A DoE-enhanced method to determine the temperature coefficients of LGS

An inverse method based on Simulated Annealing was proposed in previous work, to help determining the first and second order temperature coefficients of the components of the LGS material tensors. The motivation and objective of this work were to improve the method, by drastically reducing the optimization time that lasted from several hours to several days. The main idea was to use the Design of Experiments approach, to reduce the slow numerical algorithm commonly used to compute the required Fractional Frequency Changes curves (FFC) to simple analytical formulas (one formula per cut). In this paper, two such formulas are derived for two distinct LGS cuts. The formulas describe the FFCs with a good enough accuracy. This validates the general feasibility of the method.