Athermal Optical Frameworks for Stable Lens Alignment
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Solution Overview
Problem
Optical elements experience alignment loss due to thermal expansion and contraction, affecting the focus and functionality of telescopes and laser optics, particularly in varying ambient temperatures.
Innovation Solution
Athermal optical frameworks are designed with multiple framework portions made of materials with varying lengths and thermal expansion coefficients, where the thermal expansion of one portion is offset by another to maintain a constant distance between lenses despite temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical elements are supported by a conventional framework, then the framework provides structural support, but thermal expansion and contraction cause alignment loss between lenses
Solution Approach 1:
The patent applies thermal expansion by selecting framework materials with different coefficients of thermal expansion to counteract each other. The first framework portion uses a material with a higher coefficient of thermal expansion, while the second framework portion uses a material with a lower coefficient, creating a balanced system where thermal expansions offset each other to maintain constant lens alignment.
Solution Approach 2:
The patent employs composite materials by combining different framework materials (such as metals and polymers or ceramics) with distinct thermal expansion properties. This composite approach allows the framework to leverage the complementary thermal characteristics of each material, achieving net-zero thermal displacement while maintaining structural integrity.
2Device complexity
If the framework is made of a single material, then the structure is simple, but it cannot compensate for thermal expansion effects
Solution Approach 1:
The patent segments the framework into distinct portions (first framework portion and second framework portion), each made from different materials with specific thermal expansion coefficients. This segmentation allows independent selection of materials optimized for their thermal characteristics, enabling the overall structure to compensate for thermal effects while maintaining manageable complexity.
Solution Approach 2:
The patent applies local quality by assigning different material properties to different portions of the framework based on their specific functional requirements. The first framework portion uses a material suited for its location and load, while the second framework portion uses a different material optimized for its thermal compensation role, creating a heterogeneously optimized structure.
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 frameworks ensure precise optical alignment by canceling out thermal expansion effects, maintaining lens spacing and optical performance across a wide temperature range.
Implementation Method 1
The first and second framework portions are formed of distinct materials such that thermal expansion of the first framework portion is equal and opposite to thermal expansion of the second framework portion
Data Source
AI summary
Configurations and compositions for frameworks supporting optics such as lenses are described that provide an invariant structure regardless of temperature swings, thereby maintaining alignment and focus. Frameworks may comprise tiered structures of materials having multiple distinct coefficients of thermal expansion. An optical framework includes a first framework portion coupled to a first lens and a second framework portion coupled to a second lens. The first framework portion and second framework portion comprise materials having a coefficient of thermal expansion such that expansion of the first framework portion in one direction is offset by expansion of the second framework portion in an opposite direction.