Thermal Expansion Mapper

The proposed innovation is aimed at the Focus Area 10 - Advanced Telescope Technologies, subtopic S2.03 - Advanced Optical Systems and Fabrication/Testing/Control Technologies for Extended-Ultraviolet/Optical and Infrared Telescope (Scope Title: Fabrication, Test, and Control of Advanced Optical Systems). Specifically, NASA needs a reliable, easy-to-use metrology solution that allows highly precise characterization of thermal expansion of large-format glass substrates (e.g. 4-m class Zerodur or 2-m class ULE). To address the NASA need, Hedgefog Research Inc. (HFR) proposes to continue development of its unique Thermal Expansion Mapper (TEM), which provides ultra-precise, rapid, nondestructive characterization of the coefficient of thermal expansion (CTE) homogeneity. HFRrsquo;s TEM offers a highly sensitive, stable, and scalable sensor package with low system overhead that allows 1 ppb/K-level CTE characterization over a few days/weeks for large-format glass substrates. In TEM,nbsp;HFR adopts multiple design features that eliminatenbsp;various systematic/random error sources in displacement sensing, thereby providing high sensitivity and repeatability in the presence of environmental perturbations (e.g., temperature variation, vibration, presence of dust, etc.). This new characterization capability promises significant savings in time and cost by allowing the selection of mirror substrates before they undergo costly manufacturing process to turn into lightweight space mirrors for NASArsquo;s telescopes.