Dielectric Microstructure Step for Angular-Selective Shielding
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Solution Overview
Problem
Current techniques fail to effectively shield sub-wavelength-scale objects, such as quantum dots, from electromagnetic waves, particularly for angular-selective shielding, which is crucial for transparent displays and augmented reality glasses exposed to ambient light, as existing methods like smart glass and metamaterial cloaking face limitations in dynamic and static shielding respectively.
Innovation Solution
A dielectric microstructure with a step of refractive index is used to create quiet zones and nanojet beams, allowing for angular-selective shielding of sub-wavelength-scale objects by generating a low electromagnetic field intensity region, known as a quiet zone, where objects can be hidden from incident electromagnetic waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If smart glass is used for shielding, then dynamic shielding capability is improved, but the shielding is not angular-selective and cannot protect from specific directions
Solution Approach 1:
The patent applies local quality by creating a dielectric microstructure with a localized step of refractive index at a specific position and orientation. This step structure is positioned to interact with electromagnetic waves from a particular direction, creating angular-selective shielding. The local geometric feature (the step) provides direction-dependent electromagnetic field manipulation, allowing shielding from specific angles while maintaining transparency from other directions.
2Object-affected harmful factors
If metamaterial cloaking is used, then angular-selective shielding is improved, but the device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The patent employs parameter changes by utilizing a simple dielectric material with a specific refractive index rather than complex metamaterials. The key parameter is the step of refractive index created by the dielectric layer, which can be controlled by adjusting the layer thickness and positioning. This approach achieves angular-selective shielding through geometric parameter optimization (step position, height, and orientation) rather than complex material composition, significantly reducing manufacturing complexity.
3Object-affected harmful factors
If a dielectric microstructure with step of refractive index is used, then angular-selective shielding is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies partial action by creating a step structure that only needs to be precise in the critical dimension affecting angular selectivity (the step height and position), while other dimensions can have larger tolerances. The design focuses manufacturing precision on the essential parameters that control the electromagnetic field interaction, allowing less critical dimensions to be manufactured with standard tolerances, thereby reducing overall manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution provides effective angular-selective shielding of sub-wavelength-scale objects, preventing unwanted excitation and degradation, and can be implemented using standard micro-fabrication technologies, making it suitable for various optical applications including QD displays and AR glasses.
Implementation Method 1
A dielectric microstructure with a step of refractive index is used to create quiet zones and nanojet beams, allowing for angular-selective shielding of sub-wavelength-scale objects by generating a low electromagnetic field intensity region
Implementation Method 2
the formation of one or several quiet zone(s) and nanojet beam(s) in the near zone appears with a plane (or locally plane) wave incident on the device
Data Source
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Figure 3~4(e)
Figure 5~5(e)
AI summary
A device for shielding at least one sub-wavelength-scale object (10) from an electromagnetic wave (20), which is incident on said device, comprises at least one layer of a dielectric material (Media 1), a surface of which having at least one abrupt change of level forming a step. At least a lower and lateral part of said surface with respect to said step is in contact with a medium (111) having a refractive index (n2) lower than that (n1) of said dielectric material. Said at least one sub-wavelength-scale object (10) is located within said device in a quiet zone (QZ) where an electromagnetic field intensity is below a threshold, said quiet zone extending above said surface, in the vicinity of said step, in a direction of incidence of said electromagnetic wave (20).