The four-level diffractive triplicator has been optimized to yield the maximum efficiency for such kind of a device. First, the optimization procedure is carried out in the scalar domain, where an analytical approach is used to obtain the values of the grating parameters. Then, a full-wave method is adopted for the analysis of the grating in the resonance domain of the diffractive optics and an algorithm based on genetic evolution is used for the maximization of its efficiency. Numerical results are presented for efficiencies and grating parameters as functions of the grating period, which are shown to tend to those pertinent to the scalar limit when the grating period is very large compared to the wavelength of the incident light.
Borghi, R., Frezza, F., Pajewski, L., Santarsiero, M., Schettini, G. (2001). Optimization of a four-level triplicator using genetic algorithms RID B-3453-2010. JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, 15(9), 1161-1174 [10.1163/156939301X01084].