阅读说明：本技术 使用电场的电可重构的光学设备 (Electrically reconfigurable optical device using electric fields ) 是由 孙庆儿 文贞顺 瑞安·G·夸福特 于 2019-03-07 设计创作，主要内容包括：一种光学设备可以包括：电可重构的光学层,其包含至少一种相变材料,其中,所述相变材料的光学性质能通过电场重构；光学透明的顶部电极和底部电极,所述顶部电极和所述底部电极被配置为向所述电可重构的光学层施加电场,其中,所述电可重构的光学层设置在光学透明的顶部电极和底部电极之间；以及高K介电层,其设置在所述电可重构的光学层和所述底部电极之间。所述电可重构的光学层的相变材料可以包含相变镍酸盐或氧化钨。所述电可重构的光学层的相变材料可以具有钙钛矿结构。相变镍酸盐或氧化钨可以通过向所述相变材料施加电场以大于1kHz的相重构的高速在红外波长光谱处激发大于1的大折射率变化。(An optical device may include: an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material is reconfigurable by an electric field; optically transparent top and bottom electrodes configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top and bottom electrodes; and a high-K dielectric layer disposed between the electrically reconfigurable optical layer and the bottom electrode. The phase change material of the electrically reconfigurable optical layer may comprise a phase change nickelate or tungsten oxide. The phase change material of the electrically reconfigurable optical layer may have a perovskite structure. Phase-change nickelates or tungsten oxides can excite large refractive index changes of greater than 1 at infrared wavelength spectra at high speeds of phase reconstruction of greater than 1kHz by applying an electric field to the phase-change material.)

1. An electrically programmable reflector comprising:

a two-dimensional array of electrically reconfigurable optical elements comprising phase change related perovskite nickelate or tungsten oxide, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements containing phase change nickelate or tungsten oxide is changeable at infrared wavelengths.

2. The electrically programmable reflector according to claim 1, wherein the electrically reconfigurable optical elements are not mechanically movable relative to each other.

3. An electrically programmable reflector as claimed in claim 1 wherein the refractive index of the electrically reconfigurable optical element comprising the phase change related perovskite nickelate or tungsten oxide can be varied by more than 0.1.

4. An electrically programmable reflector as claimed in claim 1 wherein the refractive index of an electrically reconfigurable optical element comprising the phase change related perovskite nickelate or tungsten oxide can be varied by more than 1.

5. An electrically programmable reflector as claimed in claim 1 wherein the phase transition related perovskite nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

6. The electrically programmable reflector according to claim 1, wherein the electrically programmable reflector is configured to excite the change in refractive index of the electrically reconfigurable optical element with an applied electric field by more than 0.1.

7. The electrically programmable mirror or focusing mirror of claim 1, further comprising a high-K dielectric layer disposed proximate the electrically reconfigurable optical element.

8. The electrically programmable mirror or focusing mirror of claim 7, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

9. An optical device, comprising:

one or more electrically reconfigurable optical elements comprising a phase change nickelate or tungsten oxide, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements comprising the phase change nickelate or tungsten oxide is changeable by greater than 0.1 at infrared wavelengths.

10. The optical device of claim 9, wherein the electrically reconfigurable optical element comprising the phase change nickelate or tungsten oxide has a perovskite structure.

11. The optical device of claim 9, wherein the phase change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

12. The optical device of claim 9, wherein the optical device is configured to excite the electrically reconfigurable optical element with an applied electric field with a change in refractive index of greater than 0.1.

13. The optical device of claim 9, further comprising a high-K dielectric layer disposed proximate to the electrically reconfigurable optical element.

14. The optical device of claim 13, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, or strontium titanate.

15. An optical device, comprising:

an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material in a predetermined wavelength range is reconfigurable by an electric field;

a top electrode and a bottom electrode configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top electrode and the bottom electrode, and the top electrode is optically transparent over the range of wavelengths; and

a high-K dielectric layer disposed between the electrically reconfigurable optical layer and at least one of the top electrode and the bottom electrode.

16. The optical device of claim 15, wherein the phase change material of the electrically reconfigurable optical layer comprises a phase change nickelate or tungsten oxide.

17. The optical device of claim 16, wherein the phase change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

18. The optical device of claim 15, wherein the phase change material of the electrically reconfigurable optical layer has a perovskite structure.

19. The optical device of claim 15, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

20. The optical device of claim 16, wherein the optically transparent top electrode comprises an Ag nanowire-based material, a graphene-based material, and an ultra-thin metal film made by atomic layer deposition.

21. The optical device of claim 16, wherein the change in refractive index of the electrically phase-change material is greater than 0.1 at infrared wavelength spectra.

22. The optical device of claim 16, wherein the change in refractive index of the electrically phase-change material is greater than 1 at infrared wavelength spectra.

23. The optical apparatus of claim 16, wherein the electrically reconfigurable optical layer comprises a pixelated array of the phase change material.

24. The optical device of claim 21, wherein the optical device is configured to excite the phase change material with an applied electric field with a change in refractive index of greater than 0.1.

Technical Field

Some embodiments of the present disclosure relate to an electrically reconfigurable optical device, in particular to an electrically reconfigurable infrared optical element or pixel comprising a phase change material; the phase change material has one or more optical properties that can be continuously changed or reconfigured by application of an electric field.

Background

Reconfiguration of the optical properties of the material can achieve functional advantages in consumer products, automotive and aerospace systems. Dynamic changes in optical material properties, including absorption, diffraction, reflection and scattering, have been the subject of intense research. Various stimuli can trigger optical reconstruction of these properties, including heat, light, chemistry, and electric fields.

Optoelectronic materials can be used in reconfigurable imaging. Conventional photovoltaic materials have challenges in exciting large optical property changes in infrared wavelengths at high reconstruction speeds. For example, as shown in FIG. 1, no conventional technique can provide a refractive index change greater than 1 and a high reconstruction speed greater than 1 kHz.

By non-linear Kerr and Pockels photoelectric or electric absorption effectsThe refractive index tuning that should be done is small for free space modulation, for example, FIG. 1 shows that the change in refractive index (△ n) for the Kerr electro-optic effect (100) is less than 10^-2And the change of the refractive index of the Pockels photoelectric effect (110) is 10^-4Within the range of (1).

Although liquid crystals (120) exhibit substantial refractive index changes, such as just below 1, their application in reconfigurable imaging may be limited due to slow tuning speeds (e.g., below 10 milliseconds) and high loss in infrared wavelengths.

Based on the Drude-Lorentz model, when a large amount of free carrier charges, e.g. greater than 10, is introduced¹⁹/cm³When charge is injected into the semiconductor (130), the refractive index can be adjusted. However, as shown in FIG. 1, the refractive index variation of conventional semiconductors (e.g., Si, III-V) is limited to less than 10^-2。

With respect to these and other general considerations, the following embodiments have been described. Additionally, while relatively specific problems have been discussed, it should be understood that the embodiments should not be limited to solving the specific technical problems identified in the background.

Disclosure of Invention

The features and advantages of the present disclosure will become more fully apparent and apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings.

According to various embodiments of the present disclosure, an electrically reconfigurable optical element (e.g., a pixel) may include one or more phase change materials as electrically controllable optical materials having one or more optical properties that can be reconfigured or changed by an electric field applied to the phase change material.

According to some embodiments of the present disclosure, phase change materials, such as phase change related perovskites nickelates and tungsten oxides (WO)₃) Excitation of large optical property changes can be achieved, such as, but not limited to, refractive index changes greater than 0.1 or 1 over the wavelength range from Short Wave Infrared (SWIR) to Long Wave Infrared (LWIR) spectra. The excitation may be by, for example but not limited to, applying an electric field to the phase change materialHigh speed generation, not limited to greater than 1 kHz.

According to some embodiments of the present disclosure, an optical apparatus may include: one or more electrically reconfigurable optical elements comprising phase change related perovskite nickelates or tungsten oxides (WO)₃) Wherein one or more optical properties of the electrically reconfigurable optical element are reconfigurable by an electric field such that phase transition-related perovskite nickelate or tungsten oxide is included (WO)₃) The refractive index (n) of the electrically reconfigurable optical element of (a) may be significantly altered or modified in the infrared wavelength spectrum (such as, but not limited to △ n > 0.1), or comprise phase change related perovskite nickelates or tungsten oxides (WO)₃) The electrically reconfigurable optical element of (a) has a refractive index change in the infrared wavelength spectrum of greater than 1. The phase change nickelate comprising the electrically reconfigurable optical element may have a perovskite structure. The optical device may be configured to excite a refractive index change of the electrically reconfigurable optical element greater than 1 under an electric field of, for example, less than 0.1 MV/cm. The optical device may be configured, for example, to include phase change related perovskite nickelates or tungsten oxides in a parallel plate capacitor structure (WO)₃) Applying an electric field to inject, for example, greater than 10²¹/cm³The charge density of (2). The optical device may further include a layer of high-K dielectric material disposed proximate to the electrically reconfigurable optical element. The high-K dielectric material may have a dielectric constant greater than 1000. The high dielectric material layer may include at least one of barium strontium titanate, barium titanate, and strontium titanate.

According to some embodiments of the present disclosure, an optical apparatus may include: an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material is reconfigurable by an electric field; optically transparent top and bottom electrodes configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top and bottom electrodes; and a high-K dielectric layer disposed between the electrically reconfigurable optical layer and the bottom electrode. The phase change material of the electrically reconfigurable optical layer may comprise a phase change phasePerovskite nickelates or tungsten oxides of interest (WO)₃). The phase change material of the electrically reconfigurable optical layer may have a perovskite structure. The dielectric constant of the high-K dielectric layer may be greater than 1000. The high-K dielectric layer may include at least one of barium strontium titanate, barium titanate, and strontium titanate. The optically transparent top electrode may comprise an Ag nanowire-based material, a graphene-based material, or an ultra-thin platinum material grown by Atomic Layer Deposition (ALD). The electrically controllable phase change material may have a refractive index change of more than 1 at the infrared wavelength spectrum. The electrically reconfigurable optical layer may include a pixelated array of phase change material. The optical device may be configured to excite a change in refractive index of the phase change material of greater than 1 at an electric field of less than 0.1 MV/cm. The optical device may be configured to apply an electric field to the electrically reconfigurable optical layer to inject greater than 10²¹/cm³The charge density of (2).

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Drawings

Various embodiments according to the present disclosure will be described with reference to the accompanying drawings, in which:

fig. 1 shows a graph of refractive index change versus reconstruction speed for an optoelectronic material.

FIG. 2 shows a deposited and electron doped samarium nickelate material (SmNiO)₃Also known as SNO) versus the complex refractive index at wavelength λ.

FIG. 3 shows a schematic diagram of an electrically reconfigurable optical device according to an example embodiment of the present disclosure;

4A-4C illustrate partial top views of an electrically reconfigurable optical device according to exemplary embodiments of the present disclosure;

fig. 5 shows a graph of optical transmittance versus wavelength for a graphene-based electrode according to an exemplary embodiment of the present disclosure;

FIG. 6 shows a schematic diagram of an electrically reconfigurable infrared lens in accordance with an exemplary embodiment of the present disclosure;

FIG. 7 shows reflection phases for a 32 x 32 pixel array with F-numbers (F/D) of 4, 2, 1, and 0.5 according to an exemplary embodiment of the present disclosure; and

fig. 8 shows simulation results of lens configurations having F-numbers (F/ds) of 4, 2, 1, and 0.5 according to an exemplary embodiment of the present disclosure.

Corresponding numerals and symbols in the various drawings generally refer to corresponding parts unless otherwise indicated. The drawings are drawn to clearly illustrate relevant aspects of the embodiments and are not necessarily drawn to scale.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof. The same numbers in the drawings indicate the same components, as should be apparent from the context of use.

According to various embodiments of the present disclosure, an electrically reconfigurable optical element (e.g., an infrared optical element), such as a pixel, may include one or more phase change materials as electrically controllable optical materials having one or more optical properties that are reconfigurable or changeable by a change in an electric field applied to the phase change material. The electrically reconfigurable optical elements may not be able to move mechanically relative to each other.

Phase change materials can have widely tunable electronic structures that can accommodate various phases. For example, the phase change material may have a perovskite structure, such as, but not limited to, ABO₃Wherein "A" and "B" are two atoms of very different atomic sizesSeed element and "O" is oxygen. Related perovskite nickelates, such as but not limited to GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃And may be an example of a phase change material having an octahedral configuration. The associated perovskite nickelates exhibit phase transitions (i.e., transitions between metal and insulator, opaque and transparent, paramagnetic and antiferromagnetic) accompanied by NiO₆Structural changes in the octahedral configuration. Charge doping changes the nickel (Ni) orbital occupancy, which leads to structural changes, resulting in a reconstruction of the electronic band structure. According to the Lorentz-Lorentz relationship, structural changes in the associated perovskite nickelate may open the band gap and cause changes in dielectric polarizability and refractive index.

Large optical refractive index changes may be associated with electron doping-induced phase transitions of perovskite nickelates, which may be used to achieve intense light modulation. For example, a deposited samarium nickelate material (SmNiO)₃Also known as SNO) is electrically conductive and optically opaque, while electron doped SmNiO₃Is electrically insulating and optically transparent. In the original SmNiO₃Single electrons can introduce strong optical losses through free carrier absorption. Additional electrons can be acquired and the quadruple electron manifold is occupied by two electrons. The strong intra-orbital coulomb repulsion between two electrons can open up a band gap of up to 3eV and can substantially suppress the absorption of free carriers. In this way, SmNiO₃Can be converted to an optically transparent dielectric. Thus, the optical properties of the phase change material can be reconfigured or altered by electron doping or extraction.

Detailed examples of related perovskites are described in "New Platform for super-Broadband-Tunable Photonics" of Li, Zhaoyi et al (2016), Advanced Materials (Deerfield Beach, Fla.).28.10.1002/adma.201601204, the entire contents of which are incorporated herein by reference.

FIG. 2 shows a raw and electron-doped samarium nickelate material (SmNiO)₃Also known as SNO) versus the complex refractive index at wavelength λ. As shown in FIG. 2, SmNiO₃Shown in, for example, λ 10 ~ 15The refractive index between the two different phases (the original phase and the electron-doped phase) in the infrared wavelength range of μm has a significant variation (△ n) between 3 and 5, when for example but not limited to greater than 10²¹/cm³Can achieve a refractive index change greater than 1 at infrared wavelengths (△ n).

The level of charge injected into the phase change material and the resulting degree of refractive index change (Δ n) can be controlled by the strength of the applied electric field. Therefore, the adjustment of the refractive index of the phase change material can be continuously and reversibly performed.

Phase change and tuning of optical properties of phase change materials may be based on electron doping or extraction independent of temperature constraints. Phase change materials such as SNO and WO₃The electron doping in (140 of fig. 1) can be performed electrochemically, but their reconstitution speed is slower than 10^-2Hz, as shown in FIG. 1. However, electron doping can be performed at a high reconstruction speed by applying an electric field to the phase change material. An electric field that can control the doping level can be used to induce a doping driven phase change of the phase change nickelate. Phase-change nickelates can undergo an electric field tunable phase change and have the greatest change in optical properties near the phase change.

Thus, according to some embodiments of the present disclosure, a phase change material, such as phase change related perovskite nickelates or tungsten oxide (WO)₃) Excitation of large optical property changes can be achieved, such as, but not limited to, refractive index changes greater than 1 over the wavelength range from Short Wave Infrared (SWIR) to Long Wave Infrared (LWIR) spectra. By applying an electric field to the phase change material, excitation may occur at high speeds, such as, but not limited to, greater than 1 kHz.

Fig. 3 shows a schematic diagram of an electrically reconfigurable optical device according to an exemplary embodiment of the present disclosure. Fig. 4A-4C show partial top views of an electrically reconfigurable optical device according to exemplary embodiments of the present disclosure.

The electrically reconfigurable optical device 300 may include: one or more top electrodes 310, one or more bottom electrodes 320, an electrically controllable/reconfigurable optical layer 330 having a two-dimensional array of electrically reconfigurable optical elements, a dielectric layer 340, a controller 350, an electrically insulating layer 360, and an optional substrate 370. FIG. 4A shows a stack of layers of an electrically reconfigurable optical device 300 that includes an electrically controllable/reconfigurable optical layer 330, a dielectric layer 340, a bottom electrode 320, an electrically insulating layer 360, and a substrate 370. Fig. 4B shows a top electrode 310 disposed on the stack of layers shown in fig. 4A. As shown in fig. 4C, the electrically reconfigurable optical device 300 can also include contact pads 315 and 325 for the controller 350. For example, a first contact pad 315 may be disposed on the top electrode 310 to connect between the top electrode 310 and the controller 350. A second contact pad 325 may be disposed on the bottom electrode 320 to connect between the bottom electrode 320 and the controller 350. In the exemplary embodiment shown in fig. 4B and 4C, an opaque metal film may be used for the top electrode 310 for visual recognition.

The top electrode 310 may be disposed on or over the electrically reconfigurable optical layer 330. The top electrode 310 may be optically transparent for at least one wavelength range. The top electrode 310 may include, for example, but not limited to, a transparent conductor based on silver (Ag) nanowires, a transparent graphene-based material, or an ultra-thin metal (e.g., Pt) film grown by Atomic Layer Deposition (ALD). For example, fig. 5 shows a graph of light transmittance versus wavelength for a graphene-based electrode. As shown in FIG. 5, the graphene-based electrode has a light transmittance of greater than 95% over a wavelength range of 2-16 pm.

The bottom electrode 320 may be disposed under or below the electrically reconfigurable optical layer 330. The bottom electrode 320 may include a metal. Additionally, the bottom electrode 320 may be grounded. Fig. 4C shows an example of a contact pad 325 for the bottom electrode 320.

Electrically reconfigurable/controllable optical layer 330 may include one or more of the phase change materials described in detail above. As described above, the phase change material may have a perovskite structure, and may include, for example and without limitation, phase change nickelates, such as the related perovskite nickelates (i.e., GdNiO)₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃) And tungsten oxide (WO)₃)。

The top electrode 310 and the bottom electrode 320 may be configured to apply an electric field to the electrically reconfigurable optical layer 330. The electric field applied by electrodes 310 and 320 may change an optical property, such as the refractive index, of electrically reconfigurable optical layer 330.

A dielectric layer 340 may be disposed between the electrically reconfigurable optical layer 330 and the bottom electrode 320. The dielectric layer 340 may comprise one or more high dielectric constant, large (i.e., having a dielectric constant exceeding a value of the real part of 1000) dielectric materials. Barium strontium titanate (BST: Ba)_xSr_1-xTiO₃Such as but not limited to BaTiO₃And SrTiO₃Superlattice) may be one example of a dielectric material having a high dielectric constant ().

The integration of the high-K dielectric layer 340 may cause strong electric field effects. By integrating the electrically reconfigurable optical layer 330 with the associated perovskite nickelate with the high-K dielectric layer 340, the electrically reconfigurable optical layer 330 may be continuously tunable while allowing a refractive index change greater than 1 at electric fields below 0.1MV/cm and maintaining a breakdown field of the high-K dielectric layer 340 greater than 1 kMV/cm.

A controller 350 may be connected to the top electrode 310 and the bottom electrode 320 to control the electric field applied to the electrically reconfigurable optical layer 330. The controller 350 may be configured to control the top electrode 310 and the bottom electrode 320. For example, the controller 350 may be configured to supply a voltage to the top electrode 310 and the bottom electrode 320. The controller 350 may be, for example, but not limited to, a circuit with a voltage supply.

Electrically insulating layer 360 may be disposed under or below bottom electrode 320 and/or dielectric layer 340. The insulating layer 360 may cover at least a portion of the bottom electrode 320 and/or the dielectric layer 340. For example, the insulating layer 360 may include silicon dioxide (SiO)₂). In addition, the substrate 370 may be disposed under or below the insulating layer 360.

The electrically reconfigurable optical device 300 may be monolithically integrated on top of a Complementary Metal Oxide Semiconductor (CMOS) control Integrated Circuit (IC).

Furthermore, the phase change material described above may be provided in several different architectures. For example, the phase change material may be implemented in high-speed reconfigurable infrared optical devices (such as, but not limited to, infrared mirrors, lenses, and gratings).

Optionally, the bottom electrode 320, the insulating layer 360, and the substrate 370 may also be optically transparent according to embodiments of the present disclosure. For example, in the infrared wavelength range, BST may be used for the transparent insulating layer 360, and GaAs may be used for the transparent substrate 370; however, in the visible wavelength range, SiO₂Or Si₃N₄May be used for the transparent insulating layer 360, and glass, polymer (e.g., polyimide, PET, and PDMS), and sapphire may be used for the transparent substrate 370.

Fig. 6 shows a schematic view of an electrically reconfigurable infrared lens according to an exemplary embodiment of the present disclosure.

The electrically reconfigurable optical device 300 of FIG. 3 may be used for a mirror in a reconfigurable mirror lens (or focusing mirror) 600.

The electrically controllable optical layer 330 may include a pixelated array 610 of phase change material cells 620. The phase change material unit 620 may include one or more of the phase change materials described above. The pixelated array 610 of phase change material cells 620 may be an electrically programmable two-dimensional array. For example, the pixelated array 610 of phase change material cells 620 can be programmed to a spatially varying refractive index profile with almost zero DC power dissipation and no temperature rise. Each phase change material cell 620 may be tuned by an electric field applied by the respective top and bottom electrodes 310, 320. At least one controller 350 connected to the top and bottom electrodes 310, 320 may be configured to control the electric field applied to each of the electrically controllable material elements 620 by providing a voltage to the respective top and bottom electrodes 310, 320. The electric field may adjust the optical properties of each of the electrically controllable material elements 620. Thus, the controller 350 can independently control each of the electrically controllable material units 620. For example, the optical properties of each electrically controllable material unit 620 may be independently controlled. Modulation of the optical properties (e.g., refractive index) of the electrically controllable material elements 620 may provide depth of focus tunability of the array lens 600. For example, assuming a small (e.g., 1mm) hole diameter, the depth of focus of the lens 600 changes by 2cm for every 0.1 increase in the change in refractive index Δ n. Accordingly, the reconfigurable reflective lens 600 can set the pixelsThe spatial distribution of the refractive index of the phase change material cells 620 of the array 610 is varied to change the focal length of the incident plane wave. The reconfigurable reflective lens 600 can independently control the reflected phase of the optical beam at each phase change material cell 620 of the pixelated array 610 over a range of 0 to 360 degrees, and thus can control near field focusing or far field radiation. The pixilated arrays 610 of phase change material cells 620 may be individually controlled to have a reflection phase of the light beam of 0-360 degrees. These reflective phases may be achieved by adjusting the refractive index of the phase change material cell 620. The phase shift θ through a phase change material of thickness d and refractive index n is: theta 2dnk₀Wherein k is₀Is the free space wavenumber. It is to be considered that in reflective optics, the wave passes twice through the material thickness (2d) due to reflection at the back surface.

Fig. 7 shows reflection phases for a 32 × 32 pixel array with F-numbers (F/D) of 4, 2, 1, and 0.5 according to an exemplary embodiment of the present disclosure. F is the focal length of the mirror and D is the diameter of the aperture. Each reflection phase of each pixel of the 32 x 32 pixel array can be independently varied in the range of 0 to 360 degrees, thus allowing control of near field focusing or far field radiation. The reflected phase of the 32 x 32 pixel array may be set to provide a varying focal length for the incident plane wave. The reflected phase shown in fig. 7 is a calculated/modeled phase shift, not measured data.

Fig. 8 shows simulation results of lens configurations having F-numbers (F/ds) of 4, 2, 1, and 0.5 according to an exemplary embodiment of the present disclosure. As shown in FIG. 8, the reconfigurable lens can be reconfigured to obtain a wide range of focal lengths, resulting in great adjustability of the f-number, while only requiring the ability to achieve phase reflections from θ -0-2 π. However, as with conventional lenses, a larger focal length results in a larger focal point due to diffraction.

According to some embodiments of the present disclosure, phase change materials, such as phase change nickelates and tungsten oxides (WO)₃) Large optical property changes can be excited, such as, but not limited to, refractive index changes in the infrared wavelength spectrum greater than 1 by applying an electric field across the phase change material at high phase reconstruction speeds, such as, but not limited to, greater than 1 KHz.

According to certain embodiments of the present disclosure, by integrating an electrically reconfigurable optical layer with an associated perovskite nickelate with a high-K dielectric layer, the electrically reconfigurable optical layer may be continuously tunable while allowing a refractive index change of greater than 0.1 or 1 at electric fields below 0.1MV/cm and remaining within a breakdown field of the high-K dielectric layer of greater than 1 MV/cm.

Although the exemplary embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the embodiments and alternative embodiments. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Preferably comprising all of the elements, parts and steps described herein. It will be understood that any of these elements, portions and steps may be substituted for other elements, portions and steps or deleted entirely as will be apparent to those skilled in the art.

Broadly, this work discloses at least the following: an optical device may include: an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material is reconfigurable by an electric field; optically transparent top and bottom electrodes configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top and bottom electrodes; and a high-K dielectric layer disposed between the electrically reconfigurable optical layer and the bottom electrode. The phase change material of the electrically reconfigurable optical layer may comprise a phase change nickelate or tungsten oxide. The phase change material of the electrically reconfigurable optical layer may have a perovskite structure. Phase-change nickelates or tungsten oxides can excite large refractive index changes of greater than 1 at infrared wavelength spectra at high speeds of phase reconstruction of greater than 1kHz by applying an electric field to the phase-change material.

The invention conception

The following concepts are also presented herein:

concept 1. an electrically programmable reflector comprising:

a two-dimensional array of electrically reconfigurable optical elements comprising phase change associated perovskite nickelate or tungsten oxide, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements comprising phase change nickelate or tungsten oxide is changeable at infrared wavelengths.

Concept 2. an electrically programmable reflector according to any of the preceding and/or subsequent concepts, wherein the electrically reconfigurable optical elements are not mechanically movable relative to each other.

Concept 3. the electrically programmable reflector of any of the foregoing and/or subsequent concepts, wherein the refractive index of the electrically reconfigurable optical element comprising the phase change associated perovskite nickelate or tungsten oxide can change by greater than 0.1.

Concept 4. an electrically programmable reflector according to any of the preceding and/or subsequent concepts, wherein the refractive index of the electrically reconfigurable optical element comprising the phase change related perovskite nickelate or tungsten oxide may vary by more than 1.

Concept 5. the electrically programmable reflector of any preceding and/or subsequent concept, wherein the phase-change associated perovskite nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

Concept 6. the electrically programmable reflector of any of the foregoing and/or subsequent concepts, wherein the electrically programmable reflector is configured to excite the electrically reconfigurable optical element with an applied electric field to change the refractive index by more than 0.1.

Concept 7. the electrically programmable mirror or focusing mirror according to any of the preceding and/or subsequent concepts, further comprising a high-K dielectric layer disposed proximate the electrically reconfigurable optical element.

Concept 8. the electrically programmable mirror or focusing mirror of any of the preceding and/or subsequent concepts, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

Concept 9. an optical device, comprising:

one or more electrically reconfigurable optical elements comprising a phase change nickelate or tungsten oxide, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements comprising the phase change nickelate or tungsten oxide is changeable by greater than 0.1 at infrared wavelengths.

Concept 10. an optical device according to any preceding and/or subsequent concept, wherein the electrically reconfigurable optical element comprising the phase change nickelate or tungsten oxide has a perovskite structure.

Concept 11. the optical device of any of the preceding and/or subsequent concepts, wherein the phase-change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

Concept 12. the optical device of any preceding and/or subsequent concept, wherein the optical device is configured to excite the electrically reconfigurable optical element with an applied electric field with a refractive index change greater than 0.1.

Concept 13. an optical device according to any of the preceding and/or subsequent concepts, further comprising a high-K dielectric layer disposed proximate the electrically reconfigurable optical element.

Concept 14. the optical device of any of the preceding and/or subsequent concepts, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, or strontium titanate.

Concept 15. an optical device, comprising:

an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material in a predetermined wavelength range is reconfigurable by an electric field;

a top electrode and a bottom electrode configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top electrode and bottom electrode, and the top electrode is optically transparent over the wavelength range; and

a high-K dielectric layer disposed between the electrically reconfigurable optical layer and at least one of the top electrode and the bottom electrode.

Concept 16. the optical device of any preceding and/or subsequent concept, wherein the phase change material of the electrically reconfigurable optical layer comprises a phase change nickelate or tungsten oxide.

Concept 17. the optical device of any of the preceding and/or subsequent concepts, wherein the phase-change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

Concept 18. an optical device according to any preceding and/or subsequent concept, wherein the phase change material of the electrically reconfigurable optical layer has a perovskite structure.

Concept 19. the optical apparatus of any of the preceding and/or subsequent concepts, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

Concept 20. the optical device of any preceding and/or subsequent concept, wherein the optically transparent top electrode comprises an Ag nanowire-based material, a graphene-based material, and an ultra-thin metal film made by atomic layer deposition.

Concept 21. the optical device of any of the preceding and/or subsequent concepts, wherein the change in refractive index of the electro-phase change material is greater than 0.1 at infrared wavelength spectra.

Concept 22. the optical device of any of the preceding and/or subsequent concepts, wherein the change in refractive index of the electro-phase change material is greater than 1 at infrared wavelength spectra.

Concept 23. the optical device of any of the preceding and/or subsequent concepts, wherein the electrically reconfigurable optical layer comprises a pixelated array of phase change material.

Concept 24. the optical device of any preceding and/or subsequent concept, wherein the optical device is configured to excite the phase change material with an applied electric field with a change in refractive index of greater than 0.1.

The claims (modification according to treaty clause 19)

1. An electrically programmable reflector comprising:

a two-dimensional array of electrically reconfigurable optical elements comprising phase change related perovskite nickelates or tungsten oxides, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements containing the phase change related nickelates or tungsten oxides is changeable at infrared wavelengths.

2. The electrically programmable reflector according to claim 1, wherein the electrically reconfigurable optical elements are not mechanically movable relative to each other.

3. An electrically programmable reflector as claimed in claim 1 wherein the refractive index of the electrically reconfigurable optical element comprising the phase change related perovskite nickelate or tungsten oxide can be varied by more than 0.1.

4. An electrically programmable reflector as claimed in claim 1 wherein the refractive index of an electrically reconfigurable optical element comprising the phase change related perovskite nickelate or tungsten oxide can be varied by more than 1.

5. An electrically programmable reflector as claimed in claim 1 wherein the phase change related perovskite nickelateComprising GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

6. The electrically programmable reflector according to claim 1, wherein the electrically programmable reflector is configured to excite the change in refractive index of the electrically reconfigurable optical element with an applied electric field by more than 0.1.

7. The electrically programmable reflector of claim 1, further comprising a high-K dielectric layer disposed proximate the electrically reconfigurable optical element.

8. The electrically programmable reflector of claim 7, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

9. An optical device, comprising:

one or more electrically reconfigurable optical elements comprising a phase change nickelate or tungsten oxide, wherein one or more optical properties of the electrically reconfigurable optical elements are reconfigurable by an electric field such that the refractive index of the electrically reconfigurable optical elements comprising the phase change nickelate or tungsten oxide is changeable by greater than 0.1 at infrared wavelengths.

10. The optical device of claim 9, wherein the electrically reconfigurable optical element comprising the phase change nickelate or tungsten oxide has a perovskite structure.

11. The optical device of claim 9, wherein the phase change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

12. The optical device of claim 9, wherein the optical device is configured to excite the electrically reconfigurable optical element with an applied electric field with a change in refractive index of greater than 0.1.

13. The optical device of claim 9, further comprising a high-K dielectric layer disposed proximate to the electrically reconfigurable optical element.

14. The optical device of claim 13, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, or strontium titanate.

15. An optical device, comprising:

an electrically reconfigurable optical layer comprising at least one phase change material, wherein an optical property of the phase change material in a predetermined wavelength range is reconfigurable by an electric field;

a top electrode and a bottom electrode configured to apply an electric field to the electrically reconfigurable optical layer, wherein the electrically reconfigurable optical layer is disposed between the optically transparent top electrode and the bottom electrode, and the top electrode is optically transparent over the range of wavelengths; and

a high-K dielectric layer disposed between the electrically reconfigurable optical layer and at least one of the top electrode and the bottom electrode.

16. The optical device of claim 15, wherein the phase change material of the electrically reconfigurable optical layer comprises a phase change nickelate or tungsten oxide.

17. The optical device of claim 16, wherein the phase change nickelate comprises GdNiO₃、EuNiO₃、SmNiO₃、NdNiO₃And PrNiO₃At least one of (1).

18. The optical device of claim 15, wherein the phase change material of the electrically reconfigurable optical layer has a perovskite structure.

19. The optical device of claim 15, wherein the high-K dielectric layer comprises at least one of barium strontium titanate, barium titanate, and strontium titanate.

20. The optical device of claim 16, wherein the optically transparent top electrode comprises an Ag nanowire-based material, a graphene-based material, and an ultra-thin metal film made by atomic layer deposition.

21. The optical device of claim 16, wherein the change in refractive index of the electrically phase-change material is greater than 0.1 at infrared wavelength spectra.

22. The optical device of claim 16, wherein the change in refractive index of the electrically phase-change material is greater than 1 at infrared wavelength spectra.

23. The optical apparatus of claim 16, wherein the electrically reconfigurable optical layer comprises a pixelated array of the phase change material.

24. The optical device of claim 21, wherein the optical device is configured to excite the phase change material with an applied electric field with a change in refractive index of greater than 0.1.