Output / wavelength division multiplexing LIDAR architecture

Abstract

The invention relates to an output / wavelength division multiplexing LIDAR architecture. A multi-wavelength transmitter adapted for use in LiDAR applications in which an array of output beams comprising multiple wavelengths is spatially modulated with low amplification requirements. The optical transmitter includes one or more light sources, such as a plurality of laser transmitters operable at different wavelengths. The light source (s) is coupled to an optical switching network comprising one or more switches, for example through one or more planar waveguides. The switching network is used to route the source light beam to each of the plurality of switched output ports in a time division manner to modulate the wavelength of the light beam exiting each of the switched output ports. Multiple output couplers, e.g., including edge-coupled spot size converters, are coupled to individual ones of the switched output ports, e.g., through one or more planar waveguides and / or one or more beam splitters.

Description

Background Art

[0001] LIDAR is an abbreviation for "light detection and ranging" or "laser imaging, detection and ranging", in which the distance to a far-field object or surface targeted by a light emission is determined by measuring the time it takes for the reflected light to return to a receiver. LIDAR has been widely used in autonomous robots and vehicles, mobile devices, and space mapping. In LIDAR, beam steering is typically employed, which can be mechanical but now typically relies on silicon photonics that provide a path for low-cost chip-scale LIDAR systems. LIDAR system architectures sometimes adopt a multi-wavelength approach, in which the emitted light (e.g., light emitted from a photonic integrated circuit (PIC)) cycles through several wavelengths to scan the emission angle.

[0002] LIDAR faces the challenge of covering a wide field of view with high spatial resolution so that it is beneficial to increase the N final outputs. The light can be routed to an output that includes a dispersive element (such as a grating) that directs the beam to different locations in the far field. In this approach, a single initial emission wavelength is selected, amplified, and split until it is emitted from the array of the final N outputs. Continuous wavelengths can be emitted from the output into the dispersive element. When each wavelength is selected, a different array of spots is aimed in the far field. This approach enables an array of N emission beams to be emitted from the transmitter in a direction selected by the wavelength used. However, as the number N increases, successive amplification stages are required to achieve sufficient emission power without excessive laser power. For example, for each 1x4 splitter, at least 6dB of amplification may be required to maintain sufficient power in each channel. For a single wavelength used at any given moment, if it is split and routed to N output couplers, a total gain of N is required to maintain the output power in each channel. The same gain is then required for the second wavelength and each successive wavelength used to interrogate a total of NxM spots, where M is the number of wavelengths or channels.

[0003] Optical transmission technologies and architectures that can produce a given far-field spot count with lower power requirements, smaller transmitter form factor, and / or lower cost are commercially advantageous. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In the accompanying drawings, the material described herein is illustrated by way of example and not by way of limitation. For simplicity and clarity of illustration, the elements illustrated in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated between the drawings to indicate corresponding or similar elements. In the drawings:

[0005] Figure 1A , Figure 1B and Figure 1C is a schematic diagram of a LIDAR transmitter (LIDAR Tx) architecture in three different time division states according to some embodiments;

[0006] Figure 2A and Figure 2B is a diagram further illustrating variations in beam splitter architecture according to some embodiments. Figure 1A-Figure 1C Schematic diagram of the LIDAR Tx architecture illustrated in FIG;

[0007] Figure 3 According to some embodiments, the switching network is implemented using a tunable array waveguide grating (AWG), Figure 2B Schematic diagram of the LIDAR Tx architecture illustrated in FIG;

[0008] Figure 4 According to some embodiments, it is possible to Figure 3 A planar AWG of a switching network of the LIDAR architecture illustrated in FIG.

[0009] Figure 5 is a schematic diagram of a LIDAR Tx architecture in which a switching network is implemented using fixed multiplexers and tunable drop filters according to some embodiments;

[0010] Figure 6 is a schematic diagram of a LIDAR Tx architecture according to some embodiments in which a switching network is implemented using a tunable ring waveguide filter having eight laser sources and sixteen output couplers according to some embodiments;

[0011] Figure 7 According to some embodiments, Figure 1A-Figure 6 A schematic diagram of one or more LIDAR systems in a LIDAR Tx architecture;

[0012] Figure 8 is a functional block diagram of an electronic computing device according to some embodiments, which can implement Figure 7 One or more components of the LIDAR system illustrated in . DETAILED DESCRIPTION

[0013] Various embodiments are described with reference to the accompanying drawings. Although specific configurations and arrangements are described and discussed in detail, this is done for illustrative purposes only. Those skilled in the relevant art will recognize that other configurations and arrangements are possible without departing from the spirit and scope of the present description. It will be apparent to those skilled in the relevant art that the techniques and / or arrangements described herein may also be used in various other systems and applications in addition to the systems and applications described in detail herein.

[0014] In the following detailed description, reference is made to the accompanying drawings, which form part of this document and illustrate exemplary embodiments. Further, it should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the claimed subject matter. It should also be noted that directions and references (e.g., up, down, top, bottom, etc.) may be used only to facilitate the description of features in the drawings. Therefore, the following detailed description should not be understood in a limiting sense, and the scope of the claimed subject matter is limited only by the appended claims and their equivalents.

[0015] In the following description, numerous details are set forth. However, it will be apparent to those skilled in the art that various embodiments can be implemented without these specific details. In some instances, known methods and devices are shown in block diagram form rather than in detail to avoid obscuring various embodiments. References throughout this specification to "embodiment" or "one embodiment" or "some embodiments" mean that specific features, structures, functions or characteristics described in conjunction with the embodiment are included in at least one embodiment. Therefore, phrases "in an embodiment" or "in one embodiment" or "in some embodiments" appearing in multiple locations throughout this specification do not necessarily refer to the same embodiment. In addition, in one or more embodiments, specific features, structures, functions or characteristics can be combined in any suitable manner. For example, in any case where specific features, structures, functions or characteristics associated with the first embodiment and specific features, structures, functions or characteristics associated with the second embodiment are not mutually exclusive, the first embodiment can be combined with the second embodiment.

[0016] As used in the specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0017] The terms "coupled" and "connected" and their derivatives can be used to describe functional or structural relationships between components. These terms are not intended to be synonymous with each other. On the contrary, in certain embodiments, "connected" can be used to indicate that two or more elements are in direct physical, optical or electrical contact with each other. "Coupled" can be used to indicate that two or more elements are in direct or indirect (with other intervening elements between them) physical or electrical contact, and / or that two or more elements cooperate or interact with each other (e.g., in a causal relationship).

[0018] As used herein, the terms "above," "below," "between," and "on" refer to the relative position of one component or material with respect to other components or materials where such physical relationship is noteworthy. For example, in the context of materials, a material or layer above or below another material may be in direct contact or may have one or more intervening materials or layers. Additionally, a material between two materials or layers may be in direct contact with both materials / layers or may have one or more intervening materials / layers. In contrast, a first material or layer that is "above" a second material or layer is in direct contact with the second material / layer. Similar distinctions are made in the context of assemblies of components.

[0019] As used throughout the specification and in the claims, a list of items linked by the term "at least one of" or "one or more of" may mean any combination of the listed items. For example, the phrase "at least one of A, B, or C" may mean A; B; C; A and B; A and C; B and C; or A, B, and C.

[0020] As previously described, the LIDAR system may advantageously include a transmitter (Tx) or "emitter" having a multi-wavelength (multi-channel) source. As further described below, the LIDAR Tx may include a switching network for modulating different wavelengths across each of a plurality of output couplers, each of which may couple a beam to any downstream optical element, which may also be operable to illuminate a plurality of far-field spots. In this way, all output couplers emit different input wavelengths at different times, thereby spatially modulating the array of output beams to obtain a complete query of the angle within the LIDAR field of view. At each moment during operation, the proportion of output couplers emitting a given input wavelength is reduced to the ratio of the total number of output couplers divided by the total number of input wavelengths. For example, relative to an architecture in which all output couplers emit a single input wavelength at any moment, the reduction in the number of far-field spots illuminated by any given wavelength reduces beam amplification requirements. According to embodiments herein, the switching network may modulate which output coupler each of the source wavelengths is routed to at any moment. The switching network may implement any desired time division algorithm to alternately select which source wavelength is emitted by each of the output couplers.

[0021] According to an exemplary embodiment, the LIDAR Tx architecture is advantageously implemented using one or more photonic integrated circuits (PICs), and more specifically, one or more silicon photonic SiPh chips (which may also include III-V semiconductor materials). Although many examples herein are therefore further described in the context of SiPh implementations, the exemplary LIDAR Tx architecture may alternatively be implemented using alternative technologies without departing from the principles disclosed herein.

[0022] Figure 1A , Figure 1B and Figure 1C is a schematic diagram of a LIDAR transmitter (Tx) architecture 101 in three different time division states according to some embodiments. Figure 1A A first state of the LIDAR Tx architecture 101 is illustrated at a first exemplary time (eg, t=0 or t0). Figure 1B A second state of the LIDAR Tx architecture 101 is illustrated at a second exemplary time (eg, t=0 or t1). Figure 1CA third state of the LIDAR Tx architecture 101 is illustrated at a third exemplary time (e.g., t=2 or t2). For clarity of discussion, three states are illustrated. However, in practice, the LIDAR transmitter architecture 101 may have any number of states depending on the parameters of a particular implementation. For example, in some embodiments described further below, the switching network may have as many different states as different wavelengths of light coupled into the switching network.

[0023] First reference Figure 1A , the LIDAR Tx architecture 101 includes a multi-wavelength or multi-channel beam source 110 optically coupled to a switching network 120. The switching network 120 is optically coupled to an output coupler array 130 through any number of optical elements 125, which are drawn in dashed lines to emphasize that the intervening optical elements 125 are optional. The output coupler array 130 outputs to (one or more) downstream optical elements 150, which, in an exemplary embodiment, include a dispersive element that spatially separates the beams exiting the output coupler array 130 so that they propagate in free space and illuminate a set of far-field spots. In an exemplary embodiment, the (one or more) optical elements 150 include a diffraction grating having parameters suitable for the wavelength range of the multi-channel source 110. The (one or more) optical elements 150 may also include one or more lenses suitable for spot size conversion, etc.

[0024] One or more of the source 110, the switching network 120, the optical element 125, and the output coupler array 130 may be implemented in a SiPh chip. In some embodiments, the switching network 120 and the output coupler array 130 and any intervening optical elements 125 are implemented in a single (e.g., first) SiPh chip. In an exemplary embodiment, the multi-wavelength source 110 is implemented in the same SiPh chip as the switching network 120. However, in some multi-chip implementations, the switching network 120, the output coupler array 130, and the optical element 125 are implemented in a first PIC, while the source 110 is implemented in a second PIC chip.

[0025] In some embodiments, the multi-wavelength source 110 includes a plurality of M laser emitters 1111-111 operable at different channel wavelengths. M The number of wavelengths M may vary depending on the implementation (e.g., ranging from 2 to 64, or more). In an exemplary embodiment, each laser emitter 1111-111 M Available in center channel wavelength λ1-λ M Operation under the central channel wavelength λ1-λ M In transmitter 1111-111 MIn some exemplary embodiments, the channel wavelengths λ1-λ M Spanning at least a portion of the O band of the electromagnetic spectrum (i.e., 1260-1360 nm). In some other embodiments, the channel wavelengths λ1-λ M Spanning at least part of the C-band of the electromagnetic spectrum (i.e., 1530–1565 nm). Wavelengths λ1-λ M The range of alternatives may be spanned, particularly where architecture 101 is implemented in a chip other than a silicon PIC and the wavelength may be shorter than that suitable for silicon. M Advantageously, it is a laser diode, such as a distributed-feedback (DFB) laser that can be operated in a continuous-wave (CW) emission mode, or an external cavity laser. In an exemplary embodiment, each laser emitter 1111-111 M In a further embodiment, each laser emitter 1111-111 M All are frequency modulated (FM) or chirped. For example, a frequency modulated carrier wave (FMCW) can be modulated so that the frequency as a function of time defines an approximately triangular waveform. The frequency range of one modulation cycle can vary, with an exemplary range of 1-5 GHz. In alternative embodiments, other techniques for transmit modulation can also be implemented. For example, the transmit can be directly modulated by current injection or a Mach-Zehnder (MZ) modulator.

[0026] As shown, the transmitter 1111-111 M Each of the optically coupled to a corresponding channel input port 1211-121 of the switching network 120 M Although M input ports are illustrated for clarity of discussion, the switching network 120 may have as few as one input port. In the exemplary SiPh IC embodiment, the transmitters 1111-111 M Optically coupled to input ports 1211-121 through on-chip planar optical waveguides M For input ports 1211-121 M In some embodiments, such optical waveguides may be channel specific or, if the switching network 120 includes fewer than M input ports, such optical waveguides may be multi-channel. The switching network 120 may include one or more single-channel and / or multi-channel optical switches adapted to switch input ports (e.g., 1211-121M ) are coupled to each of the M optical switch output ports 122. In some exemplary embodiments, the switching network 120 implements an MxM non-blocking optical matrix switch, whereby the input ports 1211-121 M Each of the two may be selectively and / or switchably routed or coupled to output ports 1221-122 M Each one of them.

[0027] exist Figure 1A , enter port 1211-121 M With output ports 1221-122 M The solid line between represents the active optical path at time t=0. Input ports 1211-121 M With output ports 1221-122 M The dashed line between represents an alternative optical path that is inactive at time t=0. Thus, at time t=0, switch input port 1211 is optically coupled to switch output port 1221. At the same time (i.e., at t=0), switch input port 1212 is optically coupled to switch output port 1222, and switch input port 1211 is optically coupled to switch output port 1221. M With switch output port 122 M Optically coupled.

[0028] Switch output port 1221-122 M The output coupler array 130 is optically coupled to one or more corresponding output couplers 132 of the array 130, optionally via one or more optical elements 125. As shown, the output coupler array 130 includes a plurality (N) of output couplers 1321-132 N The number N may vary depending on the implementation (e.g., ranging from 2 to 64, or more). Figure 1A , N is equal to M. However, as further described below, for embodiments in which the intervening optical element 125 includes one or more optical beam splitters, N and M are not equal and N is an integer greater than M, depending on any beam splitting ratio desired to achieve any number of transmissions suitable for a particular LIDAR application.

[0029] In the exemplary SiPh IC embodiment, output ports 1221-122 M The output couplers 132 are optically coupled to the output couplers 132 through one or more on-chip planar optical waveguides. For such embodiments, each output coupler 1321-132 NAdvantageously comprises an edge coupler (EC), but may alternatively comprise, for example, a grating coupler (GC). The output coupler 132 may also comprise a spot size converter, such as any known converter suitable for extending an optical mode from the size of a single-mode planar waveguide having a particular refractive index to the mode size of any off-chip optical element 150.

[0030] When the switching network is in the first state at a first time (t=0), a light beam with a wavelength of λ1 is routed to the output coupler 1321, for example, where it is emitted off-chip. A second light beam with a wavelength of λ2 is similarly emitted off-chip by the output coupler 1322, and a light beam with a wavelength of λ M The Mth beam is similarly output by the output coupler 132 M During operation, the switching network 120 is used to transmit the signals from the transmitters 1111-111 in a time-division manner. M The beams are routed to alternate output ports 1221-122 M , thereby modulating the output from ports 1221-122 M The wavelength of each of the light beams leaving the output couplers 1321-132 N Similarly, a beam with a modulated central wavelength is emitted. Therefore, over time, the wavelength λ1-λ M Each of the output couplers 1321-132 N Each of is emitted. For example, Figure 1B The switching network 120 is depicted in a second state at another time (t=2), wherein a light beam having a wavelength λ1 is coupled to the switch output port 1222. Thus, the light beam is now emitted from the output coupler 1322, while a light beam having a wavelength λ2 is emitted by the output coupler 1322. N emission, and the wavelength is λ M Another light beam is emitted by the output coupler 1321. Figure 1C In the third state shown, the switching network 120 couples the light beam with wavelength λ1 to the switch output port 122 at another time (t=3). M and output coupler 132 N , and the light beam with wavelength λ2 is coupled to the switch output port 1221 and the output coupler 1321. M The light beam is coupled to the switch output port 1222 and the output coupler 1322 at the same time. Figure 1A-Figure 1C Only three states are illustrated, but the switching network 120 can similarly transition between M different states, where each of the M states routes M wavelengths through N different output couplers.

[0031] The switching network state transitions may be based on any scheduling algorithm (such as polling or other circular queues). In some exemplary embodiments, the output couplers 1321-132 N Each of the emitted wavelengths λ1-λ M The duration of each of is time-averaged to be approximately equal across all wavelengths.

[0032] In some embodiments, the optical element 125 within the beam path between the switching network 125 and the output coupler array 130 includes a plurality of optical splitters. Figure 2A and Figure 2B 2 is a schematic diagram of LIDAR Tx architectures 201A and 201B, which also include an optical splitter array 225. Figure 2A In the LIDAR Tx architecture 201A, the optical splitter array 225 includes one splitter corresponding to each switch output port. Therefore, the optical splitter array 225 includes M channel splitters 2251-225 M , each channel splitter has a switch output port 1221-122 coupled to the M Depending on the splitting ratio, the optical splitter 2251-225 M Each may have any number of output ports for a total of N output ports that match the N output couplers of output coupler array 130. In architecture 201A, splitters 2251-225 M Each of has a split ratio of 1:2, so that N = 2M. Figure 2B , the LIDAR Tx architecture 201B includes a splitter with an alternative 1:4 split ratio, such that N = 4M. Thus, the split ratio may vary depending on the implementation, for example, from 1:64 or higher.

[0033] Optical splitter 2251-225 M Any architecture suitable for the application can be used. M Coupled to splitters 2251-225 through multiple planar optical waveguides M In an exemplary embodiment (eg, in a SiPh implementation), splitters 2251-225 M Each of the SiPh embodiments includes a planar light circuit (PLC) splitter. The PLC splitter can be a single-mode or multi-mode passive device, as the embodiments are not limited in this respect. In some SiPh embodiments, the splitters 2251-225 MThe output port is coupled to the output coupler 1321-132 through N planar single-mode waveguides. N , each planar single-mode waveguide has a lateral dimension of, for example, 1-2 μm.

[0034] like Figure 2A-2B As further illustrated, one or more optical elements 228 may be located on either side of the optical splitter array 225. In some embodiments, the optical element 228 includes one or more optical gain stages. The number of optical gain stages may vary (e.g., from none to four or more) depending on the splitting efficiency of the optical splitter array 225 and / or the output power of the multi-channel source 110 and / or the far-field parameters associated with a particular LIDAR application. Each optical gain stage may be of any suitable architecture. In some exemplary embodiments, a single gain stage includes a semiconductor optical amplifier (SOA) including any suitable gain medium and / or pump architecture. SiPh embodiments may implement SOA, for example, by heterogeneous integration with one or more III / V materials.

[0035] The switching network 120 can be implemented using any (one or more) optical switches, such as MEMs mirror arrays and solid-state optical switches. In an exemplary SiPh embodiment, the switching network 120 includes one or more of the following: an echelon grating, an arrayed waveguide grating, a ring filter, or any other tunable optical multiplexer / demultiplexer. Figure 3 3 is a schematic diagram of a LIDARTx architecture 301, wherein the switching network 120 is implemented using a tunable arrayed waveguide grating (AWG) 420. The AWG 420 includes an input coupler optically coupled to a plurality of grating waveguides of varying lengths, which converge at an output coupler. The varying waveguide path lengths result in the switching output ports 1221-122 M For this switch architecture, the switching network 120 is coupled to a phase tuner 421, which is used to control the phase of the output ports 1221-122 out of the switch. M The temporal modulation of the wavelength of each .

[0036] Figure 4 4 is a plan view of a planar implementation of an AWG 420 according to some SiPh embodiments. As shown, grating waveguides 424 of varying lengths are between input couplers 422 and output couplers 423. One or more input waveguides 421 may enter input coupler 422. Channels λ1-λ M The beams converge at the output coupler 423 and exit across the output port array 122 as separate channels.

[0037] Phase tuner 421 ( Figure 3 ) can be coupled to the AWG 420 to modulate one or more parameters of the AWG 420, for example, by one or more of the following: electro-refraction, electro-absorption, or thermo-optical effects. In some exemplary SiPh embodiments, the tuner 421 comprises a thermo-optical phase tuner. In other embodiments, the AWG 420 comprises one or more physically displaceable waveguides. For example, one or more input waveguides, output waveguides, or grating waveguides of the AWG 420 can be displaced relative to other optical elements. Figure 4 In some of the illustrated embodiments, the input waveguide(s) 421 are displaceable relative to the AWG input coupler 422. The input waveguide(s) 421 may be at least partially released from the substrate 450 so that it may be physically displaced within the plane of the input coupler 422, for example, by a MEMs actuator (not depicted). The MEMs actuator may have any architecture, such as, but not limited to, an electrostatic comb drive.

[0038] Figure 5 is a schematic diagram of a LIDAR Tx architecture 501 in which the switching network 120 includes a fixed multiplexer 521 and a tunable drop filter 522 according to some embodiments. As shown, the multiplexer 521 is optically coupled to the M channel source 110. The multiplexer 521 may include an M:1 AWG, which need not be tunable in this example. The multiplexer 521 may alternatively include a step grating. The output port of the multiplexer 521 is coupled to a multi-channel (i.e., bus) waveguide 520, for example, through an optical isolator 523. The bus waveguide 520 is also coupled to the tunable drop filter 522. In the illustrated example, the drop filter 522 includes a plurality of resonant add / drop ring waveguide filters, each of which is coupled to the switch output ports 1221-122 M The discard filter 522 may be tunable to achieve the above-mentioned channel (λ) modulation, for example, by one or more of the following: electro-refraction, electro-absorption, or thermo-optical effect. Figure 5 As further illustrated, the splitter array 225 includes M 1:4 optical splitters, each splitter output port being optically coupled to one of four amplifiers (eg, SOAs) 511-514. The amplifiers 511-514 output to respective output couplers 1321-1324.

[0039] Figure 6 is a schematic diagram of a LIDAR Tx architecture 601, which further illustrates that the multi-channel source 110 includes eight laser emitters 1111-1118 and the output coupler array 130 includes sixteen output couplers 1321-132 16Some embodiments of the present invention. Figure 6 Further illustrated is an embodiment in which the optical element 228 includes eight optical amplifiers between the switching network 120 and the splitter array 225. In this example, the splitter array 225 includes eight 1:2 splitters. The switching network 120 includes an eight-ring multiplexer that couples the transmitters 1111-1118 to the bus waveguide 520. Eight tunable drop ring waveguide filters 522 also couple the bus waveguide 520 to each of the eight switch output ports 1221-1228.

[0040] The LIDAR Tx architecture according to embodiments herein may be paired with any suitable receiver Rx architecture for integration into a LIDAR system having one or more of lower power requirements, higher spatial resolution. Figure 7 is a schematic diagram of a LIDAR system 700 including one or more of the LIDAR Tx architectures 101-601 according to some embodiments. The LIDAR system 700 can be integrated into any application platform. In some examples, the LIDAR system 700 is integrated into a virtual reality (VR) head mounted device. In some other examples, the LIDAR system 700 is integrated into an autonomous device, such as a robot or a vehicle.

[0041] System 700 includes a LIDAR transceiver 701. In an exemplary embodiment, transceiver 701 includes one or more PICs. In some embodiments, one or more PICs are SiPh PICs. Transceiver 701 includes one or more controllers 710 coupled to control multiple concurrent free-space beam emissions from a LIDAR transmitter 720, for example, according to one or more frequency modulated waveforms 730. The beam emissions are used to query far-field targets at different angles. Controller 710 is also coupled to a LIDAR receiver 760, which is operable to collect optical signals from the far field, such as optical signals reflected from one or more far-field objects 740.

[0042] In an exemplary embodiment, the LIDAR transmitter 720 includes at least one of the LIDAR Tx architectures 101-601, e.g., as described elsewhere herein. In some embodiments, the LIDAR transmitter 720 is implemented in a single SiPh chip. In other embodiments, the LIDAR transmitter 720 is implemented using multiple SiPh chips. For example, the LIDAR transmitter 720 may include a multi-channel source on a first SiPh chip and a matrix optical switch on a second SiPh chip.

[0043] In some embodiments, the LIDAR transmitter 720 and the receiver 760 are implemented in a single SiPh chip. In other embodiments, the LIDAR transmitter 720 is implemented on one or more first SiPh chips, and the LIDAR receiver 760 is implemented on one or more second SiPh chips. In some embodiments, two or more of the controller 710, the LIDAR transmitter 720, and the LIDAR receiver 760 are implemented on a single CMOS / SiPh chip. In some advantageous embodiments, the controller 710, the LIDAR transmitter 720, and the LIDAR receiver 760 are all implemented on a single CMOS / SiPh chip. For multi-chip embodiments, two or more of the multiple SiPh chips may be co-packaged into a single multi-chip package. In some embodiments, the controller 710, the LIDAR transmitter 720, and the LIDAR receiver 760 are all co-packaged into a single multi-chip package.

[0044] Figure 8 800 may implement one or more of the components of LIDAR system 701. Computing device 800 may include any of the LIDAR devices or structures discussed elsewhere herein. Figure 8 800, but any one or more of these components may be omitted or duplicated as appropriate for the application. In some embodiments, some of the components included in computing device 800 may be attached to one or more printed circuit boards (e.g., a motherboard). In some embodiments, individual components of these components may be manufactured on a single system-on-a-chip (SoC) die, or implemented using separate multiple chiplets or slices that are packaged together. Additionally, in various embodiments, computing device 800 may not include Figure 8 800, but the computing device 800 may include interface circuitry for coupling to the one or more components. For example, the computing device 800 may not include the display device 803, but may include display device interface circuitry (e.g., connector and driver circuitry), and the display device 803 may be coupled to the display device interface circuitry.

[0045] The computing device 800 may include a processing device 801 (e.g., one or more processing devices). As used herein, the term processing device or processor indicates a device that processes electronic data from registers and / or memory to convert the electronic data into other electronic data that can be stored in registers and / or memory. The processing device 801 may include a memory 821, a communication device 822, a refrigeration / active cooling device 823, a battery / power regulation device 824, a logic 825, an interconnect 826, a thermal regulation device 827, and a hardware security device 828.

[0046] The processing device 801 may include one or more digital signal processors (DSP), application-specific integrated circuits (ASIC), central processing units (CPU), graphics processing units (GPU), or any other suitable processing device suitable as a LIDAR controller.

[0047] The processing device 801 may include a memory 802, which may itself include one or more memory devices, such as volatile memory (e.g., dynamic random-access memory (DRAM)), non-volatile memory (e.g., read-only memory (ROM)), flash memory, solid-state memory, and / or a hard drive. In some embodiments, the processing device 801 shares a package with the memory 802. The memory may be used as a cache memory and may include an embedded dynamic random-access memory (eDRAM) or a spin transfer torque magnetic random-access memory (STT-M RAM).

[0048] The computing device 800 may include a thermal conditioning / cooling device 823. The thermal conditioning / cooling device 823 may maintain the processing device 801 (and / or other components of the computing device 800) at a predetermined low temperature during operation. The predetermined low temperature may be any temperature discussed elsewhere herein.

[0049] In some embodiments, the computing device 800 may include a communication chip 807 (e.g., one or more communication chips). For example, the communication chip 807 may be configured to manage wireless and / or optical communications for transmitting data to and from the computing device 800. The term "wireless" and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communication channels, etc. that can communicate data through a non-solid medium using modulated electromagnetic radiation. The communication chip 807 may implement any of a variety of wireless and / or optical standards or protocols.

[0050] Computing device 800 may include LIDAR system 700 for facilitating optical far-field interrogation.

[0051] Computing device 800 may include battery / power circuitry 808. Battery / power circuitry 808 may include one or more energy storage devices (e.g., batteries or capacitors) and / or circuitry for coupling components of computing device 800 to an energy source separate from computing device 800 (e.g., AC line power).

[0052] Computing device 800 may include a display device 803 (or corresponding interface circuitry, as discussed above). Display device 803 may include, for example, any visual indicator (such as a heads-up display, a computer monitor, a projector, a touch screen display, a liquid crystal display (LCD), a light emitting diode display, or a flat panel display).

[0053] Computing device 800 may include audio output device 804 (or corresponding interface circuitry, as discussed above). Audio output device 804 may include, for example, any device that generates an audible indicator (such as a speaker, a head-mounted device, or earbuds).

[0054] The computing device 800 may include an audio input device 810 (or corresponding interface circuitry, as discussed above). The audio input device 810 may include any device that generates a signal representing sound, such as a microphone, a microphone array, or a digital instrument (e.g., an instrument with a musical instrument digital interface (MIDI) output).

[0055] The computing device 800 may include a global positioning system (GPS) device 809 (or corresponding interface circuitry, as discussed above). The GPS device 809 may communicate with a satellite-based system and may receive the location of the computing device 800.

[0056] Computing device 800 may include another output device 805 (or corresponding interface circuitry, as discussed above). Examples include an audio codec, a video codec, a printer, a wired or wireless transmitter for providing information to other devices, or an additional storage device.

[0057] The computing device 800 may include another input device 811 (or corresponding interface circuitry, as discussed above). Examples may include an accelerometer, a gyroscope, a compass, an image capture device, a keyboard, a cursor control device (such as a mouse), a stylus, a touchpad, a barcode reader, a Quick Response (QR) code reader, any sensor, or a radio frequency identification (RFID) reader.

[0058] The computing device 800 may include a security interface device 812. The security interface device 812 may include any device that provides security measures for the computing device 800, such as intrusion detection, biometric authentication, security encoding or decoding, management access lists, malware detection, or spyware detection.

[0059] The computing device 800 or a subset of its components may have any suitable form factor, such as a handheld or mobile computing device (e.g., a cellular phone, a smart phone, a mobile Internet device, a music player, a tablet computer, a laptop computer, a notebook computer, an ultrabook computer, a personal digital assistant (PDA), an ultra-mobile personal computer, etc.), a desktop computing device, a server or other networked computing component, a printer, a scanner, a monitor, a set-top box, an entertainment control unit, an in-vehicle control unit, a digital camera, a digital video recorder, or a wearable computing device.

[0060] Although certain features set forth herein have been described with reference to various implementations, this description is not intended to be interpreted in a limiting sense. Therefore, various modifications and other implementations of the implementations described herein that are obvious to those skilled in the art to which the present disclosure belongs are considered to fall within the spirit and scope of the present disclosure.

[0061] In a first example, one or more photonic integrated circuits (PICs) include: a plurality of optical transmitters for outputting a plurality of central wavelengths; a plurality of optical output couplers; and one or more switches optically coupled to the optical transmitters. The switch includes a plurality of output ports, each of which is optically coupled to a subset of the optical output couplers. The switch is used to optically couple each of the optical transmitters to each of the output ports in a time-division manner.

[0062] In a second example, for any of the first example, the PIC further includes an optical beam splitter between the output port and the optical output coupler.

[0063] In a third example, for any item in the second example, the multiple optical emitters include M optical emitters, the multiple optical output couplers include N optical output couplers, each of the optical beam splitters has a splitting ratio of 1xN / M, and the switch optically couples each of the M optical emitters to each of the N optical output couplers.

[0064] In a fourth example, for any one of the first to third examples, each of the output ports is optically coupled to the optical output couplers through each of the optical beam splitters, wherein the output port of each of the optical beam splitters is optically coupled to N / M optical output couplers of the optical output couplers.

[0065] In a fifth example, for any one of the first to fourth examples, the switch includes one or more of: a resonant ring filter, an arrayed waveguide grating (AWG), or an echelon grating.

[0066] In a sixth example, for any of the fifth examples, the switch includes an AWG including M output waveguides optically coupled to the switch output port, and the PIC further includes a phase tuner coupled to the AWG.

[0067] In a seventh example, for any of the fifth examples, the switch includes a tunable drop ring waveguide.

[0068] In an eighth example, for any of the seventh examples, the switch includes a plurality of add ring waveguides coupled to a multi-wavelength bus waveguide, which is further coupled to a tunable drop ring waveguide.

[0069] In a ninth example, for any of the eighth examples, the switch includes a step grating coupled to the optical transmitter and the tunable drop ring waveguide.

[0070] In a tenth example, for any one of the first to ninth examples, the PIC includes: a semiconductor optical amplifier between each of the output ports and each of the optical output couplers.

[0071] In an eleventh example, for any one of the first to tenth examples, the optical emitter is a semiconductor laser emitter, and the switch and the optical output coupler are located on a single chip.

[0072] In a twelfth example, the semiconductor emitter is a continuous wave diode pumped laser, the plurality of center wavelengths comprises an O-band or a C-band of the electromagnetic spectrum, and the optical output coupler comprises an edge-coupled spot size converter.

[0073] In a thirteenth example, a device includes a multi-wavelength light source of a light detection and ranging (LiDAR) transmitter. The light source includes M light emitters. M is an integer not less than 2, and each light emitter is used to output at a different wavelength. The device includes an array of N optical output couplers. N is an integer not less than 2. The device includes an optical switching network, which includes M input ports and M output ports, the M input ports are optically coupled to the multi-wavelength light source, and the M output ports are optically coupled to the optical output coupler. Each of the input ports is optically coupled to each of the light emitters, and each of the output ports is optically coupled to N / M optical output couplers in the optical output coupler.

[0074] In a fourteenth example, for any one of the thirteenth examples, a switching network is used to couple each of the input ports to each of the output ports in a time division manner.

[0075] In the fifteenth example, for any one of the thirteenth to fourteenth examples, each of the output ports is optically coupled to the optical output coupler through each of the M optical beam splitters, wherein the output port of each of the optical beam splitters is optically coupled to N / M optical output couplers of the optical output couplers.

[0076] In the sixteenth example, N is an integer multiple of M for any of the items in the fifteenth example.

[0077] In the seventeenth example, for any of the sixteenth examples, N is at least 16 and N / M is at least 2.

[0078] In an eighteenth example, a multi-wavelength light detection and ranging (LIDAR) system includes one or more photon signal receiving circuits and one or more photon signal transmitting circuits. The photon signal transmitting circuit includes: a plurality of laser emitters, which are coupled to one or more optical switches through one or more first planar optical waveguides. The optical switch includes a plurality of output ports, which are used to optically couple to each of the laser emitters in a time-division manner. The photon signal transmitting circuit includes a plurality of output couplers, each of which is optically coupled to a respective switch output port in the switch output port through one or more second planar optical waveguides.

[0079] In a nineteenth example, for any of the eighteenth examples, each of the output couplers is used to simultaneously output a light beam generated by a corresponding one of the plurality of laser emitters. The laser emitters are coupled to the optical switch via one or more optical isolators.

[0080] In a twentieth example, for any of the nineteenth examples, an optical switch is used to modulate which of the output couplers are used to output light beams generated by respective ones of the laser emitters, and light emitted from each of the output couplers is frequency modulated.

[0081] It will be appreciated that the principles of the present disclosure are not limited to the embodiments described above, but instead, can be practiced with modifications and changes without departing from the scope of the appended claims. The above embodiments may include only a subset of such features, a different order of such features, a different combination of such features, and / or additional features other than those features explicitly listed. Therefore, the scope of each embodiment should be determined with reference to the appended claims together with the full scope of equivalents to which these claims are assigned.

Claims

1. One or more photonic integrated circuits (PICs), comprising: A plurality of optical transmitters for outputting a plurality of central wavelengths; a plurality of optical output couplers; as well as One or more switches optically coupled to the optical emitters, wherein the switches include a plurality of output ports, each of the output ports being optically coupled to a subset of the optical output couplers, and wherein the switches are used to optically couple each of the optical emitters to each of the output ports in a time division manner.

2. The PIC of claim 1, further comprising: An optical beam splitter is between the output port and the optical output coupler.

3. The PIC of claim 2, wherein: The plurality of light emitters include M light emitters; The plurality of optical output couplers comprises N optical output couplers; Each of the optical beam splitters has a splitting ratio of 1xN / M; and The switch optically couples each of the M optical emitters to each of the N optical output couplers.

4. The PIC according to claim 3, wherein: Respective ones of the output ports are optically coupled to the optical output couplers through respective ones of the M optical beam splitters, wherein the output port of each of the optical beam splitters is optically coupled to N / M ones of the optical output couplers.

5. The PIC according to any one of claims 1 to 4, wherein: The switch includes one or more of the following: a resonant ring filter, an arrayed waveguide grating AWG, or an echelon grating.

6. The PIC of claim 5, wherein: The switch includes the AWG; The AWG comprises M output waveguides optically coupled to the output port; and The PIC also includes a phase tuner coupled to the AWG.

7. The PIC according to claim 5, wherein: The switch includes a tunable discard ring waveguide.

8. The PIC according to claim 7, wherein: The switch includes a plurality of add ring waveguides coupled to a multi-wavelength bus waveguide, which is further coupled to the tunable drop ring waveguide.

9. The PIC according to claim 8, wherein: The switch includes an echelon grating coupled to the optical transmitter and the tunable discard ring waveguide.

10. A PIC as claimed in any one of claims 1 to 4, comprising a semiconductor optical amplifier between each of the output ports and each of the optical output couplers.

11. The PIC according to any one of claims 1 to 4, wherein: The optical transmitter is a semiconductor laser transmitter, and the switch and the optical output coupler are located on a single chip.

12. The PIC according to any one of claims 1 to 4, wherein: The optical transmitter is a continuous wave diode pumped laser; The plurality of center wavelengths include an O-band or a C-band of the electromagnetic spectrum; and The optical output coupler comprises an edge-coupled spot size converter.

13. A device, comprising: A multi-wavelength light source for a light detection and ranging LiDAR transmitter, the multi-wavelength light source comprising M light emitters, wherein M is an integer not less than 2, and wherein each of the light emitters is configured to output at a different wavelength; An array of N optical output couplers, wherein N is an integer not less than 2; as well as An optical switching network, the optical switching network comprising M input ports and M output ports, the M input ports being optically coupled to the multi-wavelength light source, the M output ports being optically coupled to optical output couplers, wherein each of the input ports is optically coupled to each of the optical emitters, and each of the output ports is optically coupled to N / M optical output couplers.

14. The device of claim 13, wherein: The optical switching network is used to couple each of the input ports to each of the output ports in a time division manner.

15. The device of claim 13, wherein: The respective ones of the output ports are optically coupled to the optical output couplers through respective ones of the M optical beam splitters, wherein the output port of each of the optical beam splitters is optically coupled to N / M ones of the optical output couplers.

16. The device of claim 15, wherein: N is an integer multiple of M.

17. The device of claim 16, wherein: N is at least 16, and N / M is at least 2.

18. A multi-wavelength light detection and ranging LIDAR system comprising: one or more photon signal receiving circuits; as well as One or more photon signal transmission circuits, wherein the photon signal transmission circuits include: a plurality of laser emitters coupled to one or more optical switches via one or more first planar optical waveguides, wherein the optical switch comprises a plurality of output ports for optically coupling to each of the laser emitters in a time-division manner; as well as A plurality of output couplers, each of the output couplers being optically coupled to a respective one of the output ports through one or more second planar optical waveguides.

19. The system of claim 18, wherein: Each of the output couplers is used to simultaneously output a light beam generated by a corresponding one of the plurality of laser emitters, and wherein the laser emitters are coupled to the optical switch via one or more optical isolators.

20. The system of claim 19, wherein: The optical switch is used to modulate which of the output couplers are used to output light beams generated by respective ones of the laser emitters, and light emitted from each of the output couplers is frequency modulated.

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