Reconfigurable optical components using multiple metamaterial elements

Abstract

An optical component can include a substrate. The optical component can further include metasurface elements formed on one or both sides of the substrate. At least two of the metasurface elements can have different refractive properties. The metasurface elements can be spaced a distance apart from each other on the same substrate.

Description

RECONFIGURABLE OPTICAL COMPONENTS USING MULTIPLEMETAMATERIAL ELEMENTSCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S. C. §119 of U.S. Provisional Application Serial No. 63 / 634987 filed on April 17, 2024, the content of which is relied upon and incorporated herein by reference in its entirety.FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to reconfigurable control of spatial and polarization properties of an optical or electromagnetic signal.BACKGROUND OF THE DISCLOSURE

[0003] Most optical or radio frequency (RF) components in use today have properties set at the time of manufacture. There is an ongoing effort to develop components whose properties can be reconfigured or changed dynamically so that they can improve performance across a wider range of use cases.SUMMARY

[0004] In an example, a component can include: a substrate and a plurality of metamaterial elements formed on one or both sides of the substrate. At least two metamaterial elements of the plurality can have different refractive, diffractive, or polarization properties. The plurality of metamaterial elements can be spaced a distance from others of the plurality.

[0005] In an example, a device can include a component. The component can include a substrate and a plurality of metamaterial elements formed on one or both sides of the substrate. At least two metamaterial elements of the plurality can have different refractive or polarization properties. The plurality of metamaterial elements can be spaced a distance from others of the plurality. The optical device can further include a first actuator configured to move the substrate along a first axis relative to a signal source such that a signal from the signal source passes through a selected metamaterial element of the plurality of metamaterial elements.

[0006] In an example, a method can include providing a substrate and forming a plurality of metamaterial elements on a side of the substrate. At least twometamaterial elements of the plurality of metamaterial elements can have different refractive or polarization properties. The plurality of metamaterial elements can be spaced a distance from others of the plurality. The method can include moving the substrate along a first axis relative to a signal coupling optics such that a signal from the signal source passes through a selected metamaterial element of the plurality of metamaterial elements.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 illustrates a component in accordance with some embodiments.

[0008] FIG. 2 illustrates a device in accordance with some embodiments.

[0009] FIG. 3 illustrates a second configuration of a component in accordance with some embodiments.

[0010] FIG. 4 illustrates a device in accordance with some embodiments.

[0011] FIG. 5 illustrates a third configuration of a component in accordance with some embodiments.

[0012] FIG. 6 illustrates a device in accordance with some embodiments.

[0013] FIG. 7A through 7C illustrate patterned illuminator functions according to some embodiments.

[0014] FIG. 8A through 8C illustrate lens with multiple focal lengths according to some embodiments.

[0015] FIG. 9A through 9D illustrate example reconfigurable polarization transformers having linearly polarized lasers to produce a source.

[0016] FIG. 10A through 10C illustrate reconfigurable beam deflectors / scanners having discrete deflection angles according to some embodiments.

[0017] Corresponding reference characters indicate corresponding parts throughout the several views. Elements in the drawings are not necessarily drawn to scale. The configurations shown in the drawings are merely examples and should not be construed as limiting in any manner.DETAILED DESCRIPTION

[0018] Many optical elements, such as lenses, wavelength filters, polarizers, and diffractive optical elements, have fixed functional properties once they are fabricated. There are many applications in which it would be beneficial to change some aspect of the optical system in response to the conditions under which the component is being used. For example, it may be desirable to change the focal length of a lens, or to modify the scale factor of illumination patterns tomatch the optical properties of the needs of a particular use and thus improve performance of the complete system. However, current approaches to provide this reconfigurability are complex or limited in function. For example, zoom lenses can allow changes in focal length but typically rely on multiple optical elements which can be bulky, expensive to manufacture and require precise location of multiple elements relative to each other. Micro-electrical mechanical system (MEMS) mirrors can be provided wherein a micro-mirror is moved to deflect light in a changeable direction, but aperture sizes are often limited to a few millimeters and range of angular deflection is often limited to a few degrees. Other known approaches to providing tunability involve heating, stretching, or deforming some optical or electromagnetic element (e.g., mirror) of an optical system. These and other available tuning methods only provide tuning over a limited range of device properties (i.e. focal length or output angle).Furthermore, as the optical component is tuned across its range of operation, the optical performance or function that the device implements may degrade across the tuning range, especially at the limits of the tuning range. For example, filter function, illumination pattern or effective aperture changes or beam may become distorted.

[0019] Components and devices according to embodiments address these concerns by providing optical and radio frequency (RF) metamaterial elements or wave processing elements with compact cross sections. A metamaterial is a more general category of materials whereas a metasurface is a metamaterial that is formed only on the surface. Local metamaterials provide spatial control of optical / electromagnetic waves such as optical power to focus beams. Local metamaterials can be formed with sub-wavelength pillars or other structures whose dimensions can be modified to provide a local phase delay of the electromagnetic wave that can span a range of 0 to 2TT around an arbitrary fixed value. Other structures can also be used to achieve other design objectives such as improving throughput.

[0020] Frequency dependent transfer functions that provide filter functionality can be implemented with non-local metasurfaces. Non-local metasurfaces can be implemented with photonic crystal slabs, guided mode resonances, etc. Adding absorption to a nonlocal metasurface using a guided mode resonanceallows independent control of the spectral properties of the filter element at different wavelengths.

[0021] In embodiments, multiple optical or RF elements with different properties are fabricated and placed near each other on a single substrate. As a result, various optical parameters can be changed simply by changing the optical element through which a signal is passed. An actuator or motor can be controlled to move the substrate relative to the signals going into or out of the device. Components

[0022] FIG. 1 illustrates a component 100 in accordance with some embodiments. The component 100 can include a substrate 102 and a plurality of metasurface elements 104, 106, 108, 110, 112, 114, 116 formed on at least one side of the substrate 102. In examples, at least two metasurface elements 104, 106, 108, 110, 112, 114, 116 of can have different refractive or polarization properties from each other, and in examples all of the metasurface elements 104, 106, 108, 110, 112, 114, 116 can have a different refractive property.

[0023] The metasurface elements 104, 106, 108, 110, 112, 114, 116 can be arranged in an array along the substrate such that the elements 104, 106, 108, 110, 112, 114, 116 are all spaced a common distance from each other. The metasurface elements 104, 106, 108, 110, 112, 114, 116 can be spaced along an axis 118 in a first dimension. Other configurations are described below with respect to FIG. 3-6.

[0024] Metasurface elements can include subwavelength-spaced arrays of nanostructures. The nanostructures can control the phase, amplitude, and polarization of light with very high spatial resolution, such as less than a wavelength. In some examples, each nanostructure can have a value of birefringence and an orientation, with the values of birefringence and the orientations varying from nanostructure to nanostructure. In some examples, the metasurface elements can include multiple layers of nanostructures, so that incident light passes through a first layer of nanostructures, then passes through a second layer of nanostructures, and so forth. In some examples, two or more layers can be formed directly upon one another.

[0025] Each metasurface element 104, 106, 108, 110, 112, 114, 116 can implement an optical function. For example the metasurface elements 104, 106, 108, 110, 112, 114, 116 can provide a series of lenses with different focallengths, or structured illumination patterns with different densities or patterns. Each metasurface element 104, 106, 108, 110, 112, 114, 116 in the array 100 can implement the same function (e.g., each can provide a lens) with different parameters such as focal length. Alternatively, the elements 104, 106, 108, 110, 112, 114, 116 could implement different functions such as focusing an incident light beam, deflecting an incident light beam, etc.

[0026] The dimensions and / or geometry of the nanostructures can vary from nanostructure to nanostructure. Metasurface elements can provide multiple optical functions on a single metasurface element and can be fabricated using conventional nanofabrication techniques. For example, a top-down approach for forming a metasurface element can include growing a thin film on a substrate, coating the thin film with photoresist, using lithography to define features (using e-beam, photolithography, and / or nanoimprint techniques), etching around the features, adding cladding material, and adding an optional reflective layer (such as a metal layer) or depositing a layer of resin and using precision nanoimprint lithography for form the nanostructures. As another example, a bottom-up approach forming a metasurface element can include coating photoresist on a substrate, using lithography to define features in the photoresist, growing a thin film on the photoresist, lifting the thin film off (which can remove all but the defined features), adding a cladding material, and adding an optional reflective layer (such as a metal layer). Other suitable design and manufacturing techniques can also be used. For fabrication of metasurface elements that include multiple layers of nanostructures, either the top-down approach and / or bottom- up approach can be repeated per layer of nanostructures.

[0027] FIG. 2 illustrates a device 200 in accordance with some embodiments. The device 200 can include a component 202 like the component described above with respect to FIG. 1. Incident light 204 can be provided from the coupling optics 206 (which can accept the incoming signal from an optical fiber or a free space beam). A component housing 207, and the component housing 207 can include, for example, input fiber for optical fiber-coupled device. The signal can pass through a selected metasurface element 208 of the plurality of metasurface elements 208, 210, 212, 214, 216, 218.

[0028] The device 200 therefore provides a reconfigurable optical component using an array of metasurface wave processing elements 208, 210, 212, 214,216, 218. A beam 220 can be transmited from the device 200 for metasurface elements 208, 210, 212, 214, 216, 218 that operate in transmission. Converging functionality of a lens can be included in elements 208, 210, 212, 214, 216, 218 to direct light into a fiber without the need for additional components.

[0029] The device 200 can include an actuator 222 configured to move the substrate along a first axis 224 relative to a signal coupling optics 206. The metasurface element array (including elements 208, 210, 212, 214, 216, 218) can be translated relative to incident optical beam (or component housing thereof) to change optical component function. The actuator 222 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 202 along one or more axes. Additional configurations are described below with reference to FIGs. 3-6. In one example, the device 200 comprises a first actuator configured to move the substrate along a first axis relative to a signal source such that a signal from the signal source passes through a first metasurface element to a second metasurface element. In a further example, the first metasurface element has a first effective focal length and the second metasurface element has a second effective focal length.

[0030] FIG. 3 illustrates a second configuration of a component 300 in accordance with some embodiments. Similar to the component 100 (FIG. 1) the component 300 can include a substrate 302 and a plurality of metasurface elements arranged in an array (or other patern) of metasurface elements 302- Ithrough 302 -N implementing the same function (e.g., lens) but with different parameters such as focal length. The component 300 can include a greater number of metasurface elements 302-1 through 302-N than component 100 (FIG. 1). For example, the component 300 can include a number of rows of metasurface elements.

[0031] As shown in FIG. 4, the component 300 can also provide greater variation and options for displacement of the array. FIG. 4 illustrates a device 400 in accordance with some embodiments. The device 400 can include a component 402 like the component described above with respect to FIG. 3. Incident light 404 can be provided from the signal coupling optics 406 (which can accept the incoming signal from an optical fiber or a free space beam). A component housing 407 can be mechanically coupled to the incident beam, and the component housing 407 can include, for example, input fiber for opticalfiber-coupled device. The signal can pass through a selected metasurface element 408-1 of the plurality of metasurface elements 408-1 through 408-N.

[0032] The device 400 therefore provides a reconfigurable optical component using an array of metasurface wave processing elements 408-1 through 408-N. A beam 410 can be transmitted from the device 400 for metasurface elements 408- 1 through 408-N that operate in transmission. Converging functionality of a lens can be included in elements 408-1 through 408-N to direct light into a fiber without the need for additional components.

[0033] The device 400 can include one or more actuators 412, 414 configured to move the substrate along a first axis 416 or additional axis 418 relative (e.g., perpendicular) to the signal coupling optics 406. The metasurface element array (including elements 408-1 through 408-N) can be translated relative to incident optical beam (or component housing 407 thereof) to change optical component function. The actuator / s 412, 414 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 402 along one or more axes.

[0034] FIG. 5 illustrates a third configuration of a component 500 in accordance with some embodiments. Similar to the component 100 (FIG. 1) and component 300 (FIG. 3) the component 500 can include a substrate and a plurality of metasurface elements arranged in a circular pattern (e.g., around a circumference or part of a circumference of a circular, elliptical, oval, or other geometric shape) of metasurface elements 502-lthrough 502-N implementing the same function (e.g., lens) but with different parameters such as focal length.

[0035] As shown in FIG. 6, the component 500 can provide different variations for displacement of the array. FIG. 6 illustrates a device 600 in accordance with some embodiments. The device 600 can include a component 602 like the component described above with respect to FIG. 5. Incident light 604 can be provided from the signal coupling optics 606 (which can accept light from an optical fiber or a free space beam). A component housing 607 can be mechanically coupled to the incident beam, and the component housing 607 can include, for example, input fiber for optical fiber-coupled device. The signal can pass through a selected metasurface element 608-1 of the plurality of metasurface elements 608-1 through 608-N.

[0036] The device 600 therefore provides a reconfigurable optical component using an array of metasurface wave processing elements 608-1 through 608-N. A beam 610 can be transmitted from the device 600 for metasurface elements 608- 1 through 608-N that operate in transmission. Converging functionality of a lens can be included in elements 608-1 through 608-N to direct light into a fiber without the need for additional components.

[0037] The device 600 can include at least one actuator 610 configured to rotate the substrate relative to incident optical beam (or component housing 407 thereof) to change optical component function. The actuator 610 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 602. In some examples, while the device 600 may take up more space in a system compared to devices 200 and 400, actuators for the device 600 may be relatively simple and require fewer components than for devices 200 and 400.

[0038] Different devices and functions can be provided using any of the configurations described above with reference to FIG. 1-6. Some functionalities and devices can include a patterned illuminator with variable spacing or shape of illumination bands (as shown in FIG. 7A-7C) so that the illumination patterned can be scaled to match objects of different sizes or at different distances from the optical system. Functionalities can include a lens with multiple focal lengths (as shown in FIG. 8A-8C). Functionalities can include a polarization controller (FIG. 9A-9D) . Functionalities can further include a discrete beam deflector with discrete positions and cascading to increase resolution (FIG. 10A-10C). The functionalities listed here are only examples and other functions can be provided with devices and metasurface elements described herein. In some devices, a combination of two or more functionalities can be provided.Structured illumination using components of FIGs. 1-6

[0039] Patterned light is used for a numerous applications including 3D sensing in augmented reality systems or mobile phones. Structured illumination, in which the light illuminating an object of interest is spatially modulated, is used in microscopy and inspection systems to increase the resolution (or equivalently the range of spatial frequencies) at which an illumination system can detect an object. In microscopy applications, a system excites the sample under study with a known spatially structured pattern of light and performs mathematical processing on interference patterns that are generated by the sample. Inspectionsystems similarly can receive reflections to detect shape of objects inspected, often down to the nanostructure level. In many applications, multiple illumination patterns may be needed but available systems provide fixed diffractive elements for spatially modulating the output of a relatively unform source (e.g., a laser). Furthermore, when sensing a 3D environment by imaging a projected pattern of light, the \ density of features needed varies with distance between source and object and accordingly illumination patterns should be maintained at various distances based on the object of interest size, distance from sensor, etc.

[0040] Systems according to embodiments address these and other concerns by providing systems that can efficiently generate different and selectable illumination patterns. FIG. 7A through 7C illustrate patterned illuminator functions according to some embodiments. Devices according to embodiments provide a reconfigurable source of illumination that varies spatially in amplitude / intensity, phase, or polarization. Systems shown in FIG. 7A through 7C each provide a series of metasurface elements which add different patterns of spatial variability to the amplitude, phase, or polarization of the light emitted by a source. The illumination pattern provided by the source is changed by moving the metasurface element array relative to the illumination source to be able to select the desired metasurface element.

[0041] For example, referring to FIG. 7A, a component 700 is provided that is similar to component 202 described above with respect to FIG. 2. Incident light 702 can be provided from the coupling optics 704 (which can accept signals from optical fiber or a free space beam). The signal can pass through a selected metasurface element 706 of the plurality of metasurface elements 706, 708, 710, 712, 714, 716, 718. A wide-angle illumination pattern 720 can be provided by the selected metasurface element 706 to cover a large object 722. The device 700 therefore provides a reconfigurable optical component using an array of metasurface wave processing elements 706, 708, 710, 712, 714, 716, 718.

[0042] The device 700 can include an actuator 724 configured to move the substrate along an axis relative to the signal source 704. The metasurface element array (including elements 706, 708, 710, 712, 714, 716, 718) can be translated relative to incident optical beam (or component housing thereof) to change optical component function. The actuator 724 can comprise a steppermotor, MEMs flexure drive, or other component capable of moving the element 700 along one or more axes.

[0043] As seen in FIG. 7B, a closer or smaller object 726 can be provided with a denser illumination pattern 728 by selection of a different element 710.Similarly, as seen in FIG. 7C, an even narrower angle illumination pattern 730 can provide a denseer field of illumination to cover nearby objects 732 a closer or smaller object 726 can be provided with a different illumination pattern 728 by selection of a different element 710. Other illumination patterns or densities can be provided by controlling the actuator 724 to change which element 706, 708, 710, 712, 714, 716, 718 is selected to receive input signals from the source 704. While seven elements 706, 708, 710, 712, 714, 716, 718 are shown any number of elements can be provided in any configuration (e.g., round (FIG. 6) or multi -row (FIG. 4) by way of example).

[0044] As can be seen by the examples given in FIG. 7A-7C, systems according to embodiments provide structured (spatially varying) illumination whose pattern can be changed to maintain system performance over a range of conditions (e.g., a 3D sensor can provide accurate sensing of any size object at varying depths or distances form the sensor). Further, multiple illumination patterns can be provided simultaneously or sequentially to provide additional information about an object of interest that may be of different size (e.g., the car 722, cat 726 or cup 732) or a similarly sized object further away. Furthermore, costs and complexity can be reduced by providing a single apparatus or device comprised of multiple metasurface elements 706, 708, 710, 712, 714, 716, 718.

[0045] Lens with multiple focal lengths provided using components of FIGs. 1-6

[0046] A component that functions as a lens with selectable focal length could be used in various applications, such as camera or machine vision systems that are used to view objects at different distances. Some techniques in use today for providing tuning or changing of a lens focal length include liquid crystal lenses, or other types of liquid lenses. These approaches provide continuous tunability, but typically use a continuous actuation mechanism (e.g., electrical voltage), a continuous control system that can drive the actuator and, in many cases, require the addition of sensing and feedback mechanisms by which the state of the lens can be monitored against a target focal length or a more easily measured physical parameter that serves as a surrogate for the focal length. This addscomplexity to the system. In addition, any residual error in adjusting the focal length of the lens results in an error in the resulting focal length and this error may be difficult to predict in advance.

[0047] Systems according to embodiments improve upon this tunable lens technology by eliminating the continuously variable actuation mechanism and the control system used in continuously tunable lenses. Systems according to embodiments provide a plurality of lenses, each with multiple focal points and manufactured using components described above with reference to FIG. 1-6. In this case, reconfiguring the focal length of the lens requires moving the metasurface element array relative to the optical beam. This operation can be designed to have relaxed mechanical tolerances by selecting the beam and filter element sizes to be compatible with the mechanical precision of the actuation mechanism.

[0048] By integrating multiple lens elements in a single device and providing for selection of an appropriate lens from the multiple lens elements, optical properties can be maintained in the lens because shape and other parameters of the lenses are left unchanged. In contrast, tuning mechanisms currently available may change a liquid lens shape, which can eventually degrade the lens. For example, if a lens is nominally spherical, revising the lens may eventually cause the lens to lose its ideal spherical surface. This tends to be more pronounced for large relative changes in focal length. By selecting the discrete focal lengths available, the focus error resulting from only having a discrete set of filter elements can be offset by improved performance of each of the lens elements.

[0049] FIGs. 8A through 8C illustrate lens with multiple focal lengths according to some embodiments. Devices according to embodiments provide a reconfigurable lens focal length by providing different metasurface elements that have different effective focal lengths allowing images to be in focus or approximately in focus at varying distances. The lens focal length pattern provided by the source is changed by moving the metasurface element relative to the illumination source.

[0050] For example, referring to FIG. 8A, a component 800 is provided that is similar to component 202 described above with respect to FIG. 2. Incident light 802 can be provided from the source 804 (which can include optical fiber or afree space beam). The signal can pass through a selected metasurface element 806 of the plurality of metasurface elements 806, 808, 810, 812, 814, 816, 818.

[0051] The different metasurface elements 806, 808, 810, 812, 814, 816, 818 can provide respective different effective focal lengths allowing images to be in focus at a range of distances. For example, by selecting metasurface element 806, a focal length 820 can be provided by the lens corresponding to metasurface element 806 to provide focus at a range that includes object 822. The device 800 therefore provides a reconfigurable lens by providing an array of metasurface lens that provide different focal lengths.

[0052] The device 800 can include an actuator 824 configured to move the substrate along an axis relative to the signal source 804. The metasurface element array (including elements 806, 808, 810, 812, 814, 816, 818) can be translated relative to incident optical beam (or component housing thereof) to change the optical component function. The actuator 824 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 700 along one or more axes.

[0053] As seen in FIG. 8B, a closer object 826 can be focused on using a different focal length 828 using metalens 808. Similarly, as seen in FIG. 8C, a closer object 830 can be focused on using a different focal length 832 using metalens 810. Other focal length (and metalens) selections can be provided by controlling the actuator 824 to change which element 806, 808, 810, 812, 814, 816, 818 is selected to receive input signals from the source 804. While seven elements 806, 808, 810, 812, 814, 816, 818 are shown any number of elements can be provided in any configuration (e.g., round (FIG. 6) or multi-row (FIG. 4) by way of example).

[0054] As can be seen by the examples given in FIG. 8A-8C, systems according to embodiments provide varying lens focal lengths that can be changed to maintain system performance over a range of conditions (e.g., focusing on any size object at varying distances form the sensor). Furthermore, costs and complexity can be reduced by providing a single apparatus or device comprised of multiple metasurface elements 806, 808, 810, 812, 814, 816, 818.Polarization controller using components of FIGs. 1-6

[0055] Optical components to manipulate the polarization of light are generally expensive. Furthermore, implementing an arbitrary transformation from an input(polarized) state to any output state may require at least two optical elements with an angular orientation to be controlled to provide a given polarization. For example, an arbitrary polarization transformation can be implemented with a quarter wave plate and a half wave plate but the polarization would require specific orientation of the plate axes.

[0056] In some applications, a finite number of discrete polarization transformations may be required, and a full continuum of polarizations may not be necessary. For example, a source may be needed that provides one of several linearly polarized outputs including a horizontally polarized polarization, a vertically polarized polarization, and a finite number of intermediate linear polarizations. By way of additional example, a source may be required that can alternate between right and left circularly polarized output. Systems according to embodiments can provide a finite number of polarizations by providing a corresponding number of metasurfaces similar to those described above with reference to FIGs. 1-6.

[0057] Additionally, if more complex polarization transformations are needed, systems according to embodiments can provide cascaded discrete polarization transformation components. Any number of cascaded elements can be provided to generate polarization to meet any desired precision requirements.

[0058] FIG. 9A through 9D illustrate example reconfigurable polarization transformers having linearly polarized lasers to produce a source. Outputs 900, 902, 904, 906 include a discrete set of output linear polarizations. Arrays 908, 910, 912, 914 of metasurfaces 916, 918, 920, 922, 924, 926, 928 provide together allow a set of different polarization transformations to convert light from signal input optics 930 into desired output states, e.g., a mix of linear, circular of elliptical states. Metasurface elements 916, 918, 920, 922, 924, 926, 928 may also include optical focusing power to e.g., collimate a beam into the output waveguide.

[0059] Incident light 932 can be provided from the signal coupling optics 930 (which can include optical fiber or a free space beam). The signal can pass through a selected metasurface element 916, 918, 920, 922, 924, 926, 928. Polarization state 934, 936, 938, 940 can be provided by the selected metasurface element. The device 700 therefore provides a reconfigurable opticalcomponent using an array of metasurface wave processing elements 916, 918, 920, 922, 924, 926, 928.

[0060] An actuator 942 can move the substrate along an axis relative to the signal source 930. The metasurface element array (including elements 916, 918, 920, 922, 924, 926, 928) can be translated relative to incident optical beam (or component housing thereof) to change optical component function. The actuator 942 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 908, 910, 912, 914 along one or more axes.

[0061] As can be seen by the examples given in FIG. 9A-9D, systems according to embodiments can provide simplified actuation and control compared to polarization control using conventional polarization optics, waveplates with continuous alignment. Continuous tuning devices can be ‘open loop’ control in which the polarization transformation of the device is determined by the state of the actuator, which must have sufficient precision and repeatability to deliver the required polarization transformation over the life of the device. Alternatively, ‘closed loop’ control can be used where the output state of the light or the transformation provided by the system is measured and the control system works to minimize the difference between the target and the current value. Both of these approaches can be expense. Precision can be increased or enhanced in the current disclosure because the output polarization depends on the optical elements and is not affected by positioning errors relative to the target position as could be the case with waveplates. Systems according to embodiments can also provide desired controllable polarization in a reduced space because metasurface elements 916, 918, 920, 922, 924, 926, 928 can be manufactured to have a small cross section to match beam size of input beams used in a particular application.Reconfigurable beam deflector / scanner using components of FIGs. 1-6

[0062] Rotating or pivoting flat or polygon mirrors are frequently used to scan optical beams. Rotating mirror scanners can deflect an input beam according to a controllable scheme to provide control of the output beam at any defined angle. However, this control can rely upon precise angular actuation, and / or sensors or other devices that can accurately sense the output angle (or a surrogate such as the mirror position) and provide feedback to the controller.

[0063] Systems according to embodiments address these and other concerns by providing discrete angle beam deflectors. For example, metasurfaces can each provide discrete angle beam deflectors that can be controllably selected similarly to the other systems described above with respect to FIGs. 1-6.

[0064] FIG. 10A through 10C illustrate reconfigurable beam deflectors / scanners having discrete deflection angles according to some embodiments. Devices 1000 shown in FIG. 10- 10C provide a reconfigurable beam deflector wherein a series of metasurface elements 1002, 1004, 1006, 1008, 1010, 1012, 1014 deflect the incoming beam 1016 by different amounts. A lens function can be included in each of the elements to collimate a diverging beam. Alternatively, the deflector could include additional optical power to focus the beam in output space or the device 1000 could include no optical power.

[0065] Referring to FIG. 10A, a component 1000 is provided that is similar to component 202 described above with respect to FIG. 2. Incident light 1016 can be provided from the source 1018 (which can include optical fiber or a free space beam). The signal can pass through a selected metasurface element 1002 of the plurality of metasurface elements 1002, 1004, 1006, 1008, 1010, 1012, 1014. Deflection can be provided at output 1020 based on the varying metasurface. For example, a metasurface m the selected element 1002 can by nanopdlars of different diameters that bend the input light 1016 in different directions. This metasurface beam deflector can generate random points simultaneously and has potential to make beam steering by switching each pixel of the beam deflector, winch can be applied on motion detection, facial recognition, and light detection and ranging. The device 1000 therefore provides a reconfigurable optical component using an array of metasurface wave processing elements 1002, 1004, 1006, 1008, 1010, 1012, 1014.

[0066] The device 1000 can include an actuator 1022 configured to move the substrate along an axis relative to the signal source 1018. The metasurface element array (including elements 1002, 1004, 1006, 1008, 1010, 1012, 1014) can be translated relative to incident optical beam (or component housing thereof) to change optical component function. The actuator 1022 can comprise a stepper motor, MEMs flexure drive, or other component capable of moving the element 1000 along one or more axes.

[0067] As can be seen by the examples given in FIG. 10A-10C, systems according to embodiments provide beam deflection at angles depending on the metasurfaces provided in the selected metasurface element 1002, 1004, 1006, 1008, 1010, 1012, 1014. Further, when reconfiguring the device 1000, it is only necessary to roughly position the desired metasurface element in the beam. Small errors in alignment do not translate into beam deflection errors. In some applications is possible to reduce the number of optical components in the broader system by incorporating optical power (lens functionality) into the beam-deflecting optical processing elements to reduce or eliminate the need for external lenses needed to collimate or otherwise adjust the output beams.

Claims

WHAT IS CLAIMED IS:

1. A component, comprising: a substrate; and a plurality of metamaterial elements formed on one or both sides of the substrate, at least two metamaterial elements of the plurality of metasurface elements having different refractive properties, the plurality of metamaterial elements spaced a distance from others of the plurality.

2. The component of claim 1, wherein the plurality of metasurface elements are spaced along an axis in a first dimension.

3. The component of claim 1, wherein the plurality of metasurface elements are arranged in at least two rows along a first axis and wherein within each row the plurality of metasurface elements are spaced apart from each other along a second axis perpendicular to the first axis.

4. The component of claim 1, wherein the plurality of metasurface elements are arranged around a circumference of a geometric shape.

5. The component of claim 1, wherein each metasurface element includes a plurality of nanostructures.

6. The component of claim 5, wherein different refractive properties are provided using different numbers or types of nanostructures within each respective metasurface element.

7. A device comprising: a component comprising: a substrate; a plurality of metasurface elements formed on one or both sides of the substrate, at least two metasurface elements of the plurality of metasurface elements having different refractive properties, the pluralityof metasurface elements spaced a distance from others of the plurality; and a first actuator configured to move the substrate along a first axis relative to a signal source such that a signal from the signal source passes through a selected metasurface element of the plurality of metasurface elements.

8. The device of claim 7, further comprising a second actuator to move the substrate along a second axis relative to the signal source.

9. The device of claim 7, wherein the plurality of metasurface elements is configured to provide a plurality of illumination patterns.

10. The device of claim 9, wherein nanostructures within each of the plurality of metasurface elements are varied respective to others of the plurality of metasurface elements to provide a structured illumination pattern scaled to provide different spatial or angular densities.

11. The device of claim 7, wherein the plurality of metasurface elements is configured to provide a lens with multiple focal lengths.

12. The device of claim 11, wherein nanostructures within each of the plurality of metasurface elements are varied respective to others of the plurality of metasurface elements to provide different effective focal lengths.

13. The device of claim 11, wherein the first actuator a first actuator is configured to move the substrate along a first axis relative to a signal source such that a signal from the signal source passes through a first metasurface element to a second metasurface element.

14. The device of claim 13, wherein the first metasurface element has a first effective focal length and the second metasurface element has a second effective focal length.

15. The device of claim 7, wherein the plurality of metasurface elements is configured to each provide different output polarizations.

16. The device of claim 15 wherein each of the plurality of metasurfaces is configured to provide at least one of a linear output state, a circular output state or an elliptical output state.

17. The device of claim 15, wherein the actuator is configured to rotate the substrate.

18. The device of claim 7, wherein at least two metasurface elements of the plurality of metasurface elements is configured to deflect the signal source by a different amount.

19. A method comprising: providing a substrate; forming a plurality of metasurface elements on a side of the substrate, at least two metasurface elements of the plurality of metasurface elements having different refractive properties, the plurality of metasurface elements spaced a distance from others of the plurality; and moving the substrate along a first axis relative to a electromagnetic coupling optics such that light from the frequency source passes through a selected metasurface element of the plurality of metasurface elements.

20. The method of claim 19, further comprising moving the substrate along a second axis relative to the coupling optics.

21. The method of claim 19, wherein the plurality of metasurface elements is configured to provide a plurality of illumination patterns, and wherein moving the substrate provides a structured illumination pattern scaled to objects of different sizes or distances from the substrate.

22. The method of claim 19, wherein the plurality of metasurface elements is configured to provide a lens with multiple focal lengths and wherein moving the substrate provides different effective focal lengths.

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