Universal Apparatus & Method to Certify Infrared Optical Material Properties

This SBIR Phase I proposal proposes the feasibility study leading to aáuniversal refractometryáapparatus to certify infrared (IR) optical material properties of refractive indices and its dependence on wavelength and temperature, in the 3-12ámm.áTheáapparatus is housed inside a temperature chamber with temperature range -73 oC to 85 oC to allow the measurement of complex refractive index of various samples of Germanium (Ge), ZnS, ZnSe, GaAs, BaF?, AMTIR-1, IRG-24, etc., over -40ľ70 oC temperature range. The apparatus overcomes the limitations by spectroscopic ellipsometry (SE) which yields material refractive indices that vary with the measuring beam incident angle, and by interferometry that needs very high precision surface treatment of the sample. The apparatus can measure indices of not only transparent but also lossy IR material with a precision better than 0.001.During Phase I, a thorough investigation into the apparatus hardware design, data collection algorithm and software, as well as performance assessment based on both experiment tests and mathematical evaluation will be conducted followed by a pre-prototype integration and validation. Various aspects, such as data reliability, measurement precision, data collection and process time, and endurance will be analyzed to guarantee that the chosen platform can proficiently perform and maintain a stable measurement, with a preliminary design reaching TRL 3.á The Phase II is to develop and validate the prototype of TRL 6 or higher.