An adaptive synthesis tool for rib waveguide design

The use of optimization methods to automatically synthesize novel structures is attractive for optoelectronic design. However, the application of such methods to practical components is hindered by the long run times required to evaluate the performance of each particular trial design. This paper investigates, for the first time, how systematically adapting the accuracy of the simulations during the optimization process can be used to speed up the synthesis of effective designs. Adaptive accuracy variation is achieved in two ways: altering the acceptable error demanded of a particular simulation method and using a hierarchy of different methods. This novel method of synthesis is applied to quickly obtain optimal rib waveguide structures for two practical problems, namely modal degeneracy and low-loss fiber coupling.