asymmetric beam splitter, with each second portion comprising more of the original exit beam than the corresponding first portion.

[0016] The output beam splitter may be further configured to emit one or more light beams from the optical aperture in a direction away from the transmit array and the transmit steering camera.

[0017] The downstream interface may further include a receiving array comprising a plurality of optical receiving assemblies each configured to receive one of the incident beams to receive transmissions transmitted over the respective optical communication links.

[0018] Each of the receiving assemblies may include a receiver configured to receive one of the incident beams along the incident beam path and a receiving lens assembly configured to adjust parameters of the incident beam.

[0019] The receiver lens assembly may include a focusing lens configured to adjust the divergence of the incident beam, and / or one or more positioning lenses each configured to adjust the direction of the incident beam.

[0020] The focusing lens and / or the positioning lens may be liquid lenses, and the controller is configured to adjust respective parameters of the incident beam by applying electrical signals to selectively change the shape of one or more of the lenses of the receiving lens assembly.

[0021] The focusing lens and / or the positioning lens are solid lenses, and the controller is configured to adjust respective parameters of the incident beam by operating the actuators to selectively adjust the position and / or orientation of one or more of the lenses of the receiving lens assembly.

[0022] The downstream interface may further include a receive steering arrangement configured to facilitate determining the position of the incident beam, and the controller is configured to operate one or more of the receiver assemblies to adjust the position of the respective incident beam based on information provided by the receive steering arrangement.

[0023] The receive steering arrangement may include a receive steering camera and an incident beam splitter configured to split each of the incident beams into a first portion emitted toward the receive steering camera and a second portion emitted toward each of the receiving assemblies.

[0024] The input beam splitter may be an asymmetric beam splitter, with each second portion comprising more of the original output beam than the corresponding first portion.

[0025] The input beam splitter may be further configured to emit one or more light beams from the optical aperture in a direction away from the receive array and the receive steering camera.

[0026] The receive array may include a receive guide assembly configured to guide each of the plurality of incident beams received from the incident beam path through the optical aperture towards each of the receive assemblies.

[0027] The transmit array may include a transmit guide assembly configured to guide multiple output beams emitted from the transmit assembly toward substantially parallel paths along output beam paths no larger in lateral dimension than the optical aperture.

[0028] The transmit guide assembly and / or the receive guide assembly may include a plurality of mirrors configured to facilitate steering of the beam.

[0029] One or more of the mirrors may be dichroic. One or more of the mirrors may be semi-transparent.

[0030] The transmit guide assembly and / or the receive guide assembly may further include a relay lens disposed in the beam path.

[0031] Each of the downstream optical communication links may comprise a modulated beam, the downstream interface comprising: a transmit array comprising one or more transmit assemblies each configured to generate one of the output beams for transmission over a respective optical communication link; an aperture assembly defining an optical aperture; a diffusing device having an incident surface and a transmitting surface, the diffusing device configured to transmit each of the output beams from its transmitting surface toward a predetermined location in the optical aperture, the predetermined location depending on where the output beam strikes the incident surface; Equipped with.

[0032] The transmit array may comprise multiple transmit assemblies, each configured to generate a beam in a single direction.

[0033] The transmit array may comprise transmit assemblies each configured to selectively generate a plurality of outgoing beams in one of several directions.

[0034] Each of the transmitter assemblies may include a light source configured to generate one of the output beams and a steering mechanism configured to direct the output beam in a predetermined direction.

[0035] The light source may comprise a laser and / or an LED.

[0036] The steering mechanism may comprise a steering mirror, a mirror array, a micro-opto-electro-mechanical system assembly (eg, a device, an assembly, etc.), and / or a light steering arrangement.

[0037] The diffusing device may be configured to increase the diameter of the beam.

[0038] The diffusing device may be configured to transmit the beam toward an optical aperture having near-field characteristics that produce a predetermined far-field pattern.

[0039] The diffusing device may comprise a light diffuser.

[0040] The diffusing device may comprise a holographic diffuser.

[0041] The diffusing device may comprise a metasurface and / or a microlens array.

[0042] The diffusing device may comprise ground glass.

[0043] The diffusing device may be planar and / or curved. The optical router may be configured to orbit the Earth and remain within a predetermined maximum distance from each of the multiple satellite nodes.

[0044] The upstream interface may be configured to communicate with a device configured to establish an upstream communication link.

[0045] According to another aspect of the presently disclosed subject matter, there is provided a system configured to facilitate communications between a satellite communications constellation and a plurality of satellite nodes, the system comprising: an optical router as described above; a plurality of terminal modules configured to communicate with the optical router via an optical communication link, each terminal module being connected to one of the satellite nodes and configured to communicate with one of the satellite nodes; Equipped with.

[0046] According to another aspect of the subject matter disclosed herein, there is provided a method of communicating with a satellite node, the method comprising: providing an optical router as described above; establishing an upstream communication link between the optical router and the satellite communication constellation; establishing a downstream optical communication link between the satellite node and the optical router; and communicating with the satellite node comprises transmitting information between the satellite node and the satellite constellation via an optical router.

[0047] In accordance with another aspect of the presently disclosed subject matter, there is provided a free-space optical communications device configured to establish and simultaneously maintain multiple optical communications links with multiple nodes, each optical communications link comprising a modulated laser beam, the free-space optical communications device configured to establish and maintain the multiple optical communications links through a single optical aperture.

[0048] The free space optical communications device may be configured to form part of a vehicle or to operate while carried by a vehicle, which may be an aircraft.

[0049] The aircraft may be one or more selected from the group including a rotorcraft, a fixed-wing aircraft, an aerostat, a satellite, and a spacecraft.

[0050] The free space optical communications device may form part of the optical router described above.

[0051] The free space optical communications device may be, for example, a fixed ground-mounted device around which one or more of the nodes orbit.

[0052] At least one of the nodes may be configured to form part of a vehicle or to operate while carried by a vehicle, which may be an aircraft.

[0053] The aircraft may be one or more selected from the group including a rotorcraft, a fixed-wing aircraft, an aerostat, a satellite, and a spacecraft.

[0054] At least one of the nodes may form part of the optical router described above.

[0055] At least one of the nodes may be, for example, a ground-based fixed device around which one or more of the nodes and / or a free space orbiting communication device orbits.

[0056] At least one of the nodes may be, for example, a ground-based fixed device around which one or more of the nodes and / or the free space orbital communications device orbits, and one of the nodes may form part of a vehicle or be configured to operate while being carried by a vehicle, which may be an aircraft.

[0057] Each of the communication links may carry a bitstream that is independent of the bitstreams carried by the other communication links.

[0058] The free space optical communications device may be further configured to facilitate communications between the network and the node.

[0059] The communications network may comprise at least one satellite, which may be part of a satellite communications constellation, that communicates directly with the free-space optical communications device.

[0060] According to another aspect of the presently disclosed subject matter, there is provided an interface configured to simultaneously transmit multiple beams in different directions through a single optical aperture, the interface comprising: a transmit array comprising one or more transmit assemblies each configured to generate one of the output beams for transmission in a predetermined direction; an aperture assembly defining an optical aperture; a diffusing device having an incident surface and a transmitting surface, the diffusing device configured to transmit each of the output beams from its transmitting surface toward a predetermined location in the optical aperture, the predetermined location depending on where the output beam strikes the incident surface; Equipped with.

[0061] The transmit array may comprise multiple transmit assemblies, each configured to generate a beam in a single direction.

[0062] The transmit array may comprise transmit assemblies each configured to selectively generate a plurality of outgoing beams in one of several directions.

[0063] Each of the transmitter assemblies may include a light source configured to generate one of the output beams and a steering mechanism configured to direct the output beam in a predetermined direction.

[0064] The light source may comprise a laser and / or an LED.

[0065] The steering mechanism may comprise a steering mirror, a mirror array, a micro-opto-electro-mechanical system assembly (eg, a device, an assembly, etc.), and / or a light steering arrangement.

[0066] The diffusing device may be configured to increase the diameter of the beam.

[0067] The diffusing device may be configured to transmit the beam toward an optical aperture having near-field characteristics that produce a predetermined far-field pattern.

[0068] The diffusing device may comprise a light diffuser.

[0069] The diffusing device may comprise a holographic diffuser.

[0070] The diffusing device may comprise a metasurface and / or a microlens array.

[0071] The diffusing device may comprise ground glass.

[0072] The diffusion device may be planar and / or curved.

[0073] In order to provide a proper understanding of the subject matter disclosed herein and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0074] [Figure 1] 1 is a schematic diagram of a system for establishing inter-satellite communications; [Figure 2A] 2A and 2B are side and front views, respectively, of a hotspot defined by an optical router of the system shown in FIG. 1. [Figure 2B] 2A and 2B are side and front views, respectively, of a hotspot defined by an optical router of the system shown in FIG. 1. [Figure 3] This is a satellite node in the system shown in Figure 1. [Figure 4] FIG. 2 is a schematic diagram of a downstream interface of an optical router of the system shown in FIG. 1. [Figure 5] FIG. 2 is a schematic diagram of an improved downstream interface of an optical router of the system shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0075] 1, a system is provided that is configured to facilitate the establishment of a communications link between a satellite constellation, generally designated 10, and a plurality of satellite nodes 20 in orbit around the Earth. The system includes an optical router 30 that is configured to forward network traffic, for example in the form of data packets, between one or more satellites of the satellite constellation 10 and selected ones of the satellite nodes 20.

[0076] Thus, satellite nodes 20 can connect to the network established by satellite constellation 10 without having to establish and / or maintain communication links with each other. An orbital router 30 manages communications with satellite nodes at its downstream end and with satellite constellation 10 at its upstream end.

[0077] According to some examples, the optical router 30 is configured to establish communication links between the satellite constellation 10 and each of the satellite nodes 20 and forward network traffic therethrough by facilitating communication via an upstream communication link, e.g., an optical communication link, with the satellite constellation 10 and a downstream optical communication link with each of the satellite nodes 20.

[0078] According to some examples, optical router 30 is configured to establish an upstream communication link.

[0079] According to another example, optical router 30 is configured to communicate with a device configured to establish an upstream communication link, e.g., optical router 30 may constitute a secondary payload carried by a primary payload, the primary payload being configured to establish an upstream communication link with a satellite constellation.

[0080] To establish and simultaneously maintain multiple downstream optical communication links with satellite node 20, optical router 30 may be configured to simultaneously generate multiple modulated optical communication beams directed independently in various directions and to simultaneously receive multiple modulated optical communication beams from various directions.

[0081] According to some examples, multiple optical communication beams are generated and / or received through a single aperture of optical router 30. According to other examples, multiple optical communication beams are generated and / or received through two or more apertures of optical router 30.

[0082] According to some examples, optical router 30 may generate / receive beams within a range of up to about 2π steradians.

[0083] According to some examples, optical router 30 may be configured to multiplex two or more downstream optical communication links using, for example, space division multiplexing, time division multiplexing, and / or wavelength division multiplexing.

[0084] 2A, optical router 30 defines hotspot 40 where it establishes downstream optical communication links with satellite nodes 20. Satellite nodes 20 located and / or positioning themselves within hotspot 40 may establish communication links with the satellite constellation via optical router 30.

[0085] The range of the hotspot 40, i.e., the maximum distance from the optical router 30 at which a satellite node 20 may reside for a communication link to be established, may be any suitable distance, depending, for example, on the operating parameters of the optical router and / or node. According to some examples, the optical router 30 may define different ranges within a single hotspot, each associated with a different data rate (e.g., minimum and / or average data rate), e.g., greater distances from the optical router are typically associated with lower data rates. According to some examples, the optical router 30 may define the hotspot 40 having a range of approximately 2000 km, 1500 km, 1000 km, or 500 km. According to some examples, the optical router 30 may establish a downstream communication link with the satellite node 20 at a data rate of approximately 100 Mbps within a first range and at a data rate of approximately 50 Mbps within a second range greater than the first range.

[0086] According to some examples, range may include the minimum distance from optical router 30 that satellite node 20 may reside.

[0087] From the perspective of an optical router 30, a hotspot 40 is defined by a predetermined angle from the optical router, e.g., a field of view within which downstream communication links with satellite nodes 20 can be established. As shown in FIG. 2B , two or more zones 42 can be defined within a single hotspot. Each zone 42 may overlap with one or more other zones. According to some examples, all downstream communication links established within a given zone 42 are at different wavelengths, conforming to standards established by, e.g., the International Telecommunications Union, IEEE, etc., to increase the number of downstream communication links a single orbital router 30 can establish within the hotspot 40 and avoid co-channel interference while regulating the number of possible channels.

[0088] 3, each satellite node 20 comprises a satellite 22 and a communications terminal 24 onboard the satellite 22 configured to facilitate the establishment of an upstream optical communications link with an optical router 30. The satellite may be any conventional satellite, for example, a small satellite such as a microsatellite or a nanosatellite.

[0089] The communications terminal 24 may include an optical communications interface 26 configured to receive and generate optical communications beams, and is configured to communicate with the satellite 22 to complete the upstream optical communications link.

[0090] According to some examples, communications terminal 26 is further configured to direct the operation of satellite 22, for example, to ensure that the satellite's position and / or orientation is suitable for maintaining an upstream optical communications link with optical router 30. Accordingly, communications terminal 26 may include, for example, an attitude determination and control system (ACDS) as known in the art.

[0091] According to some examples, one or more of the satellite nodes 20 may comprise a satellite 22 as described above configured to perform, in whole or in part, the functions of a communications terminal as described above. According to such examples, a separate communications terminal may not be provided.

[0092] 4, orbital router 30 includes a downstream interface, generally designated 100, configured to facilitate simultaneous communication with satellite nodes 20 in multiple different directions, e.g., as described above. According to some examples, downstream interface 100 is configured to establish multiple downstream optical communication links through a single aperture.

[0093] The orbital router 30 may further comprise a controller (not shown) configured to direct operation, including, among other things, operation of the downstream interface 100. Although the term "controller" is used herein and in the claims, with reference to a single element, it is understood that in practice a controller may comprise a combination of elements, including, but not limited to, multiple controllers that may or may not be in physical proximity to one another, without departing from the scope of the presently disclosed subject matter, mutatis mutandis. Furthermore, any disclosure in this specification, including the appended claims, of a controller performing, configured to perform, or other similar language is intended to imply that other elements of the orbital router also perform, are configured to perform, etc., those functions, without departing from the scope of the individually disclosed subject matter, mutatis mutandis.

[0094] Downstream interface 100 comprises a transmit array 102 configured to generate a plurality of outgoing beams, each modulated to carry information to satellite node 20 via a respective optical communication link, a receive array 104 configured to receive an individual incoming beam modulated by one of the satellite nodes, for example, to carry information via a respective optical communication link, and an aperture assembly 106 defining an optical aperture 108. The downstream interface may further comprise a transmit steering arrangement 110 and / or a receive steering arrangement 112 configured to facilitate determining the positions of the outgoing and incoming beams, respectively.

[0095] The transmit array 102 comprises one or more transmit assemblies 114, each comprising a laser 116 configured to generate one of the output beams, and a transmit lens assembly 118 configured to adjust parameters of the output beams, e.g., to facilitate steering and / or focusing of the output beams. Accordingly, the transmit lens assembly 118 may comprise one or more adjustable lenses.

[0096] According to some examples, at least some of the adjustable lenses of the transmit lens assembly 118 are liquid lenses, and the controller is configured to selectively change the shape of the liquid lenses to appropriately adjust one or more beam parameters. According to some examples, at least some of the adjustable lenses of the transmit lens assembly 118 are solid lenses, and the controller is configured to selectively change the position and / or orientation of the solid lenses to appropriately adjust one or more beam parameters.

[0097] According to some examples, the transmit lens assembly 118 includes one or more focusing lenses 120 configured to adjust the divergence of the output beam. According to some examples, the transmit lens assembly 118 includes one or more positioning lenses 122 configured to adjust the direction of the output beam.

[0098] The transmit array 102 may further include a transmit guide assembly 124 configured to collect, i.e., guide, the output beams after they are emitted from the transmit assembly 110 onto substantially parallel paths through a relatively narrow output beam path. The beam path is no larger than the optical aperture 108, i.e., a circle the size of the optical aperture completely circumscribes the cross section of the beam path and encompasses all of the collected output beams.

[0099] The transmit guide assembly 124 may include a plurality of mirrors 126 configured to facilitate directing the output beam onto a final output beam path. The transmit guide assembly 124 may further include a relay lens 128 disposed within the beam path.

[0100] In some examples, some or all of the mirrors are dichroic. In some examples, some or all of the mirrors are semi-transparent.

[0101] According to some examples, some or all of the mirrors comprise segmented deformable mirrors, such as the "Hex Tip-Tilt-Piston" segmented deformable mirrors sold by Boston Micromachines, Inc., Cambridge, Mass. Such deformable mirrors can be used to provide fine steering of the direction of the output beam, for example, within a tolerance of ±0.5°.

[0102] As described above, the transmit steering arrangement 110 is configured to facilitate determining the position of the output beam. Accordingly, the transmit steering arrangement 110 is in communication with a controller configured to, for example, direct the operation of one or more elements of the transmit assembly 114 to adjust the position of the output beam based on input received from the transmit steering arrangement 110 regarding the position of the output beam.

[0103] According to some examples, the transmit steering arrangement 110 branches off portions of the output beam from the output beam path and detects the position of each of the component output beams. A controller may interpret the position data detected by the transmit steering arrangement 110. Thus, the transmit steering arrangement 110 forms part of a feedback mechanism for monitoring and adjusting the position of the beam.

[0104] Thus, the transmit steering configuration 110 may include a transmit steering camera 130 configured to detect the branched portions of the output beams, and an output beam splitter 132 configured to split each output beam into a first portion branched toward the transmit steering camera 130 and a second portion emitted toward the optical aperture 108.

[0105] According to some examples, exit beam splitter 132 is an asymmetric beam splitter, i.e., it splits the exit beam unequally. In particular, exit beam splitter 132 can be configured such that each second portion comprises more of the original exit beam than the corresponding first portion.

[0106] The receive array 104 comprises one or more receive assemblies 134, each comprising a receiver 136 configured to receive one of the incident beams, and a receive lens configured to adjust parameters of the incident beam, e.g., to facilitate steering and / or focusing of the incident beam toward each of the receivers. Accordingly, the receive lens assembly 138 may comprise one or more adjustable lenses.

[0107] According to some examples, at least some of the adjustable lenses of receiver lens assembly 138 are liquid lenses, and the controller is configured to selectively change the shape of the liquid lenses to appropriately adjust one or more beam parameters. According to some examples, at least some of the adjustable lenses of receiver lens assembly 138 are solid lenses, and the controller is configured to selectively change the position and / or orientation of the solid lenses to appropriately adjust one or more beam parameters.

[0108] According to some examples, receiver lens assembly 138 includes one or more focusing lenses 140 configured to adjust the divergence of the incident beam toward receiver 136. According to some examples, receiver lens assembly 138 includes one or more positioning lenses 142 configured to adjust the direction of the incident beam toward receiver 136.

[0109] The receive array 104 may further include a receive guide assembly 144 configured to guide each of the incident beams received through the optical aperture 108 from the incident beam path toward each of the receive assemblies 134, i.e., from the incident beam path defined by the optical aperture toward the respective receive assembly.

[0110] The receive guide assembly 144 may include a plurality of mirrors 146 configured to facilitate directing the incident beam from the incident beam path ultimately towards the receiver 136. The receive guide assembly 144 may further include a relay lens 148 disposed within the beam path.

[0111] In some examples, some or all of the mirrors are dichroic. In some examples, some or all of the mirrors are semi-transparent.

[0112] According to some examples, some or all of the mirrors comprise segmented deformable mirrors, such as the "Hex Tip-Tilt-Piston" segmented deformable mirrors sold by Boston Micromachines, Inc., Cambridge, Mass. Such deformable mirrors can be used to provide fine steering of the direction of the output beam, for example, within a tolerance of ±0.5°.

[0113] As described above, the receive steering arrangement 112 is configured to facilitate determining the position of the incident beam. Accordingly, the receive steering arrangement 112 is in communication with a controller configured, for example, to direct the operation of one or more elements of the receive assembly 134 and adjust the path of the incident beam as received by the receiver 136 based on input received from the receive steering arrangement 112 regarding the position of the incident beam.

[0114] According to some examples, the receive steering arrangement 112 branches off portions of the incident beam from the incident beam path and detects the position of each of the component incident beams. A controller may interpret the position data detected by the receive steering arrangement 112. Thus, the receive steering arrangement 112 forms part of a feedback mechanism for monitoring and adjusting the position of the incident beam.

[0115] Thus, the receive steering arrangement 112 may include a receive steering camera 150 configured to detect the branched portions of the incident beam, and an incident beam splitter 152 configured to split each of the incident beams into a first portion branched toward the receive steering camera and a second portion emitted toward each of the receiving assemblies 134.

[0116] According to some examples, input beam splitter 152 is an asymmetric beam splitter, i.e., it splits the input beam unequally. In particular, input beam splitter 152 can be configured such that each second portion comprises more of the original input beam than the corresponding first portion.

[0117] In some examples, the exit beam splitter 132 also functions as a mirror to direct the incoming beam. Thus, the exit beam splitter 132 may be configured to completely reflect light from the direction of the optical aperture 108 away from the transmit array 102 and away from the transmit steering camera 130, while also splitting a portion of the light coming from the transmit array toward the transmit steering camera 130 and emitting a portion of that light toward the optical aperture, as described above.

[0118] According to some examples, such as that shown in Figure 5, the orbital router may include a modified downstream interface generally designated 200. While Figure 5 does not show a receive array such as that described above with reference to and shown in Figure 4, it will be understood that the downstream interface described with reference to and shown in Figure 5 may include a suitable receive array. The receive array may be provided according to any suitable design, including, but not limited to, the design as described above with reference to and shown in Figure 4, mutatis mutandis.

[0119] Downstream interface 200 comprises a transmit array 202 configured to generate a plurality of outgoing beams, each directed in a predetermined direction, a diffusing device 204 configured to transmit a beam corresponding to the incoming beam, and an aperture assembly 206 defining an optical aperture 208. Each of the outgoing beams may be modulated to carry information to satellite node 20 via a respective optical communications link.

[0120] The transmit array 202 includes one or more transmit assemblies 210. Each of the transmit assemblies 210 may include a light source 212 for generating a beam and a steering mechanism 214 configured to steer the beam generated by the light source in a predetermined direction, for example, toward a predetermined location on the diffusing device 204. The beam may be directed to form a spot on the diffusing device 204 or to impinge on an area thereof.

[0121] The light source 212 may comprise a laser, an LED, and / or any other suitable device for generating a beam. The steering mechanism 214 may comprise a steering mirror or mirror array, a micro-optical electromechanical systems (MOEMS) device or assembly, a light steering arrangement, and / or any other suitable device for steering a beam generated by the light source.

[0122] The transmit assemblies 210 may include additional auxiliary optics configured to facilitate forming, focusing, dispersing, steering, filtering, etc. the respective beams. Thus, each of the transmit assemblies 210 may include, for example, one or more fixed mirrors, steering mirrors, lenses, dichroic filters, prisms, diffraction gratings, etc., apart from the light source 212 and / or steering mechanism 214.

[0123] The transmit array 202 may include, for example, multiple transmit assemblies 210 each configured to generate an output beam in a predetermined direction. According to some examples, the transmit array 202 may include a single transmit assembly 210 configured to selectively generate multiple output beams, each in one of multiple directions, e.g., alternately generate beams along different directions. According to some examples, the transmit array may include one or more transmit assemblies 210 each configured to generate a single output beam and one or more transmit assemblies 210 each configured to selectively generate multiple output beams in several directions, as described above.

[0124] While the transmit assembly 210 is described herein as including separate light sources 212 and steering mechanisms 214, it is understood that this is for purposes of disclosure and not of limitation. In fact, the transmit assembly 210 may be provided as a single element that generates a beam in a predetermined direction, mutatis mutandis, without departing from the scope of the subject matter disclosed herein. Furthermore, the steering mechanism 214 may be configured to adjust the position of the light source 212 itself to steer the beam in a predetermined direction, mutatis mutandis, without directly interacting with the beam.

[0125] As mentioned above, the diffusing device 204 is configured, among other things, to transmit a beam corresponding to the incident beam, and thus includes an incident surface 216 onto which the outgoing beam generated by the transmit array 202 impinges, and a transmit surface 218 from which the beam is transmitted.

[0126] The diffusing device 204 may be configured to increase the diameter of the beam, i.e., the beam transmitted from the transmitting surface 218 has a larger diameter than the corresponding incident beam. Furthermore, the diffusing device may be configured to transmit the beam from the transmitting surface 218 at a predetermined angle (within a relatively wide range) that is independent of the angle of incidence of the incident beam with respect to the incident surface 216. Thus, the beam may be transmitted by the diffusing device 204 in a predetermined direction toward a predetermined location in the optical aperture 208 based substantially solely on the location at which the beam strikes the incident surface 216. Thus, the incident beam may be transmitted from a relatively large area, i.e., the transmitting assembly 210 may be positioned in any suitable location without being limited by the angle at which each beam strikes the diffusing device 204.

[0127] Thus, multiple beams may be transmitted from the diffusing device 204 toward respective positions in the optical aperture 208 without the beams being required to be coaxial, e.g., transmitted in parallel, etc. Furthermore, the generation of each beam may be controlled independently, provided that the position at which each beam strikes the incident surface 216 of the diffusing device 204 is not affected by the generation of other beams. Thus, the design of the transmit array 202 may be simplified, as the beams generated by the transmit array 202 are not limited to following a particular optical path before striking the diffusing device 204.

[0128] The diffusing device 204 may further be configured to transmit a beam toward the optical aperture 208 such that the phase and amplitude in the near field produce a beam with a desired pattern in the far field, thereby facilitating communication over long distances.

[0129] The diffusing device 204 may be made of any suitable material and may be of any suitable design. According to some examples, the diffusing device 204 comprises a diffuser, a metasurface, a microlens array, and / or any other suitable configuration. According to some examples, the diffusing device comprises a holographic diffuser. According to other examples, the diffusing device comprises frosted glass or a similar substrate. The diffusing device may have any suitable shape, such as planar, curved, or any other suitable shape to facilitate the required optical properties, for example, as described above.

[0130] Aperture assembly 206 may comprise a telescope configured to facilitate transmission of the beam transmitted by diffusing device 204 to remote satellite node 20, for example as described above.

[0131] Although the downstream interfaces 100, 200 have been described herein with reference to use in a satellite communication system for transmitting beams over long distances, this is by way of example only. Those skilled in the art will recognize that the downstream interfaces 100, 200 and portions thereof (such as the transmit array 102 and / or receive array 104 of the downstream interface 100 as described above with reference to and shown in FIG. 4, and / or the transmit array 202 as described above with reference to and shown in FIG. 5) may be provided, mutatis mutandis, for use in any suitable application. Such applications may include, but are not limited to, microscopy and / or targeting using multi-point illumination, light detection and ranging (LiDAR) systems, and / or any other application requiring simultaneous control of multiple beams.

[0132] It is recognized that the examples, embodiments, improvements, options, etc. described herein are inclusive and non-limiting, i.e., should not be construed as mutually exclusive or in any other way limiting, unless expressly stated and / or otherwise made clear. Those skilled in the art to which the present invention pertains will readily appreciate that numerous changes, modifications, and improvements may be made thereto without departing from the scope of the subject matter disclosed herein, mutatis mutandis.

Claims

1. 1. An optical router configured to facilitate communication between a satellite constellation and a plurality of satellite nodes, comprising: an upstream interface configured to facilitate communication over an upstream communication link to the satellite communication constellation; a downstream interface configured to simultaneously communicate with the satellite node via multiple downstream optical communication links in different directions, the multiple optical communication links being established through a single optical aperture; and a controller for directing operation of the optical router; An optical router comprising:

2. Each of the downstream optical communication links comprises a modulated beam, and the downstream interface comprises: a transmit array comprising one or more transmit assemblies each configured to generate one of the output beams for transmission over a respective optical communication link; an aperture assembly defining the optical aperture; a diffusing device having an entrance surface and a transmitting surface, the diffusing device configured to transmit each of the exit beams from its transmitting surface toward a predetermined location in the optical aperture, the predetermined location depending on where the exit beam strikes the entrance surface; The optical router of claim 1 , comprising:

3. The optical router of claim 2 , wherein the transmit array comprises a plurality of transmit assemblies each configured to generate a beam in a single direction.

4. The optical router of claim 2 , wherein the transmit array comprises transmit assemblies each configured to selectively generate a plurality of outgoing beams in one of several directions.

5. 5. The optical router of claim 2, wherein each of the transmitting assemblies comprises a light source configured to generate one of the output beams and a steering mechanism configured to direct the output beam in a predetermined direction.

6. The optical router of claim 5 , wherein the light source comprises a laser and / or an LED.

7. The optical router of claim 5 or 6, wherein the steering mechanism comprises a steering mirror, a mirror array, a micro-opto-electro-mechanical system assembly, and / or an optical steering arrangement.

8. The optical router of any one of claims 2 to 7, wherein the diffusing device is configured to increase a diameter of the beam.

9. The optical router of any one of claims 2 to 8, wherein the diffusing device is configured to transmit a beam towards the optical aperture having near-field characteristics that produce a predetermined far-field pattern.

10. The optical router of any one of claims 2 to 9, wherein the diffusing device comprises an optical diffuser.

11. The optical router of claim 10 , wherein the diffusing device comprises a holographic diffuser.

12. The optical router of any one of claims 2 to 11, wherein the diffusing device comprises a metasurface and / or a microlens array.

13. The optical router of any one of claims 2 to 12, wherein the diffusing device comprises frosted glass.

14. The optical router of any one of claims 2 to 13, wherein the diffusing device is planar.

15. The optical router of any one of claims 2 to 14, wherein the diffusing device is curved.

16. 10. The optical router of claim 1, wherein each of the downstream optical communication links comprises a modulated beam, and the downstream interface comprises a transmit array comprising a plurality of transmit assemblies each configured to generate one of the outgoing beams for transmission over a respective optical communication link, and an aperture assembly defining the optical aperture.

17. 17. The optical router of claim 16, wherein each of the transmit assemblies comprises a laser configured to generate one of the output beams along an output beam path and a transmit lens assembly configured to adjust parameters of the output beam.

18. 20. The optical router of claim 17, wherein the transmit lens assembly comprises a focusing lens configured to adjust the divergence of the output beam and / or one or more positioning lenses each configured to adjust the direction of the output beam.

19. 20. The optical router of claim 18, wherein the focusing lens and / or the positioning lens are liquid lenses, and the controller is configured to adjust respective parameters of the output beam by applying electrical signals to selectively change the shape of one or more lenses of the transmit lens assembly.

20. 20. The optical router of claim 18, wherein the focusing lens and / or the positioning lens are solid lenses, and the controller is configured to adjust respective parameters of the output beam by operating actuators to selectively adjust the position and / or orientation of one or more lenses of the transmit lens assembly.

21. The optical router of any one of claims 16 to 20, wherein the downstream interface further comprises a transmit steering arrangement configured to facilitate determining a position of the output beam, and the controller is configured to operate one or more of the transmit assemblies to adjust the position of their respective output beams based on information provided by the transmit steering arrangement.

22. 22. The optical router of claim 21 , wherein the transmit steering arrangement comprises a transmit steering camera and an output beam splitter configured to split each of the output beams into a first portion emitted toward the transmit steering camera and a second portion emitted toward the optical aperture.

23. 23. The optical router of claim 22, wherein the output beam splitter is an asymmetric beam splitter, and each of the second portions comprises more of the original output beam than the corresponding first portion.

24. 24. The optical router of claim 21, wherein the output beam splitter is further configured to emit one or more light beams from the optical aperture in a direction away from the transmit array and the transmit steering camera.

25. 25. The optical router of claim 1 or any one of claims 16 to 24, wherein the downstream interface further comprises a receive array comprising a plurality of optical receive assemblies each configured to receive one of the incident beams for receiving transmissions transmitted over a respective optical communication link.

26. 26. The optical router of claim 25, wherein each of the receive assemblies comprises a receiver configured to receive one of the incident beams along an incident beam path and a receive lens assembly configured to adjust parameters of the incident beam.

27. 27. The optical router of claim 26, wherein the receiver lens assembly comprises a focusing lens configured to adjust the divergence of the incident beam and / or one or more positioning lenses each configured to adjust the direction of the incident beam.

28. 28. The optical router of claim 27, wherein the focusing lens and / or the positioning lens are liquid lenses, and the controller is configured to adjust respective parameters of the incident beam by applying electrical signals to selectively change the shape of one or more lenses of the receiver lens assembly.

29. 28. The optical router of claim 27, wherein the focusing lens and / or the positioning lens are solid lenses, and the controller is configured to adjust respective parameters of the incident beam by operating actuators to selectively adjust the position and / or orientation of one or more lenses of the receive lens assembly.

30. 29. The optical router of any one of claims 25 to 28, wherein the downstream interface further comprises a receive steering arrangement configured to facilitate determining the position of the incident beam, and the controller is configured to operate one or more of the receive assemblies to adjust the position of each incident beam based on information provided by the receive steering arrangement.

31. 31. The optical router of claim 30, wherein the receive steering arrangement comprises a receive steering camera and an incident beam splitter configured to split each of the incident beams into a first portion emitted toward the receive steering camera and a second portion emitted toward each of the receive assemblies.

32. 32. The optical router of claim 31, wherein the input beam splitter is an asymmetric beam splitter, and each of the second portions comprises more of the original output beam than the corresponding first portion.

33. The optical router of any one of claims 30 to 32, wherein the input beam splitter is further configured to emit one or more light beams from the optical aperture in a direction away from the receive array and the receive steering camera.

34. The optical router of any one of claims 25 to 33, wherein the receiving array comprises a receiving guide assembly configured to guide each of the plurality of incident beams received from an incident beam path through the optical aperture toward each of the receiving assemblies.

35. The optical router of any one of claims 16 to 34, wherein the transmit array comprises a transmit guide assembly configured to guide the plurality of output beams emitted from the transmit assembly toward substantially parallel paths along output beam paths no larger in lateral dimension than the optical aperture.

36. 36. The optical router of claim 34, wherein the transmit guide assembly and / or the receive guide assembly comprises a plurality of mirrors configured to facilitate steering of the beam.

37. 35. The optical router of claim 34, wherein one or more of the mirrors are dichroic.

38. 38. The optical router of any one of claims 36 and 37, wherein one or more of the mirrors are semi-transparent.

39. The optical router of any one of claims 36 to 38, wherein the transmit guide assembly and / or the receive guide assembly further comprises a relay lens disposed in the beam path.

40. An optical router according to any preceding claim, configured to define hotspots within which the downstream optical communication links are established.

41. 41. The optical router of claim 40, further configured to define two or more zones within the hotspot, wherein the wavelength of each of the downstream optical communication links is unique in each of the zones.

42. 42. The optical router of claim 40, further configured to define two or more zones within the hotspot, wherein the downstream optical communication links in each of the zones are time division multiplexed.

43. An optical router according to any preceding claim, configured to orbit the Earth and remain within a predetermined maximum distance from each of said plurality of satellite nodes.

44. The optical router of any preceding claim, wherein the upstream communication link is an optical communication link.

45. The optical router of any preceding claim, wherein the upstream communication link is a radio frequency communication link.

46. The optical router of any preceding claim, wherein the upstream interface is configured to communicate with a device configured to establish the upstream communication link.

47. 1. A system configured to facilitate communications between a satellite communications constellation and a plurality of satellite nodes, comprising: An optical router according to any one of claims 1 to 46; a plurality of terminal modules configured to communicate with the optical router via an optical communication link, each terminal module being connected to one of the satellite nodes and configured to communicate with one of the satellite nodes; A system comprising:

48. 1. A method of communicating with a satellite node, comprising: Providing an optical router according to any one of claims 1 to 46; establishing an upstream communication link between the optical router and a satellite communication group; establishing a downstream optical communication link between said satellite node and said optical router; wherein the communication with the satellite node comprises transmitting information between the satellite node and the satellite constellation via the optical router.

49. 1. A free-space optical communications device configured to establish and simultaneously maintain multiple optical communications links with multiple nodes, each of said optical communications links comprising a modulated laser beam, said free-space optical communications device configured to establish and maintain said multiple optical communications links through a single optical aperture.

50. 50. The free space optical communications device of claim 49, configured to form part of a vehicle or to operate while carried by a vehicle.

51. 51. The free space optical communications device of claim 50, wherein the vehicle is an aircraft.

52. 52. The free space optical communications device of claim 51, wherein the aircraft is one or more selected from the group including a rotorcraft, a fixed wing aircraft, an aerostat, a satellite, and a spacecraft.

53. A free space optical communications device according to claim 51 forming part of an optical router according to any one of claims 1 to 46.

54. 50. The free space optical communications device of claim 49, which is a ground-mounted fixed device.

55. A free space optical communications device according to any one of claims 40 to 54, wherein at least one of the nodes forms part of a vehicle or is configured to operate whilst carried by a vehicle.

56. 56. The free space optical communications device of claim 55, wherein the vehicle is an aircraft.

57. 57. The free space optical communications device of claim 56, wherein the aircraft is one or more selected from the group including a rotorcraft, a fixed wing aircraft, an aerostat, a satellite, and a spacecraft.

58. A free space optical communications device according to any one of claims 49 to 57, wherein at least one of said nodes forms part of an optical router according to any one of claims 1 to 46.

59. A free space optical communications device according to any one of claims 49 to 58, wherein at least one of said nodes is a fixed ground mounted device.

60. 59. A free space optical communications device according to any one of claims 49 to 58, wherein at least one of the nodes is a ground mounted fixed device and one of the nodes forms part of a vehicle or is configured to operate whilst carried by a vehicle.

61. 61. The free space optical communications device of claim 60, wherein the vehicle is an aircraft.

62. A free space optical communications device according to any one of claims 49 to 61, wherein each of said communications links carries a bit stream independent of the bit streams carried by the other of said communications links.

63. 63. The free space optical communications device of any one of claims 49 to 62, further configured to facilitate communications between a communications network and said node.

64. 64. The free space optical communications device of claim 63, wherein said communications network comprises at least one satellite in direct communication with said free space optical communications device.

65. 65. The free space optical communications device of claim 64, wherein the at least one satellite in direct communication with the free space optical communications device is part of a satellite communications constellation.

66. 1. An interface configured to simultaneously transmit multiple beams in different directions through a single optical aperture, comprising: a transmit array comprising one or more transmit assemblies each configured to generate one of the output beams for transmission in a predetermined direction; an aperture assembly defining the optical aperture; a diffusing device having an entrance surface and a transmitting surface, the diffusing device configured to transmit each of the exit beams from its transmitting surface toward a predetermined location in the optical aperture, the predetermined location depending on where the exit beam strikes the entrance surface; An interface comprising:

67. 67. The interface of claim 66, wherein the transmit array comprises a plurality of transmit assemblies each configured to generate a beam in a single direction.

68. 68. The interface of claim 67, wherein the transmit array comprises transmit assemblies each configured to selectively generate a plurality of outgoing beams in one of several directions.

69. 69. An interface according to any one of claims 66 to 68, wherein each of the transmitting assemblies comprises a light source configured to generate one of the output beams and a steering mechanism configured to direct the output beam in a predetermined direction.

70. 70. The interface of claim 69, wherein the light source comprises a laser and / or an LED.

71. 71. The interface of any one of claims 69 and 70, wherein the steering mechanism comprises a steering mirror, a mirror array, a micro-opto-electro-mechanical system assembly, and / or a light steering arrangement.

72. An interface according to any one of claims 66 to 71, wherein the diffusing device is configured to increase a diameter of the beam.

73. 73. An interface according to any one of claims 66 to 72, wherein the diffusing device is configured to transmit a beam towards the optical aperture having near field characteristics that produce a predetermined far field pattern.

74. An interface according to any one of claims 66 to 73, wherein the diffusion device comprises a light diffuser.

75. 75. The interface of claim 74, wherein the diffusing device comprises a holographic diffuser.

76. The interface of any one of claims 66 to 75, wherein the diffusion device comprises a metasurface and / or a microlens array.

77. An interface according to any one of claims 66 to 76, wherein the diffusion device comprises frosted glass.

78. An interface according to any one of claims 66 to 77, wherein the diffusion device is planar.

79. An interface according to any one of claims 66 to 77, wherein the diffusing device is curved.

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