Holographic Notch Filter for Laser Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current laser protection filters are complex, costly, and often restrict visible light transmission, making them unsuitable for aircraft windshields, as they are either rigid or cause significant color distortion due to limited wavelength blocking capabilities.
Innovation Solution
A method involving a holographic exposure process on a photosensitive polymeric film to create notch filter regions that precisely block specific laser wavelengths while incorporating color balancing regions to maintain high visible light transmission and prevent color distortion, allowing for the formation of conformable filters that can block multiple laser threats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a nanoparticle metamaterial structure is used to block laser wavelengths, then laser protection is achieved, but the film becomes complex and costly to manufacture
Solution Approach 1:
The patent changes the fundamental parameter of filter structure from complex nanoparticle metamaterials to simple holographic notch filters. By using holographic exposure to create periodic refractive index modulations, the patent achieves laser wavelength blocking without the complex multi-layer nanoparticle structures, thereby reducing manufacturing complexity while maintaining protection effectiveness.
Solution Approach 2:
The patent replaces the physical nanoparticle metamaterial structure with an optical field-based holographic pattern. Instead of using complex material arrangements, the invention uses interference patterns from coherent light sources to create the filtering effect, substituting a mechanical/material system with an optical field system that is simpler to manufacture.
2Object-affected harmful factors
If a nanoparticle metamaterial structure is used to block laser wavelengths, then laser protection is achieved, but the manufacturing cost increases
Solution Approach 1:
The patent employs conventional photosensitive polymeric materials and standard holographic exposure equipment instead of expensive nanoparticle metamaterial fabrication processes. The use of off-the-shelf photopolymers and commercial holographic lasers significantly reduces material and equipment costs compared to specialized nanoparticle synthesis and assembly required for metamaterial structures.
Solution Approach 2:
The patent replaces expensive nanoparticle fabrication and assembly processes with a straightforward holographic exposure process. The optical field-based approach using interference patterns eliminates the need for complex nanofabrication equipment and specialized manufacturing facilities, thereby reducing overall manufacturing costs.
3Ease of manufacture
If a holographic exposure process is used to form a transparent filter, then the filter is conformable and easy to manufacture, but the blocked wavelength bandwidth is high causing pronounced color distortion and low visible light transmission
Solution Approach 1:
The patent divides the filtering function into multiple discrete notch filters, each targeting a specific laser wavelength. Instead of using a single broad-band holographic filter that blocks large wavelength ranges, the invention creates multiple narrow notches at specific wavelengths (e.g., 532nm, 650nm, 445nm), allowing other visible wavelengths to pass through, thereby maintaining high overall visible light transmission while providing targeted laser protection.
Solution Approach 2:
The patent applies local quality by creating spatially distributed notch filters with different wavelength specificities across the filter substrate. Each region of the filter can be optimized for specific laser threats while maintaining overall transparency. The holographic patterns are locally tuned to block only the necessary laser wavelengths rather than applying a uniform broad-band filtering approach across the entire filter.
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 solution achieves high visible light transmission (>70%) while effectively blocking multiple laser wavelengths, reducing the risk of color distortion and ensuring clear visibility for pilots, even when multiple laser threats are present.
Implementation Method 1
holographic exposure of a photosensitive polymeric film
Implementation Method 2
configured to substantially block incident radiation thereon of wavelengths within a first predetermined wavelength band
Data Source
AI summary
A method of forming a filter, comprising the steps of: —selecting at least a first wavelength corresponding to a predetermined laser threat and having a first colour in the visible spectrum; —providing a generally transparent substrate and forming a first notch filter region therein configured to substantially block incident radiation thereon of wavelengths within a first predetermined wavelength band including said first wavelength; —selecting a second wavelength having a second colour in the visible spectrum and forming a colour balancing notch filter region in said substrate configured to block incident radiation thereon of wavelengths within a wavelength band including said second wavelength, thereby to balance or neutralise any colour distortion of said substrate caused by said first notch filter region.