Saez Landete, JoséSalcedo Sanz, SanchoRosa Zurera, ManuelAlonso Fernández, JoséBernabeu Martínez, Eusebio2023-06-202023-06-202005-10-150146-959210.1364/OL.30.002724https://hdl.handle.net/20.500.14352/51195© 2005 Optical Society of America. This research was supported by the National Research Program project DPI2004-7334 and by a project of the Universidad de Alcalá (UAH PI2005/078).A new technique for the generation of optical reference signals with optimal properties is presented. In grating measurement systems a reference signal is needed to achieve an absolute measurement of the position. The optical signal is the autocorrelation of two codes with binary transmittance. For a long time, the design of this type of code has required great computational effort, which limits the size of the code to ~30 elements. Recently, the application of the dividing rectangles (DIRECT) algorithm has allowed the automatic design of codes up to 100 elements. Because of the binary nature of the problem and the parallel processing of the genetic algorithms, these algorithms are efficient tools for obtaining codes with particular autocorrelation properties. We design optimum zero reference codes with arbitrary length by means of a genetic algorithm enhanced with a restricted search operator.engjournal articlehttp://dx.doi.org/10.1364/OL.30.002724http://www.opticsinfobase.orgopen access535OpticsÓptica (Física)2209.19 Óptica Física