High Refractive Index Adhesive for IR Beam Splitters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a lack of a suitable transparent adhesive with a high refractive index for middle (3.0-5.0 μm) and far (8.0-12.0 μm) infra-red wavelength bands, which is necessary for beam splitter prism sets used in electro-optical monitoring systems, as existing adhesives do not meet the required refractive index matching and optical transparency, leading to beam misalignment and image aberrations.
Innovation Solution
A metallic-nonmetallic adhesive composition with a refractive index of 2.0 or higher, specifically Ti(IV) Ax formulation, is used to join optical elements, ensuring optical transparency, good adhesion, and stability across varying environmental conditions, and is applied in a solid phase to prevent light loss and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional adhesives are used to join optical elements, then the adhesive can be applied and joined, but the refractive index mismatch causes beam misalignment and image aberrations
Solution Approach 1:
The patent changes the refractive index parameter of the adhesive by selecting specific materials (ZnSe with n=2.43, ZnS with n=2.24) that match the optical elements' refractive indexes. This parameter matching eliminates beam misalignment and image aberrations, resolving the contradiction between manufacturing precision and optical transmission reliability.
Solution Approach 2:
The patent uses composite adhesive materials consisting of zinc selenide and zinc sulfide with specific refractive index characteristics. These composite materials provide both the required mechanical bonding strength and the optical properties (refractive index matching) necessary for precise beam alignment and reliable optical transmission in middle and far infra-red wavelength bands.
2Manufacturing precision
If an adhesive with high refractive index (2.0 or higher) is used, then beam alignment is improved, but finding a suitable adhesive material becomes difficult
Solution Approach 1:
The patent identifies and specifies particular materials (ZnSe and ZnS) with refractive indexes of 2.43 and 2.24 respectively, which are suitable for middle and far infra-red applications. By changing the parameter specification to match these specific materials, the patent makes high refractive index adhesives practically available and manufacturable.
Solution Approach 2:
The patent applies the principle of local quality by selecting adhesive materials with specific local properties (refractive index, transparency in infra-red bands) that match the requirements of the optical elements. This localized material selection ensures both beam alignment precision and material availability.
3Ease of operation
If the adhesive refractive index is significantly different from the optical units, then the adhesive can be easily applied, but the critical angle becomes very small causing beam path deviation
Solution Approach 1:
The patent changes the refractive index parameter of the adhesive to match the optical elements (n=2.43 for ZnSe, n=2.24 for ZnS). This parameter matching increases the critical angle according to Snell's law, ensuring that beams follow the correct path through the optical units without deviation, while still allowing for practical adhesive application.
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 adhesive effectively joins optical elements with high refractive indexes, maintaining integrity and functionality in challenging conditions, allowing for accurate beam separation and reduction of image aberrations in electro-optical monitoring systems, particularly in thermal monitoring systems.
Implementation Method 1
The refractive index shall have the refractive index value of at least one of the triangle prisms to be joined or shall be close to its refractive index... If there is significant difference between mentioned refractive indexes, critical values determined according to Snell law will be very small. Therefore due to mentioned small critical angle, the coming beam will follow a different path instead of transmitting over the optical units.
Data Source
AI summary
An adhesive with a refractive index of 2.0 and over is transparent at an infra-red band. A production method of the adhesive and a beam splitter prism set is provided. The beam splitter prism set separates middle and far infra-red beam paths for electro-optical monitoring systems according to wavelengths of the middle and far infra-red beam paths, wherein in the electro-optical monitoring systems the adhesive is used.