Multi-directional adaptive optics device

Abstract

Multi-directional optical devices are disclosed. The optical devices can employ a multi-input / multi-output optical coupling structure to determine a propagation direction of received light (in a receiver configuration), and / or to control a propagation direction of emitted light (in an emitter configuration). The propagation direction can be determined without requiring moving components. According to some embodiments, designs of solid-state photonic integrated circuits (PICs) are disclosed herein that utilize NxM star couplers to perform a Fourier transform on light passing between N ports and M ports, resulting in light reaching one or more of the N ports being distributed across the M ports with a linear phase profile. A slope of the linear phase profile depends on which of the N ports the light is received from. The light exits from waveguides coupled to the M ports in one or more propagation directions that depend on the linear phase profile.

Description

Background Technology

[0001] Photonic integrated circuits (PICs) are used in many fields to transmit or receive data modulated onto or otherwise contained in optical signals. Optical signals are typically in the infrared or visible spectrum. Applications such as fiber optic communication, biomedicine, and photonic computing can leverage PICs to integrate various photonic functions into the transmitted or received light. Such applications can benefit from multidirectional point-to-point optical communication capabilities. However, many important challenges remain in providing multidirectional optical communication. Attached Figure Description

[0002] Figure 1 This is a schematic diagram of a photonic integrated circuit having a light source and a photodetector according to an embodiment of the present disclosure.

[0003] Figures 2A to 2C This is a schematic diagram illustrating example operation of an optical element of a photonic integrated circuit according to some embodiments of the present disclosure, the optical element including a coupling region, a first plurality of waveguides, and a second plurality of waveguides.

[0004] Figure 3A and 3B This is a schematic diagram illustrating additional example operation of an optical element of a photonic integrated circuit according to some embodiments of the present disclosure, the optical element including a coupling region, a first plurality of waveguides, and a second plurality of waveguides.

[0005] Figure 4 This is a schematic diagram illustrating an example operation of a system for a photonic integrated circuit according to embodiments of the present disclosure.

[0006] Figure 5A and 5B This is a schematic diagram of a photonic integrated circuit used as a receiver with a different output stage design according to some embodiments of the present disclosure.

[0007] Figure 6 This is a schematic diagram of a photonic integrated circuit used as a transmitter with a specific input stage design according to embodiments of the present disclosure.

[0008] Figure 7 This is a schematic diagram of a photonic integrated circuit having multiple interconnected optical elements according to an embodiment of the present disclosure.

[0009] Figure 8A This is a schematic diagram of another photonic integrated circuit having an array of optical elements according to an embodiment of the present disclosure.

[0010] Figures 8B to 8D These are schematic diagrams of different photodetector designs for any photonic integrated circuit according to some embodiments of this disclosure.

[0011] Figure 9 This is a schematic diagram of a lens arrangement for use with the photonic integrated circuit of FIG8, according to an embodiment of the present disclosure.

[0012] Figure 10 This is an illustration of an electrical device including a photonic integrated circuit according to some embodiments of the present disclosure.

[0013] Figure 11 This is a flowchart of an example method for determining one or more propagation directions of received light using a multi-directional optical device, according to some embodiments of the present disclosure.

[0014] Figure 12 This is a flowchart of an example method for using a multi-directional optical device to emit light in different propagation directions, according to some embodiments of the present disclosure.

[0015] These and other features of this embodiment will be better understood by reading the following detailed description in conjunction with the accompanying drawings. Detailed Implementation

[0016] An optical device structure is disclosed. The superposition principle is applied, allowing for multidirectional communication. In one embodiment, the optical device employs a multiple-input / multiple-output (MIMO) optical coupling structure to determine the propagation direction of received light (in a receiver configuration) and / or control the propagation direction of emitted light (in a transmitter configuration). In either case, note that the propagation direction is determined in a non-motion manner, requiring no moving parts. According to some such embodiments, a solid-state photonic integrated circuit (PIC) uses an NxM star coupler to perform a Fourier transform on light passing between N and M ports, such that light arriving at one or more of the N ports is distributed across the M ports with a linear phase profile. The slope of the linear phase profile depends on which of the N ports the light is received from. The light is emitted from the waveguide coupled to the M ports with a propagation direction dependent on the linear phase profile. Conversely, light received at the M ports from a given propagation direction will exhibit a corresponding phase profile on the M ports. Light received from the M ports will be coupled to one or more of the N ports based on the phase profile of the received light. In this way, the PIC can be designed to act as a light emitter capable of controlling the emission direction of the generated light and / or a light receiver capable of determining the propagation direction of the received light. Many embodiments and variations thereof will be understood according to this disclosure.

[0017] Overview

[0018] As mentioned earlier, many important issues remain regarding the provision of multidirectional optical communication. More specifically, the ability to distinguish and / or control the direction of light propagation is useful for many optical applications, such as synchronous point-to-point optical communication systems, channel-adaptive optical communication systems, and for performing multidirectional optical sensing. Unfortunately, existing devices designed for these applications use moving elements, such as adjustable micromirrors, to change the direction of emitted light propagation. Moving elements as part of the optical path, or moving the optics themselves, requires additional complexity and power, and further contributes to wear and tear on the moving parts over time, leading to thermal management issues related to the generated heat.

[0019] Therefore, techniques for designing and using multidirectional adaptive optics devices are disclosed, which can determine the propagation direction of received light and / or change the propagation direction of emitted light without the use of moving elements. The term "light" as used herein can refer to any portion of the electromagnetic (EM) spectrum. In some embodiments, light refers to the visible portion of the EM spectrum or the infrared portion of the EM spectrum. For example, light can refer to infrared radiation with wavelengths between 1.3 μm and 1.7 μm. According to some embodiments, the multidirectional adaptive optics device uses one or more NxM star couplers, each coupler having N ports on one side of the coupling region and M ports on the other side. In operation, light arriving at one or more of the N ports of the star coupler is distributed across the M ports of the star coupler with a linear phase profile that depends on which of the N ports the light is received from. By changing this phase profile, light exits from the ends of the waveguides coupled to the M ports with different phase leads. The propagation direction of the exiting light depends on the phase lead of the light. Given the interchange principle, this interchange also holds in the opposite communication direction, such that light with a given phase lead is received by the M ports of the star coupler and guided to one or more of the N ports based on the phase lead of the light. In this way, the propagation direction of the received light can be determined based on which of the N ports includes the routed light. Light can be emitted simultaneously from a set of waveguides in multiple directions, and light can be received simultaneously from multiple different directions from the same set of waveguides.

[0020] Many PICs or other optical device designs can be implemented using one or more of the star couplers described herein. As will be explained further below, optical multiplexers, phase modulators, and amplitude modulators may be included to control and / or better distinguish light. In some embodiments, multiple PICs can be used in an optical system to communicate with each other using free-space optical signals, wherein the determined direction of the optical signal can be used to determine which PIC the signal originates from. Furthermore, the direction of the emitted optical signal from a given PIC can be controlled to select which downstream PIC receives the optical signal. In some embodiments, optical reception or emission can occur across a two-dimensional region on a substrate by using multiple linked star couplers. Light can also be collected from various propagation directions with minimal loss and without requiring moving the path surface or rotating the PIC, which is highly beneficial for many applications, such as telescope-based applications or any other application that collects light from a relatively large area.

[0021] Many optical device structures will be readily apparent. For example, according to an exemplary embodiment, an integrated photonic system includes a substrate and optical elements on the substrate. The optical elements include a coupling region, a first plurality of waveguides, and a second plurality of waveguides. Each of the first plurality of waveguides has a first end configured to collect light and a second end coupled to a first side of the coupling region. Each of the second plurality of waveguides is coupled to a second side of the coupling region. The coupling region is designed to couple light into one or more of the second plurality of waveguides based on the relative phase difference of light received from the first plurality of waveguides in each of the first plurality of waveguides. In some such embodiments, the integrated photonic system also includes one or more photodetectors configured to receive light from one or more of the second plurality of waveguides, such that light received from each of the second plurality of waveguides is associated with a different propagation direction. As will be understood, this configuration is particularly useful in optical receiver applications.

[0022] According to another exemplary embodiment, the integrated photonic system includes a substrate, one or more light sources on the substrate, and optical elements on the substrate. The optical elements include a coupling region, a first plurality of waveguides, and a second plurality of waveguides. Each of the first plurality of waveguides has a first end and a second end, the first end being configured to collect light from at least one of the one or more light sources, and the second end being coupled to a first side of the coupling region. Each of the second plurality of waveguides is coupled to a second side of the coupling region. The coupling region is designed to couple light received from one or more of the first plurality of waveguides into the second plurality of waveguides such that the relative phase difference of the light in each of the second plurality of waveguides is based on which of the first plurality of waveguides the light was received from. Therefore, light is emitted from the second plurality of waveguides in different propagation directions based on the relative phase difference of the light in each of the second plurality of waveguides. As will be understood, this configuration is particularly useful in optical transmitter applications.

[0023] According to another exemplary embodiment, a method using a multidirectional optical device includes coupling incident light received in one or more propagation directions into a first plurality of waveguides on a substrate; coupling light from the first plurality of waveguides to a first side of a coupling region on the substrate; and selectively coupling light from the coupling region to one or more second waveguides of a plurality of second waveguides at a second side of the coupling region. The one or more second waveguides are selected based on one or more propagation directions of the received light coupled into the first plurality of waveguides.

[0024] According to another exemplary embodiment, a method of using a multidirectional optical device includes emitting light into one of a plurality of first waveguides on a substrate; coupling light from the one waveguide to a first side of a coupling region on the substrate; and coupling light from the coupling region to each of a second plurality of waveguides coupled to a second side of the coupling region, such that light exits from each of the second plurality of waveguides in different propagation directions, the different propagation directions being based on which waveguide the light was emitted into.

[0025] The specification uses the phrases "in one embodiment" or "in some embodiments," which may each refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," etc., used in relation to embodiments of this disclosure are synonymous.

[0026] Various operations can be described as multiple discrete actions or sequential operations in a manner most conducive to understanding the claimed subject matter. However, the order of description should not be construed as implying that these operations necessarily depend on that order. In particular, these operations may not be performed in the order presented. The described operations may be performed in a different order than the described embodiments. In additional embodiments, various additional operations may be performed, and / or the described operations may be omitted.

[0027] System Architecture

[0028] Figure 1The illustration shows an example photonic integrated circuit (PIC) 100, which can be part of a larger system for collecting, analyzing, emitting, and / or modulating light. For example, PIC 100 can be used to capture light received from a long distance (e.g., from space) in different propagation directions. PIC 100 includes a substrate 101, which can be any material commonly used in photonic applications. Such substrate materials include glass substrates, rigid polymer substrates, or semiconductor substrates. Glass substrates can include Pyrex glass or borosilicate glass. Polymer substrates can be flexible enough to roll or bend without tearing. Exemplary polymer materials include, to name just a few, polydimethylsiloxane (PDMS), parylene, polyethylene glycol (PEG), or polyethylene terephthalate (PET). Semiconductor substrates can be thin enough to be flexible as well, and can include, to name just a few, materials such as silicon, gallium arsenide, indium phosphide, or any tertiary or quaternary variant thereof. In some embodiments, the semiconductor substrate includes a top cladding material, such as an oxide material, on which various photonic elements, such as waveguides, are formed.

[0029] According to some embodiments, PIC 100 includes a light source 102 and a photodetector 104. Although only one light source 102 and one photodetector 104 are shown, it should be understood that the light source 102 can represent any number of light sources, and similarly, the photodetector 104 can represent any number of photodetectors. Because it has both a light source and a detector, PIC 100 is capable of simultaneously emitting and receiving light. In some embodiments, PIC 100 includes only the light source 102, such that PIC 100 functions solely as a light emitter. In some embodiments, PIC 100 includes only the photodetector 104, such that PIC 100 functions solely as a light receiver.

[0030] The light source 102 may be monolithically integrated into the substrate 101, for example, one or more diode lasers or light-emitting diodes (LEDs) formed of layers having gallium and arsenic or layers having indium and phosphorus. In some other embodiments, the light source 102 refers to one or more light sources incorporated into the substrate 101. The light source 102 generates light 103 that can be coupled to one or more waveguides patterned on the substrate 101.

[0031] The photodetector 104 can be monolithically integrated into the substrate 101, for example, formed from one or more PN junctions, such as layers having gallium and arsenic, layers having indium and phosphorus, or layers having doped silicon or doped germanium. In some other embodiments, the photodetector 104 represents one or more optical detectors incorporated into the substrate 101. The photodetector 104 receives light 105 that can be coupled into the photodetector 104 from one or more waveguides patterned on the substrate 101.

[0032] PIC 100 includes an optical element having a coupling region 106, wherein a first plurality of waveguides 108 are coupled to a first side of the coupling region 106 and a second plurality of waveguides 110 are coupled to a second side of the coupling region 106. In some embodiments, the coupling region 106, the first plurality of waveguides 108, and the second plurality of waveguides 110 together form an NxM star coupler having N inputs and M outputs (or M inputs and N outputs). In some embodiments, the first plurality of waveguides 108 includes a greater number of waveguides than the second plurality of waveguides 110.

[0033] Each of the first plurality of waveguides 108 has one end coupled to a coupling region 106 and the other end designed to emit light 112 (when used as an optical transmitter) or receive light 112 (when used as an optical receiver). Light 112 may represent free-space light emitted from or received by the first plurality of waveguides 108. According to some embodiments, each of the first plurality of waveguides 108 has substantially the same optical path length. In this document, "substantially the same" means optical path lengths that are close to each other based on a collaborative effort to design the plurality of waveguides 108 to produce optical path lengths that are as close to each other as possible. Therefore, the physical length of each of the first plurality of waveguides 108 can be designed to achieve substantially the same optical path length across the first plurality of waveguides 108. In some embodiments, passive or active delay elements can be used on any number of the first plurality of waveguides 108 to achieve substantially the same optical path length. For example, active delay elements can be used to eliminate differences in optical path length caused by the wavelength of light due to dispersion or other reasons. When used in communication systems operating with variable wavelength light sources, the wavelength of the light can be varied.

[0034] According to some embodiments, coupling region 106 is formed of the same material as the first plurality of waveguides 108 and the second plurality of waveguides 110. In some embodiments, coupling region 106, the first plurality of waveguides 108, and the second plurality of waveguides 110 all comprise silicon nitride, although any other material that can be used as a waveguide core for visible or infrared wavelengths may also be used. Coupling region 106 may have the shape and form of a star coupler that passively performs a Fourier transform on light passing between its input and output. Thus, coupling region 106 can be configured to take advantage of the characteristics of a Rowland circle. In the light emission example, light is received at coupling region 106 from one or more of the second plurality of waveguides 110 and distributed across each of the first plurality of waveguides 108, wherein a linear phase profile spans the first plurality of waveguides 108. The slope of the linear phase profile depends on which waveguide of the second plurality of waveguides 110 receives the light. The light will ultimately exit from the first plurality of waveguides 108 as light 112 having a propagation direction based on the linear phase profile. In the optical receiving example, light is received from a first plurality of waveguides 108 at coupling region 106, wherein the light has a linear phase profile based on the propagation direction of the received light 112. Coupling region 106 is designed to selectively couple the light to one or more of a second plurality of waveguides 110 based on the linear phase profile of the light. As described above, the same PIC 100 can be used to simultaneously receive and transmit light.

[0035] Due to the selective coupling capability of the coupling region 106 based on the linear phase profile of light, the propagation direction of the received light can be determined based on which waveguide among the second plurality of waveguides 110 receives the light. Similarly, the propagation direction of the emitted light can be controlled by selecting which waveguide among the second plurality of waveguides 110 to send the light thereto.

[0036] In some embodiments, PIC 100 includes a coupler 114, which may include a multiplexer configured to direct light 103 into or from selected one or more waveguides of the second plurality of waveguides 110. Therefore, the multiplexer may include a network of switches comprising optical switches that direct light into specific waveguides. The optical switches may be microelectromechanical (MEMS) switches, mechanically moving portions of the waveguide to switch between different paths. Other examples of optical switches include Mach-Zehnder interferometers, or switches that utilize optical modulation to direct light into specific paths. Optical modulation can be performed using any of electro-optic modulators, thermo-optic modulators, or acousto-optic modulators. In some other embodiments, coupler 114 may combine light received from the second plurality of waveguides 110 into light 105, or distribute the generated light 103 across each of the second plurality of waveguides 110. Therefore, coupler 114 may include a 1xN multi-mode interference (MMI) coupler, a 1xN star coupler, or any similar coupling element. Although only one coupler 114 is shown, it should be understood that coupler 114 may represent any number of discrete couplers. For example, a first coupling element may be used to guide light 103 into one or more of a second plurality of waveguides 110, while a second coupling element may be used to receive light 105 from one or more of the second plurality of waveguides 110.

[0037] Any waveguide discussed above for the PIC 100 can be a strip, ridge, or rib waveguide. Any waveguide can include a core material having a first refractive index, surrounded by a cladding material having a second refractive index lower than the first. Furthermore, in some embodiments, the top layer of the substrate 101 is the material used as the cladding for any waveguide.

[0038] According to some embodiments, each of the first plurality of waveguides 108 includes a modulation element 116. The modulation element 116 can be configured to change any one of the phase, frequency, amplitude, or delay of the propagating light within each of the first plurality of waveguides 108. In the illustrated example, the modulation element 116 includes a phase modulator that can be individually addressed to correct the phase profile of the received light 112. The modulation element 116 may include any one of an electro-optic modulator, a thermo-optic modulator, or an acousto-optic modulator.

[0039] According to some embodiments, each of the second plurality of waveguides 110 includes a modulation element 118. The modulation element 118 can be configured to change any one of the phase, frequency, amplitude, or delay of the propagating light within each of the second plurality of waveguides 110. In the illustrated example, the modulation element 118 includes a phase modulator that can be individually addressed to correct for different phase delays of the propagating light within the second plurality of waveguides 110. The modulation element 118 may include any one of an electro-optic modulator, a thermo-optic modulator, or an acousto-optic modulator.

[0040] According to some embodiments, PIC 100 includes modulation element 116 but not modulation element 118. In some other embodiments, PIC 100 includes modulation element 118 but not modulation element 116. In some other embodiments, PIC 100 does not include either modulation element 116 or modulation element 118 (e.g., a design for digital phase correction via signal processing).

[0041] According to one embodiment, optical heterodyne can be performed to mix with received or transmitted optical signals for subsequent filtering or tuning. In one example, an optical signal having a local oscillator (LO) frequency can be mixed with light within each of the first plurality of waveguides 108 to generate a down-converted or up-converted optical signal with a given intermediate frequency (IF). The LO optical signal can also be received by coupling region 106 from the same side as the first plurality of waveguides 108. By performing controlled optical mixing of the input optical signals, waveform distortion of the received or transmitted optical signals can be digitally corrected via signal processing, eliminating the need for phase control via a phase modulator. In some other embodiments, the phase information in the outputs of different waveguides after heterodyne can enable optimal control of modulation elements 118 and / or modulation elements 116 to suppress such waveform distortion.

[0042] Figures 2A to 2C Different examples are shown of using a star coupler element from the PIC 100 to change the propagation direction of emitted light according to some embodiments. Figures 2A to 2C The various features of the star coupler shown are not necessarily drawn to scale, and some features may be exaggerated for easier viewing.

[0043] Figure 2AAn example is shown where light is transmitted through one of the second plurality of waveguides 110 into a coupling region 106. The light is then distributed through the coupling region 106 into each of the first plurality of waveguides 108, whereby the light exits from aperture 202 as free-space light having a propagation wavefront 204. In some embodiments, apertures 202 are arranged parallel to each other along a common plane. In some embodiments, apertures 202 represent cleaved facets at the ends of the first plurality of waveguides 108. In some embodiments, apertures 202 include grating structures or nanoantennas to influence the wavefront 204 of the propagating light. Additional optical elements, such as micromirrors or microlenses designed to reflect or focus light, may be present at or near apertures 202.

[0044] exist Figure 2A In the example shown, since the light is received from the center waveguide of the second plurality of waveguides 110, the phase of the light is substantially the same in each of the first plurality of waveguides 108, so the light propagates away from the aperture 202 in a direction substantially perpendicular to (as indicated by the arrows) the line in which each aperture 202 is placed. The wavefront 204 shows no tilt in the phase profile of the outgoing light.

[0045] Figure 2B Another example is shown, in which light is transmitted through one of the second plurality of waveguides 110 to the coupling region 106. Figure 2B In the example shown, since the light is received from waveguides offset from the central waveguide of the plurality of waveguides 110, the phase of the light within each of the first plurality of waveguides 108 has a constant phase difference (e.g., a linear phase profile), so the light propagates away from aperture 202 at a small angle to the vertical direction (as indicated by the positive x-direction). Wavefront 206 shows a slight tilt to the phase profile of the outgoing light. The magnitude of the slope of the linear phase profile depends on which waveguide of the second plurality of waveguides 110 receives the light from, increasing for waveguides further away from the central waveguide.

[0046] Figure 2C Another example is shown, in which light is transmitted through one of the second plurality of waveguides 110 to the coupling region 106. Figure 2C In the example shown, light is received from the waveguide furthest from the center waveguide of the plurality of waveguides 110, resulting in a constant phase difference (e.g., a linear phase profile) with the maximum possible slope given the design shown. Therefore, light propagates away from aperture 202 at a greater angle to the vertical direction (as indicated by the arrow in the positive x-direction). Wavefront 208 shows a greater tilt in the phase profile of the outgoing light.

[0047] It should be understood that, according to one embodiment, by inputting light via a mirrored waveguide on the other side of the central waveguide of a plurality of second waveguides 110, the direction of propagation of light can also be in the negative x-direction. Furthermore, light can be transmitted through more than one of the second plurality of waveguides 110, which will generate light propagating simultaneously in different directions.

[0048] Figure 3A and 3B Different examples of receiving light from different propagation directions using star coupler elements from PIC 100 according to some embodiments are shown. Figure 3A and Figure 3B The various features of the star coupler shown are not necessarily drawn to scale, and some features may be exaggerated for easier viewing.

[0049] Figure 3A The illustration shows light with a wavefront 302 being received by apertures 202 of a first plurality of waveguides 108 according to one embodiment. Because the wavefront 302 has a phase profile parallel to the lines through which each aperture 202 is placed, the collected light within each of the first plurality of waveguides 108 will have substantially the same phase (e.g., a phase offset of approximately 0). When coupling region 106 receives light with substantially equal phase across each of the first plurality of waveguides 108, the light is directed to a center waveguide in a second plurality of waveguides 110. The center waveguide is selected based on the phase difference between the light beams (approximately 0 in this example), and this phase difference is determined at least by the direction of propagation of the light when it is received by the first plurality of waveguides 108. It should be understood that in some embodiments, most of the light is coupled through the center waveguide, while some light may be coupled through other waveguides of the second plurality of waveguides 110. For example, at least 75%, at least 80%, at least 85%, at least 90%, or at least 95% of the light is coupled through the center waveguide, and the remainder of the light is coupled through one or more of the other waveguides of the second plurality of waveguides 110.

[0050] like Figure 3A As further shown in the diagram, the intermediate waveguide C of the second plurality of waveguides 110 n The amplitude of the received light is equal to Among them, a n Represents the zeroth order of magnitude of light. This represents the relative phase profile of light from a given waveguide. Similarly, the adjacent waveguides C of the second plurality of waveguides 110... n+1 and C n-1 The amplitude of each received light beam is zero or close to zero.

[0051] Figure 3BAn example according to one embodiment is shown, wherein light is received from more than one direction, resulting in a nonlinear wavefront 304. This may occur, for example, when light passes through turbulent atmospheric conditions that distort the wavefront of the light. In most practical cases, free-space light rarely reaches its destination without some form of wavefront distortion due to any amount of air conditions. In the example shown, wavefront 304 can be conceptualized as a combination of three different propagation modes or phase profiles (which can be decomposed based on Fourier analysis). According to one embodiment, when light is received by coupling region 106, the light is guided to more than one of the second plurality of waveguides 110 corresponding to different phase profiles of the received light.

[0052] For example, as shown in the figure, light can be coupled into the central waveguide and waveguides on either side of the central waveguide. Therefore, received light having a phase-difference-free contribution (mode 1) across each of the first plurality of waveguides 108 is coupled into the central waveguide C. n In addition, the received light with some positive phase difference (mode 2) across each of the first plurality of waveguides 108 is coupled to waveguide C above the central waveguide. n+1 In the middle. The received light, having some negative phase difference (mode 3) across each of the first plurality of waveguides 108, is coupled to waveguide C above the central waveguide. n-1 In the middle. For example Figure 3B As further shown in the diagram, the intermediate waveguide C of the second plurality of waveguides 110 n The amplitude and phase of the received light are equal to Such as about Figure 3A The subject of discussion. For example, in Figure 3B As can be further seen in the image, the upper adjacent waveguide C... n+1 The amplitude and phase of the received light are equal to And the second waveguide 110 is adjacent to the lower waveguide C n-1 The amplitude and phase of the received light are equal to

[0053] Therefore, unlike standard collimation systems, which are sensitive only to ideal modes or components (those with a flat front phase), the non-ideal portion of the incident light is lost. Instead, a greater amount of incident light is received by capturing not only the ideal modes or components, but also other modes or components available at different waveguides in the second plurality of waveguides 110. These different modes or components can then be photodetected and digitized separately for further digital processing, depending on the given application. In another example, the various modes or components can be frequency- and / or phase-tuned and coherently combined.

[0054] These are merely examples, and based on the phase profile of the received light incident on the first plurality of waveguides 108, the light can be coupled to any number of second plurality of waveguides 110 via coupling region 106. Furthermore, as described above, in some embodiments, most of the light is coupled to a specific waveguide of the second plurality of waveguides 110 based on the phase profile, but some portions of the light can still be coupled to some other or all other waveguides of the second plurality of waveguides 110, where each such portion can be used for pre-detection processing (e.g., frequency and / or phase adjustment for coherent applications), light detection of one or more available modes, and post-detection processing (e.g., using the received optical signal to control a computer, system, or process).

[0055] Figure 4 Examples are shown of how different transmitters transmit light from different angles to the same receiver, and how the receiver distinguishes the transmissions based on the angle of light reception propagation (also referred to herein as the direction of propagation). According to one embodiment, this component may be part of a system comprising, for example, more than one PIC communicating with each other. Figure 4 The examples shown include PIC 402, PIC 404, and PIC 406, each of which can be a separate chip communicating with each other across free space. The separate chips can be within the same device, such as within an optical communication bus on a computer or other host platform. In some embodiments, each of PIC 402, PIC 404, and PIC 406 is integrated into a separate device that communicates with each other across free space.

[0056] In the example use case shown, PIC 402 and PIC 404 act as light transmitters, while PIC 406 acts as a light receiver. In other examples, any one of PIC 402, PIC 404, and PIC 406 can act as either a transmitter or a receiver. According to one embodiment, PIC 402 emits a first beam with a first propagation angle toward PIC 406. Similarly, PIC 404 emits a second beam with a second propagation angle toward PIC 406. According to some such embodiments, the propagation angle from each of PIC 402 and PIC 404 is selected by coupling the emitted light into a specific waveguide to the left of coupling region 106. This can be achieved, for example, by activating a light source connected to the selected waveguide, or by using an optical switching network and / or modulation elements to guide light from the light source to the selected waveguide (or multiple waveguides if multidirectional propagation is required). It can be seen that the activated light source and the selected waveguide are shown in bold to distinguish them from the inactive light source and the unselected waveguide. Figure 4 As can be further seen, light passes through the selected input waveguide and coupling region 106 to each output waveguide to the right of coupling region 106, and is emitted from those output waveguides at a propagation angle associated with the selected input waveguide.

[0057] When PIC 406 receives the emitted light, it is coupled into a receiving waveguide and guided to coupling region 106 on PIC 406, whereby the light is guided to one or more specific waveguides based on the light's reception propagation angle (direction). In the example shown, the first light received from PIC 402 is received at a first propagation angle, and therefore the first light is coupled into the waveguide connected to photodetector 408, while the second light received from PIC 404 is received at a second propagation angle, and therefore the second light is coupled into the waveguide connected to photodetector 410. In this way, photodetector 408 receives the first light emitted by PIC 402, and photodetector 410 receives the second light emitted by PIC 404. The first and second lights can be emitted and received simultaneously or at different times.

[0058] In some embodiments, one or more of PIC 402, PIC 404, and PIC 406 are designed to function simultaneously as both a light transmitter and a light receiver. In one such exemplary embodiment, PIC 402 transmits light to PIC 406 and receives light from PIC 406. Similarly, PIC 404 transmits light to PIC 406 and receives light from PIC 406, and PIC 406 transmits light to one or both of PIC 402 and PIC 404 and receives light from one or both of PIC 402 and PIC 404. The light transmitter and receiver may be bonded to the same PIC, as referenced above. Figure 1 The above discussion, and in more detail, and according to some embodiments, can utilize various optical elements between coupling region 106 and the light source / photodetector to distinguish emitted and received light in bidirectional applications, and / or generate coherent light or otherwise modulate the light as required by a given application. Recall that when two modes of light have the same frequency and the same phase or a constant phase difference, they are said to be coherent. Some examples of such optical elements include optical circulators, multiplexers and switching networks, phase modulators, frequency modulators, adaptive lenses, polarization beam splitters, and optical isolators.

[0059] Figure 5A and 5B An example photonic circuit receiver design according to some embodiments is shown. Figure 5AA PIC 500 according to an embodiment is shown, comprising a coupling region 106 and a 1xN coupler 502 located between a second plurality of waveguides 110 and a photodetector 504. Coupler 502 may include, for example, a multiplexer that selects one of N inputs to couple to a single output received by photodetector 504. In some embodiments, coupler 502 uses time-division multiplexing to switch between the N inputs to capture light received from more than one input. In some embodiments, coupler 502 is designed to couple any light received from any waveguide 110 to a single waveguide coupled to photodetector 504. Thus, coupler 502 may be a 1xN multimode interference (MMI) coupler, a 1xN star coupler, or any similar or comparable coupling element. In embodiments where coupler 502 combines light received from waveguide 110, modulation elements may be used on each waveguide 110 to modulate the light received by photodetector 504. Example modulation elements may include phase or frequency modulation elements. For example, optical phase modulators on each waveguide 110 can be used to compensate for different components (e.g., The relative phase delays are then coherently combined before photodetection.

[0060] Figure 5B Another PIC 501 is shown, which includes a coupling region 106 and a plurality of phase modulation elements 506 on a second plurality of waveguides 110 prior to waveguide coupling to a photodetector 508. As described above, the photodetector 508 can represent any number of photodetectors, such that each waveguide 110 can be coupled to a separate photodetector. For example, the phase modulation elements 506 can be used to modulate the phase of light within each of the second plurality of waveguides 110 to enhance the coherence of the light received by the photodetector 508. The phase modulation elements 506 can include one or more of an electro-optic modulator, a thermo-optic modulator, or an acousto-optic modulator. In some embodiments, other modulators are used in place of or in conjunction with the phase modulation elements 506, such as frequency modulators, amplitude modulators, or delay elements. In a more general sense, the received light can be modulated (e.g., amplified, phase-adjusted, frequency-adjusted, and / or filtered) or otherwise processed to facilitate its detection for a given application.

[0061] For each of the PIC 500 or PIC 501, in some embodiments, additional modulation elements may be used in conjunction with the first plurality of waveguides 108 to provide correction of the phase profile of the incident light. The additional modulation elements may include, for example, phase modulation elements coupled to each of the first plurality of waveguides 108, although any optical processing components (e.g., filters, frequency modulators, phase modulators, adaptive lenses) may also be used.

[0062] Figure 6 A PIC 600, exemplified according to some embodiments, is shown as a photon emitter. According to an embodiment, the PIC 600 includes a coupling region 106 and a 1xN coupler 604 located between a second plurality of waveguides 110 and a light source 602. The coupler 604 may include, for example, a multiplexer that selects one of N outputs to couple to a single input received from the light source 602. In some embodiments, the coupler 604 uses time-division multiplexing to switch between the N outputs to emit light generated from the light source 602 into more than one of the second plurality of waveguides 110. In some embodiments, the coupler 604 is designed to couple light received from the light source 602 to each of the second plurality of waveguides 110. Thus, the coupler 604 may be a 1xN multimode interference (MMI) coupler, a 1xN star coupler, or any similar coupling element.

[0063] According to some embodiments, each of the second plurality of waveguides 110 includes an amplitude modulation element 606. Each amplitude modulation element 606 can be individually controlled to change the amplitude of light within the corresponding waveguide. For example, the amplitude modulation element 606 can be controlled to not apply amplitude modulation to the three central waveguides (as shown), while reducing the amplitude to near zero for the other waveguides. Any amplitude modulation scheme can be implemented using the amplitude modulation element 606. According to some embodiments, the amplitude modulation element 606 can be one or more of an electro-optic modulator, a thermo-optic modulator, or an acousto-optic modulator. In some embodiments, additional modulation elements, such as phase modulators and / or frequency modulators, are also provided on each of the second plurality of waveguides 110.

[0064] According to some embodiments, additional modulation elements are used in conjunction with the first plurality of waveguides 108 to provide, for example, correction of the phase and / or frequency distribution of the emitted light. The additional modulation elements may include, for example, phase modulation elements attached to each of the first plurality of waveguides 108.

[0065] The various embodiments of the PIC discussed above receive and / or emit light along a one-dimensional array of output waveguides. However, in some embodiments, any PIC design discussed herein can be adapted to receive and / or emit light across a two-dimensional region by arranging waveguide apertures in a 2D pattern on a substrate. Figure 7An example PIC 700 according to an embodiment is shown, comprising a first plurality of optical elements 701, each optical element 701 having coupling regions 702-1 to 702-4, each coupling region 702-1 to 702-4 having a waveguide 707 connected to additional coupling regions 704-1 to 704-4 of a second plurality of optical elements 703, for capturing or emitting light from apertures 706 of a 2D array connected to the first plurality of waveguides 708. Each of the coupling regions 702-1 to 702-4 and coupling regions 704-1 to 704-4 can be, for example, a star coupler, designed to couple light between various waveguides as described above with reference to Figures 2 and 3. Although the example shown includes a 4×4 array of apertures 706 and a total of eight coupling regions, it should be understood that any size array of apertures 706 and any number of coupling regions for interfacing with apertures 706 of a 2D array can be designed.

[0066] According to an embodiment, each coupling region in the first plurality of optical elements 701 includes a subset of the first plurality of waveguides 708 coupled to one side of the respective coupling region. The ends of the first plurality of waveguides 708 include apertures 706 for emitting or receiving light. Each aperture 706 may include any of a slit waveguide end face, an angled end face, a grating structure, a nanoantenna, a micromirror, or other such optical elements to facilitate the reception of light into the waveguide 708 via the aperture 706.

[0067] Each of the second plurality of waveguides 707 connects a coupling region from the first plurality of optical elements 701 to a coupling region of the second plurality of optical elements 703. For example, each coupling region 702-1 to 702-4 includes a first waveguide connected to coupling region 704-1, a second waveguide connected to coupling region 704-2, a third waveguide connected to coupling region 704-3, and a fourth waveguide connected to coupling region 704-4. In other words, each coupling region 702-1 to 702-4 includes waveguides that are all coupled to different coupling regions 704-1 to 704-4, and conversely, each coupling region 704-1 to 704-4 includes waveguides that are all coupled to different coupling regions 702-1 to 702-4. The different line types (solid and dashed lines) in the figures are used to distinguish which waveguides in the second plurality of waveguides 707 are associated with each of coupling regions 702-1 to 702-4.

[0068] According to one embodiment, when light is received by aperture 706 of the 2D array, the light is coupled into a first plurality of waveguides 708 and received by each of the first plurality of optical elements 701. Focused on coupling region 702-1, the light is received and guided to one or more of the plurality of solid-line waveguides in the second plurality of waveguides 707, based on the propagation direction of the received light. A similar process occurs for the other coupling regions 702-2 to 702-4. Depending on which waveguide in the second plurality of waveguides 707 the light is coupled into, not all coupling regions 704-1 to 704-4 can receive light. For example, if the light is received at an angle such that each coupling region 702-1 to 702-4 guides the light primarily to the corresponding top waveguide of the second plurality of waveguides 707 in that coupling region, then only coupling region 704-1 will receive a significant amount of light energy. Of course, as mentioned above, in some embodiments, at least some portions of the light are coupled to each of the second plurality of waveguides 707 through coupling regions 702-1 to 702-4.

[0069] Each of coupling regions 704-1 to 704-4 receives light via a second plurality of waveguides 707 and couples the light into one or more of a third plurality of waveguides 710. One or more photodetectors may be coupled into the third plurality of waveguides 710. According to one embodiment, the propagation angle of light received by aperture 706 across the 2D array will affect which waveguide of the third plurality of waveguides 710 the light will ultimately be coupled into. (Refer to above) Figure 3A and Figure 3B The working principle described also applies here, but it is extended to determine the direction of light propagation across a 2D region.

[0070] In an example of optical emission, according to one embodiment, light is emitted through one or more of a third plurality of waveguides 710 and enters coupling regions 704-1 to 704-4. Each of the coupling regions 704-1 to 704-4 couples the received light into a corresponding second plurality of waveguides 707, wherein the light from each of the coupling regions 704-1 to 704-4 will have a linear phase shift based on which of the third plurality of waveguides 710 the light was received from.

[0071] Each of coupling regions 702-1 to 702-4 receives light via a second plurality of waveguides 707 and couples the light to one or more of the first plurality of waveguides 708. Depending on which of the third plurality of waveguides 710 the light within the first plurality of waveguides 708 is emitted from the aperture 706 of the 2D array, the propagation direction is determined by the light's position within the third plurality of waveguides 710. (Refer to the above...) Figures 2A to 2C The working principle described also applies here, but is extended to control the direction of light propagation across a 2D region.

[0072] Figure 8AAnother example PIC 800 according to some embodiments is shown, comprising cell arrays 802-1 to 802-n, each cell comprising its own linear array of apertures 804 for receiving or emitting light. Cell 802-1 is shown in more detail in Figure 8. Although a linear array of cells 802-1 to 802-n is shown, a 2D array of cells may also be used, wherein there is any number of cells in each row or column of the array. Similar to aperture 706, each aperture 804 may include any of a slit waveguide endface, an angled endface, a grating structure, a nanoantenna, a micromirror, or other such optical elements to facilitate the reception of light into waveguide 806 via aperture 804.

[0073] According to some embodiments, any one or each of the waveguides 806 includes a modulation element 808. The modulation element 808 can be configured to change any one of the phase, frequency, amplitude, or delay of the propagating light within each waveguide 806. In the illustrated example, the modulation element 808 includes a phase modulator that can be individually addressed to correct the phase profile of the light received via the aperture 804. The modulation element 808 may include any one of an electro-optic modulator, a thermo-optic modulator, or an acousto-optic modulator.

[0074] Each unit of the PIC 800 includes an optical element with a coupling region 810, wherein waveguide 806 is coupled to a first side of the coupling region 810 and waveguide 812 is coupled to a second side of the coupling region 810. In some embodiments, the coupling region 810, waveguide 806, and waveguide 812 together form an NxM star coupler with N inputs and M outputs (or M inputs and N outputs). The coupling region 810 may be functionally and designally similar to the coupling region 106 as described above.

[0075] Waveguide 812 is coupled between coupling region 810 and photodetector 814. As described above, photodetector 814 can represent any number of photodetectors, such that each waveguide 812 can be coupled to a separate photodetector. The function and design of photodetector 814 can be similar to photodetector 104 as described above.

[0076] Figures 8B to 8D Some exemplary designs of the photodetector 814 are shown. Figure 8B In the photodetector 814, there is an optical sensor array 816, each of which may include one or more PN diodes, PIN diodes, avalanche photodiodes (APDs), or single-photonavalanche diodes (SPADs). Each waveguide 812 (identified by a thick line) may be coupled to the corresponding sensor 816.

[0077] exist Figure 8C In one embodiment, before the mixed light is received by the corresponding sensor 816, the light from each waveguide 812 (identified by thick lines) is mixed at mixer 818 with a local oscillator optical signal provided by oscillator 820. Mixer 818 can be any type of unbalanced mixer, balanced mixer, or quadrature (IQ) mixer, and in some embodiments, it is implemented by means of one or more multimode interference (MMI) couplers. The LO signal from oscillator 820 can have a fixed frequency to perform frequency down-conversion of the received optical signal from each waveguide 812.

[0078] exist Figure 8D In, similar to Figure 8C In one embodiment, before the mixed light is received by the corresponding sensor 816, the light from each waveguide 812 (identified by thick lines) is mixed at mixer 818 with a local oscillator optical signal provided by oscillator 820. Mixer 818 can be any type of unbalanced mixer, balanced mixer, or quadrature (IQ) mixer, and in some embodiments, it is implemented by means of one or more multimode interference (MMI) couplers. However, the frequency of the LO signal from oscillator 820 may be affected by phase-locked loop (PLL) 822, which uses feedback from sensor 816 to stabilize and / or control the LO frequency of oscillator 820.

[0079] It should be noted that, for reference Figures 8B to 8D The embodiments of the various photodetectors described herein are applicable to any photodetector derived from any photonic integrated circuit described herein.

[0080] In the PIC 700, cascaded optics 701 and 703 were used to achieve light reception analysis (or light emission control) across a 2D region. In the PIC 800, the use of cascaded optics has been replaced by the use of separate lens arrangements to achieve a similar 2D Fourier transform of light. Figure 9 An exemplary lens arrangement 900 according to some embodiments is shown for coupling light into or out of an aperture 804. The lens arrangement 900 may be coupled to or otherwise aligned on one side of a substrate 101 to collect or transmit light through the thickness of the substrate 101 to the aperture 804 on the opposite side of the substrate 101. Thus, according to embodiments, the substrate 101 is a material substantially transparent to the wavelength of the light used. In one example, the substrate 101 is a silicon substrate, and the light is infrared light.

[0081] According to an embodiment, the lens arrangement 900 includes a first cylindrical lens 902 extending through each unit in the PIC 800. In some examples, the cylindrical lens 902 is a cylindrical lens. The cylindrical lens 902 affects light focusing in only one direction and can be used in a Fourier transform configuration to provide a 1D Fourier transform effect similar to that of one of the cascaded optical elements in the PIC 700. In some embodiments, the lens arrangement 900 also includes a lens array 904. The lens array 904 may extend through each unit in the PIC 800, or the separate lens array 904 may be aligned across the aperture 804 of each unit in the PIC 800. The lens array 904 may include any type of lens that focuses light through the substrate 101 onto a given aperture 804. In some instances, an anti-reflective (AR) coating 906 is applied to the same surface of the substrate 101 as the aperture 804.

[0082] Figure 10 An example device 1000 according to some embodiments is shown, which includes a PIC 1002 and electrical components interfaced to the PIC 1002, such as logic circuitry 1004, power supply 1006, and user interface 1008. The PIC 1002 may represent any of the PIC designs described herein for transmitting and / or receiving free-space light.

[0083] According to one embodiment, logic circuitry 1004 may include any combination of hardware and / or software for controlling various components of PIC 1002 or for receiving and analyzing electrical signals from one or more photodetectors on PIC 1002. For example, logic circuitry 1004 may provide electrical signals to control one or more active optical modulators (e.g., phase modulators, frequency modulators, or amplitude modulators) on PIC 1002, or to control selection switching elements such as optical multiplexers. Logic circuitry 1004 may receive electrical outputs from one or more photodetectors to determine the propagation direction of received light based on the characteristics of the received signals and / or from which signals are received. In some embodiments, logic circuitry 1004 may control one or more light sources and / or modulation elements to transmit light at a given time or in a specific propagation direction.

[0084] The logic circuit 1004 can represent any number of processors or processing devices. In some embodiments, the logic circuit 1004 includes any suitable processor and may include one or more coprocessors or controllers to assist in the control and processing operations associated with the PIC 1002. In some embodiments, the processor can be implemented as any number of processor cores. The processor (or processor core) can be any type of processor, such as a microprocessor, embedded processor, digital signal processor (DSP), graphics processor (GPU), network processor, field-programmable gate array, or other device configured to execute code.

[0085] Logic circuit 1004 can be designed to execute code or software stored in memory 1010. According to some embodiments, memory 1010 can be implemented using any suitable type of digital memory, including, for example, flash memory and / or random-access memory (RAM). In some embodiments, memory 1010 can include various layers of a memory hierarchy and / or memory cache. Memory 1010 can be implemented as a volatile memory device, such as, but not limited to, RAM, dynamic RAM (DRAM), or static RAM (SRAM) devices. Note that code or instructions can be used, for example, to control the light source fed to PIC 1002, or, depending on the application, to turn on one or more optical elements (e.g., phase adjusters, etc.), or to set the sensitivity or other settable parameters of the photodetector receiving light from PIC 1002.

[0086] According to one embodiment, power supply 1006 may be included within device 1000 to provide power to various electrical components of device 1000. Power supply 1006 may represent any known energy storage component, such as a battery or capacitor, and / or circuitry for coupling components of device 1000 to an energy source separate from device 1000 (e.g., AC line power).

[0087] According to some embodiments, the user interface 1008 may include any means for a user to interact with the device 1000. The user interface 1008 may include devices (not shown) such as a display element, touchpad, keyboard, mouse, speaker, etc. Therefore, a user can interact with the device 1000 using input via a touchpad, keyboard, or mouse, and can read information received via the display. In some embodiments, a user can receive audio output from the device 1000.

[0088] method

[0089] Figure 11 An example method 1100 for receiving light from one or more propagation directions using a multidirectional optical device according to certain embodiments of the present disclosure is shown. It can be seen that the example method includes multiple stages and sub-processes, the order of which may vary depending on the embodiment. However, when considered together, these stages and sub-processes form a process for receiving light from multiple propagation directions and determining the propagation direction of the received light, as described above, for example, referring to... Figure 3A and Figure 3B This method can be implemented on any of the various PIC embodiments described herein; however, it will be apparent from this disclosure that other system architectures can be used in other embodiments. Therefore, Figure 11 The relation of the various functions shown to the figures and the specific components shown in the other figures is not intended to imply any structural limitations and / or usage limitations. Many variations and alternative configurations will be apparent from this disclosure.

[0090] According to one embodiment, method 1100 begins with operation 1102, in which light is received from one or more propagation directions and coupled into a first plurality of waveguides. The light can have any wavelength between approximately 400 nm and approximately 2000 nm. The light can be received by an aperture aligned along a plane passing through a substrate that also includes the first plurality of waveguides. The aperture can include an optical element designed to receive light and couple it into a corresponding waveguide, such as a grating structure, micromirror, or nanoantenna. In some embodiments, the apertures are arranged as a 2D array across the surface of the substrate. In some examples, light is received directly by a slit endface at an end of the first plurality of waveguides. In some examples, light is coupled into the first plurality of waveguides via one or more refractive index-matched structures or optical elements, such as gratings, microlenses, or micromirrors. According to some embodiments, the light within the first plurality of waveguides has a phase profile that depends on the propagation direction of the received light.

[0091] According to an embodiment, method 1100 continues to operation 1104, in which light in the first plurality of waveguides is coupled to a first side of a coupling region. The coupling region may be in the form of a star coupler. The star coupler may be formed on a substrate of the same material as the first plurality of waveguides.

[0092] According to an embodiment, method 1100 continues to operation 1106, in which light is selectively coupled to one or more waveguides on a second side of the coupling region. The coupling region is designed to couple the received light to a specific waveguide in one or more second waveguides based on the phase profile of the received light, as referenced above. Figures 2A to 2C To be discussed in more detail.

[0093] According to an embodiment, method 1100 continues to operation 1108, in which one or more propagation directions of the received light are determined based on which waveguide of one or more second waveguides the light is received from. The light from the one or more second waveguides can be received by one or more photodetectors to be converted into electrical signals. In some embodiments, the determined propagation direction of the light can be used to determine where the light is emitted from and thereby identify a specific source of that emitted light. The one or more propagation directions can be determined using a processor (e.g., discussed with respect to logic circuit 804), the processor being configured to receive electrical signals from one or more photodetectors that receive light from the one or more second waveguides.

[0094] Figure 12 An exemplary method 1200 for emitting light in one or more propagation directions using a multidirectional optical device according to certain embodiments of the present disclosure is shown. It can be seen that the example method includes multiple stages and sub-processes, the order of which may vary depending on the embodiment. However, when considered together, these stages and sub-processes form a process for controlling the transmission of light in multiple propagation directions, as described above, for example, referring to... Figures 2A to 2C This method can be implemented on any of the various PIC embodiments described herein; however, it will be apparent from this disclosure that other system architectures can be used in other embodiments. Therefore, Figure 12 The relation of the various functions shown to the figures and the specific components shown in the other figures is not intended to imply any structural limitations and / or usage limitations. Many variations and alternative configurations will be apparent from this disclosure.

[0095] According to one embodiment, method 1200 begins with operation 1202, in which light is emitted into a waveguide among a first plurality of waveguides. Waveguides can be selectively chosen by activating a specific light source coupled to a selected waveguide, by guiding light into a specific waveguide using an optical switching network, or by using modulation elements to suppress and / or amplify light in a specific waveguide among the first plurality of waveguides. The light source used to generate the emitted light can be a laser or an LED. In some embodiments, light can be emitted into more than one of the first plurality of waveguides to emit light simultaneously in more than one propagation direction.

[0096] According to an embodiment, method 1200 continues to operation 1204, in which light is coupled from the first plurality of waveguides to a first side of the coupling region. The coupling region may be in the form of a star coupler. The star coupler may be formed on a substrate of the same material as the first plurality of waveguides.

[0097] According to an embodiment, method 1200 continues to operation 1206, in which light is coupled to a second plurality of waveguides at a second side of the coupling region. The coupling region is designed to couple light to the second plurality of waveguides with a phase profile depending on which waveguide from which light is received, as referenced above. Figures 2A to 2C This will be discussed in more detail. The phase profile determines the final propagation direction of light as it exits from the second or more waveguides.

[0098] According to an embodiment, method 1200 continues to operation 1208, in which light is emitted from a second plurality of waveguides in a propagation direction depending on which waveguide of the first plurality of waveguides the light was emitted into. If the light is emitted into only one of the first plurality of waveguides, the light will exit from the second plurality of waveguides with a linear phase front, forming a single propagation direction. However, in some examples, if the light is emitted into more than one of the first plurality of waveguides, the light will exit from the second plurality of waveguides with a non-linear phase front (formed by contributions from different phase profiles), forming multiple propagation directions.

[0099] Unless otherwise specified, it will be understood that terms such as “processing,” “computing,” “operation,” and “determining” refer to the actions and / or processes of a computer or computing device or similar electronic computing device that manipulate data represented as physical quantities (e.g., electronic) in the registers and / or storage units of a computer system and / or convert that data into other data represented as physical quantities in the registers, storage units, or other such information storage, transmission, or display of the computer system. In this context, the embodiments are not limited.

[0100] As used in any embodiment herein, the term "circuit" or "circuit system" may, for example, individually or in any combination, include hard-wired circuit systems, programmable circuit systems such as computer processors including one or more individual instruction processing cores, state machine circuit systems, and / or firmware storing instructions executed by the programmable circuit system. The circuit system may include a processor and / or controller configured to execute one or more instructions to perform one or more operations described herein. Instructions may be embodied as, for example, an application program, software, firmware, etc., configured to cause the circuit system to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets, and / or data recorded on a computer-readable storage device. Software may be embodied or implemented as including any number of processes, and processes, in turn, may be embodied or implemented as including any number of threads, etc., in a hierarchical manner. Firmware may be embodied as hard-coded (e.g., non-volatile) code, instructions, or instruction sets and / or data in a memory device. The circuit system can be embodied collectively or individually as circuitry forming part of a larger system, such as integrated circuits (ICs), application-specific integrated circuits (ASICs), system-on-a-chip (SoCs), desktop computers, laptop computers, tablet computers, servers, smartphones, etc. Other embodiments can be implemented as software executed by a programmable control device. As described herein, various embodiments can be implemented using hardware elements, software elements, or any combination thereof. Examples of hardware elements may include processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, etc.), integrated circuits, application-specific integrated circuits (ASICs), programmable logic devices (PLDs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), logic gates, registers, semiconductor devices, chips, microchips, chipsets, etc.

Claims

1. An integrated photonic system, comprising: Substrate; A plurality of optical elements on the substrate, each of the plurality of optical elements comprising: Coupling region; First plurality of waveguides, each coupled to a first side of the coupling region, each waveguide having substantially the same optical path length, and The second plurality of waveguides are all coupled to the second side of the coupling region. The coupling region is configured to couple the light to one or more of the second plurality of waveguides based on the relative phase difference across the first plurality of waveguides. Wherein, the ends of the first plurality of waveguides spanning the plurality of optical elements are arranged in a two-dimensional array on the substrate; and One or more photodetectors are configured to receive light from one or more of the second plurality of waveguides, such that the light received from each of the one or more of the second plurality of waveguides is associated with different propagation directions as the light is incident through free space onto the ends of the first plurality of waveguides.

2. The integrated photonic system according to claim 1 further includes a phase modulation element coupled to a corresponding waveguide in the second plurality of waveguides and / or a phase modulation element coupled to a corresponding waveguide in the first plurality of waveguides.

3. The integrated photonic system of claim 1 further includes a processing device coupled to the one or more photodetectors and configured to determine the propagation direction of light collected by the first plurality of waveguides.

4. The integrated photonic system according to claim 1, wherein, The one or more photodetectors include one or more mixers configured to mix light received from one or more of the second plurality of waveguides with light received from a local oscillator.

5. The integrated photonic system according to any one of claims 1-4, wherein, The plurality of optical elements are a first plurality of optical elements, and the integrated photonic system further includes a second plurality of optical elements, wherein each of the second plurality of optical elements includes a coupling region, and each of the second plurality of waveguides coupled to a second side of a given coupling region of the first plurality of optical elements is coupled to a different coupling region of the second plurality of optical elements.

6. The integrated photonic system according to any one of claims 1-4, wherein, The coupling region, the first plurality of waveguides, and the second plurality of waveguides all comprise silicon nitride.

7. The integrated photonic system according to any one of claims 1-4, wherein, Each of the first plurality of waveguides has an aperture at its end, the aperture comprising a grating structure, nanoantenna, or micromirror configured to couple received light into a corresponding waveguide of the first plurality of waveguides.

8. The integrated photonic system of claim 7 further includes a cylindrical lens disposed above the substrate and configured to guide light into the aperture.

9. The integrated photonic system of claim 8 further includes a lens array disposed between the cylindrical lens and the substrate and configured to focus light received from the cylindrical lens toward the aperture.

10. An integrated photonic system, comprising: Substrate; One or more light sources on the substrate; as well as A plurality of optical elements on the substrate, each of the plurality of optical elements comprising: Coupling region; A plurality of waveguides, each of which is coupled to a first side of the coupling region, and each of which has substantially the same optical path length; and The second plurality of waveguides, each having a first end configured to receive light from at least one of the one or more light sources, and each having a second end coupled to a second side of the coupling region. The coupling region is configured to couple light received from one or more of the second plurality of waveguides into the first plurality of waveguides, such that the relative phase difference of the light across the first plurality of waveguides is based on which waveguide the light was received from. Wherein, light propagates through free space from each of the one or more waveguides in the propagation direction based on the relative phase difference between each of the waveguides in the plurality of waveguides, and The ends of the first plurality of waveguides spanning the plurality of optical elements are arranged in a two-dimensional array on the substrate.

11. The integrated photonic system of claim 10, further comprising a phase modulation element coupled to any one of the first plurality of waveguides and / or a phase modulation element coupled to any one of the second plurality of waveguides.

12. The integrated photonic system of claim 10, further comprising an amplitude modulation element coupled to any one of the first plurality of waveguides.

13. The integrated photonic system of claim 10 further includes a multiplexer having an input coupled to the one or more light sources and a plurality of outputs coupled to the second plurality of waveguides.

14. The integrated photonic system of claim 13, further comprising logic circuitry coupled to the multiplexer and configured to select one or more of the plurality of outputs to propagate light, wherein, The propagation direction of the light emitted from the second plurality of waveguides is based on the selection.

15. The integrated photonic system according to any one of claims 10-14, wherein, The plurality of optical elements are a first plurality of optical elements, and the integrated photonic system further includes a second plurality of optical elements, wherein each of the second plurality of optical elements includes an additional coupling region, wherein each of the second plurality of waveguides coupled to a given coupling region of the first plurality of optical elements is coupled to a different additional coupling region of the second plurality of optical elements.

16. The integrated photonic system according to any one of claims 10-14, wherein, The coupling region, the first plurality of waveguides, and the second plurality of waveguides all comprise silicon nitride.

17. The integrated photonic system according to any one of claims 10-14, wherein, The second side of the coupling region is opposite to the first side of the coupling region.

18. A method using a multi-directional optical device, the method comprising: At least a portion of free space light received from one or more propagation directions is coupled into a plurality of apertures in a plurality of first waveguides on a substrate, wherein the plurality of apertures are arranged in a two-dimensional array on the substrate, and wherein the plurality of first waveguides all have substantially the same optical path length. Optical light from the first plurality of waveguides is coupled to a first side of a plurality of coupling regions on the substrate; and On the second side of the plurality of coupling regions, light from the plurality of coupling regions is selectively coupled into one or more of the plurality of second waveguides, wherein the one or more second waveguides are selected based on one or more propagation directions of the received free-space light coupled into the plurality of first waveguides.

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