Patent Description:
Optical modulation devices that change the transmission/reflection/scattering characteristics, phase, amplitude, polarization, intensity, path, and the like of light are used in various optical devices. To control the properties of light in a desired way in an optical system, optical modulation devices having various structures have been proposed. For example, liquid crystal having optical anisotropy, a microelectromechanical system (MEMS) structure using micro-mechanical movements of light blocking/reflecting elements, and the like are used for general optical modulation devices. The optical modulation devices have a limitation in an operation response time due to the characteristics of a driving method. In the case of an MEMS structure, it is necessary to correct the nonlinearity of the characteristics of voltage-displacement, and an optimized driving voltage profile needs to be secured to compensate for an influence of vibrations of a motion system.

Recently, there have been attempts to utilize a meta structure using a surface plasmon or a gap surface plasmon for incident light in an optical modulation device.

Korean patent application <CIT> discloses an optical modulating device that includes a phase modulator having a meta surface including a nanoantenna configured to couple light incident on the phase modulator. A reflective layer is provided on the opposite side of the meta surface of the phase modulator to resonate the light coupled through the nanoantenna.

US patent application <CIT> discloses an optical modulation device including a nano-antenna, a conductor, and an active layer located between the nano-antenna and the conductor. The optical modulation device includes a first dielectric layer located between the active layer and the conductor and a second dielectric layer located between the active layer and the nano-antenna.

US patent application <CIT> discloses an optical device having a mirror array including a plurality of mirror elements, a nano-antenna array including a plurality of nano-antennas, and an active layer disposed between the mirror array and the nano-antenna array.

US patent application <CIT> discloses a beam scanning device including a spatial light modulator configured to modulate a phase of a light for a corresponding pixel of a plurality of pixels, a phase mask including a support plate arranged in an output direction of the light that is output from the spatial light modulator, and a plurality of nanostructures arranged on the support plate differently for each of the plurality of pixels to control the phase of the light.

The document "<NPL>), discloses an electrically tunable metasurface as an optical phased array antenna employing a deep learning approach to design hybrid phase-change/plasmonic materials-based meta-atoms.

One or more example embodiments provide a phase modulator that stably maintains an over-coupling state, and a phase modulator array including the phase modulator.

One or more example embodiments also provide a phase modulator having improved light reflection properties, and a phase modulator array including the phase modulator.

One or more example embodiments also provide a phase modulator having a degree of freedom with respect to a distance between an antenna pattern and a phase change material pattern, and a phase modulator array including the phase modulator.

However, the objectives to be achieved are not limited to the above-described disclosure.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of example embodiments of the disclosure.

According to an aspect of an example embodiment, there is provided a phase modulator including an antenna pattern, a lower reflective layer spaced apart from the antenna pattern in a vertical direction, a spacer provided between the antenna pattern and the lower reflective layer, and a phase shift pattern included in the spacer, the phase shift pattern including a phase shift material.

The phase shift pattern is surrounded by the spacer.

A thickness in the vertical direction of a part of the spacer disposed between the phase shift pattern and the antenna pattern may be greater than a thickness in the vertical direction of another part of the spacer disposed between the phase shift pattern and the lower reflective layer.

The phase shift pattern may overlap the antenna pattern in the vertical direction.

The phase shift pattern may be disposed in an effective resonator area in the spacer configured to generate a gap plasmon.

A width of the antenna pattern in a horizontal direction perpendicular to the vertical direction may range from <NUM> to <NUM>.

A width of the phase shift pattern in a horizontal direction perpendicular to the vertical direction may be the same as a width of the antenna pattern in the horizontal direction.

The phase modulator may further include a power source configured to apply a voltage to the antenna pattern, wherein the antenna pattern is configured to generate heat based on the voltage being applied to the antenna pattern.

The phase shift pattern may be spaced apart from the antenna pattern such that a difference between a highest temperature of the phase shift pattern and a lowest temperature of the phase shift pattern is minimal based on the heat being generated from the antenna pattern.

Based on the heat being generated from the antenna pattern, the phase shift pattern may be spaced apart from the antenna pattern such that a lowest temperature of the phase shift pattern is greater than or equal to <NUM>.

The antenna pattern may include a plurality of antenna patterns disposed in a horizontal direction perpendicular the vertical direction, the phase shift pattern may include a plurality of phase shift patterns disposed between the plurality of antenna patterns and the lower reflective layer, the plurality of antenna patterns may have a same shape, and the plurality of phase shift patterns may be disposed in the horizontal direction.

The phase modulator may further include a power source configured to respectively apply a same voltage to the plurality of antenna patterns, wherein theplurality of antenna patterns are configured to generate heat based on the voltage being applied to the plurality of antenna patterns.

According to an aspect of an example embodiment, there is provided a phase modulator array including a first phase modulator, a second phase modulator spaced apart from the first phase modulator in a horizontal direction, a first power source configured to apply a voltage to the first phase modulator, and a second power source configured to apply a voltage to the second phase modulator, wherein each of the first phase modulator and the second phase modulator includes antenna patterns disposed in the horizontal direction, a lower reflective layer spaced apart from the antenna patterns in a vertical direction perpendicular to the horizontal direction, a spacer disposed between the antenna patterns and the lower reflective layer, and phase shift patterns included in the spacer and disposed in the horizontal direction, the phase shift patterns respectively including a phase shift material.

The first power source may be further configured to apply a first voltage to the antenna patterns included in the first phase modulator, the second power source is configured to apply a second voltage to the antenna patterns included in the second phase modulator, and the first voltage and the second voltage may be independent of each other.

A number of the phase shift patterns included in the first phase modulator may be the same as a number of the phase shift patterns included in the second phase modulator.

The spacer included in the first phase modulator and the spacer included in the second phase modulator may be different parts of one dielectric film.

The phase modulator array may further include a trench provided between the first phase modulator and the second phase modulator, wherein the trench exposes the lower reflective layer.

The phase modulator array may further include an insulation pattern provided in the trench, wherein a thermal conductivity of the insulation pattern is lower than a thermal conductivity of the spacer.

In each of the first phase modulator and the second phase modulator, the phase shift patterns may be surrounded by the spacer.

In each of the first phase modulator and the second phase modulator, a thickness in the vertical direction of a part of the spacer disposed between the phase shift patterns and the antenna patterns may be greater than a thickness in the vertical direction of another part of the spacer disposed between the phase shift patterns and the lower reflective layer.

According to an aspect of an example embodiment, there is provided a phase modulator including an antenna pattern, a lower reflective layer spaced apart from the antenna pattern in a vertical direction, a spacer provided between the antenna pattern and the lower reflective layer, the spacer including a dielectric material, and a phase shift pattern included in the spacer, the phase shift pattern including a phase shift material.

Hereinafter, the example embodiments of the disclosure are described in detail with reference to the accompanying drawings. Throughout the drawings, like reference numerals denote like elements. Sizes of components in the drawings may be exaggerated for convenience of explanation.

When a constituent element is disposed "above" or "on" to another constituent element, the constituent element may be only directly on the other constituent element or above the other constituent elements in a non-contact manner.

An expression used in a singular form in the specification also includes the expression in its plural form unless clearly specified otherwise in context. When a part may "include" a certain constituent element, unless specified otherwise, it may not be construed to exclude another constituent element but may be construed to further include other constituent elements.

Furthermore, terms such as "∼ portion," "∼ unit," "∼ module," and "∼ block" stated in the specification may signify a unit to process at least one function or operation.

<FIG> is a perspective view of a phase modulator <NUM> according to an example embodiment. <FIG> is a cross-sectional view of the phase modulator <NUM> taken along line I-I' of <FIG>. <FIG> is a graph of a real part of a refractive index of a phase change pattern of <FIG>. <FIG> is a graph of an imaginary part of the refractive index of the phase change pattern of <FIG>. <FIG> is a graph of a reflection phase of the phase modulator <NUM> according to an image of the phase change pattern of <FIG>. <FIG> is a graph of a reflectivity of the phase modulator <NUM> according to the image of the phase change pattern of <FIG>. <FIG> is a graph of a modulation phase of the phase modulator <NUM> of <FIG>.

Referring to <FIG> and <FIG>, the phase modulator <NUM> may be provided. The phase modulator <NUM> may include a lower reflective layer <NUM>, an antenna pattern <NUM>, a spacer <NUM>, a phase shift pattern <NUM>, and a power element <NUM>. The lower reflective layer <NUM> may extend in a first direction DR1, for example, a horizontal direction, and a second direction DR2 crossing each other. The lower reflective layer <NUM> may include an electrically conductive material. For example, the lower reflective layer <NUM> may include at least one metal selected from the group consisting of copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), cobalt (Co), zinc (Zn), titanium (Ti), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), iridium (Ir), silver (Ag), gold (Au), and the like, and an alloy including at least one thereof. However, embodiments are not limited thereto. For example, the lower reflective layer <NUM> may include a thin film in which metal nanoparticles of Ag, Au, and the like are distributed, a carbon nanostructure of graphene or carbon nanotube (CNT), and the like, a conductive polymer such as poly(<NUM>,<NUM>-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy), poly(<NUM>-hexylthiophene) (P3HT), and the like, a conductive oxide, and the like.

The antenna pattern <NUM> may be provided on the lower reflective layer <NUM>. The antenna pattern <NUM> may be spaced apart a first distance t5 from the lower reflective layer <NUM> in a third direction DR3, for example, a vertical direction, perpendicular to the first direction DR1 and the second direction DR2 as illustrated in <FIG>. For example, when the phase modulator <NUM> modulates a phase of near infrared having a wavelength of <NUM> nanometers (nm), the first distance t5 may be <NUM> to <NUM>. The antenna pattern <NUM> may have a first width w1 and a first thickness t1. The first width w1 may be a size of the antenna pattern <NUM> in the first direction DR1. The first thickness t1 may be a size of the antenna pattern <NUM> in the third direction DR3. The first width w1 and the first thickness t1 may be less than a wavelength of an electromagnetic wave incident on the phase modulator <NUM>. For example, the first width w1 and the first thickness t1 may be tens to hundreds of nanometers. In an example, the first width w1 with respect to an electromagnetic wave of a near infrared wavelength band may be <NUM> to <NUM>. The antenna pattern <NUM> may have a first side surface <NUM> in the first direction DR1 and a second side surface <NUM> in a fourth direction DR4 opposite to the first direction DR1. The antenna pattern <NUM> may include a conductive material. For example, the antenna pattern <NUM> may include at least one metal selected from the group consisting of Cu, Al, Ni, Fe, Co, Zn, Ti, Ru, Rh, Pd, Pt, Os, Ir, Ag, Au, and the like, and an alloy including at least one thereof. However, embodiments are not limited thereto. For example, the antenna pattern <NUM> may include a thin film in which metal nanoparticles of Ag, Au, and the like are distributed, a carbon nanostructure of graphene or CNT, and the like, a conductive polymer such as PEDOT, PPy, P3HT, and the like, a conductive oxide, and the like. In an example, the antenna pattern <NUM> may include the same material as the lower reflective layer <NUM>.

The spacer <NUM> may be provided between the lower reflective layer <NUM> and the antenna pattern <NUM>. The spacer <NUM> may include a dielectric material. For example, the spacer <NUM> may include a dielectric silicon compound, for example, a silicon oxide (SiOx), a silicon nitride (SixNy), or a silicon oxynitride (SiON), or a dielectric metal compound, for example, an aluminum oxide (Al<NUM>O<NUM>), a hafnium oxide (HfO), a zirconium oxide (ZrO), or a hafnium silicon oxide (HfSiO).

A first reflection boundary <NUM> and a second reflection boundary <NUM> in the spacer <NUM> may be determined by the antenna pattern <NUM>. The first reflection boundary <NUM> may be a boundary from which a gap plasmon traveling in the spacer <NUM> in the first direction DR1 is reflected in the fourth direction DR4. The gap plasmon is described below. The second reflection boundary <NUM> may be a boundary from which a gap plasmon traveling in the spacer <NUM> in the fourth direction DR4 is reflected in the first direction DR1. The first reflection boundary <NUM> and the second reflection boundary <NUM> may be respectively aligned with the first side surface <NUM> and the second side surface <NUM> of the antenna pattern <NUM>. An area between the first reflection boundary <NUM> and the second reflection boundary <NUM> may be referred to as an effective resonator area. The first reflection boundary <NUM> and the second reflection boundary <NUM> may be spaced apart by a second distance w3 from each other in the first direction DR1. The second distance w3 may be referred to as an effective resonator length. The second distance w3 may be substantially the same as the first width w1.

The lower reflective layer <NUM>, the spacer <NUM>, and the antenna pattern <NUM> may form a gap plasmon resonator having a metal-dielectric-metal (MIM) structure. A gap plasmon is a coupling of a photon and an electron resonating in a dielectric of a MIM structure. A resonance condition of a gap plasmon resonator including the lower reflective layer <NUM>, the antenna pattern <NUM>, and the spacer <NUM> to generate a gap plasmon is shown in Equation <NUM> below.

Here, λ<NUM> is a wavelength of an incident electromagnetic wave, l is a width (w1) of the antenna pattern <NUM>, neff is an effective refractive index of a gap plasmon, ϕ ϕref is a reflection phase of a gap plasmon when reflected from the first reflection boundary <NUM> and the second reflection boundary <NUM>, and m is a resonance order.

The phase shift pattern <NUM> may be provided in the spacer <NUM>. The phase shift pattern <NUM> may be inserted into the spacer <NUM>. The phase shift pattern <NUM> may be surrounded by the spacer <NUM>. For example, the spacer <NUM> may be provided on an upper surface, a lower surface, and both side surfaces of the phase shift pattern <NUM>. The phase shift pattern <NUM> may overlap the antenna pattern <NUM> in the third direction DR3. The phase shift pattern <NUM> may be spaced apart by a third distance t3 from the lower reflective layer <NUM> in the third direction DR3. The phase shift pattern <NUM> and the antenna pattern <NUM> may be spaced apart by a fourth distance t4 from each other in the third direction DR3 a fourth distance t4. The fourth distance t4 may be greater than the third distance t3. The phase shift pattern <NUM> may be located between the first reflection boundary <NUM> and the second reflection boundary <NUM>. The phase shift pattern <NUM> may have a second width w2 and a second thickness t2. The second width w2 may be a size of the phase shift pattern <NUM> in the first direction DR1. The second thickness t2 may be a size of the phase shift pattern <NUM> in the third direction DR3. Although the second width w2 is illustrated to be less than the first width w1, embodiments are not limited thereto. In another example, the second width w2 may be equal to or greater than the first width w1. The phase shift pattern <NUM> may include a phase shift material. For example, the phase shift pattern <NUM> may include germanium antimony telluride (GeSbTe) or vanadium oxide (VO<NUM>).

The power element <NUM> may be a power source that is electrically connected to the antenna pattern <NUM>. The power element <NUM> may apply an AC voltage to both end portions of the antenna pattern <NUM>. For example, both end portions of the antenna pattern <NUM> may be spaced apart from each other in the second direction DR2. When the power element <NUM> applies an AC voltage to the antenna pattern <NUM>, heat may be generated from the antenna pattern <NUM>. The heat generated from the antenna pattern <NUM> may reach the phase shift pattern <NUM> and change a temperature of the phase shift pattern <NUM>. Accordingly, the power element <NUM> may adjust the temperature of the phase shift pattern <NUM>.

When the antenna pattern <NUM> generates heat, the temperature of the phase shift pattern <NUM> may be accordingly changed differently for each part of the phase shift pattern <NUM>. For example, the temperature of a part of the phase shift pattern <NUM> relatively close to the antenna pattern <NUM> may rise relatively quickly, and the temperature of other part of the phase shift pattern <NUM> relatively far from the antenna pattern <NUM> may rise relatively slowly. The fourth distance t4 may be determined such that a difference between the highest temperature and the lowest temperature of the phase shift pattern <NUM> when heat is generated from the antenna pattern <NUM> is the lowest, thereby optimizing the phase modulator <NUM>. For example, the lowest temperature of the phase shift pattern <NUM> may be about <NUM> or more. During the manufacturing of the phase modulator <NUM>, as the fourth distance t4 is adjustable by using the spacer <NUM>, there is a degree of freedom with respect to the fourth distance t4, and the phase modulator <NUM> may be optimized.

Referring to <FIG> and <FIG>, the phase shift pattern <NUM> may have a refractive index that is determined according to a phase. <FIG> illustrates a real part of a refractive index according to the phase of the phase shift pattern <NUM>, and <FIG> illustrates an imaginary part of the refractive index according to the phase of the phase shift pattern <NUM>. The phase of the phase shift pattern <NUM> may be determined according to the temperature of the phase shift pattern <NUM>. For example, the phase shift pattern <NUM> may have an amorphous phase, a crystalline phase, and a medium phase according to the temperature of the phase shift pattern <NUM>. A real part and an imaginary part of a refractive index of the phase shift pattern <NUM> having a medium phase may have values between real parts and imaginary parts of refractive indexes of the phase shift pattern <NUM> having an amorphous phase and the phase shift pattern <NUM> having a crystalline phase. In <FIG>, a graph C1 indicates a real part of a refractive index when the phase shift pattern <NUM> has a crystalline phase, and a graph A1 indicate a real part of a refractive index when the phase shift pattern <NUM> has an amorphous phase. In <FIG>, a graph C2 indicates an imaginary part of a refractive index when the phase shift pattern <NUM> has a crystalline phase, and a graph A2 indicates an imaginary part of a refractive index when the phase shift pattern <NUM> has an amorphous phase.

A real part of a refractive index difference according to the phase of the phase shift pattern <NUM> may be related to a degree of movement of a reflection phase spectrum of the phase modulator <NUM> along a wavelength axis. As the difference in the real part of a refractive index increases, a reflection phase spectrum of a phase modulator may significantly move along a wavelength axis. For example, as illustrated in <FIG>, when the phase shift pattern <NUM> includes GST (GexSbyTez), a difference of the real part of a refractive index in a near infrared wavelength band (about <NUM> band) may be <NUM> to <NUM>.

Referring to <FIG>, a reflection phase spectrum C4 when the phase shift pattern <NUM> has a crystalline phase may be a reflection phase spectrum that is moved along a wavelength axis from a reflection phase spectrum A4 when the phase shift pattern <NUM> has an amorphous phase. Referring to <FIG>, the phase modulator <NUM> according to example embodiments may modulate a phase in a near infrared wavelength band in a range of about <NUM>. According to example embodiments, the phase modulator <NUM> may have a large phase modulation width.

An amount of an imaginary part of a refractive index according to the phase of the phase shift pattern <NUM> may be related to a light absorption rate of the phase shift pattern <NUM>. As the imaginary part of a refractive index decreases, the light absorption rate of the phase shift pattern <NUM> may decrease as well. For example, as illustrated in <FIG>, in an amorphous phase, the imaginary part A2 of a refractive index of the phase shift pattern <NUM> is about <NUM>, and in a crystalline phase, the imaginary part C2 of a refractive index of the phase shift pattern <NUM> is about <NUM> to <NUM>, which are both relatively small values.

The phase shift pattern <NUM> according to example embodiments may be surrounded by the spacer <NUM>. As the spacer <NUM> includes a dielectric material, an imaginary part of an effective refractive index of a gap plasmon may be less than an imaginary part of a refractive index of the phase shift pattern <NUM>. Accordingly, an imaginary part of an effective refractive index of a gap plasmon between the lower reflective layer <NUM> and the antenna pattern <NUM> may have a relatively small value. Referring to <FIG>, the phase modulator <NUM> of the disclosure may have a high reflectivity of <NUM>% or more in a near infrared wavelength band. In <FIG>, a graph C3 indicates a reflectivity when the phase shift pattern <NUM> has a crystalline phase, and a graph A3 indicates a reflectivity when the phase shift pattern <NUM> has an amorphous phase. The phase modulator <NUM> according to example embodiments may have a low light absorption rate.

Photons and electrons in the phase modulator <NUM> may have an over-coupling state. In this case, a reflection phase spectrum of the phase modulator <NUM> may be gradually changed within a range of about <NUM>. When the photons and the electrons have an under-coupling state, not the over-coupling, a maximum phase difference may be about <NUM>°. As the light absorption rate of the phase modulator <NUM> decreases, the over-coupling state of photons and electrons may be stably maintained in the phase modulator <NUM>. According to example embodiments, as the phase shift pattern <NUM> having a small imaginary part of a refractive index and the spacer <NUM> surrounding the phase shift pattern <NUM> may be used, and the light absorption rate of the phase modulator <NUM> may be reduced. Accordingly, the photons and electrons in the phase modulator <NUM> may stably have an over-coupling state.

<FIG> is a perspective view of a phase modulator <NUM> according to an example embodiment. <FIG> is a cross-sectional view of the phase modulator <NUM> taken along line II-II' of <FIG>. For brevity of explanation, descriptions that are substantially the same as those presented with reference to <FIG> and <FIG> may not be provided.

Referring to <FIG> and <FIG>, the phase modulator <NUM> may be provided. The phase modulator <NUM> may include the lower reflective layer <NUM>, antenna patterns <NUM>, the spacer <NUM>, phase shift patterns <NUM>, and the power element <NUM>. The lower reflective layer <NUM>, the spacer <NUM>, and the power element <NUM> may be may be substantially the same as those described with reference to <FIG> and <FIG>.

The antenna patterns <NUM> may be provided on the spacer <NUM>. Each of the antenna patterns <NUM> may be substantially the same as the antenna pattern <NUM> described with reference to <FIG> and <FIG>. The antenna patterns <NUM> may be arranged in the first direction DR1. For example, an arrangement period ap of the antenna patterns <NUM> may be <NUM> to <NUM>. The antenna patterns <NUM> may have substantially the same shape and size. Accordingly, surface plasmon resonators respectively including the antenna patterns <NUM> may form a gap plasmon by receiving an electromagnetic wave having substantially the same wavelength. The power element <NUM> may be electrically connected to the antenna patterns <NUM>. The power element <NUM> may apply substantially the same AC voltages to each of the antenna patterns <NUM>. Accordingly, the antenna patterns <NUM> may generate heat of substantially the same level.

The phase shift patterns <NUM> may be provided in the spacer <NUM>. Each of the phase shift patterns <NUM> may be substantially the same as the phase shift pattern <NUM> described with reference to <FIG> and <FIG>. The phase shift patterns <NUM> may be arranged in the first direction DR1. For example, a distance between the phase shift patterns <NUM> may be <NUM> to <NUM>. The phase shift patterns <NUM> may respectively overlap the antenna patterns <NUM> in the third direction DR3. The third and fourth distances t3 and t4 of the phase shift patterns <NUM> may be substantially the same as those in <FIG>. As the antenna patterns <NUM> generate heat of substantially the same level and the fourth distances t4 is the same, a change in temperature of the phase shift patterns <NUM> may be substantially the same.

<FIG> is a perspective view of a phase modulator array <NUM> according to an example embodiment. For brevity of explanation, descriptions that are substantially the same as those presented with reference to <FIG> and <FIG> may not be provided.

Referring to <FIG>, the phase modulator array <NUM> may be provided. The phase modulator array <NUM> may include a plurality of phase modulators 12a arranged in two dimensions. For example, the phase modulator array <NUM> may include the phase modulators 12a arranged in the first direction DR1 and the phase modulators 12a arranged the second direction DR2 respectively therefrom. Each of the phase modulators 12a may be substantially the same as the phase modulator <NUM> described with reference to <FIG> and <FIG>. The lower reflective layers <NUM> of the phase modulators 12a may be respectively connected to the spacers <NUM>. For example, the lower reflective layers <NUM> may be different parts of that lower reflective layer <NUM> that is integrally formed, and the spacers <NUM> may be different parts of the spacer <NUM> that is integrally formed. The phase modulators 12a may respectively include the power elements <NUM>. In each of the phase modulators 12a, the power element <NUM> may apply substantially the same AC voltages to the antenna patterns <NUM>. The power elements <NUM> may apply AC voltages that are independent of each other. For example, the power element <NUM> included in one phase modulator 12a may apply a first AC voltage to the antenna patterns <NUM> included in another phase modulator 12a, and the power element <NUM> included in the another phase modulator 12a may apply a second AC voltage that is the same as or different from the first AC voltage, to the antenna patterns <NUM> included in the another phase modulator 12a. The phase modulators 12a may have light modulation properties that are independent of each other.

The phase modulator array <NUM> is not limited to one including the phase modulators 12a arranged in two dimensions. In another example, the phase modulator array <NUM> may include the phase modulators 12a that are arranged in one dimension, for example, in the first direction DR1 or the second direction DR2.

<FIG> is a perspective view of a phase modulator array <NUM> according to an example embodiment. For brevity of explanation, descriptions that are substantially the same as those presented with reference to <FIG> may not be provided.

Referring to <FIG>, the phase modulator array <NUM> may be provided. The phase modulator array <NUM> may include a plurality of phase modulators 13a arranged in two dimensions. Unlike the description presented with reference to <FIG>, the trenches TR may be provided between the spacers <NUM> of each of the phase modulators 13a. The trenches TR may separate the spacers <NUM> from each other. The trenches TR may extend in the first direction DR1 and in the second direction DR2 between the spacers <NUM>. The trenches TR may be connected to each other. The trenches TR may expose an upper surface of the lower reflective layer <NUM>. The trenches TR may be filled with air. As air has a thermal conductivity lower than the spacers <NUM>, the phase modulators 13a neighboring and provided adjacent to each other may be thermally separated from each other. For example, an effect of the heat generated from the antenna patterns <NUM> in one phase modulator 13a on the phase shift patterns <NUM> in another phase modulator 13a neighboring the one phase modulator 13a may be reduced or prevented.

The phase modulator array <NUM> is not limited to including the phase modulators 13a arranged in two dimensions. In another example, the phase modulator array <NUM> may include the phase modulators 13a arranged in one dimension, for example, in the first direction DR1 or the second direction DR2.

<FIG> is a perspective view of a phase modulator array <NUM> according to an embodiment. For brevity of explanation, descriptions that are substantially the same as those presented with reference to <FIG> may not be provided.

Referring to <FIG>, the phase modulator array <NUM> may be provided. The phase modulator array <NUM> may include a plurality of phase modulators 14a arranged in two dimensions. Unlike the description presented with reference to <FIG>, a plurality of insulation patterns 14b may be provided in the trenches TR. For example, the insulation patterns 14b may fill the trenches TR. The insulation patterns 14b may extend in the first direction DR1 and the second direction DR2 and may be connected to each other. The insulation patterns 14b may include a dielectric material having a low thermal conductivity than the spacers <NUM>. For example, when the spacers <NUM> includes Al<NUM>O<NUM>, the insulation patterns 14b may include amorphous SiO<NUM> having a lower thermal conductivity than Al<NUM>O<NUM>. Accordingly, the phase modulators 14a neighboring and provided adjacent to each other may be thermally separated from each other. For example, an effect of the heat generated from the antenna patterns <NUM> in one phase modulator 14a on the phase shift patterns <NUM> in another phase modulator 14a neighboring the one phase modulator 14a may be reduced or prevented.

The phase modulator array <NUM> is not limited to including the phase modulators 14a arranged in two dimensions. In another example, the phase modulator array <NUM> may include the phase modulators 14a arranged in one dimension, for example, in the first direction DR1 or the second direction DR2.

<FIG> is a conceptual view of a beam steering device 1000A according to an example embodiment.

Referring to <FIG>, the beam steering device 1000A may be provided. The beam steering device <NUM>000A may include a non-mechanical beam scanning apparatus. The beam steering device 1000A may steer a beam in a one-dimensional direction. The beam steering device 1000A may steer a beam toward an object OBJ in a first adjustment direction DD1. The beam steering device 1000A may include one of the phase modulator arrays <NUM>, <NUM>, and <NUM> described with reference to <FIG>, <FIG>, and <FIG>.

<FIG> is a conceptual view of a beam steering device 1000B according to an example embodiment.

Referring to <FIG>, the beam steering device 1000B may be provided. The beam steering device 1000B may include a non-mechanical beam scanning apparatus. The beam steering device 1000B may steer a beam in a two-dimensional direction. For example, the beam steering device 1000B may steer a beam toward the object OBJ in the first adjustment direction DD1 and a second adjustment direction DD2 crossing the first adjustment direction DD1. The beam steering device 1000A may include one of the phase modulator arrays <NUM>, <NUM>, and <NUM> described with reference to <FIG>, <FIG>, and <FIG>.

<FIG> is a block diagram of an electronic device A1 according to an example embodiment.

Referring to <FIG>, the electronic device A1 may be provided. The electronic device A1 may include a beam steering device <NUM>. The beam steering device <NUM> may be substantially the same as the beam steering devices 1000A and 1000B of <FIG> and <FIG>. The electronic device A1 may include a light source in the beam steering device <NUM>, or a light source provided separately from the beam steering device <NUM>.

The electronic device A1 may include a detection unit <NUM> for detecting light that is steered by the beam steering device <NUM> and reflected by an object. The detection unit <NUM> may include a plurality of light detection elements and further include optical members. Furthermore, the electronic device A1 may further include a circuit unit <NUM> connected to at least one of the beam steering device <NUM> or the detection unit <NUM>. The circuit unit <NUM> may include an operation unit for obtaining and operating data, and further include a driving unit, a control unit, and the like. Furthermore, the circuit unit <NUM> may further include a power unit, a memory, and the like.

Although <FIG> illustrates an example in which the electronic device A1 includes the beam steering device <NUM> and the detection unit <NUM> in one device, the beam steering device <NUM> and the detection unit <NUM> may be provided in separate devices. Furthermore, the circuit unit <NUM> may be connected to the beam steering device <NUM> or the detection unit <NUM> in a wireless communication method, not in a wired manner. In addition, the configuration of the electronic device A1 of <FIG> may be changed in various ways.

The beam steering device <NUM> according to the above-described example embodiment may be applied to various electronic devices. In an example, the beam steering device <NUM> may be applied to a light detection and ranging (LiDAR) device. The LiDAR device may include a phase-shift type device or a time-of-flight (TOF) type device. Furthermore, a phase modulator according to an example embodiment, or a beam steering device including the phase modulator may be mounted on electronic devices such as smartphones, wearable devices (augmented reality (AR) and virtual reality (VR) implementing glasses-type devices, and the like), Internet of Things (IoT) devices, home appliances, tablet personal computers (PCs), personal digital assistants (PDAs), portable multimedia players (PMPs), navigations, drones, robots, driverless cars, autonomous driving cars, advanced drivers assistance systems (ADASs), and the like.

<FIG> and <FIG> are conceptual views showing a case in which a LiDAR device <NUM> according to an example embodiment is applied to a vehicle <NUM>.

Referring to <FIG> and <FIG>, the LiDAR device <NUM> may be applied to the vehicle <NUM>, and information about an object <NUM> may be obtained by using the LiDAR device <NUM>. The vehicle <NUM> may be a vehicle having an autonomous driving function. The LiDAR device <NUM> may detect objects or humans, that is, the object <NUM>, present in a direction in which the vehicle <NUM> drives. The LiDAR device <NUM> may measure a distance from the object <NUM> by using information such as a time difference between a transmitting signal and a detection signal, and the like. As illustrated in <FIG>, the LiDAR device <NUM> may obtain information about an object <NUM> closely located within a scanning range and an object <NUM> located farther than the object <NUM>.

<FIG> is a conceptual view of a holographic display device <NUM> according to an example embodiment.

Referring to <FIG>, the holographic display device <NUM> may be provided. The holographic display device <NUM> may include a backlight unit <NUM>, a Fourier lens <NUM>, a phase modulation device <NUM>, and an image processor <NUM>. The phase modulation device <NUM> may include a plurality of pixels arranged in two dimensions. The phase modulation device <NUM> may include any one of the phase modulation arrays <NUM>, <NUM>, and <NUM> of <FIG>. In an example, the phase modulators 12a, 13a, and 14a respectively included in the phase modulation arrays <NUM>, <NUM>, and <NUM> may correspond to the respective pixels of the phase modulation device <NUM>. In another example, the phase modulators 12a, 13a, and 14a included in the phase modulation arrays <NUM>, <NUM>, and <NUM> may be classified into a plurality of phase modulator groups, and the phase modulator groups may correspond to the pixels of the phase modulation device <NUM>. Each of the phase modulator groups may include phase modulators adjacent to each other.

The image processor <NUM> may be connected to the phase modulation device <NUM> in a wired or wireless manner. The phase modulation device <NUM> may receive a hologram data signal from the image processor <NUM>. The phase modulation device <NUM> may control the phase of light according to the hologram data signal from the image processor <NUM>.

The backlight unit <NUM> may emit coherent light. For example, the backlight unit <NUM> may include a laser diode to provide light having high coherence. The backlight unit <NUM> may include, in addition to a laser diode, any light source capable of emitting light having spatial coherence. Furthermore, the backlight unit <NUM> may further include an optical system that magnifies light emitted from a laser diode and produces a collimated parallel light having a uniform intensity distribution. Accordingly, the backlight unit <NUM> may provide parallel coherence light having a spatially uniform intensity distribution to the entire area of the phase modulation device <NUM>.

The Fourier lens <NUM> may focus a holographic image or an image in space. For example, a holographic image may be reproduced on a focal plane of the Fourier lens <NUM>, and the eye E of a user may be arranged on the focal plane to see the holographic image. Although the Fourier lens <NUM> is located on an incident light surface of the phase modulation device <NUM>, that is, between the backlight unit <NUM> and the phase modulation device <NUM>, the location of the Fourier lens <NUM> is not limited thereto. For example, the Fourier lens <NUM> may be located on a light exit surface of the phase modulation device <NUM>.

<FIG> is a schematic block diagram of a configuration of an electronic device <NUM> according to an example embodiment.

Referring to <FIG>, in a network environment <NUM>, the electronic device <NUM> may communicate with another electronic device <NUM> through a first network <NUM> (a short-range wireless communication network, and the like), or another electronic device <NUM> and/or a server <NUM> through a second network <NUM> (a long-range wireless communication network, and the like). The electronic device <NUM> may communicate with the electronic device <NUM> through the server <NUM>. The electronic device <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, an audio output device <NUM>, a display device <NUM>, an audio module <NUM>, a sensor module <NUM>, an interface <NUM>, a haptic module <NUM>, a camera module <NUM>, a power management module <NUM>, a battery <NUM>, a communication module <NUM>, a subscriber identification module <NUM>, and/or an antenna module <NUM>. In the electronic device <NUM>, some of the constituent elements (the display device <NUM>, and the like) may be omitted or another constituent element may be added. Some of these constituent elements may be implemented as one integrated circuit. For example, a fingerprint sensor <NUM>, an iris sensor, an illuminance sensor, and the like of the sensor module <NUM> may be implemented by being embedded in the display device <NUM> (a display, and the like).

The processor <NUM> may control, by executing software (a program <NUM>, and the like), one or a plurality of other constituent elements (a hardware or software constituent element, and the like) of the electronic device <NUM>, and perform various data processing or operations. As part of data processing or operations, the processor <NUM> may load commands and/or data received from other constituent elements (the sensor module <NUM>, the communication module <NUM>, and the like) in a volatile memory <NUM>, process the command and/or data stored in the volatile memory <NUM>, and store resultant data in a non-volatile memory <NUM>. The processor <NUM> may include a main processor <NUM> (a central processing unit, an application processor, and the like) and an auxiliary processor <NUM> (a graphics processing unit, an image signal processor, a sensor hub processor, a communication processor, and the like), which are operable independently or together. The auxiliary processor <NUM> may consume less power than the main processor <NUM> and may perform a specialized function.

The auxiliary processor <NUM> may control functions and/or states related to some constituent elements (the display device <NUM>, the sensor module <NUM>, the communication module <NUM>, and the like) of the electronic device <NUM>, instead of the main processor <NUM> when the main processor <NUM> is in an inactive state (a sleep state), or with the main processor <NUM> when the main processor <NUM> is in an active state (an application execution state). The auxiliary processor <NUM> (an image signal processor, a communication processor, and the like) may be implemented as a part of functionally related other constituent elements (the camera module <NUM>, the communication module <NUM>, and the like).

The memory <NUM> may store various pieces of data needed for constituent element (the processor <NUM>, the sensor module <NUM>, and the like) of the electronic device <NUM>. The data may include, for example, software (the program <NUM>, and the like) and input data and/or output data regarding commands related thereto. The memory <NUM> may include the volatile memory <NUM> and/or the non-volatile memory <NUM>.

The program <NUM> may be stored as software in the memory <NUM>, and may include an operating system <NUM>, a middleware <NUM>, and/or an application <NUM>.

The input device <NUM> may receive commands and/or data to be used in the constituent elements (the processor <NUM>, and the like) of the electronic device <NUM>, from the outside (a user, and the like) of the electronic device <NUM>. The input device <NUM> may include a microphone, a mouse, a keyboard, and/or a digital pen (a stylus pen, and the like).

The audio output device <NUM> may output an audio signal to the outside of the electronic device <NUM>. The audio output device <NUM> may include a speaker and/or a receiver. The speaker may be used for general purposes such as multimedia playback or recording playback, and the receiver may be used to receive incoming calls. The receiver may be combined as a part of the speaker or implemented as an independent separate device.

The display device <NUM> may visually provide information to the outside of the electronic device <NUM>. The display device <NUM> may include a display, a hologram device, or a projector, and a control circuit for controlling such a device. The display device <NUM> may include a touch circuitry set to sense a touch, and/or a sensor circuit (a pressure sensor, and the like) set to measure the strength of a force generated by the touch.

The audio module <NUM> may convert sound into an electrical signal or reversely an electrical signal into sound. The audio module <NUM> may obtain sound through the input device <NUM>, or output sound through the audio output device <NUM> and/or a speaker and/or a headphone of another electronic device (the electronic device <NUM>, and the like) connected to the electronic device <NUM> in a wired or wireless manner.

The sensor module <NUM> may sense an operation state (power, a temperature, and the like) of the electronic device <NUM>, or an external environment state (a user state, and the like), and generate an electrical signal and/or data value corresponding to a sensed state. The sensor module <NUM> may include the fingerprint sensor <NUM>, an acceleration sensor <NUM>, a position sensor <NUM>, a 3D sensor <NUM>, and the like, and further include an iris sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, and/or an illuminance sensor.

The 3D sensor <NUM> may sense a shape, a movement, and the like of an object by radiating light to the object and analyzing light reflected from the object, and may include any one of the phase modulators the above-described embodiments.

The interface <NUM> may support one or more designated protocols to be used for connecting the electronic device <NUM> to another electronic device (the electronic device <NUM>, and the like) in a wired or wireless manner. The interface <NUM> may include a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, and/or an audio interface.

A connection terminal <NUM> may include a connector for physically connecting the electronic device <NUM> to another electronic device (the electronic device <NUM>, and the like). The connection terminal <NUM> may include an HDMI connector, a USB connector, an SD card connector, and/or an audio connector (a headphone connector, and the like).

The haptic module <NUM> may convert electrical signals into mechanical stimuli (vibrations, movements, and the like) or electrical stimuli that are perceivable by a user through tactile or motor sensations. The haptic module <NUM> may include a motor, a piezoelectric device, and/or an electrical stimulation device.

The camera module <NUM> may capture a still image and a video. The camera module <NUM> may include a lens assembly including one or a plurality of lenses, image sensors, image signal processors, and/or flashes. The lens assembly included in the camera module <NUM> may collect light emitted from an object that is a target for image capturing, and the lens assembly may include any one of the phase modulators according to the above-described embodiments.

The power management module <NUM> may be implemented as a part of a power management integrated circuit (PMIC).

The battery <NUM> may supply power to the constituent elements of the electronic device <NUM>. The battery <NUM> may include non-rechargeable primary cells, rechargeable secondary cells, and/or fuel cells.

The communication module <NUM> may establish a wired communication channel and/or a wireless communication channel between the electronic device <NUM> and another electronic device (the electronic device <NUM>, the electronic device <NUM>, the server <NUM>, and the like), and support a communication through an established communication channel. The communication module <NUM> may be operated independently of the processor <NUM> (the application processor, and the like), and may include one or a plurality of communication processors supporting a wired communication and/or a wireless communication. The communication module <NUM> may include a wireless communication module <NUM> (a cellular communication module, a short-range wireless communication module, a global navigation satellite system (GNSS) communication module, and the like), and/or a wired communication module <NUM> (a local area network (LAN) communication module, a power line communication module, and the like). Among the above communication modules, a corresponding communication module may communicate with another electronic device through the first network <NUM> (a short-range communication network such as Bluetooth, WiFi Direct, or infrared data association (IrDA)) or the second network <NUM> (a long-range communication network such as a cellular network, the Internet, or a computer network (LAN, WAN, and the like)). These various types of communication modules may be integrated into one constituent element (a single chip, and the like), or may be implemented as a plurality of separate constituent elements (multiple chips). The wireless communication module <NUM> may verify and authenticate the electronic device <NUM> in a communication network such as the first network <NUM> and/or the second network <NUM> by using subscriber information (an international mobile subscriber identifier (IMSI), and the like) stored in the subscriber identification module <NUM>.

The antenna module <NUM> may transmit signals and/or power to the outside (another electronic device, and the like) or receive signals and/or power from the outside. An antenna may include an emitter formed in a conductive pattern on a substrate (a printed circuit board (PCB), and the like). The antenna module <NUM> may include one or a plurality of antennas. When the antenna module <NUM> includes a plurality of antennas, the communication module <NUM> may select, from among the antennas, an appropriate antenna for a communication method used in a communication network such as the first network <NUM> and/or the second network <NUM>. Signals and/or power may be transmitted or received between the communication module <NUM> and another electronic device through the selected antenna. Other parts (an RFIC, and the like) than the antenna may be included as a part of the antenna module <NUM>.

Some of the constituent elements may be connected to each other through a communication method between peripheral devices (a bus, general purpose input and output (GPIO), a serial peripheral interface (SPI), a mobile industry processor interface (MIPI), and the like) and may mutually exchange signals (commands, data, and the like).

The command or data may be transmitted or received between the electronic device <NUM> and the external electronic device <NUM> through the server <NUM> connected to the second network <NUM>. The electronic devices <NUM> and <NUM> may be of a type that is the same as or different from the electronic device <NUM>. All or a part of operations executed in the electronic device <NUM> may be executed in one or a plurality of the electronic devices (<NUM>, <NUM>, and <NUM>). For example, when the electronic device <NUM> needs to perform a function or service, the electronic device <NUM> may request one or a plurality of electronic devices to perform part of the whole of the function or service, instead of performing the function or service. The one or a plurality of the electronic devices receiving the request may perform additional function or service related to the request, and transmit a result of the performance to the electronic device <NUM>. To this end, cloud computing, distributed computing, and/or client-server computing technology may be used.

<FIG> is a schematic block diagram of a configuration of the camera module <NUM> provided in the electronic device <NUM> of <FIG>.

Referring to <FIG>, the camera module <NUM> may include a lens assembly <NUM>, a flash <NUM>, an image sensor <NUM>, an image stabilizer <NUM>, a memory <NUM> (a buffer memory, and the like), and/or an image signal processor <NUM>. The lens assembly <NUM> may collect light emitted from an object for image capturing, and may include any one of the above-described phase modulators. The lens assembly <NUM> may include one or more refraction lenses and phase modulators. The phase modulator equipped in the lens assembly <NUM> may have a certain phase profile and a compensation structure, thereby enabling design of a lens with decreasing phase discontinuity. The lens assembly <NUM> equipped with the phase modulator may implement a desired optical performance and a short optical overall length.

In addition, the camera module <NUM> may further include an actuator. The actuator may drive a position of lens elements forming the lens assembly <NUM> and adjust a separation distance between the lens elements, for example, for zooming and/or autofocus (AF).

The camera module <NUM> may include a plurality of lens assemblies <NUM>, and in this case, the camera module <NUM> may include a dual camera, a <NUM> degrees camera, or a spherical camera. Some of the lens assemblies <NUM> may have the same lens attributes (a viewing angle, a focal length, auto focus, F Number, optical zoom, and the like), or other lens attributes. The lens assembly <NUM> may include a wide angle lens or a telescopic lens.

The flash <NUM> may emit light used to reinforce light emitted or reflected from the object. The flash <NUM> may include one or a plurality of light-emitting diodes (a red-green-blue (RGB) LED, a white LED, an infrared LED, an ultraviolet LED, and the like), and/or a xenon lamp. The image sensor <NUM> may convert light emitted or reflected from the object and transmitted through the lens assembly <NUM> into electrical signals, thereby obtaining an image corresponding to the object. The image sensor <NUM> may include one or a plurality of sensors selected from image sensors having different attributes such as an RGB sensor, a black and white (BW) sensor, an IR sensor, or UV sensor. Each sensor included in the image sensor <NUM> may be implemented by a charged coupled device (CCD) sensor and/or a complementary metal oxide semiconductor (CMOS) sensor.

The image stabilizer <NUM> may move, in response to a movement of the camera module <NUM> or an electronic device including the same, one or a plurality of lenses included in the lens assembly <NUM> or the image sensor <NUM> in a particular direction or may compensate a negative effect due to the movement by controlling (adjusting a read-out timing, and the like) the movement characteristics of the image sensor <NUM>. The image stabilizer <NUM> may detect a movement of the camera module <NUM> or the electronic device <NUM> by using a gyro sensor (not shown) or an acceleration sensor (not shown) arranged inside or outside the camera module <NUM>. The image stabilizer <NUM> may be implemented in an optical form.

The memory <NUM> may store a part or entire data of an image obtained through the image sensor <NUM> for a subsequent image processing operation. For example, when a plurality of images are obtained at high speed, only low resolution images are displayed while the obtained original data (Bayer-Patterned data, high resolution data, and the like) is stored in the memory <NUM>. Then, the memory <NUM> may be used to transmit the original data of a selected (user selection, and the like) image to the image signal processor <NUM>. The memory <NUM> may be incorporated into the memory <NUM> of the electronic device <NUM>, or configured to be an independently operated separate memory.

The image signal processor <NUM> may perform one or more image processing on the image obtained through the image sensor <NUM> or the image data stored in the memory <NUM>. The image processing may include depth map generation, three-dimensional modeling, panorama generation, feature point extraction, image synthesis, and/or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, and the like). The image signal processor <NUM> may perform control (exposure time control, or read-out timing control, and the like) on constituent elements (the image sensor <NUM>, and the like) included in the camera module <NUM>. The image processed by the image signal processor <NUM> may be stored again in the memory <NUM> for additional processing or provided to external constituent elements (the memory <NUM>, the display apparatus <NUM>, the electronic device <NUM>, the electronic device <NUM>, the server <NUM>, and the like) of the camera module <NUM>. The image signal processor <NUM> may be incorporated into the processor <NUM>, or configured to be a separate processor operated independently of the processor <NUM>. When the image signal processor <NUM> is configured by a separate processor from the processor <NUM>, the image processed by the image signal processor <NUM> may undergo additional image processing by the processor <NUM> and then displayed through the display apparatus <NUM>.

The electronic device <NUM> may include a plurality of camera modules <NUM> having different attributes or functions. In this case, one of the camera modules <NUM> may be a wide angle camera, and another may be a telescopic camera. Similarly, one of the camera modules <NUM> may be a front side camera, and another may be a read side camera.

<FIG> is a schematic block diagram of a configuration of a 3D sensor <NUM> provided in the electronic device of <FIG>.

Referring to <FIG>, the 3D sensor <NUM> may sense a shape, a movement, and the like of an object by radiating light to the object and receiving and analyzing the light reflected from the object. The 3D sensor <NUM> may include a light source <NUM>, a phase modulator <NUM>, a light detection unit <NUM>, a signal processing unit <NUM>, and a memory <NUM>. Any one of the phase modulators according to the above-described embodiments may be employed as the phase modulator <NUM>, and a target phase delay profile may be set so that the phase modulator <NUM> functions as a beam deflector or a beam shaper.

The light source <NUM> radiates light to be used for analyze the shape or position of an object. The light source <NUM> may include a light source for generating and radiating light of a certain wavelength. The light source <NUM> may include a light source, such as a laser diode (LD), a light emitting diode (LED), a super luminescent diode (SLD), and the like, which generates and radiates light in a wavelength band suitable for analysis of the position and shape of an object, for example, light in an infrared wavelength band. The light source <NUM> may include a wavelength variable laser diode. The light source <NUM> may generate and radiate light in a plurality of wavelength bands different from each other. The light source <NUM> may generate and radiate pulse light or continuous light.

The phase modulator <NUM> modulates the light radiated from the light source <NUM> and transmits the modulated light to the object. When the phase modulator <NUM> is a beam deflector, the phase modulator <NUM> may defect incident light in a certain direction to travel toward the object. When the phase modulator <NUM> is a beam shaper, the phase modulator <NUM> may modulate incident light so that the incident light has a distribution having a certain pattern. The phase modulator <NUM> may form structured light suitable for three-dimensional shape analysis.

The phase modulator <NUM>, as described above, may set a phase delay distribution (∂ϕ/∂λ) to <NUM>, a positive number, or a negative number, and implement a continuous phase delay profile. Accordingly, the phase modulator <NUM> may perform an (achromatic) light modulation having no deviation according to a wavelength. Reversely, the phase modulator <NUM> may enable irradiation of the light to the object with a varied deflection direction for each wavelength or a different beam pattern according to a wavelength, by reinforcing deviation according to the wavelength.

A light detection unit <NUM> may receive reflected light of the light radiated to the object via the phase modulator <NUM>. The light detection unit <NUM> may include an array of a plurality of sensors or only one sensor for sensing light.

The signal processing unit <NUM> may process a signal sensed by the light detection unit <NUM> and analyze the shape, and the like of the object. The signal processing unit <NUM> may analyze a three-dimensional shape of the object including a depth position.

For analysis of a three-dimensional shape, an operation to measure a time of flight may be performed. Various operation methods may be used for measurement of time of flight. For example, a direct time measurement method is to obtain a distance by measuring a time of pulse light that is projected to an object and returned after being reflected from the object. A correlation method is to measure a distance from brightness of pulse light that is projected to an object and returned after being reflected from the object. A phase delay measurement method is a method that projects continuous wave light such as a sine wave to an object, detects a phase difference of light reflected from the object, and converts the phase difference into a distance.

When structured light is radiated to an object, a depth position of the object may be operated from a pattern change of the structured light reflected from the object, that is, a result of comparison with incident structured light pattern. Depth information of an object may be extracted by tracking a pattern change for each coordinate of the structured light reflected from the object, and three-dimensional information related to the shape, a movement, and the like of the object may be extracted from the extracted depth information.

The memory <NUM> may store programs and other data necessary for the operation of the signal processing unit <NUM>.

An operation result of the signal processing unit <NUM>, that is, information about the shape, position, and the like of the object may be transmitted to other unit in the electronic device <NUM> or to another electronic device. For example, such information may be used by the application <NUM> stored in the memory <NUM>. Another electronic device to which the result is transmitted may include a display device or a printer that outputs the result. In addition, another electronic device may include autonomous driving devices such as driverless cars, autonomous cars, robots, drones, and the like, smart phones, smart watches, mobile phones, PDAs, laptops, PCs, various wearable devices, other mobile or non-mobile computing devices, and IoT devices, but the disclosure is not limited thereto.

<FIG> is a schematic block diagram of a configuration of an electronic device <NUM> according to an embodiment.

Referring to <FIG>, the electronic device <NUM> may be provided. The electronic device <NUM> may include an AR device. For example, the electronic device <NUM> may include a glasses-type AR device. The electronic device <NUM> may include a display engine <NUM>, a processor <NUM>, an eye tracking sensor <NUM>, an interface <NUM>, and a memory <NUM>.

The processor <NUM> may control an overall operation of an AR device including the display engine <NUM> by driving an operating system or an application program, and perform processing and operations of various data including image data. For example, the processor <NUM> may process image data including a left-eye virtual image and a right-eye virtual image rendered to have binocular disparity.

The interface <NUM>, through which data or operation commands from the outside is input/output, may include, for example, a user interface such as a touch pad, a controller, an operation button, and the like, which is operable by a user. The interface <NUM> may include a wired communication module such as a USB module or a wireless communication module such as Bluetooth, and may receive user operation information or virtual image data transmitted from an interface included in an external device through these modules.

A memory <NUM> may include an internal memory such as a volatile memory or a non-volatile memory. The memory <NUM> may store various data, programs or applications that drive and control an AR device, and input/output signals or data of virtual images, under the control of the processor <NUM>.

The display engine <NUM> is configured to receive image data generated from the processor <NUM> and generate light of a virtual image, and may include a left-eye optical engine <NUM> and a right-eye optical engine <NUM>. Each of the left-eye optical engine <NUM> and the right-eye optical engine <NUM> may include a light source for outputting light and a display panel for forming a virtual image by using the light output from the light source, and have a function as a compact projector. The light source may be implemented by, for example, an LED, and the display panel may be implemented by, for example, liquid crystal on silicon (LCoS).

The eye tracking sensor <NUM> may be installed at a position where a pupil of a user wearing an AR device is trackable, and may transmit a signal corresponding to user's gaze information to the processor <NUM>. As such, the eye tracking sensor <NUM> may detect gaze information such as the direction of the user's eye, the position of the pupil of the user's eye or the coordinates of a center point of the pupil, and the like. The processor <NUM> may detect the form of an eye movement based on the user's gaze information detected by the eye tracking sensor <NUM>. For example, the processor <NUM> may determine gaze information in various forms including fixation of gazing any one point, pursuit of chasing a moving object, saccade of quickly moving gaze from one point to another point, and the like, based on the gaze information obtained from the eye tracking sensor <NUM>.

<FIG> is a schematic block diagram of the eye tracking sensor <NUM> provided in the electronic device <NUM> of <FIG>.

The eye tracking sensor <NUM> may include an illumination optical unit <NUM>, a detection optical unit <NUM>, a signal processing unit <NUM>, and a memory <NUM>. The illumination optical unit <NUM> may include a light source for radiating light, for example, infrared light, to a position of an object (a user's eye). The detection optical unit <NUM> for detecting reflected light may include a meta lens <NUM> and a sensor unit <NUM>. The signal processing unit <NUM> may operate the position of a pupil of a user's eye and the like from a result of the sensing by the detection optical unit <NUM>.

Any one of the phase modulators and the phase modulator arrays according to the above-described embodiments, a combination thereof, or a modified example thereof may be used as the meta lens <NUM>. The meta lens <NUM> may focus light from the object at the sensor unit <NUM>. In the eye tracking sensor <NUM> located very close to the user's eye, an incident light of light incident on the sensor unit <NUM> may be, for example, <NUM>° or more. The meta lens <NUM> has a structure including a compensation area, and a decrease in efficiency is reduced even for light having a large incident angle. Accordingly, accuracy of gaze tracking may be increased.

The electronic device, which is used not only as an AR device but also as a VR device, may track a user's gaze to a VR image provided by the above device.

Example embodiments may provide a phase modulator and a phase modulator array which stably maintain an over-coupling state.

Example embodiments may provide a phase modulator and a phase modulator array, which have improved light reflection properties.

Example embodiments may provide a phase modulator and a phase modulator array, which have a degree of freedom with respect to a distance between an antenna pattern and a phase change material pattern.

However, the effects of the disclosure are not limited to the contents disclosed herein.

Claim 1:
A phase modulator comprising:
an antenna pattern (<NUM>);
a power source configured to apply an AC voltage to the antenna pattern,
a lower reflective layer (<NUM>) spaced apart from the antenna pattern in a vertical direction;
a spacer (<NUM>) provided between the antenna pattern and the lower reflective layer; and
a phase shift pattern (<NUM>) included in the spacer,
wherein the antenna pattern is configured to generate heat based on the AC voltage applied to the antenna pattern,
and characterized in that:
a refractive index of the phase shift pattern is determined according to a phase of the phase shift pattern and the phase of the phase shift pattern is determined according to a temperature of the phase shift pattern, wherein the phase shift pattern comprises germanium antimony telluride (GeSbTe) or vanadium oxide (VO<NUM>); and
the phase shift pattern is surrounded by the spacer such that the spacer is provided on an upper surface, a lower surface, and both side surfaces of the phase shift pattern and the phase shift pattern is spaced apart from the antenna pattern.