Patent Application
20240385397
The following relates to optical communication transceivers, including gimballess quasi-omni optical communication transceivers.
An optical transceiver may include an optical transmitter and an optical receiver. In some examples, the optical transceiver may be placed on a gimbal to enable coarse-pointing for and/or for actuating the optical transceiver. An omni-directional laser communication system is intended eliminate a usage of precision beam-pointing, which may streamline certain application scenarios. Additionally, as a size or weight of the optical transceiver increases, the ease with which the optical transceiver may be actuated may decrease. Accordingly, techniques that simplify laser beam pointing and/or maintain or reduce a size or weight of the optical transceiver in applications in which the optical transceiver is mobile may be desired.
An optical transceiver may include an optical transmitter and an optical receiver, where the optical transmitter may be configured to convey information by transmitting light (for example, via lasers) and the optical receiver may be set up to receive information by receiving the transmitted light. In mobile applications, it may be advantageous to simplify laser beam pointing to a target, which may present challenges for optical wireless communications systems, as failure to accurately point laser beams may result in failure to receive the light or failure to retrieve the correct information from the light. Additionally or alternatively, it may be advantageous to decrease a size or a weight of an assembly including the optical transceiver. One method of doing so may involve removing a gimbal (e.g., a coarse-beam-pointing gimbal) from the assembly, which may enhance the compactness and/or may decrease the assembly's weight.
One method of enabling the optical transceiver to compensate for the removal of the gimbal may be for the optical transceiver to include a support structure with multiple optical transmitters and multiple optical receivers pointing in various directions such that there is overlap between transmit beams and/or receive beams of the optical transmitters and/or optical receivers, respectively, in the far-field. In order to support transmissions with narrower beamwidths, each of the optical beam transmit paths may employ larger diameter optics (e.g., reflective or refractive types). Accordingly, as the diameter of the transmit path optics grows, less room on the surface of the support structure may be available for the optics of the optical receivers. This may lead to a smaller aperture diameter optics for each of the optical receivers. Accordingly, the magnitude of the transmit signal as collected by the receiver may decrease.
The methods and apparatuses described herein may enable increased beam collection efficiency while mitigating adverse effects associated with decreasing optical receivers' beam-condensing optics diameters. For instance, the optical transceiver may include a support structure with a surface and a set of optical transmitters perforating the surface of the support structure, where each optical transmitter of the set of optical transmitters is oriented in a different direction relative to each other within the set of optical transmitters. Additionally, the optical transceiver may include an optical receiver (e.g., a single optical receiver), where the optical receiver may include a luminescence wavelength-converting fiber and a detector. The luminescence wavelength-converting fiber may be disposed on the surface of the support structure and may be wrapped at least partially around the support structure. Additionally, at least one end of the luminescence wavelength-converting fiber (e.g., one or both ends of the luminescence wavelength-converting fiber) may be coupled with a detector (e.g., photodetector) with or without a beam concentrator. Wrapping the luminescence wavelength-converting fiber at least partially around the support structure may enable elimination of receive optics apertures (e.g., lenses). Accordingly, if the luminescence wavelength-converting fiber avoids first portions of the support structure associated with components of the optical transmitters and is wrapped around second portions of the support structure where one or more components of the optical transmitters are not present, the optical transceiver may be capable of receiving transmissions over the second portions of the support structure.
Features of the disclosure are initially described in the context of optical transceivers as described with reference to
In some mobile laser communications (lasercom) applications (e.g., mobile underwater laser communications, mobile terrestrial laser communications, mobile aerial laser communications, mobile satellite laser communications), it may be advantageous to simplify laser beam pointing to a target, which may present challenges for optical wireless communications systems, as failure to accurately point laser beams may result in failure to receive the light or failure to retrieve the correct information from the light. Some optical laser assemblies may include a coarse-pointing gimbal. However, the coarse-pointing gimbal may include mechanical components that may experience delays between when the coarse-pointing gimbal points a laser in a first direction as compared to pointing the laser in a second direction and/or that may break down unexpectedly. Additionally, a more compact or more light-weight optical transceiver 100 (e.g., an optical laser transceiver) may be used as compared to stationary laser communications applications. In order to simplify laser beam pointing and/or to enhance compactness or decrease a weight of an optical transceiver assembly, the coarse-pointing gimbal (e.g., a two-axis gimbal) may be removed and the optical transceiver may be set up as an omni optical transmitter or a quasi-omni optical transmitter.
For instance, the optical transceiver 100 may include a support structure 105 with a set (e.g., ensemble) of optical transmitters oriented such that beams of the optical transmitters overlap in the far-field. If the beams of the set of optical transmitters overlap such that there is no gap at least in the far-field, the optical transceiver 100 may be referred to as an omni optical transceiver. Additionally or alternatively, if the beams of the set of optical transmitters overlap such that no gap larger than a threshold amount is present in at least the far-field, the optical transceiver 100 may be referred to as a quasi-omni optical transceiver. Optical transceivers 100 whose lasercom assemblies do not include gimbals may be referred to as gimballess optical transceivers. The optical transceiver 100 may include enough optical transmitters with a spatial arrangement such that transmit beams overlap in the far-field (e.g., such that the optical transceiver 100 is an omni or quasi-omni optical transceiver). A total number of optical transmitters and/or optical receiver may be reduced by scanning a field-of-regard using a two-axis mechanical fine-pointing mirror.
Free-space optical communications may be advantageous for communications systems that use beams with a beamwidth below a threshold amount (e.g., narrow beamwidth communications systems). For instance, to achieve a narrow beamwidth, a wavelength of lasers of the optical transmitters may be reduced and/or associated optics diameters may be increased for a given system (e.g., optical transceiver 100) design. Such wavelengths may be, for instance, between 400 nanometers and 2000 nanometers or greater than 2000 nanometers. In some examples, the transmitter optics diameter may depend on a size of the support structure 105 (e.g., a size of the sphere) and a quantity of optical transmitters (e.g., transmit apertures) used. For instance, the diameter of the optics for each optical transmitter may be just large enough such that overlap (e.g., partial or complete overlap) between transmit beams is still present in the far-field. However, as the optics diameters of the optical transmitters increase, the optics diameters of the optical receivers may decrease by a corresponding amount. Accordingly, the optical transceiver may be less likely to receive transmissions from other devices performing laser communications with the optical transceiver.
One method of mitigating the reduced optics diameters of the optical receivers may be to have a separate support structure for the set of optical receivers. However, having the separate support structure may reduce a compactness or may increase a size, a weight, or an amount of materials used for the lasercom assembly. Accordingly, using the separate structure may decrease the ease with which such optical transceivers are moved between locations.
The present disclosure describes an optical transceiver 100 that may enable increased optics diameters for optical transceivers 100 while mitigating the amount by which optics diameters of optical receivers are decreased. Additionally, the described optical transceiver 100 may have beneficial properties related to a size, weight, or an amount of materials used for the optical transceiver 100 as compared to lasercom assemblies whose optical transceivers include a separate support structure for the optical transceiver. For instance, an optical transceiver 100 may include a support structure 105 with a surface and a set of optical transmitters perforating the surface of the support structure 105, where each optical transmitter of the set of optical transmitters is oriented in a different direction relative to each other optical transmitter of the set of optical transmitters (e.g., optical transmitter 110-a oriented in a first direction 125-a and optical transmitter 110-b oriented in a second direction 125-b different than the first direction). Additionally, the optical transceiver 100 may include an optical receiver, where the optical receiver may include a luminescence wavelength-converting fiber 115 and a detector 120. The luminescence wavelength-converting fiber 115 may be disposed on the surface of the support structure 105, where the luminescence wavelength-converting fiber 115 is wrapped at least partially around the support structure 105 and is located between at least two pairs of the set of optical transmitters (e.g., optical transmitters 110-b and 110-d). Additionally, the luminescence wavelength-converting fiber 115 may be configured to absorb light at a first wavelength and emit light within a channel of the luminescence wavelength-converting fiber 115 at a second wavelength (e.g., a second wavelength different than the first wavelength). The detector 120 may be coupled with the luminescence wavelength-converting fiber 115 at least one end (e.g., one or both ends) of the luminescence wavelength-converting fiber 115, where the detector 120 may be configured to convert the light at the second wavelength to an electrical signal. In some examples, the luminescence wavelength-converting fiber 115 may include or may be a single optical fiber. Additionally or alternatively, the luminescence wavelength-converting fiber 115 may include or be more than one optical fiber (e.g., where each end of each optical fiber is adjoined with at least one end of each other optical fiber such that the detector 120 is coupled with one or two ends, or where the detector 120 is coupled with one or more ends of each optical fiber).
In some examples, the optical transceiver 100 may include a set of lenses or a set of mirrors covering a perforated portion of the surface of the support structure 105. In such examples, each lens of the set of lenses may be associated with a respective optical transmitter of the set of optical transmitters.
In some examples, the luminescence wavelength-converting fiber 115 may be wrapped at least once around the support structure 105. Additionally, or alternatively, the luminescence wavelength-converting fiber 115 may be wrapped multiple times around the support structure 105. In some examples, the luminescence wavelength-converting fiber 115 may be wrapped around the support structure 105 such that at least one quarter of a remaining portion (e.g., the portion not covered by the set of optical transmitters 110) of the surface of the support structure is covered by the luminescence wavelength-converting fiber 115. In some examples, the luminescence wavelength-converting fiber 115 may be wrapped around the support structure 105 such that each optical transmitter and/or lenses associated with each optical transmitter are not covered. Additionally or alternatively, the luminescence wavelength-converting fiber 115 may be wrapped around the support structure 105 such that a portion (e.g., at or above 50%, at or above 75%, at or above 85%, at or above 90%,) of the surface that is not perforated by any optical transmitters and/or covered by lenses covering the optical transmitters is covered by the luminescence wavelength-converting fiber 115.
In some examples, the support structure 105 may be formed in the shape of a sphere, a spheroid (e.g., an ellipsoid), or a polyhedron (e.g., dodecahedron, octahedron, icosahedron, uniform polyhedrons, isohedrons). In other examples, the support structure 105 may be formed in a shape of at least a quarter of a sphere (e.g., a half-sphere), at least a quarter of an ellipsoid (e.g., a half-ellipsoid), or at least quarter of a polyhedron (e.g., a half-polyhedron). In some examples, each optical transmitter may be configured to emit light at the first wavelength.
In some examples, the first wavelength may have a value outside of a visible spectrum of light. Having the value outside the visible spectrum of light may decrease a likelihood that laser communications are detected for secure applications (e.g., applications in which detection of laser communications by an intercepting recipient may have an adverse effect).
In some examples, the optical transceiver 100 may perform laser communications. For instance, the optical transceiver 100 may absorb, at the luminescence wavelength-converting fiber 115 of the optical receiver, light at the first wavelength. The optical transceiver 100 may emit light within the channel of the luminescence wavelength-converting fiber 115 at a second wavelength based on absorbing the light at the first wavelength and may convert, using a detector 120 of the optical receiver, the light at the second wavelength to an electrical signal, where the detector 120 is coupled with at least one end of the luminescence wavelength-converting fiber 115.
In some examples, the luminescence wavelength-converting fiber 115 be a fiberoptics cable and may operate according to red-shifted luminescence. Additionally or alternatively, the luminescence wavelength-converting fiber 115 may be an optical waveguide (e.g., a glass fiber-optic cable, a glass slab doped with fluorescent dyes, a plasmonic nano-antenna phased-array). In some examples, incident light (e.g., laser light from a communication system) may be absorbed and re-emitted at a different wavelength (e.g., absorbed and re-emitted by dye molecules of the luminescence wavelength-converting fiber 115). The waveguide may collect a portion of the emitted light and may propagate it to the end (e.g., the end coupled with the detector 120) with re-absorption (e.g., due to red-shifted luminescence).
The methods and apparatuses described herein may eliminate receive optics apertures (e.g., lenses), which may allow for an increased transmit optics aperture diameters to be employed on a single support structure 105 as compared to lasercom assemblies that use receive optics apertures. Accordingly, beam collimation and link efficiency may increase (e.g., link margin may improve). Additionally, the optical transceiver 100 may be non-directional, which may reduce the etendue of the system such that larger active area photodetectors may be used.
Although luminescence wavelength-converting fiber 115 is illustrated as being wrapped around support structure 105 in a single direction (e.g., horizontally in the plane of X direction 112 and Z direction 116) in
In some examples the luminescence wavelength-converting fiber 115-a and optical transmitters 110-d and 110-e may be on separate assemblies or separate support structures (e.g., optical transceiver 200 may have separate transmitter and receiver configurations). For instance, luminescence wavelength-converting fiber 115-a may be wrapped around support structure 105-b and the set of optical transmitters may perforate the surface of support structure 105-a. The separate support structures may be coupled together (e.g., via a coupling component 205, which may be a rod).
Having the luminescence wavelength-converting fiber 115-a and optical transmitters 110-f and 110-g on separate assemblies may enable multiple links in different directions to be maintained simultaneously. In some examples, the luminescence wavelength-converting fiber 115-a may be wrapped around at least a portion of support structure 105-b (e.g., at or above 25%, at or above 50%, at or above 75%, at or above 85%, at or above 90%) and the optical transmitters 110-f and 110-g may perforate the surface of support structure 105-a. In some examples, support structure 105-b having the luminescence wavelength-converting fiber 115-a may have one or more advantages as compared to the support structure 105-b having receive optics apertures (e.g., lenses). For instance, the luminescence wavelength-converting fiber 115-a may be capable of covering a higher portion of the first support structure than the receive optics apertures. Additionally, in examples in which the luminescence wavelength-converting fiber 115-a consists of a single fiber-optic cable (e.g., as compared to multiple fiber-optic cables with adjoined ends), an electrical signal produced by the detector 120-a may have less noise (e.g., a higher signal-to-noise ratio).
In some examples, optical transmitter 110-h may be covered by a lens 305. Additionally, both ends of luminescence wavelength-converting fiber 115-b may be coupled with detector 120-b. In some examples, luminescence wavelength-converting fiber 115-b and detector 120-b may be included within an optical receiver 310. In one example, optical transmitter 110-h may transmit light 315 (e.g., via a laser) corresponding to information to be communicated at a first wavelength. Optical receiver 310 may receive the light 315 using luminescence wavelength-converting fiber 115-b. For instance, luminescence wavelength-converting fiber 115-b may include a layer 335 which may receive the light 315 at the first wavelength and may be doped with fluorescent dye that may absorb the light 315 at the first wavelength and emit light 325 at a second wavelength (e.g., a red-shifted wavelength). Additionally or alternatively, layer 335 may be a plasmonic nano-antenna phased-array. The light 325 emitted by the layer 335 of luminescence wavelength-converting fiber 115-b may propagate within a channel 330 to detector 120-b, where detector 120-b may convert the light to an electrical signal corresponding to the information to be communicated. In some examples, a mirror may be used in conjunction with or in place of the lens 305 for some or each of the set of lenses in order to transmit the light.
The luminescence wavelength-converting fiber 425 may be configured as or otherwise support a means for absorbing, at a luminescence wavelength-converting fiber of an optical receiver, light at a first wavelength, where the luminescence wavelength-converting fiber is disposed on a surface of a support structure such that the luminescence wavelength-converting fiber is wrapped at least partially around the support structure and located between at least two pairs of a set of optical transmitters, where the set of optical transmitters perforates the surface of the support structure, and where each optical transmitter of the set of optical transmitters is oriented in a different direction relative to each other optical transmitter of the set of optical transmitters. In some examples, the luminescence wavelength-converting fiber 425 may be configured as or otherwise support a means for emitting light within a channel of the luminescence wavelength-converting fiber at a second wavelength based at least in part on absorbing the light at the first wavelength. The detector 430 may be configured as or otherwise support a means for converting, using a detector of the optical receiver, the light at the second wavelength to an electrical signal, where the detector is coupled with at least one end of the luminescence wavelength-converting fiber.
In some examples, each optical transmitter of the set of optical transmitters is associated with a respective concentrating optical elements (e.g., a lens or a set of lenses). In some examples, the set of optical elements covers a perforated portion of the surface of the support structure.
In some examples, the luminescence wavelength-converting fiber is wrapped multiple times around the support structure.
In some examples, the luminescence wavelength-converting fiber is wrapped around the support structure such that a perforated portion of the surface of the support structure associated with the set of optical transmitters is not covered by the luminescence wavelength-converting fiber and at least one quarter of a remaining portion of the surface of the support structure is covered by the luminescence wavelength-converting fiber.
In some examples, the support structure is formed in a shape of a sphere, a spheroid, or a polyhedron.
In some examples, the support structure is formed in a shape of at least a quarter of a sphere, at least a quarter of an ellipsoid, or at least a quarter of a polyhedron.
In some examples, the detector is coupled with each end of the luminescence wavelength-converting fiber.
In some examples, the luminescence wavelength-converting fiber includes a single optical fiber.
In some examples, the luminescence wavelength-converting fiber includes more than one optical fiber.
In some examples, the optical transmitter 435 may be configured as or otherwise support a means for emitting, from an optical transmitter of the set of optical transmitters, light at the first wavelength.
In some examples, the first wavelength has a value outside of a visible spectrum of light.
At 505, the method may include absorbing, at a luminescence wavelength-converting fiber of an optical receiver, light at a first wavelength, where the luminescence wavelength-converting fiber is disposed on a surface of a support structure such that the luminescence wavelength-converting fiber is wrapped at least partially around the support structure and located between at least two pairs of a set of optical transmitters, where the set of optical transmitters perforates the surface of the support structure, and where each optical transmitter of the set of optical transmitters is oriented in a different direction relative to each other optical transmitter of the set of optical transmitters. The operations of 505 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 505 may be performed by a luminescence wavelength-converting fiber 425 as described with reference to
At 510, the method may include emitting light within a channel of the luminescence wavelength-converting fiber at a second wavelength based at least in part on absorbing the light at the first wavelength. The operations of 510 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 510 may be performed by a luminescence wavelength-converting fiber 425 as described with reference to
At 515, the method may include converting, using a detector of the optical receiver, the light at the second wavelength to an electrical signal, where the detector is coupled with at least one end of the luminescence wavelength-converting fiber. The operations of 515 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 515 may be performed by a detector 430 as described with reference to
In some examples, an apparatus as described herein may perform a method or methods, such as the method 500. The apparatus may include features, circuitry, logic, means, or instructions (e.g., a non-transitory computer-readable medium storing instructions executable by a processor), or any combination thereof for performing the following aspects of the present disclosure:
Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Some drawings may illustrate signals as a single signal; however, the signal may represent a bus of signals, where the bus may have a variety of bit widths.
The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “exemplary” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details to provide an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.
In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
As used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.”
The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.
The present application for patent is a 371 national phase filing of International Patent Application No. PCT/US2022/043869 by HEMMATI, entitled, “GIMBALLESS QUASI-OMNI OPTICAL COMMUNICATION TRANSCEIVER” filed Sep. 16, 2022, which claims the benefit of U.S. Provisional Patent Application No. 63/245,714 by HEMMATI, entitled “GIMBALLESS QUASI-OMNI LASER COMMUNICATION TRANSCEIVER,” filed Sep. 17, 2021, each of which is assigned to the assignee hereof, and each of which is expressly incorporated by reference in its entirety herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/043869 | 9/16/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63245714 | Sep 2021 | US |
