Metamaterial Optical Filters for Thin Near-Infrared Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical filters and image sensors struggle to effectively manage optical distortion and improve visibility by controlling light outside the visible light region, particularly in the near-infrared spectrum, while maintaining a thin thickness.
Innovation Solution
An optical filter comprising a near-infrared absorbing layer with metamaterial structures and a compensation layer, designed to absorb and scatter near-infrared light, enhancing light absorption and reducing transmission in the near-infrared spectrum while maintaining high transmittance in the visible spectrum, achieved through a combination of a near-infrared absorbing layer and metamaterial structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional optical filters are used to block near-infrared light, then near-infrared light transmission is reduced, but the filter thickness increases and visible light transmittance decreases
Solution Approach 1:
The patent combines metamaterial structures with conventional near-infrared absorbing materials to create a composite optical filter. The metamaterial structures (such as metal nanodisks or nanorods) work synergistically with the absorbing materials to enhance near-infrared absorption while maintaining thin thickness and high visible light transmittance. This composite approach allows achieving effective near-infrared blocking with a total thickness of less than 1 micrometer, whereas conventional filters would require much thicker layers.
Solution Approach 2:
The patent optimizes critical parameters including the size, shape, spacing, and arrangement of metamaterial structures to achieve resonance frequencies that match near-infrared wavelengths. By carefully controlling the diameter, thickness, and periodic arrangement of metal nanodisks or nanorods, the filter achieves maximum near-infrared absorption at minimal thickness. The spacing between metamaterial structures is optimized to create effective medium behavior while maintaining strong interaction with near-infrared light.
2Object-affected harmful factors
If conventional optical filters are used to block near-infrared light, then near-infrared light transmission is reduced, but visible light transmittance decreases
Solution Approach 1:
The patent applies local quality by designing metamaterial structures with specific geometric properties (size, shape, orientation) that are optimized for interacting with near-infrared light while being transparent to visible light. The metamaterial structures are positioned and dimensioned such that their resonant frequencies align with near-infrared wavelengths, creating strong absorption only in that spectral region. This localized optimization allows the filter to selectively block near-infrared light while maintaining high transmittance across the visible spectrum.
Solution Approach 2:
The patent utilizes parameter changes by tuning the optical properties of metamaterial structures through controlled variations in their geometric parameters. By adjusting the size, shape, and arrangement of metal nanodisks or nanorods, the filter achieves resonance conditions that enhance near-infrared absorption without affecting visible light transmission. The spacing and orientation of metamaterial elements are optimized to create anisotropic optical responses that are selective to near-infrared wavelengths.
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 optical filter achieves high light absorption in the near-infrared spectrum with a thin thickness, significantly increasing visible light transmittance and reducing near-infrared light transmission, thereby improving image sensor performance and camera module functionality.
Implementation Method 1
a plurality of metamaterial structures may be disposed in the near-infrared absorbing layer. The metamaterial structures may enhance the light absorption by the near-infrared absorbing layer
Implementation Method 2
a near-infrared absorbing layer with metamaterial structures and a compensation layer, designed to absorb and scatter near-infrared light
Implementation Method 3
enhancing light absorption and reducing transmission in the near-infrared spectrum while maintaining high transmittance in the visible spectrum
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An optical filter includes a near-infrared absorbing layer including a first material, the first material being configured to absorb light in a first wavelength spectrum belonging to a near-infrared wavelength spectrum. The optical filter includes a compensation layer adjacent to the near-infrared absorbing layer, the compensation layer including a second material different from the first material. The optical filter includes a metamaterial structure spaced apart from the near-infrared absorbing layer via the compensation layer, the metamaterial structure being configured to absorb or reflect light in a second wavelength spectrum at least partially overlapped with the first wavelength spectrum.