Saez Landete, JoséAlonso Fernández, JoséBernabeu Martínez, Eusebio2023-06-202023-06-202005-05-301094-408710.1364/OPEX.13.004230https://hdl.handle.net/20.500.14352/51197© 2005 Optical Society of America. This research was supported by the national research program, Project No. DPI2004-7334A method to obtain the absolute measure of the position is by means of the autocorrelation of two zero reference marks. In one-axis measurement systems one dimensional mark are used and the design of these marks is relatively complex. When the movement is in two-axes, two dimensional reference marks are required and they are even harder to design. We report a method of global optimization to calculate the optimal two dimensional zero reference marks which generate the reference signal with the highest central peak. This method proves to be a powerful tool for solving this problem.engjournal articlehttp://dx.doi.org/10.1364/OPEX.13.004230http://www.opticsinfobase.orgopen access535Reference MarksSystemsÓptica (Física)2209.19 Óptica Física