Metalens Ring Segmentation for Isotropic Peripheral Diffraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing metalenses face challenges in achieving isotropy of optical characteristics and high diffraction efficiency in peripheral regions due to anisotropic pillar arrangements, which lead to sparse pillar placement and reduced phase modulation at distances from the optical center.
Innovation Solution
A lens design with a central region and multiple ring-shaped peripheral regions, where the angular intervals in the peripheral regions follow an integer ratio, ensuring constant intervals and symmetry, allowing for optimized pillar placement and phase modulation across the lens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pillars are arranged at constant angular intervals in peripheral regions, then isotropy of optical characteristics is ensured, but pillar placement becomes sparse at longer distances from the optical center, reducing phase modulation capability and diffraction efficiency
Solution Approach 1:
The lens is divided into a center region and multiple peripheral regions (first, second, etc.). Each peripheral region has a different angular interval ratio, allowing independent optimization of pillar arrangement in each segment. This segmentation enables the lens to achieve both isotropy in each region and sufficient phase modulation capability by adjusting the number of pillars in each segmented region.
Solution Approach 2:
Different peripheral regions are assigned different angular interval ratios (M1:M2:M3...). The inner peripheral region has a larger angular interval ratio while outer peripheral regions have smaller ratios. This local differentiation allows each region to have optimized pillar density according to its specific optical requirements, maintaining isotropy while ensuring sufficient phase modulation capability in each local area.
2Manufacturing precision
If angular intervals are shortened at longer distances from the optical center to increase diffraction efficiency, then diffraction efficiency improves, but isotropy may be broken near boundaries where angular intervals change
Solution Approach 1:
By segmenting the lens into distinct peripheral regions with clearly defined boundaries and different angular interval ratios, the patent creates discrete zones where isotropy can be maintained within each segment. The segmentation prevents the isotropy breakdown that would occur with continuous angular interval variation, as each segment maintains its own consistent angular spacing.
Solution Approach 2:
Each peripheral region employs periodic pillar arrangement with constant angular intervals specific to that region. This periodic structure ensures isotropy within each region while the transition between regions with different periodicities allows for optimized diffraction efficiency at different radial distances without breaking isotropy within the periodic zones.
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 design achieves isotropic optical characteristics and high diffraction efficiency in peripheral regions, enhancing performance and ease of manufacturing by maintaining consistent pillar spacing and symmetry.
Implementation Method 1
A metalens achieve a desired lens function by modulating the phase of incident light with its microstructures and emitting outgoing light having a desired phase distribution
Implementation Method 2
A bulk lens achieves a desired lens function by refracting incident light in accordance with a thickness distribution at an interface and emitting the light at a desired emission angle based on the Snell's law
Implementation Method 3
A metalens achieve a desired lens function by modulating the phase of incident light with its microstructures
Data Source
AI summary
The present technology relates to a lens, an imaging device, and a light emitting device that enable achievement of isotropy of optical characteristics and a high diffraction efficiency in a peripheral region at a distance from the optical center of the lens. A metalens includes: a center region located in a central portion; and a plurality of ring-shaped peripheral regions located around the center region. In the metalens, a pattern in the peripheral regions has constant intervals in an angular direction, an angular interval Δθk:Δθk+1 is an integer ratio Mk:Mk+1, where Δθk represents an angular interval in the k-th peripheral region from the inner side among the peripheral regions, and Δθk+1 represents an angular interval in the (k+1)-th peripheral region from the inner side, the (k+1)-th peripheral region being adjacent to the k-th peripheral region, and the Mk+1 is an integer smaller than 10.