Silver Alloy Optical Filters with Ion-Assisted Dielectric Barriers
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Solution Overview
Problem
Metal-dielectric color filters with silver layers are environmentally unstable due to exposure to water and oxygen, limiting their optical design possibilities and requiring precise thickness adjustments for different color passbands.
Innovation Solution
A fabrication method using high-power ion-assisted deposition for dense dielectric layers and low-power ion-assisted deposition without oxygen for thin dielectric layers, sandwiching silver alloy layers to enhance stability and prevent oxidation, allowing for varied optical filter designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silver layers are used in metal-dielectric color filters, then the filters are inherently IR-blocking and have narrow color passbands, but the silver layers deteriorate when exposed to water or oxygen
Solution Approach 1:
A barrier layer is introduced as an intermediary between the silver layer and the environment. This barrier layer prevents direct contact between the silver layer and harmful substances (water and oxygen), thereby protecting the silver layer from deterioration while maintaining the optical filtering function.
Solution Approach 2:
The invention creates a composite structure consisting of multiple layers including the silver layer, barrier layer, and optical filter layers. This composite material approach combines the IR-blocking property of silver with the protective function of the barrier layer and the optical filtering function of the dielectric layers, achieving both reliability and functionality.
2Adaptability or versatility
If chemically etching is used to pattern silver layers, then different color passbands can be achieved, but the silver layers are exposed to the environment allowing deterioration
Solution Approach 1:
The barrier layer serves as a protective intermediary that remains intact during the chemical etching process. It allows for patterning of the optical filter layers to achieve different color passbands while simultaneously protecting the silver layer from environmental exposure during and after the etching process.
3Adaptability or versatility
If multiple types of metal-dielectric color filters are required for different color passbands, then color filtering can be achieved, but the device complexity and fabrication requirements increase
Solution Approach 1:
The invention creates a universal filter structure where the same basic configuration (silver layer + barrier layer + optical filter layers) can achieve different color passbands by adjusting the optical filter layer parameters. This multi-functional design eliminates the need for multiple specialized filter types, reducing device complexity while maintaining versatility.
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 method improves the reliability of silver layers by suppressing diffusion and oxidation, enabling the creation of reliable and versatile optical filters such as IR-cut, red, green, and blue filters with adjustable wavelength ranges.
Implementation Method 1
the plurality of first dielectric layers are formed by performing high-power ion-assisted deposition
Implementation Method 2
high-power ion-assisted deposition has a beam voltage which is in a range from about 1,000V to about 1,500V
Data Source
AI summary
A method for fabricating an optical element is provided. The fabrication method includes the following steps. A substrate is provided. A plurality of first dielectric layers, a plurality of metal layers of Ag or its alloy and a plurality of second dielectric layers are formed over the substrate. The plurality of first dielectric layers and the plurality of metal layers are alternately formed over the substrate. The plurality of second dielectric layers are formed on one side away from the substrate of the plurality of metal layers and located between the plurality of metal layers and the plurality of first dielectric layers. An optical element fabricated by the method is also provided.