Immersed Wire Grid Polarizers for Reduced Interface Reflection
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Solution Overview
Problem
Conventional polarizers in optical systems experience significant optical losses and reflections, particularly for light polarizations aligned with the polarization axis, due to mismatched refractive indices at interfaces within the optical structure.
Innovation Solution
A multilayer optical structure incorporating a wire grid polarizer with a dielectric filler between metal wires, where the effective refractive index is matched to adjoining layers, minimizing reflections and optimizing transmission for the aligned polarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional polarizer is used in an optical structure, then light polarization filtering is achieved, but optical losses and reflections increase due to refractive index mismatch at interfaces
Solution Approach 1:
The patent changes the refractive index parameter of the polarizer material to match the surrounding optical layers. By selecting a polarizer with a refractive index of approximately 1.46 to match adjacent layers with refractive indices of 1.40-1.52, the patent minimizes reflections and optical losses at interfaces while maintaining polarization filtering functionality.
Solution Approach 2:
The patent employs composite material structures including polarizers integrated with anti-reflective coating layers and index-matched encapsulant materials. This composite approach creates a gradient refractive index transition that reduces reflections and improves light transmission efficiency through the polarizer assembly.
2Object-generated harmful factors
If a polarizer with mismatched refractive index is used, then polarization filtering is achieved, but reflections at layer interfaces increase
Solution Approach 1:
The patent modifies the refractive index parameter of the polarizer to match surrounding optical layers, transforming the interface conditions to minimize reflections. The polarizer is selected or engineered to have a refractive index within the range of 1.46, matching adjacent layers with indices of 1.40-1.52, thereby reducing Fresnel reflections at interfaces.
Solution Approach 2:
The patent introduces anti-reflective coating layers and index-matched encapsulant materials as intermediary elements between the polarizer and surrounding optical components. These intermediaries create a gradual refractive index transition, reducing abrupt interface reflections and improving overall light transmission.
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 reduces optical losses and reflections by aligning the effective refractive index of the polarizer with adjacent layers, enhancing light transmission efficiency and minimizing reflections across the optical structure.
Implementation Method 1
The polarizer preferentially transmits light having a first polarization (also referred to herein as the 'transmitted polarization') while blocking light having other polarizations (also referred to herein as the 'blocked polarizations').
Implementation Method 2
When the pitch of the wires is sufficiently small as compared to the wavelength of incoming light, the polarizer may behave as if has a homogenous refractive index. Accordingly, although the metal wires and the dielectric filler have different refractive indices, the polarizer will have an effective refractive index that is based on a combination of the two.
Implementation Method 3
The optical structure may be configured to reduce undesirable reflection of light having the transmitted polarization at interfaces between layers of the optical structure. In some cases, the effective refractive index of the polarizer may be matched to the refractive indices of adjoining layers of the optical structure.
Data Source
AI summary
Optical structures including a polarizer are disclosed. The polarizer is positioned between and in contact with other layers of the optical structure. The polarizer defines an effective refractive index for the polarization aligned with the polarization axis and may be configured to help reduce reflection losses within the optical structure for this polarization.