Tunable optical apparatus with integrated electronics

Abstract

According to various embodiments, a tunable optical device includes a tunable optical metasurface on a substrate with integrated driver circuitry. In some embodiments, the tunable optical device includes a photon shielding layer for preventing optical radiation from interfering with operation of the drive circuit. In some embodiments, the tunable optical device includes diagnostic circuitry to detect and disable defective optical structures of the metasurface. In some embodiments, the tunable optical device includes an integrated heater circuit that maintains a liquid crystal of the metasurface above a minimum operating temperature. In some embodiments, the tunable optical device includes an integrated lidar sequencing controller, a steering mode sub-circuit, and a photodetector circuit.

Description

Technical Field

[0001] The present disclosure relates to optical metasurfaces, reflectors, deflectors, and antenna elements. The present disclosure also relates to integrated circuit and electrical component manufacturing technologies, including complementary metal oxide semiconductor (CMOS) technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] According to one embodiment, Figure 1 An example of a tunable liquid crystal metasurface (LCM) is shown.

[0003] According to one embodiment, Figure 2A Liquid crystal is shown between two metal tracks aligned in a first direction to provide a first refractive index in the absence of any applied voltage.

[0004] According to one embodiment, Figure 2B Liquid crystal is shown between two metal tracks aligned in a second direction to provide a second refractive index when a voltage of 5 volts is applied.

[0005] According to one embodiment, Figure 2C A graph showing the phase response of the LCM cell with respect to the applied voltage value is shown.

[0006] According to one embodiment, Figure 3A A simplified embodiment of an optical surface scattering device is shown having a two-dimensional array of pillars with adjustable refractive index material around the pillar pairs.

[0007] According to one embodiment, Figure 3B Shown is the process for Figure 3A Diagram of a two-dimensional active matrix circuit for a two-dimensional array of pillars in FIG.

[0008] According to one embodiment, Figure 4A Shown is a top view of parallel resonator tracks arranged on a planar reflector surface.

[0009] According to one embodiment, Figure 4B An optical wavefront is shown incident on a resonator track arranged on a planar reflector surface.

[0010] According to one embodiment, Figure 5A Shown is a top view of parallel resonator tracks arranged on a cross-back plane reflector.

[0011] According to one embodiment, Figure 5B An optical wavefront incident on the resonator track and parallel to the crossed backplane reflector is shown.

[0012] According to one embodiment, Figure 5C Shown with Figure 5A Top view of a similar arrangement of parallel resonator tracks on a crossed backplane reflector, but rotated 90 degrees.

[0013] According to one embodiment, Figure 5D Another side view of the parallel reflector elements of a cross backplate reflector is shown.

[0014] According to one embodiment, Figure 6 A layout diagram of a portion of a tunable optical device having crossed backplate reflectors using edge wiring to connect drive circuitry integrated within a substrate is shown.

[0015] According to one embodiment, Fig. 7A A simplified block diagram of a tunable optical device is shown.

[0016] Figure 7B A simplified block diagram of another embodiment of a tunable optical device is shown.

[0017] Figure 7C A simplified block diagram of another embodiment of a tunable optical device is shown.

[0018] According to one embodiment, Fig. 8A A simplified diagram of a tunable optical device showing the driving circuit integrated within the substrate.

[0019] According to one embodiment, Figure 8B A cross section of a portion of a tunable optical device with a drive circuit integrated by a complementary metal oxide semiconductor (CMOS) process is shown.

[0020] According to another embodiment, Figure 8C Another cross-section of a portion of a tunable optical device with integrated drive circuitry and a photon shielding layer is shown.

[0021] According to another embodiment, Fig.8D Another cross-section of a portion of a tunable optical device with integrated drive circuitry and heater circuitry is shown.

[0022] According to one embodiment, Fig. 9A A tunable optical device with an integrated driver that operates to simultaneously collimate and steer a beam according to a targeted deflection pattern is shown.

[0023] According to one embodiment, Fig. 9B A tunable optical device with an integrated driver for simultaneously collimating and steering a beam according to a target beam deflection pattern is shown.

[0024] According to one embodiment, Fig. 9C A tunable optical device with an integrated driver for steering a beam according to a diverging beam deflection pattern is shown.

[0025] According to one embodiment, Fig.9D A tunable optical device with an integrated driver for steering a beam according to a converging beam deflection pattern is shown.

[0026] According to one embodiment, Fig.9E A tunable optical device with an integrated driver for steering a light beam according to two different beam modes is shown.

[0027] According to one embodiment, Fig.9F A tunable optical device with an integrated driver that operates by splitting an aperture to steer a light beam into two different directions is shown.

[0028] According to one embodiment, Figure 9G A tunable optical device with an integrated driver operative to steer a light beam into two different directions with different intensities is shown.

[0029] According to one embodiment, Fig.10 A simplified block diagram showing some functionality of one example of an integrated circuit within a substrate of a tunable optical device.

[0030] According to one embodiment, Fig.11A An example diagram of a tiled LCM is shown, where each tile includes multiple tracks.

[0031] According to one embodiment, Fig. 11B Phase response plots of positions on a tile of multiple tracks of an LCM of diffraction order 4 are shown.

[0032] According to one embodiment, Fig. 11C Another phase response diagram showing the positions on a tile of multiple tracks of the LCM of diffraction order 7.

[0033] According to one embodiment, Fig.12 An example diagram showing multiple tracks forming a single tile of a multi-tile LCM.

[0034] According to one embodiment, Fig.13An example of an integrated drive circuit with a one-dimensional passive matrix of driver channels is shown, which is used to drive each individual track of the metasurface.

[0035] According to one embodiment, Fig.14 Another example of an active-switch matrix integrated driver circuit is shown, which is used to drive individual tracks in a tile of a metasurface.

[0036] According to one embodiment, Fig.15 An example of a drive circuit with a one-dimensional matrix of passive driver channels is shown, which is used to drive each individual track of each tile in a tiled metasurface.

[0037] According to one embodiment, Fig.16 An example of a 2:1 active switch matrix integrated drive circuit is shown for driving the tiled tracks of a metasurface.

[0038] According to one embodiment, Fig.17 An example of a K:1 active switch matrix integrated drive circuit is shown for driving the tiled tracks of a metasurface.

[0039] According to one embodiment, Fig.18A An example of an active switch matrix integrated drive circuit with built-in self-test (BIST) circuit is shown.

[0040] According to another embodiment, Fig.18B Another example of an active switch matrix integrated drive circuit with a BIST circuit is shown.

[0041] According to another embodiment, Fig. 18C A third example of an active switch matrix integrated drive circuit with a BIST circuit is shown. DETAILED DESCRIPTION

[0042] Tunable optical metasurfaces can be used for beamforming, including three-dimensional beamforming, two-dimensional beam steering, and one-dimensional beam steering. The systems and methods currently described can be applied to tunable metasurfaces utilizing various architectures and designs. Typically, a metasurface includes multiple optical structures that, together with a tunable dielectric material, are operable to deflect (e.g., reflect, refract, steer, defocus, focus, converge, diverge, etc.) optical radiation within an operating bandwidth.

[0043] According to various embodiments, the tunable optical device includes a tunable optical metasurface on a substrate with an integrated drive circuit. The substrate may include, for example, one or more silicon substrate bases, silicon nitride (Si3N4), silicon dioxide (SiO2), tetraethoxysilane (TEOS), and silicon oxynitride (SiON) layers. The complementary metal oxide semiconductor (CMOS) integration process and / or metasurface formation on the substrate may also utilize various dielectrics, doped semiconductor materials, and / or conductor layers. Examples of such materials include, but are not limited to, aluminum, copper, tantalum, tungsten, and other CMOS compatible materials.

[0044] In some embodiments, the tunable optical device includes a photon shield to prevent optical radiation from disrupting the operation of the drive circuit. In some embodiments, the tunable optical device includes a diagnostic circuit for detecting and disabling defective optical structures of the metasurface. In some embodiments, the tunable optical device includes an integrated heater circuit that maintains the liquid crystal of the metasurface at or above a minimum operating temperature (e.g., a minimum threshold temperature). In some embodiments, the tunable optical device includes an integrated lidar sequencing controller, a steering mode subcircuit, and a photodetector circuit.

[0045] For example, in one embodiment, a tunable optical device includes a tunable optical metasurface formed on a substrate having a plurality of optical structures. A dielectric material having a tunable refractive index is deposited around the optical structure. In some embodiments, the tunable refractive index material can also be integrated into the optical structure as part of a structural manufacturing process. For example, through a semiconductor manufacturing process, a drive circuit is integrated into a substrate (e.g., in various substrate layers deposited on a silicon substrate base). The drive circuit integrated in the substrate selectively applies a voltage pattern to a plurality of optical structures to control the deflection of incident light radiation according to a target deflection pattern. For example, the drive circuit can implement phase and amplitude control of light radiation deflected by the optical structure of the metasurface to achieve a target phase and amplitude pattern corresponding to a target far-field light radiation pattern (e.g., a deflection pattern).

[0046] Various specific examples of tunable optical metasurfaces are described herein and depicted in the figures. For example, in one specific embodiment, the tunable optical metasurface includes an array of elongated resonator tracks arranged parallel to each other relative to a light reflector (e.g., a metal light reflective layer or a Bragg reflector). In such an embodiment, the resonator tracks can be formed of metal, doped semiconductor material, or dielectric material.

[0047] Examples of suitable metals that may be used as optical reflectors and optical structures in a metasurface include, but are not limited to, copper, aluminum, gold, silver, platinum, titanium, and chromium. In embodiments where the elongated resonator tracks are copper, the elongated resonator copper tracks may be formed, for example, using a copper damascene manufacturing process, followed by etching of the intermetallic dielectric and subsequent passivation of the copper. Examples of suitable manufacturing processes that may be applicable to the presently described systems and methods are described, for example, in U.S. Patent No. 10,968,522, issued April 6, 2021, which is hereby incorporated by reference in its entirety.

[0048] Liquid crystal or another refractive index tunable dielectric material is located in the gap or channel between adjacent resonator tracks (e.g., doped semiconductor or metal tracks). Liquid crystal is used in many of the examples provided in this disclosure. However, it will be appreciated that in many cases, alternative dielectric materials with tunable refractive index and / or combinations of different dielectric materials with tunable refractive index can be used instead of liquid crystal.

[0049] For the sake of clarity and to avoid unnecessary repetition, alternative dielectric materials are not mentioned in conjunction with each example provided herein. Nevertheless, the present disclosure expressly contemplates and encompasses the use or substitution of alternative tunable dielectric materials in each example provided herein. Examples of dielectric materials with tunable refractive indices suitable for use in the various example metasurfaces described herein include, but are not limited to, various forms and combinations of liquid crystals, electro-optic polymers, chalcogenide glasses, other phase change materials, and semiconductor materials.

[0050] In some embodiments, the optically tunable metasurface includes a two-dimensional array of posts instead of (or possibly in combination with) elongated tracks. Regardless of the exact optical structure used in the metasurface, the tunable metasurface can include liquid crystals or another index-tunable dielectric material in, around, between, and / or on the optical structure. For example, liquid crystals can fill channels between resonator tracks, fill gaps between adjacent posts, and / or form a liquid crystal layer over tracks or posts. Examples of suitable metals that can be used as optical reflectors and optical structures in metasurfaces include, but are not limited to, copper, aluminum, gold, silver, platinum, titanium, and chromium.

[0051] In various embodiments, biasing the liquid crystal in the metasurface with a voltage bias pattern changes the reflection phase and amplitude (or transmission phase) of the optical radiation. For example, in an embodiment using a reflective metasurface, biasing the liquid crystal in the metasurface with a voltage bias pattern can be used to change the reflection phase and amplitude pattern of the optical radiation reflected by the underlying reflective layer. Each different voltage pattern applied across the metasurface corresponds to a different reflection phase pattern (or transmission phase pattern in a transmission design). For a one-dimensional array of optical structures (e.g., a one-dimensional array of resonator tracks), each different reflection phase pattern corresponds to a different steering angle or radiation pattern in a single dimension. A digital or analog controller (controlling current and / or voltage), such as a metasurface driver, can apply a voltage differential bias pattern (e.g., a blazed grating pattern) to the metasurface to achieve a target beam shaping (e.g., a target beam steering angle). The term "beam shaping" is used in a broad sense herein to cover one-dimensional beam steering, two-dimensional beam steering, wavelength filtering, beam divergence, beam convergence, beam focusing, and / or controlled deflection, refraction, reflection, and any phase and amplitude control of incident optical radiation.

[0052] According to various embodiments, the drive circuit of the tunable optical device includes a one-dimensional passive matrix controller whose driver channels are integrated into the substrate to individually control each optical structure of the metasurface. In other embodiments, the optical structures of the metasurface are arranged as tiled subsets of optical structures, where each tile shares a set of common control inputs. As described in some applications incorporated herein by reference, each optical structure tile can include tens, hundreds, thousands, or millions of optical structures. Each tile can be controlled by a set of common control lines so that the number of unique control inputs of the metasurface is much less than the total number of optical structures in the metasurface. The drive circuit may include control lines or driver channels integrated into the substrate to control each individual optical structure tile.

[0053] In other embodiments, the drive circuit (e.g., a CMOS integrated drive circuit) can be embodied as an active switch matrix controller that can be switched to individually control each metal optical structure of the metasurface. For example, each control output of the active switch matrix controller can be dynamically switched to control a different control input of the metasurface. The active switch matrix controller can, for example, utilize AND gates, OR gates, multiplexer digital logic gates, inverse multiplexer digital logic gates, and / or other switching elements to dynamically address any number of individual optical structures or optical structure tiles.

[0054] In some embodiments, the metasurface may include a relatively large amount (e.g., a relatively thick layer) of liquid crystal above the optical element. In such an embodiment, a large amount of liquid crystal that is not well aligned above the metasurface may reduce the optical performance of the metasurface due to the uncontrolled rotation of the incident light polarization. In such an embodiment, a transparent electrode (e.g., an indium tin oxide (ITO) electrode layer) may be formed or otherwise positioned on the surface of a cover (e.g., a glass cover) that seals the liquid crystal around the optical element. The transparent electrode may be voltage controlled to orient the liquid crystal above the metasurface, thereby improving the optical performance of the tunable optical device. In various embodiments, the drive circuit is integrated into the substrate and is further configured to control the voltage level of the transparent electrode of such a metasurface embodiment.

[0055] In some embodiments, the tunable optical device includes an integrated photodetector circuit. For example, the integrated photodetector circuit can be integrated as part of a CMOS circuit. The integrated photodetector circuit can be used to detect defective operation of the tunable optical device and respond by providing an alarm or automatically disabling the tunable optical device and / or its metasurface. For example, the integrated photodetector circuit can detect that the metasurface does not turn correctly in response to an applied voltage pattern. In some embodiments, the integrated photodetector circuit can detect that the emission power level exceeds a threshold. The threshold can be based on a maximum safe optical power level, a maximum allowed power level, and / or a maximum authorized power level.

[0056] In some embodiments, a tunable optical device includes a tunable optical metasurface on a substrate with integrated diagnostic circuitry. The diagnostic circuitry may be integrated within the substrate (e.g., within various substrate layers deposited on a silicon substrate base), for example, via a CMOS manufacturing process. The diagnostic circuitry integrated within the substrate is used to test one or more tuning characteristics and / or one or more electrical characteristics of at least some optical structures, identify one or more optical structures as defective, and disable defective optical structures. For example, the diagnostic circuitry may test the electrical characteristics of each optical structure or group of optical structures to identify defects during factory calibration and / or in the field. Testing and disabling may be done once, at startup, periodically, or on demand.

[0057] For example, the configuration or settings of the drive circuit can be updated or otherwise modified to drive the defective optical structure using a static voltage (e.g., a zero voltage or a zero-position voltage) and / or a voltage equal to the voltage used to drive an adjacent non-deflecting optical structure, which voltage can vary during operation depending on the target deflection pattern at any given time.

[0058] In some embodiments, the integrated diagnostic circuit may include or utilize an integrated photodetector. For example, the integrated diagnostic circuit may cause a single optical structure or a subset of optical structures to deflect optical radiation according to a target deflection pattern. The integrated photodetector may be used to confirm that the expected target deflection pattern has been achieved. The integrated diagnostic circuit may detect a defective optical structure or a defective subset of optical structures based on the integrated photodetector's inability to confirm transmission of the target deflection pattern. In other embodiments, the diagnostic circuit may apply a voltage to a single track and measure its electrical characteristics to determine normal function or a defective state. For example, the diagnostic circuit may measure resistance, voltage, and / or current response to the applied voltage value.

[0059] In various embodiments, the tunable optical device includes a photon shielding layer between the tunable optical metasurface and the drive circuit and / or between the optical metasurface and the diagnostic circuit. In some embodiments, the tunable optical device may include a metasurface control circuit that includes a drive circuit and a diagnostic circuit. The photon shielding may, for example, include a metal layer (e.g., copper, aluminum, etc.) or a dielectric layer to prevent photons that are not deflected by the metasurface from contacting and potentially disrupting the operation of the drive circuit and / or the diagnostic circuit.

[0060] In embodiments where the photon shield includes a dielectric layer, the photon shield may include graphite, carbon, or other light absorbing or reflecting materials. In other embodiments, the photon shield may be embodied as a Bragg reflector. In some embodiments, the photon or optical shield may include a low-K dielectric, an organically modified silane-based dielectric, a polymer (e.g., polyimide), amorphous carbon, graphite, or other material to absorb or deflect light to prevent light from disrupting the operation of an integrated circuit, including but not limited to an integrated drive circuit of a metasurface.

[0061] In various embodiments, the tunable optical device includes a heater circuit integrated with the substrate as a supplement or part of the drive circuit and / or the diagnostic circuit. The heater circuit is used to keep the tunable refractive index material (e.g., liquid crystal) at or above the minimum threshold operating temperature. For example, the heater circuit can be implemented as part of a CMOS manufacturing process with an automatic temperature control feedback loop including a heating resistor. One or more heat distribution plates can be deposited during the CMOS manufacturing process to distribute heat more evenly and / or faster to the liquid crystal (or other tunable refractive index material). The heater circuit can include, for example, resistors and / or heat distribution plates made of titanium nitride (TiN) or tantalum nitride (TaN). In some embodiments, the heater layer can include: semiconductor materials, such as but not limited to silicon carbide (SiC) and / or aluminum nitride (AlN). The heater circuit can also include conductive materials, such as but not limited to tantalum (Ta), palladium (Pt), copper magnesium nitride (CuMnNi), graphite, amorphous carbon, graphene, molybdenum disilicide (MoSi2) or other silicides and / or various polymers.

[0062] In various embodiments, the drive circuit may include a steering mode subcircuit that stores voltage patterns corresponding to defined deflection patterns. In some embodiments, the subcircuit may store encrypted voltage patterns, while in other embodiments, the subcircuit may store unencrypted voltage patterns. In some embodiments, the subcircuit may calculate the desired voltage pattern based on a programmable algorithm based on high-level user input (e.g., a desired angle or angles). The tunable optical device may be configured to implement only stored voltage patterns to prevent or reduce the possibility of dangerous or undesirable optical deflection patterns. For example, an external input or control signal used to drive a tunable optical metasurface may be mapped to a beam steering table to look up a corresponding voltage pattern to be applied to the optical structure of the metasurface. The tunable optical device may be configured to transmit only those voltage patterns stored within the steering mode subcircuit (e.g., an encrypted beam steering table to map beam steering control inputs to specific voltage patterns to be applied to the metasurface).

[0063] In some embodiments, the tunable optical device includes a light detection and ranging (lidar) sequencing controller integrated within the substrate (e.g., via a CMOS manufacturing process, as part of an integrated drive circuit, as part of an integrated diagnostic circuit, and / or the like). The lidar sequencing controller operates to sequentially drive the tunable optical metasurface according to a defined sequence of deflection patterns for lidar detection (e.g., via a lidar detector).

[0064] In other embodiments, the tunable optical device may include integrated control circuitry associated with other intended functions and applications of the tunable optical device. For example, control circuitry may be integrated within the substrate of the tunable optical device associated with communication control, optical computing control, communication control, optical sensing control, laser drivers, and the like.

[0065] It will be appreciated that the metasurface technology described herein may be combined with or otherwise utilize previous advances in surface scattering antennas, such as those described in U.S. Patent Publication No. 2012 / 0194399, U.S. Patent Publication No. 2019 / 0285798, U.S. Patent Publication No. 2018 / 0239213, and U.S. Patent Publication No. 2018 / 0241131, which are hereby incorporated by reference in their entirety. Additional elements, applications, and features of surface scattering antennas with reference or feed waves are described in U.S. Patent Publication Nos. 2014 / 0266946, 2015 / 0318618, 2015 / 0318620, 2015 / 0380828, 2015 / 0162658, and 2015 / 0372389, all of which are hereby incorporated by reference in their entirety. Detailed descriptions of optically resonant antenna configurations and characteristic dimensions are described in U.S. Patent Applications 15 / 900,676, 15 / 900,683, 15 / 924,744, and 17 / 685,621, all of which are incorporated herein by reference in their entirety.

[0066] Throughout this disclosure, examples of transmission (or reception) embodiments are provided, but it should be understood that mutual reception (or transmission) embodiments are also contemplated. Similarly, it should be understood that the system can be used only as a transmitter, only as a receiver, as a transmitter and a receiver at the same time, with a time-multiplexed transmitter / receiver, with a frequency-multiplexed transmitter / receiver, a first metasurface acting as a transmitter and a second metasurface acting as a receiver, or another transmission / reception configuration or operation technology. Similarly, many examples are described from the perspective of modifying the reflection phase pattern of the reflective metasurface. However, it should be understood that many methods, techniques, systems, methods, and principles taught herein can also be applied to transmissive metasurfaces. Therefore, each embodiment describing a reflective metasurface should be understood to implicitly teach the corresponding embodiment using a transmissive metasurface.

[0067] In addition, many of the described metasurface embodiments are described from the perspective of controlling, adjusting, or modifying a phase pattern (e.g., a reflection phase pattern or a transmission phase pattern). However, many embodiments can be used in conjunction with metasurfaces in which optical elements are adjusted or modulated to control: (i) reflection / transmission phase, (ii) reflection / transmission amplitude, or (iii) reflection / transmission phase and reflection / transmission amplitude. Thus, any of a variety of metasurfaces for controlling the complex phase and / or complex amplitude of reflected or transmitted optical radiation can be used in any of the embodiments described herein. Thus, while specific examples are described and illustrated herein, it should be understood that the various embodiments can be modified or adjusted for alternative embodiments of optical metasurfaces and are not limited to the specifically described and illustrated examples.

[0068] The presently described embodiments support optical bandwidths and are, for example, suitable for use in optical sensing systems (e.g., LiDAR, optical communication systems, optical computing systems, optical power transmission, and displays). For example, the systems and methods described herein can configure metasurfaces (generally referred to herein as "optical") that operate in the sub-infrared, mid-infrared, high-infrared, and / or visible frequency ranges. Given the required feature sizes and antenna spacing (e.g., sub-wavelength element spacing) for sub-wavelength optical antennas, the metasurfaces can be fabricated using microlithography and / or nanolithography processes, such as those commonly used to fabricate CMOS integrated circuits.

[0069] Some infrastructures that can be used with the embodiments disclosed herein are already available, such as general-purpose computers, computer programming tools and techniques, digital storage media, and communication links. Many systems, subsystems, modules, components, etc. described herein can be implemented as hardware, firmware, and / or software. Since there are so many possible implementations, various systems, subsystems, modules, and components are described according to the functions they perform. For example, it is understood that many existing programming languages, hardware devices, frequency bands, circuits, software platforms, network infrastructures, and / or data storage devices can be used alone or in combination to implement specific control functions.

[0070] It is also understood that two or more elements, devices, systems, subsystems, parts, modules, etc. described herein can be combined into a single element, device, system, subsystem, module or part. In addition, many elements, devices, systems, subsystems, parts and modules can be duplicated or further divided into discrete elements, devices, systems, subsystems, parts or modules to perform the subtasks described herein. Any embodiment described herein can be combined with any combination of other embodiments described herein.

[0071] As used herein, a computing device, system, subsystem, module, driver, or controller may include a processor, such as a microprocessor, a microcontroller, a logic circuit, etc. The processor may include one or more special processing devices, such as an application specific integrated circuit (ASIC), a programmable array logic (PAL), a programmable logic array (PLA), a programmable logic device (PLD), a field programmable gate array (FPGA), or other customizable and / or programmable devices. The computing device may also include a machine-readable storage device, such as a non-volatile memory, a static RAM, a dynamic RAM, a ROM, a CD-ROM, a disk, a tape, a magnetic, an optical, a flash memory, or other machine-readable storage medium. Various aspects of certain embodiments may be implemented or enhanced using hardware, software, firmware, or a combination thereof.

[0072] The parts of some disclosed embodiments are described and illustrated in the drawings herein to provide specific examples. Many parts thereof can be arranged and designed with various different configurations. In addition, the features, structures and operations related to an embodiment can be applied to or combined with the features, structures or operations described in conjunction with another embodiment. In many cases, well-known structures, materials or operations are not shown or described in detail to avoid blurring the aspects of the present disclosure. The right to add any described embodiment or feature to any one figure and / or as a new figure is expressly reserved.

[0073] The embodiments of the systems and methods provided in this disclosure are not intended to limit the scope of the disclosure, but are merely representative of possible embodiments. Furthermore, the steps of the method do not necessarily need to be performed in any particular order, or even sequentially, or only once. As previously mentioned, descriptions and variations in terms of a transmitter also apply to a receiver, and vice versa.

[0074] According to one embodiment, Figure 1An example of a tunable liquid crystal metasurface (LCM) 100 is shown. The tunable LCM 100 can be used, for example, as part of a solid-state optical transmitter system, receiver system, or transceiver system. As shown, the tunable LCM 100 includes an optically reflective substrate 190 and a dielectric layer 195. A plurality of elongated tracks 191 are arranged on the optically reflective substrate 190 at subwavelength intervals and are electrically isolated by the dielectric layer 195. The elongated tracks 191 may be referred to herein as "resonator tracks" because the gaps between them (filled with liquid crystal or other dielectrics that can be tuned to adjust the refractive index) resonate within the optical operating bandwidth of the LCM. Liquid crystal or another refractive index-adjustable dielectric material 193 is located between the elongated tracks 191. A controller or metasurface driver (not shown) may apply a voltage differential bias pattern to the elongated tracks 191 to modify the reflection phase of the resonator (or the transmission phase of the resonator in a transmissive design). The combination of the phase delays imparted by all resonators produces constructive interference in the desired beam steering direction.

[0075] Additional descriptions, variations, functions, and uses of optical metasurfaces are described in the following patents: U.S. Patent No. 10,451,800, entitled "Plasmonic Surface-Scattering Elements and Metasurfaces for Optical Beam Steering," issued on October 22, 2019; U.S. Patent No. 10,665,953, entitled "Tunable Liquid Crystal Metasurfaces," issued on May 26, 2020; and U.S. Patent No. 11,092,675, entitled "Lidar Systems based on Tunable Optical Metasurfaces," issued on August 17, 2021, each of which is incorporated herein by reference in its entirety. Many of the metasurfaces described in the above U.S. patents include parallel tracks located above a two-dimensional or planar reflective surface or layer.

[0076] According to one embodiment, Figure 2A A block diagram is shown of a liquid crystal 292 between two metal tracks 291 and 293. As shown, in the absence of a voltage applied by the voltage controller 210, the liquid crystal is aligned along a first direction corresponding to a first refractive index.

[0077] According to one embodiment, Figure 2BThe block diagram shows that the liquid crystal 292 between the two metal tracks 291 and 293 is aligned in the second direction, and based on the applied voltage of 5 volts, the liquid crystal 292 produces a second refractive index.

[0078] According to one embodiment, Figure 2C A graph 250 is shown of the phase response of an LCM cell with respect to applied voltage values.

[0079] Figure 3A A simplified embodiment of an optical surface scattering device 300 is shown having one hundred and ninety-two columnar dielectric or conductive members 301-396 (only some of which are labeled to avoid obscuring the drawing). As shown, a tunable refractive index material 399 forms an enveloping layer around the column pairs 301-396, including above the columns and between the column pairs.

[0080] According to one embodiment, Figure 3B An example diagram of a two-dimensional active matrix circuit 3000 is shown, as described herein, which may be integrated in Figure 3A The tunable optical surface scattering device 300 is arranged in the substrate layer. As shown in the figure, the two-dimensional matrix control circuit is used to individually address Figure 3A Each of the tunable columnar dielectric or conductive members 301-396 is modeled in the figure as capacitors 3006AA, 3006AB, 3006AC, 3006BA, 3006BB, 3006BC, 3006CA, 3006CB, 3006CC (collectively referred to as tunable elements 3006). Each modeled tunable element 3006 is connected to a transistor 3010, such as an integrated CMOS transistor, and / or additional integrated circuit components as described herein.

[0081] In the example shown, each transistor 3010 includes a gate (labeled "G") electrically coupled to a corresponding row line 3002, a source (labeled "S") electrically coupled to a corresponding column line 3004, and a drain (labeled "D") electrically coupled to one conductor of a corresponding tunable element 3006. The opposing conductor of each tunable element 3006 is connected to ground 3008. In an active matrix addressing scheme, the row lines 3002 are digitally controlled, such as binary control "on" and "off".

[0082] Column line 3004 is controlled by an analog voltage. When row line 3002 is in the "off" state, tunable element 3006 (modeled as a capacitor) maintains the voltage for a period of time. When row line 3002 is in the "on" state, the voltage of tunable element 3006 can be changed. During operation, digital row line 3002 activates the gates of all transistors in a particular row. Column line 3004 applies an analog voltage to tunable element 306 in a particular column through the drain of transistor 3010. When row line 3002 changes the CMOS transistor in a particular row to the "off" state, tunable element 306 maintains the applied analog voltage due to the inherent capacitance of tunable element 306. In some embodiments, additional capacitive elements can be added to each control element of the integrated circuit to increase the time that the applied analog voltage is maintained.

[0083] According to one embodiment, Figure 4A Shown is a top view of parallel resonator tracks 495 (shown as white tracks) arranged on a planar reflector surface 490 of the LCM 400. In the illustrated embodiment, the optically reflective backplane is a planar reflector surface 490, such as a copper or aluminum layer.

[0084] According to one embodiment, Figure 4B An optical wavefront 425 is shown incident on a resonator track 495 disposed on a planar reflector surface 490. As shown, a dielectric layer 480 electrically isolates the resonator track 495 from the planar reflector surface 490. A controller can apply a voltage bias pattern to the resonator track 495 to obtain a target reflection pattern of the incident optical wavefront 425. With the planar reflector surface 490, electrical connections from each track (or each subset of tracks) can be established from the edge of the LCM or through insulating holes formed in the planar reflector surface 490.

[0085] According to one embodiment, Figure 5A A top view of the LCM 500 is shown, wherein parallel resonator tracks 595 are arranged on a cross backplane reflector 590 , which is formed as a plurality of optical reflective tracks extending perpendicular to the direction of the parallel resonator tracks 595 .

[0086] According to one embodiment, Figure 5BAn optical wavefront 525 is shown incident on a resonator track 595 and parallel to the cross backplane reflector 590. In the illustrated embodiment, the resonator track 595 is insulated from the underlying optical reflector by insulating layers 580, 581, and 582. The insulating layers 580, 581, and 582 can be a single insulating layer or multiple insulating layers (e.g., combined into one or two layers, rather than the three layers shown). Optical radiation incident on the LCM perpendicular to the parallel elongated optical reflectors forming the cross backplane reflector 590 is reflected in the same manner as if the optical reflective backplane were a solid layer. As described herein, the elongated optical reflectors or the spaces between the elongated optical reflectors can be used to route electrical connections between the controller and the resonator track 595.

[0087] As described herein, a plurality of through holes may be patterned in the optically transmissive dielectric insulating layers 580, 581, and 582 at locations between adjacent optical reflectors in the cross-back plane reflector 590 (e.g., for routing between the elongated optical reflectors of the cross-back plane reflector 590 and the resonator track 595). Alternatively, through holes may be patterned in the optically transmissive dielectric insulating layers 580, 581, and 582 at locations directly above the optical reflectors in the cross-back plane reflector 590 (e.g., for embodiments in which the elongated optical reflectors are used to electrically connect the controller to the resonator track 595).

[0088] As described herein, the controller can apply a voltage to each resonator track 595 through the electrical connections between the resonator tracks 595. In some embodiments, the electrical connections can include wires, traces, or other conductive elements that extend from the resonator tracks 595 through vias in the optically transmissive dielectric insulating layers 580, 581, and 582 and then to the controller (or a connected control layer or printed circuit board (PCB) layer) between adjacent elongated optical reflectors of the crossed backplane reflector.

[0089] In other embodiments, each resonator track 595 can be connected to one or more elongated optical reflectors of the cross-backplane reflector 590 through vias in the optically transmissive dielectric insulating layers 580, 581, and 582. In such embodiments, the controller can apply a voltage differential pattern to the resonator track 595 by applying corresponding voltages to the electrically connected elongated optical reflectors of the cross-backplane reflector. As described herein, the controller can selectively apply a voltage differential pattern between adjacent resonator tracks 595 to produce a corresponding reflected phase pattern for selectively steering a beam of incident optical radiation of the optical wavefront 525.

[0090] According to one embodiment, Figure 5C Shown with Figure 5ATop view of parallel resonator tracks 595 of LCM 500 similarly arranged on crossed backplane reflectors. Figure 5C The LCM500 and Figure 5A Same LCM500 as shown in the figure, but the view is rotated 90 degrees for easier visualization Figure 5D .

[0091] According to one embodiment, Figure 5D Another side view of the parallel elongated optical reflectors of the cross backplane reflector 590 is shown. As shown in the side view of the LCM500, a single "end" resonator track 595 is visible, which is electrically isolated from the elongated optical reflectors of the cross backplane reflector 590 by insulating layers 580, 581 and 582. Examples of suitable resonator tracks 595 include dielectric tracks, doped silicon tracks, metal tracks, and combinations thereof. Examples of suitable metal tracks include, but are not limited to, metal tracks of one or more of aluminum, gold, copper, silver, platinum, titanium, and chromium. Similarly, the elongated optical reflectors of the cross backplane reflector 590 may include or consist of one or more of aluminum, gold, copper, silver, platinum, titanium, and chromium. The resonator tracks 595 may be spaced apart from each other by less than half the wavelength within the operating bandwidth. Similarly, the elongated optical reflectors of the cross backplane reflector 590 may also be spaced apart from each other by less than half the wavelength within the operating bandwidth.

[0092] According to one embodiment, Figure 6 A layout diagram 600 of a portion of a tunable optical device with cross-backplane reflectors (horizontal tracks) is shown, in which edge wiring is used to connect drive circuits integrated within the substrate. As shown, the cross-backplane reflectors may include horizontal tracks 610, 620, 630, 640, and 650, each of which is connected to a plurality of reflector tracks 681-692. The tiling arrangement and edge wiring of reflector tracks using cross-backplane reflectors are described in more detail in U.S. patent application Ser. No. 17 / 685,621, filed on March 3, 2022, and entitled “Liquid Crystal Metasurfaces with Cross-Backplane Optical Reflectors,” which is hereby incorporated by reference in its entirety. As described therein, in some embodiments, in-aperture wiring may be used instead of edge wiring.

[0093] Fig. 7AA simplified block diagram of a tunable optical device 701 is shown, which includes a metasurface 719 on a substrate 710. A drive circuit 715 is integrated into the substrate 710. According to various embodiments, the substrate 710 may include a silicon substrate base layer and one or more other layers, wherein the one or more other layers are silicon nitride (Si3N4), silicon dioxide (SiO2), tetraethoxysilane (TEOS), silicon oxynitride (SiON), and / or other materials that can be used to form the metasurface 719, the drive circuit 715, vias or other electrical conductors, etc. According to various embodiments, the drive circuit is integrated into the substrate (e.g., below the metasurface or on the edge of the metasurface). For example, the drive circuit 715 and the metasurface 719 can be formed during various stages of a CMOS manufacturing process including any number of deposition, masking, and etching steps.

[0094] The metasurface 719 can be formed and configured according to any of a variety of configurations and adjustments, including any of the various embodiments described in the patent applications cited and incorporated by reference herein. Additional examples of suitable metasurfaces and manufacturing techniques are described in U.S. Patent Application No. 17 / 697,888, filed on March 17, 2022, entitled “Tunable Optical Device Configurations and Packaging,” which is hereby incorporated by reference in its entirety.

[0095] According to one embodiment, Figure 7B A simplified block diagram of another embodiment of a tunable optical device 702 is shown. The optical device 702 shown may include drivers off-chip and / or otherwise externally connected to the metasurface 719. However, the tunable optical device 702 includes diagnostic circuitry 725 integrated with the metasurface within the substrate 710. The diagnostic circuitry 725 may be configured to automatically diagnose the functionality of the metasurface 719 once after fabrication, automatically diagnose at power-up, in response to an external request to perform diagnostic tests, periodically and / or randomly according to a defined schedule.

[0096] The diagnostic circuit 725 may test electrical properties (or optical deflection properties) of at least some of the optical structures of the metasurface 719. The diagnostic circuit 725 may include, or operate in conjunction with, an integrated or external optical sensor, photodiode, or photodetector. The diagnostic circuit 725 may identify one or more defective optical structures of the metasurface (e.g., due to damage or manufacturing defects). The diagnostic circuit 725 may disable the defective optical structure. In embodiments where the defective optical structure is part of a tile of optical structures, the diagnostic circuit 725 may disable each copy of the defective optical structure in each tile, which may include disabling some commonly controlled non-defective optical structures.

[0097] The diagnostic circuit 725 can operate to increase the effective yield of manufacturing tunable optical devices. A tunable optical device including a metasurface with a sufficiently small number of defective optical structures (or a sufficiently small number of defective optical structure tilings) can be determined to be suitable for a particular application. By disabling defective optical structures, tunable optical devices do not need to be discarded due to minor manufacturing defects.

[0098] Figure 7C A simplified block diagram of another embodiment of a tunable optical device 703 is shown. Again, substrate 710 is generally described as comprising a substrate base layer and as many other semiconductor fabrication layers as necessary to form drive circuitry 704, diagnostic circuitry 725, optical shield 705, heater circuitry 718, metasurface 719, and integrated photodetector circuitry 720 therein and / or thereon.

[0099] As described herein, the drive circuit 704 can be integrated within the substrate (e.g., by any of a variety of semiconductor manufacturing processes). The drive circuit 704 integrated within the substrate 710 selectively applies a voltage pattern to a plurality of optical structures of the metasurface 719 to control the deflection of incident optical radiation according to a target deflection pattern, as described herein.

[0100] The drive circuit 704 may include a steering mode subcircuit that stores a voltage pattern corresponding to a defined deflection pattern, as described herein. In some embodiments, the voltage pattern may be encrypted. Depending on the target control level for a particular application and the configuration of the metasurface 719 (e.g., a one-dimensional track metasurface or a metasurface with a two-dimensional array of columns, a tiled metasurface, etc.), the drive circuit 704 may be embodied as a one-dimensional or two-dimensional passive or active matrix controller, as described herein. Furthermore, in some embodiments, the drive circuit 704 may include control logic to control a transparent electrode (e.g., an ITO electrode) in addition to driving the optical structure of the metasurface 719.

[0101] The integrated photodetector circuit 720 may be formed, for example, as one or more transistors, photodiodes, and / or other control circuits within the substrate 710 during a semiconductor manufacturing process used to produce other components of the tunable optical device 703. The integrated photodetector circuit 720 may be used to detect defective operation of the tunable optical device 703 and to automatically disable the tunable optical device 703 and / or its metasurface 719 (e.g., in combination with Figure 7B Additionally, or alternatively, the integrated photodetector circuit 720 can detect that the metasurface 719 is not properly turning in response to an applied voltage pattern and / or exceeding a threshold power level, as described herein.

[0102] In some embodiments, the diagnostic circuit 725, the integrated photodetector circuit 720, and the driver circuit 704 can operate together to detect defects and / or ensure safe operation by disabling individual optical structures of the metasurface 719 and / or disabling the entire tunable optical device 703. Figure 7C 704, but it will be appreciated that the integrated CMOS control circuit and the integrated photodetector circuit 720, heater circuit 718, diagnostic circuit 725, and other components of the driver circuit 704 may be combined into a single integrated circuit and / or shared circuit components.

[0103] As described herein, a photon shielding layer or optical shield 705 can be used to prevent photons from negatively impacting the integrated circuits of heater circuit 718, diagnostic circuit 725, and / or driver circuit 704. Optical shield 705 can, for example, include a metal layer (e.g., copper, aluminum, etc.) or a dielectric layer to block photons that are not deflected or otherwise turned by metasurface 719.

[0104] As described herein, the tunable optical device 703 can include a heater circuit 718 as a supplement or part of the drive circuit and / or the diagnostic circuit. The heater circuit 718 is used to maintain the tunable refractive index material (e.g., liquid crystal) of the metasurface 719 at or above a minimum threshold operating temperature.

[0105] According to one embodiment, Fig. 8A A simplified side cross-sectional view of a tunable optical device 800 is shown, wherein a drive circuit 880 is integrated within a substrate. As shown, the tunable optical device 800 includes a substrate base layer 810, on which a dielectric layer 820 is formed. A cavity 855 is etched or otherwise formed in the dielectric layer 820. In the example shown, the cavity 855 is filled with a liquid crystal or another liquid dielectric material having a tunable refractive index, such as an electro-optic polymer, a chalcogenide glass, and / or a semiconductor material.

[0106] The optical structure 850 is shown within the cavity 855 and can be embodied, for example, as an elongated track for one-dimensional beam steering or an array of posts for two-dimensional beam shaping. The optical structure 850 and the liquid crystal in the cavity 855 are elements of a metasurface located within the cavity 855 of the tunable optical device 800. The metasurface can also include a reflective layer (not shown in the figure to avoid obscuring the drawing) below the optical structure 850, such as a metal reflective layer (e.g., an aluminum or copper layer) or a Bragg reflector including multiple dielectric layers with different refractive indices. In addition, in embodiments where the reflective layer is conductive and the optical structure 850 is conductive (e.g., a metal rail or post), the metasurface can also include an insulating layer between the optical structure 850 and the reflective layer.

[0107] A transparent cover 875 (e.g., a glass cover) spans the cavity 855 and is sealed to and supported by the edge of the dielectric layer 820 surrounding the perimeter of the cavity 855. In the illustrated embodiment, the epoxy 830 seals the glass cover 875 to the dielectric layer 820 to form a sealed cavity surrounding the cavity 855 and the optical structure 850. The liquid crystal is trapped or confined within the sealed cavity. The spacer beads 835 maintain a minimum gap between the glass cover 875 and the dielectric layer 820 to prevent the glass cover 875 from over-compressing the epoxy 830 (e.g., making it too thin) and / or allowing the lower surface of the glass cover 875 to contact and potentially damage the optical structure 850.

[0108] The drive circuit 880 integrated into the substrate base layer 810 and / or the dielectric layer 820 may include, for example, metal oxide semiconductor field effect transistors, resistors, inductors, capacitors, and other digital computing and logic components. As described herein, one or more metallization layers 881 may also be integrated into the substrate base layer 810 and / or the dielectric layer 820. The metallization layer 881 may provide various interconnections between digital computing and logic components (e.g., transistors, resistors, etc.) and connections to optical structures above the integrated circuit.

[0109] In all figures, the diagrams are for illustration purposes only and are not drawn to scale, nor are they intended to represent the actual size of any element, the relative size of various elements, the actual shape of the elements, or even the number of any given element. For example, the dielectric layer 820 of the substrate and the substrate base layer 810 may each include a multilayer dielectric material. As another example, although only 11 optical structures 850 are shown in the width of the cavity 855, the cavity 855 may be on the order of tens of millimeters, while the width of the optical structure 850 may be on the order of tens of nanometers. Therefore, the actual number of optical structures 850 may be thousands, tens of thousands, hundreds of thousands, or millions. Similarly, although the width of the tunable optical device 800 may be on the order of tens of millimeters, the total thickness of the tunable optical device 800 may be only a few millimeters or less. As a final example of the limitations of the illustration, the glass cover 875 may be several millimeters thick (e.g., 0.5 to 3 millimeters thick), while the spacer beads 835 in the epoxy resin 830 may be only 1 to 10 microns thick. Accordingly, it will be understood by those skilled in the art that relative sizes, dimensions, shapes, the number of elements, etc., are exaggerated and distorted to facilitate understanding and visualization of various elements.

[0110] The driving circuit 880 may be integrated (eg, as an integrated CMOS circuit) within the substrate (eg, within the substrate base layer 810 and the dielectric layer 820). The driving circuit 880 may be implemented according to any of the various embodiments described herein.

[0111] According to one embodiment, Figure 8BA cross section of a portion of a tunable optical device 801 is shown, wherein a drive circuit 880 is integrated via a CMOS manufacturing process. As shown, the integrated drive circuit 880 can be connected to an external bonding pad 851 on the upper surface of the tunable optical device 801 via one or more conductors within a routing region 860. In some embodiments, the CMOS integrated drive circuit can be connected to the bonding pad 851 and control the input of the metasurface layer 831 via deposited conductors extending through various dielectric layers.

[0112] The cross-sectional view of the tunable optical device 801 includes one or more interconnect layers 821 (eg, including a metallization layer 881, such as a combination of Fig. 8A ) and various metasurface layers 831, including optical structures 832 within the optical aperture 856 of the tunable optical device 801. The figure includes a legend 899 of example materials that can be used for each of the layers shown. It will be appreciated that functionally equivalent and functionally similar materials can be substituted in many cases. For example, the illustrated embodiments are silicon-based and utilize various copper and aluminum elements; however, it will be appreciated that alternative metals and dielectrics can be utilized in alternative semiconductor manufacturing processes (e.g., gallium nitride (GaN) semiconductor manufacturing processes).

[0113] Figure 8C Another cross-section of a portion of a tunable optical device 802 is shown, the tunable optical device having an integrated drive circuit 880, an interconnect layer 820, a metasurface layer 831, and bonding pads 851, as shown in FIG. Figure 8B In addition, the tunable optical device 802 and Figure 8B Different from the embodiment in, it also includes a photon shielding layer or optical shield 825. The optical shield 825 can be specially deposited between the tunable optical metasurface (metasurface layer 831) and the CMOS logic driver circuit 880.

[0114] The optical shield 825 is illustrated as an aluminum layer, as shown in legend 899. However, in some embodiments, the optical shield 825 can include a variety of metal layers (e.g., copper, aluminum, silver, gold, tungsten, etc.) or dielectric layers to prevent photons that are not deflected by the metasurface from contacting and potentially disrupting the operation of the drive circuitry and / or diagnostic circuitry. In embodiments where the optical shield 825 includes a dielectric layer, the optical shield 825 can include graphite, carbon, or other light absorbing or reflective materials. In other embodiments, the optical shield 825 can be embodied as a Bragg reflector.

[0115] It is worth noting that in Figure 8B and 8C, the cross-back reflector 833 is shown in a cross-sectional view extending into and out of the page. The optical structure 832 can be embodied as a two-dimensional array of optical posts or a one-dimensional array of elongated rails (e.g., elongated metal rails). In an embodiment where the optical structure 832 is embodied as an elongated rail, the cross-back reflector 833 extends in a direction perpendicular to the direction in which the elongated rails 832 extend.

[0116] According to another embodiment, Fig.8D Another cross-section of a portion of a tunable optical device 803 having an integrated drive circuit 880 and a heater circuit 815 is shown. As shown, in an enlarged view, the drive circuit 880 can be implemented as a dedicated integrated CMOS circuit of transistors. The heater circuit 815 can be integrated with the substrate as a supplement to or as a part of the drive circuit and / or diagnostic circuit, as described herein. The heater circuit 815 operates to maintain the tunable refractive index material (e.g., liquid crystal) within the cavity 855 of the metasurface 831 above a minimum threshold operating temperature. For example, the heater circuit 815 can be implemented as part of a CMOS manufacturing process with an automatic temperature control feedback loop including a heating resistor.

[0117] One or more heat distribution plates may be deposited during the CMOS fabrication process to distribute heat more evenly and / or faster to the liquid crystal (or other tunable refractive index material) within the cavity 855 surrounding the optical structure 850 of the metasurface 831. According to various embodiments, the drive circuit 880 may also include integrated control logic to control the voltage of the transparent electrode 885 deposited on the glass cover 875 of the metasurface 831.

[0118] Figures 9A-9G Examples of beam forming, beam steering, collimation, focusing, diverging beams, etc. are shown. However, the illustrated embodiments are merely examples of possible deflection patterns. According to various embodiments, the tunable optical devices described herein may include a tunable metasurface that is steerable in two dimensions or steerable in one dimension. Drive circuits integrated within a substrate (e.g., a base layer and / or a deposited dielectric layer) may be used to achieve individual phase and amplitude control of the deflected optical radiation. In various embodiments, the drive circuits may achieve arbitrary phase and amplitude control of individual optical structures of the tunable metasurface or tiled groups of optical structures of the tunable metasurface.

[0119] In many cases, external drivers are impractical due to the extremely high voltage interconnect density required for off-chip drivers. Therefore, many implementations and control modes contemplated by the present disclosure require the use of integrated drivers, as described herein in various embodiments, because each optical structure across the metasurface must be tuned to a unique phase or amplitude level to simultaneously perform functions such as collimation and beam steering. The number of unique voltage inputs to optical devices required to achieve equivalent levels of optical functionality and control makes external drivers impractical.

[0120] According to one embodiment, Fig. 9A A tunable optical device 915 is shown, wherein the integrated drive circuit operates to collimate and / or steer (e.g., collimate and steer simultaneously) a beam via a tunable optical metasurface according to a target deflection pattern. In the illustrated embodiment, a laser source 910 is located at the center and above the optical aperture of the tunable optical device 915. Incident divergent optical radiation 911 is reflected as a steered collimated optical radiation beam (at 912) according to a target radiation pattern. The integrated drive circuit of the tunable optical device can apply a voltage pattern to a metasurface optical structure corresponding to the illustrated Mod (2π) profile 921. The applied phase pattern can be a parabolic profile Mod (2π), as shown.

[0121] According to one embodiment, Fig. 9B A tunable optical device 915 is shown, wherein the integrated drive circuit operates to steer the beam through the tunable optical metasurface according to the collimated beam deflection pattern (at 912). Similarly, the laser source 910 produces divergent optical radiation, which is incident on the metasurface at 911 and is steerably reflected as a collimated beam at 912. The integrated drive circuit of the tunable optical device can apply a voltage pattern to the metasurface optical structure corresponding to the Mod (2π) profile 922 shown. The applied phase pattern can be an offset parabolic profile Mod (2π), as shown. As shown, the tunable optical device 915 can be driven to simultaneously steer and collimate the incident optical radiation.

[0122] According to one embodiment, Fig. 9C A tunable optical device 915 is shown in which an integrated drive circuit operates to steer a beam (at 912) according to a diverging beam deflection pattern.

[0123] According to one embodiment, Fig.9D A tunable optical device 915 is shown in which an integrated drive circuit operates to steer a beam according to a converging beam deflection pattern.

[0124] According to one embodiment, Fig.9EA tunable optical device 915 is shown in which an integrated drive circuit operates to steer beams (at 912 and 913) according to two different beam patterns. Specifically, the integrated drive circuit steers a first converging beam 912 to a first direction and a second diverging beam 913 to a second direction. According to various embodiments, the integrated drive circuit can steer the first and second beams 912 and 913 in two different directions simultaneously or according to a time multiplexing operation paradigm. In embodiments where two beams are generated simultaneously, the phase pattern applied to the metasurface can be a superposition of two parabolic lens functions. Other phase patterns can be generated by iterative phase estimation algorithms (e.g., the Gerchberg-Saxton algorithm).

[0125] According to various embodiments, the tunable optical device 915 can be configured and / or controlled by an integrated driver to produce two different beam modes 912 and 913, each of which is uniquely and independently steered at different angles and shaped to diverge, collimate, or converge. Simultaneously or time multiplexed, each of the two different and independent beam modes 912 and 913 can have the same intensity or different intensities while still using the entire aperture of the tunable optical device 915.

[0126] Fig.9F A tunable optical device 915 is shown with integrated drive circuitry operating to steer a beam into two different directions by splitting the aperture at 912 and 913, according to another embodiment, using two different portions of the aperture. A first portion 967 of the aperture is used to generate a first beam 912. A second portion 968 of the aperture is used to generate a second beam 913.

[0127] According to one embodiment, Figure 9G A tunable optical device is shown with an integrated drive circuit that operates to steer a light beam into two different directions at different intensities at 912 and 913. As shown, the integrated drive circuit can steer a first light beam 912 with a first intensity (shown in darker shading) greater than a second intensity (shown in lighter shading) of a second light beam 913. In some embodiments, the drive circuit can steer the first light beam 912 into a target direction with a majority (e.g., a majority) of the power according to a target deflection pattern.

[0128] The second light beam 913 can be steered to an integrated photodetector (or an external photodetector), which can be used to confirm the intended operation of the tunable optical device. For example, the first and second light beams 912 and 913 can correspond to each other according to a known relationship, such that the steering angle, intensity and / or beam shape of the second, lower intensity light beam 913 can be used to confirm the operation and transmission of the first light beam 912.

[0129] According to one embodiment, Fig.10A simplified block diagram 1000 showing some functions of an example of an integrated circuit within a substrate of a tunable optical device. As shown, the control logic 1011 includes subsystems for checking and post-processing the voltage pattern data (e.g., by decryption, cryptographic authentication, decompression, error detection / correction, etc.) before sending it to the metasurface control subsystem 1013. The control logic 1011 also includes error handling in the event that the pattern is deemed invalid. The control logic 1011 may also implement self-test diagnostics to monitor the metasurface health.

[0130] The control logic applies the voltage differential pattern to the optical structure of the metasurface (or the optical structure tile of the metasurface) through the metasurface control subsystem 1013. According to various embodiments, the memory control subsystem 1007 controls the transfer of data from the system memory 1005 to the control logic 1011 through the local memory buffer 1009 of the driver. In some embodiments, the local memory buffer 1009 can be omitted. As described herein, the system memory 1005 can store information defining acceptable voltage patterns that can be applied to the optical structure of the metasurface by the control logic 1011 and the metasurface control subsystem 1013.

[0131] According to various embodiments, the voltage pattern can be encrypted or cryptographically signed to prevent intentional or accidental modification, which could result in the application of an unauthorized or approved voltage pattern. A user or external controller can specify a target deflection pattern to be achieved by the metasurface. The specified target deflection pattern can be matched (e.g., via a lookup table, etc.) with an encrypted or cryptographically signed voltage pattern that can be applied to the metasurface to obtain the target deflection pattern.

[0132] According to one embodiment, Fig.11A An example diagram of a tiled LCM 1150 is shown, where each tile includes multiple tracks. The simplified diagram includes three subsets or "tiles" 1151, 1152, 1153, 1154, and 1155 of reflector tracks. Any number of tiles (tens, hundreds, thousands, etc.) can be used to form the LCM, and each tile can include any number of reflector tracks. During operation, the same voltage pattern V1 to Vx can be applied to the resonator tracks of each tile 1151-1155 to obtain a target reflection pattern.

[0133] According to one embodiment, Fig. 11B A phase response graph 1110 is shown for positions on a tile of multiple tracks of an LCM having diffraction order 4. As shown, the phase response for each position along the tile varies between 0 and 2π over the distance corresponding to the selected diffraction order.

[0134] According to one embodiment, Fig. 11CAnother phase response graph 1120 is shown for a position on a tile of multiple tracks of a 7th diffraction order LCM. The higher diffraction orders result in larger phase changes over shorter distances than a 4th diffraction order LCM.

[0135] According to one embodiment, Fig.12 An example diagram of multiple resonator tracks 1295 forming a single tile 1250 of a multi-tile LCM is shown. As shown, voltages V1, V2, ... V N A period P may be applied to the resonator tracks 1295 to generate a modulation pattern that is a function of the tile size divided by the diffraction order. The tile size W is a function of the center spacing or distance d between the resonator tracks (e.g., 300 nanometers) multiplied by the total number of tracks in each tile (e.g., 10, 100, 10,000, 100,000, or more).

[0136] According to one embodiment, Fig.13 An example of an integrated drive circuit 1375 is shown having a one-dimensional passive matrix of driver channels 1390 for driving each individual track 1350 of the metasurface of the tunable optical device 1300. The driver circuit 1375 shown functions as a one-dimensional passive matrix controller, where each track 1350 in the metasurface of the tunable optical device 1300 has a separate driver channel 1390. This can also be conceptually the same as a single tiled metasurface, where all tracks of the metasurface are part of the same tile. As shown, N control outputs and associated driver channels 1390 are used to drive N tracks 1350 of the metasurface of the tunable optical device 1300, where N is an integer value.

[0137] According to one embodiment, Fig.14 Another example of an active switch matrix integrated driver circuit 1475 is shown for driving individual tracks 1450 in a tile of a metasurface of a tunable optical device 1400. The driver circuit 1475 shown functions as a one-dimensional active switch matrix controller having N / 2 control outputs and associated driver channels 1490 for driving N tracks 1450 of a metasurface of a tunable optical device 1400, where N is an integer value.

[0138] According to one embodiment, Fig.15An example of a driver circuit 1575 is shown having a one-dimensional passive matrix of driver channels 1590 for driving each individual track of each tile 1550 in a tiled metasurface of a tunable optical device 1500 having tile [t] 1510 and tile [t+1] 1520. The driver circuit 1575 is shown as a one-dimensional passive matrix controller, where the i-th track in each tile 1510 and 1520 is connected together such that the number of driver outputs or driver channels is equal to the number of tracks in each tile.

[0139] According to one embodiment, Fig.16 An example of an active switch matrix integrated driver circuit 1675 is shown for driving tiled tracks 1650 of a metasurface of a tunable optical device 1600. A simplified embodiment includes tile [t] 1610 and tile [t+1] 1620, each tile including a plurality of tiles R[0] to R[N-1], where N is any integer value. As shown, the output of the driver circuit 1675 is switched by a switch circuit 1690 to reduce the number of drive outputs while still maintaining separate control of the tracks 1650 in each tile 1610 and 1620. Again, the i-th track in each tile is connected together, so the reduction in the number of drive outputs in the driver circuit 1675 is based on the number of switch driver channels in the switch circuit 1690 to which each drive output can be switched.

[0140] In the illustrated embodiment, the switching circuit 1690 actively switches each drive output between two tracks such that the number of drive outputs D is half the number of an equivalent one-dimensional passive matrix controller. As described herein and generally applicable to the illustrated embodiment, the drive circuit operates to apply a voltage pattern to the tracks of a metasurface (tile or untile) to cause the metasurface to deflect (e.g., reflective beam steering or transmissive beam steering) incident optical radiation according to a target deflection pattern.

[0141] In embodiments where the drive circuit is embodied as a one-dimensional passive matrix controller, the drive circuit can continuously drive each track (or each corresponding track in each tile) with a voltage value that is constant for a given beam steering deflection pattern. In embodiments where the drive circuit is embodied as a two-dimensional active switch matrix controller, the applied voltage value on any single track persists through inherent capacitance until the driver reapplies bias and refreshes the track's charge. In some embodiments, capacitive elements can be used to increase the duration of the applied voltage on each track as the driver output switches between other tracks in the metasurface.

[0142] According to one embodiment, Fig.17An example of a K:1 active switch matrix integrated driver circuit 1775 is shown for driving a tiled track 1750 of a metasurface of a tunable optical device 1700. The K:1 active switch matrix integrated driver circuit may be embodied as a plurality of 1 to K multiplexers (MUXs) 1791 and 1792. The 1:K MUXs 1791 and 1792 switch each driver output between K driver channels, where K is an integer value that is an integer factor of the number of tracks N in each tile 1710 and 1720 of the metasurface of the tunable optical device 1700. Thus, the number of driver outputs D may be reduced from N in an equivalent one-dimensional passive matrix controller to N / K driver outputs, where each driver output switches between K driver channels.

[0143] According to one embodiment, Fig.18A An example of an active switch matrix integrated drive circuit 1875 is shown with built-in self-test (BIST) circuits 1881 and 1882 prior to 1:KMUX 1891 and 1892. The drive circuit 1875 drives the optical structure 1850 (e.g., elongated metal tracks) of each tile 1810 and 1820 of the metasurface of the tunable optical device 1800 as described herein. The BIST circuits 1881 and 1882 can be operated to perform the functions of the diagnostic circuits described herein. For example, the BIST circuits 1881 and 1882 can be integrated within the substrate of the tunable optical device 1800 and configured to test one or more tuning or electrical characteristics of the optical structure 1850 of the metasurface of the tunable optical device 1800. The BIST circuits 1881 and 1882 can be used to identify and disable defective optical structures and / or groups of optical structures.

[0144] In the illustrated embodiment, the BIST circuits 1881 and 1882 are located in front of the MUXs 1891 and 1892 such that the number of BIST circuits 1881 and 1882 is equal to the number of tracks N divided by the number of driver channels K, with each driver output being switched between by each 1:K MUX 1891 and 1892. Each BIST circuit may be used to test the electrical characteristics (e.g., resistance, capacitance, inductance, resonance, and / or other characteristics, such as tuning characteristics) of K tracks in each tile in the metasurface of the tunable optical device 1800. Thus, disabling an optical structure 1850 associated with one of the BIST circuits 1881 and 1882 results in disabling K times T optical structures, where T is the number of tiles 1800 in the metasurface of the tunable optical device.

[0145] Fig.18BAnother example of an active switch matrix integrated driver circuit 1875 is shown having a BIST circuit 1880 on the output of 1:KMUX 1891 and 1892. The illustrated embodiment includes N BIST circuits 1880, where N is the number of optical structures in each tile of the metasurface of the tunable optical device 1800. As described above, the BIST circuits 1880 can be used to test the tuning or electrical characteristics of the downstream optical structure 1850. The increased number of BIST circuits 1880 allows for more sophisticated testing and disabling of optical structures. Specifically, disabling an optical structure 1850 associated with one of the BIST circuits 1880 results in disabling T optical structures, where T is the number of tiles in the metasurface 1800.

[0146] Fig. 18C A third example of an active switch matrix integrated drive circuit 1875 is shown, where each individual optical structure of the metasurface of the tunable optical device 1800 has a BIST circuit 1885. The illustrated embodiment includes N times T BIST circuits 1885, where N is the number of optical structures 1850 in each tile (e.g., 1810 and 1820) of the metasurface of the tunable optical device 1800, and T is the number of tiles in the metasurface of the tunable optical device 1800. The significantly increased number of BIST circuits 1885 allows each discrete optical structure 1850 of the metasurface of the tunable optical device 1800 to be individually tested and disabled.

[0147] The present disclosure has been made with reference to various exemplary embodiments (including best mode). However, those skilled in the art will recognize that the exemplary embodiments may be changed and modified without departing from the scope of the present disclosure. Although the principles of the present disclosure have been shown in various embodiments, many modifications of structure, arrangement, ratio, elements, materials and parts may be adjusted for specific environments and / or operational requirements without departing from the principles and scope of the present disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure.

[0148] The present disclosure should be considered illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the present disclosure. Likewise, benefits, other advantages, and solutions to problems have been described above for various embodiments. However, benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more apparent should not be interpreted as key, essential, or necessary features or elements. Therefore, the present disclosure should be determined to at least cover the claims and all possible arrangements thereof.

Claims

1. A tunable optical device, comprising: substrate; Tunable metasurfaces, comprising: a set of optical structures on the substrate, and a dielectric material having a tunable refractive index around the optical structure of the metasurface; and A metasurface control circuit integrated in the substrate, the metasurface control circuit comprising: a drive circuit integrated within the substrate for selectively applying a voltage pattern to the optical structure to control the deflection of incident optical radiation according to a target deflection pattern; and A diagnostic circuit integrated into the substrate for: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

2. The tunable optical device according to claim 1, further comprising: A photon shielding layer between the tunable metasurface and the metasurface control circuit, wherein the photon shielding layer is configured to prevent optical radiation from disrupting the operation of the metasurface control circuit.

3. The tunable optical device according to claim 1 or 2, further comprising: A heater circuit is integrated into the substrate for automatically maintaining the dielectric material having the tunable refractive index above a minimum threshold temperature.

4. A tunable optical device, comprising: substrate; A tunable optical metasurface comprising: a plurality of metallic optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the plurality of metallic optical structures of the metasurface; a drive circuit integrated within the substrate for selectively applying a voltage pattern to the plurality of metallic optical structures to control the deflection of incident optical radiation according to a target deflection pattern; and Diagnostic circuitry is integrated into the substrate for identifying defective metallic optical structures by testing electrical characteristics of at least some of the metallic optical structures.

5. The tunable optical device according to claim 4, further comprising: A photon shielding layer between the tunable optical metasurface and the drive circuit, wherein the photon shielding layer is configured to prevent optical radiation from disrupting the operation of the drive circuit. The tunable optical device of claim 5 , wherein the photon shielding layer comprises a metal layer.

7. The tunable optical device of claim 5, wherein the photon shielding layer comprises a dielectric layer comprising one or more of: amorphous carbon, organically modified glass, polymer, and graphite.

8. The tunable optical device of claim 4, wherein the drive circuit comprises a steering pattern subcircuit for storing voltage patterns corresponding to defined deflection patterns.

9. The tunable optical device of claim 4, wherein the drive circuit comprises a lidar sequencing controller integrated within the substrate for sequentially driving the tunable optical metasurface according to a defined deflection pattern sequence for targeted lidar operation.

10. The tunable optical device of claim 4, 8 or 9, wherein the metallic optical structures of the metasurface are arranged in a tiled configuration with T tiles, each tile comprising N metallic optical structures, wherein the N metallic optical structures of each of the T tiles share C common control inputs, wherein N, T and C are all integer values, and Wherein the driver circuit comprises a separate driver channel for each of the C common control inputs.

11. The tunable optical device of claim 4, 8 or 9, wherein the metallic optical structures of the metasurface are arranged in a tiled configuration with T tiles, each tile comprising N metallic optical structures, wherein the N metallic optical structures spread across the T tiles share a common control input such that there are N control inputs, and The drive circuit includes an active switch matrix controller integrated within the substrate, the active switch matrix controller having D driver channels that switch between the N common control inputs shared by the N metal optical structures of each of the T tiles, wherein each driver channel switches between K metal optical structures such that N=K*D, wherein each of T, N, D and K is an integer value.

12. A tunable optical device according to claim 4, 8 or 9, wherein the driving circuit includes an active switch matrix controller integrated in the substrate, which can be switched to control the individual metal optical structures of the metasurface, so that D driver channels of the switch matrix controller are switched between N metal optical structures, wherein each driver channel is switched between K metal optical structures, so that N=K*D, where each of D, K and N is an integer value.

13. The tunable optical device of claim 4, wherein the dielectric material having the tunable refractive index comprises one or more of: a liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material.

14. A tunable optical device according to claim 4, 8 or 9, wherein the diagnostic circuit integrated within the substrate is further configured to disable at least the identified defective metallic optical structure.

15. A tunable optical device according to claim 4, 8 or 9, wherein the driving circuit integrated within the substrate is configured to control a voltage level of a transparent electrode above the metasurface.

16. The tunable optical device of claim 4, 8 or 9, further comprising: A photodetector circuit integrated within the substrate for: an operation of detecting defects in the tunable optical device, and An operation responsive to the detected defect disables the tunable optical device.

17. A tunable optical device comprising: substrate; A tunable optical metasurface comprising: a plurality of metallic optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the plurality of metallic optical structures of the metasurface; as well as a drive circuit integrated within the substrate for selectively applying a voltage pattern to the plurality of metallic optical structures to control the deflection of incident optical radiation according to a target deflection pattern, wherein the metallic optical structures of the metasurface are arranged in a tiled configuration having T tiles, each tile comprising N metallic optical structures, wherein the N metallic optical structures of each of the T tiles share C common control inputs, wherein each of N, T, and C is an integer value, Wherein the driver circuit includes a separate driver channel for each of the C common controls.

18. The tunable optical device of claim 17, wherein the plurality of metallic optical structures of the metasurface comprises a one-dimensional array of elongated metallic tracks arranged parallel to one another relative to an underlying optical reflector.

19. The tunable optical device of claim 17, wherein the plurality of metallic optical structures of the metasurface comprises a two-dimensional array of metallic pillars arranged at a sub-wavelength element pitch, wherein each of the metallic pillars extends from an underlying optical reflector.

20. The tunable optical device of claim 17, further comprising: A diagnostic circuit integrated into the substrate for: testing electrical properties of at least some of said metallic optical structures, Identify defects in metal optical structures, and At least the identified defective metal optical structure is disabled.

21. A tunable optical device comprising: substrate; Tunable metasurfaces, comprising: a set of optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the optical structure of the metasurface; as well as A diagnostic circuit integrated into the substrate for: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

22. The tunable optical device of claim 21, further comprising: A photon shielding layer between the tunable optical metasurface and the diagnostic circuit, wherein the photon shielding layer is configured to prevent optical radiation from interfering with the operation of the diagnostic circuit.

23. The tunable optical device of claim 21, wherein the optical structure of the metasurface comprises an array of one-dimensional elongated tracks arranged parallel to each other relative to an underlying optical reflector, and Each of the elongated tracks is composed of at least one of: a metal, a dielectric, and a semiconductor material.

24. The tunable optical device of claim 21, wherein the optical structure of the metasurface comprises a two-dimensional array of metal pillars arranged at a sub-wavelength element pitch, wherein each of the metal pillars extends from an underlying optical reflector.

25. The tunable optical device of claim 21 or 24, further comprising: A drive circuit is integrated into the substrate for selectively applying a voltage pattern to the optical structure to control the deflection of incident optical radiation according to a target deflection pattern.

26. (Original) A tunable optical device according to claim 25, wherein the diagnostic circuit integrated within the substrate is configured to disable the identified defective optical structure by updating the configuration of the drive circuit to apply a zero voltage difference to the disabled optical structure during operation.

27. A tunable optical device comprising: substrate; A tunable optical metasurface comprising: a plurality of optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the plurality of optical structures of the metasurface; as well as An active switch matrix driver circuit integrated within the substrate is used to selectively apply a voltage pattern to the multiple optical structures to control the deflection of incident optical radiation according to a target deflection pattern, wherein the active switch matrix driver circuit includes a plurality of driver channels, each driver channel switching between a different subset of the optical structures to allow individual control of each optical structure.

28. The tunable optical device of claim 27, wherein the active switch matrix controller comprises D driver channels to drive N optical structures, each driver channel being capable of switching between K metal optical structures such that N = K*D, wherein each of D, K and N is an integer value.

29. A tunable optical device according to claim 27 or 28, wherein the optical structure comprises a metallic optical structure.

30. A tunable optical device according to claim 27 or 28, wherein the optical structure comprises a dielectric optical structure.

31. A tunable optical device according to claim 27 or 28, wherein the plurality of optical structures of the metasurface comprises an array of one-dimensional elongated tracks arranged parallel to each other relative to an underlying optical reflector.

32. A tunable optical device according to claim 27 or 28, wherein the plurality of optical structures of the metasurface comprises a two-dimensional array of posts extending from an underlying optical reflector.

33. The tunable optical device of claim 32, wherein: The column includes one of the following: a rectangular column, a circular column, a square column and an elliptical column.

34. The tunable optical device of claim 27, further comprising: A photon shielding layer between the tunable optical metasurface and the active switch matrix drive circuit, wherein the photon shielding layer is configured to prevent optical radiation from interfering with the operation of the active switch matrix drive circuit.

35. The tunable optical device of claim 34, wherein: The photon shielding layer includes one or more of the following: a metal layer, an amorphous carbon layer, an organic modified glass layer, a polymer layer and a graphite layer.

36. The tunable optical device of claim 27, wherein: The active switch matrix drive circuit includes a steering pattern subcircuit for storing voltage patterns corresponding to defined deflection patterns.

37. The tunable optical device of claim 27, wherein the active switch matrix drive circuit comprises a lidar sequencing controller integrated within the substrate to sequentially drive the tunable optical metasurface according to a defined deflection pattern sequence for targeted lidar operation.

38. The tunable optical device of claim 27, wherein the dielectric material having a tunable refractive index comprises one or more of: a liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material.

39. The tunable optical device of claim 27, further comprising: A diagnostic circuit integrated into the substrate for: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

40. A tunable optical device comprising: substrate; A tunable optical metasurface comprising: a plurality of optical structures on the substrate, and a dielectric material having a tunable refractive index around the plurality of optical structures of the metasurface, wherein the N optical structures of the metasurface are arranged in a tiled configuration with T tiles, each tile comprising M optical structures, wherein the M optical structures in each tile share a common control input, wherein M, T and N are integer values, N=T*M; as well as An active switch matrix driver circuit integrated within the substrate is used to selectively apply a voltage pattern to the multiple optical structures to control the deflection of incident optical radiation according to a target deflection pattern, wherein the active switch matrix driver circuit includes multiple driver channels, each driver channel switching between different subsets of the tiles to allow individual control of each tile.

41. A tunable optical device according to claim 40, wherein the active switch matrix controller includes D driver channels to drive the N optical structures, each driver channel can switch between a subset K of the T tiles, such that N = K*D, where D and K are integer values.

42. A tunable optical device according to claim 40 or 41, wherein the optical structure comprises a metallic optical structure.

43. A tunable optical device according to claim 40 or 41, wherein the optical structure comprises a dielectric optical structure.

44. A tunable optical device according to claim 40 or 41, wherein each tile of the optical structure comprises a one-dimensional array of elongated tracks arranged parallel to each other relative to an underlying optical reflector.

45. A tunable optical device according to claim 40 or 41, wherein each occurrence of the optical structure comprises a two-dimensional array of posts extending from an underlying optical reflector.

46. ​​The tunable optical device of claim 45, wherein: The column includes one of the following: a rectangular column, a circular column, a square column and an elliptical column.

47. A tunable optical device according to claim 40 or 41, wherein: The dielectric material having the tunable refractive index includes one or more of the following: liquid crystal, electro-optic polymer, chalcogenide glass, and semiconductor material.

48. The tunable optical device of claim 40 or 41, further comprising: A diagnostic circuit integrated in the substrate is used to: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

49. A tunable optical device comprising: substrate; A tunable optical metasurface comprising: a plurality of metallic optical structures on a substrate, and a dielectric material having a tunable refractive index surrounding the plurality of metallic optical structures of the metasurface; and An active switch matrix driver circuit having a plurality of driver channels integrated within the substrate is used to selectively apply voltage patterns to the plurality of metallic optical structures to control the deflection of incident optical radiation according to a target deflection pattern.

50. A tunable optical device comprising: substrate; Tunable metasurfaces, comprising: a plurality of optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the plurality of optical structures of the metasurface; a drive circuit integrated within the substrate for selectively applying a voltage pattern to the plurality of optical structures to control the deflection of incident optical radiation according to a target deflection pattern; and A heater circuit is integrated into the substrate for automatically maintaining the dielectric material above a minimum threshold temperature.

51. The tunable optical device of claim 50, wherein: The drive circuit enables phase and amplitude control of optical radiation deflected by the optical structure of the metasurface to achieve a target deflection pattern corresponding to a target far-field optical radiation pattern.

52. The tunable optical device of claim 50, further comprising: A photon shielding layer is provided between the metasurface and the driving circuit, wherein the photon shielding layer is configured to prevent optical radiation from disrupting the operation of the driving circuit.

53. The tunable optical device of claim 52, wherein the photon shielding layer comprises a metal layer.

54. The tunable optical device of claim 52, wherein the photon shielding layer comprises a dielectric layer comprising one or more of: amorphous carbon, organically modified glass, a polymer, and graphite.

55. The tunable optical device of claim 50, wherein the heater circuit comprises at least one resistor, at least one heat distribution plate, and an automatic temperature control feedback loop.

56. The tunable optical device of claim 50, wherein each of the plurality of optical structures comprises at least one of: a metal, a dielectric, and a semiconductor material.

57. The tunable optical device of claim 50, wherein the plurality of optical structures of the metasurface comprises a one-dimensional array of elongated metal tracks arranged parallel to one another relative to an underlying optical reflector.

58. A tunable optical device as claimed in claim 57, wherein the elongated metal tracks comprise elongated copper tracks formed using a damascene fabrication process, followed by etching an inter-metal dielectric and then passivating the copper.

59. The tunable optical device of claim 50, wherein the plurality of optical structures of the metasurface comprises a two-dimensional array of metal pillars arranged at a subwavelength element pitch, wherein each of the metal pillars extends from an underlying optical reflector.

60. The tunable optical device of claim 50, wherein the dielectric material having the tunable refractive index comprises one or more of: a liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material.

61. The tunable optical device of claim 50, wherein the drive circuit comprises a steering pattern subcircuit for storing voltage patterns corresponding to defined deflection patterns.

62. A tunable optical device according to claim 50, wherein the drive circuit includes a lidar sequencing controller integrated into the substrate, which is used to drive the metasurface in sequence according to a defined deflection pattern sequence for targeted lidar operation.

63. The tunable optical device of claim 50, wherein the drive circuit comprises a one-dimensional passive matrix controller having drive channels integrated within the substrate for individually controlling each optical structure of the metasurface.

64. A tunable optical device according to claim 50, wherein the driving circuit includes an active switch matrix controller integrated within the substrate, and the active switch matrix controller can be switched to control the individual optical structures of the metasurface, so that D driver channels of the switch matrix controller are switched between N optical structures, wherein each driver channel is switched between K optical structures, so that N=K*D, where each of D, K and N is an integer value.

65. The tunable optical device of claim 50, wherein the optical structures of the metasurface are arranged in a tiled configuration with T tiles, each tile comprising N optical structures, wherein the N optical structures of each of the T tiles share C common control inputs, wherein N, T, and C are each integer values, and Wherein the driver circuit comprises a separate driver channel for each of the C common control inputs.

66. The tunable optical device of claim 50, wherein the optical structures of the metasurface are arranged in a tiled configuration with T tiles, each tile comprising N metallic optical structures, wherein the N metallic optical structures spread across the T tiles share a common control input such that there are N control inputs, and The drive circuit includes an active switch matrix controller integrated within the substrate, having D driver channels that switch between the N common control inputs shared by the N metal-optical structures in each of the T tiles, wherein each driver channel switches between K metal-optical structures such that N=K*D, where each of T, N, D and K is an integer value.

67. The tunable optical device of claim 50, further comprising: A diagnostic circuit integrated into the substrate for: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

68. The tunable optical device of claim 67, wherein: The diagnostic circuit integrated within the substrate is configured to disable the identified defective optical structure by updating the configuration of the driver circuit to apply a zero voltage differential to the disabled optical structure during operation.

69. The tunable optical device of claim 50, further comprising: A photodetector circuit integrated within the substrate for: an operation of detecting defects in the tunable optical device, and An operation responsive to the detected defect disables the tunable optical device.

70. A tunable optical device comprising: substrate; Tunable metasurfaces, comprising: a plurality of optical structures on the substrate, and a dielectric material having a tunable refractive index surrounding the plurality of optical structures of the metasurface; as well as A heater circuit is integrated into the substrate for automatically maintaining the dielectric material having the tunable refractive index above a minimum threshold temperature.

71. The tunable optical device of claim 70, wherein the heater circuit comprises at least one resistor, at least one heat distribution plate, and an automatic temperature control feedback loop.

72. The tunable optical device of claim 70, further comprising: A drive circuit integrated within the substrate is configured to selectively apply a voltage pattern to the plurality of optical structures to control the deflection of incident optical radiation according to a target deflection pattern.

73. A tunable optical device according to claim 72, wherein the drive circuit comprises a steering pattern subcircuit for storing voltage patterns corresponding to defined deflection patterns.

74. A tunable optical device according to claim 72, wherein the drive circuit includes a lidar sequencing controller integrated in the substrate, which is used to drive the metasurface in sequence according to a defined deflection pattern sequence for lidar detection.

75. The tunable optical device of claim 70 or 72, further comprising: A diagnostic circuit integrated into the substrate for: testing electrical characteristics of at least some of said optical structures, Identify defective optical structures, and At least the identified defective optical structure is disabled.

76. The tunable optical device of claim 75, further comprising: A photodetector circuit integrated within the substrate for: an operation of detecting defects in the tunable optical device, and An operation responsive to the detected defect disables the tunable optical device.

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