Multilayer Meta-Optics for Broadband Phase Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing meta-structure devices suffer from light efficiency reduction due to discontinuities in phase delay profiles, particularly when operating across a broadband wavelength range, leading to unintended light diffraction.
Innovation Solution
A meta-optical device with a multi-layer structure, where each layer has different refractive index characteristics and dispersion properties, minimizing phase discontinuity by using nanostructures with specific materials and arrangements to achieve a continuous phase delay profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-layer meta-structure is used to achieve a simple device structure, then device complexity is reduced, but phase discontinuity occurs leading to reduced light efficiency
Solution Approach 1:
The meta-optical device is divided into multiple layers, each layer contributing a portion of the total phase delay. This segmentation allows the phase profile to be constructed continuously across layers, avoiding the discontinuities that occur in single-layer designs and thereby maintaining high light efficiency while managing device complexity.
Solution Approach 2:
The solution transitions from a two-dimensional single-layer structure to a three-dimensional multi-layer structure. By adding the vertical dimension (z-axis) with multiple layers, the device achieves continuous phase control that is impossible in a single layer, resolving the contradiction between structural simplicity and optical performance.
2Manufacturing precision
If a meta-structure is designed for a specific wavelength to achieve optimal phase control, then phase delay precision is improved, but the device fails to operate efficiently across a broadband wavelength range
Solution Approach 1:
Each layer is designed with specific refractive index and thickness parameters that are optimized for different portions of the wavelength spectrum. By varying these parameters across multiple layers, the device achieves broadband operation while maintaining precise phase control at each wavelength, resolving the contradiction between wavelength-specific optimization and broadband versatility.
Solution Approach 2:
The device uses multiple layers with different material compositions and refractive indices. This composite structure allows each layer to contribute differently to the overall phase delay across the spectrum, enabling the device to maintain high efficiency across a broad wavelength range rather than being limited to a single wavelength.
3Device complexity
If discontinuity appears in the phase delay profile to simplify the design process, then design complexity is reduced, but light diffraction occurs in unintended directions reducing light efficiency
Solution Approach 1:
The phase delay profile is segmented across multiple layers rather than attempting to achieve it in a single layer. Each layer contributes a continuous portion of the phase profile, and the cumulative effect of all layers produces the desired overall phase distribution without discontinuities, thereby maintaining high light efficiency while keeping design manageable through modular layer design.
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
The device operates with high efficiency and minimal light loss across a broad spectrum, enabling applications such as ultra-thin lenses and beam shaping for mobile devices and augmented reality systems.
Implementation Method 1
a first layer 121 includes a plurality of first nanostructures NS1... configured to modulate a phase of incident light L... to exhibit a first phase delay profile... a second layer 161 includes a plurality of second nanostructures NS2... configured to modulate the phase of the incident light L to exhibit a second phase delay profile
Implementation Method 2
The first nanostructure NS1 may have a higher refractive index than the first surrounding material EN14... The second nanostructure NS2 may have a higher refractive index than the second surrounding material EN24... different refractive index characteristics
Implementation Method 3
each layer has different refractive index characteristics and dispersion properties... The first layer 121 and the second layer 161 may have different ratios of a dispersion change rate to an effective refractive index change rate
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a meta-optical device including a first layer (120) including a plurality of first nanostructures (NS1) with sub-wavelength dimensions and a first material disposed adjacent to the plurality of first nanostructures, a second layer (160) disposed on the first layer, the second layer including a plurality of second nanostructures (NS2) with sub-wavelength dimensions and a second material disposed adjacent to the plurality of second nanostructures, wherein the phase delay of the second layer is chosen to compensate for the wavelength dependent deviations from the target phase delay by choosing for either the first or the second material of the first or second nanostructures a material with a high index of refraction and low dispersion and for the other one a material with a low refractive index and a high dispersion to compensate for chromatic aberration due to wavelength dispersion.