Recently, there has been a significant interest in performing holistic design of microwave and optical systems driven by the emergence of new requirements in the areas such as 5G and 6G communications, Internet of Things (IoT), Wireless Power Transfer (WPT), and advanced radar technologies. The RF, microwave, mmWave antenna and optical systems are therefore expected to attain more stringent objectives such as higher radiation efficiency, agile beam steering capabilities, larger data rates, high transmission throughput, multiband and/or broadband operation, etc. Due to these increasingly challenging requirements, optimization techniques are often indispensable to achieve a system design that satisfies the above specified objectives. The optimization methodologies catering to these complex problems are in general often plagued by computational bottlenecks arising from multiple function calls (forward full-wave solutions), poor convergence, improper choice of initial guess, inaccuracies in gradient computations, etc. Therefore, there is a significant need and an interest in finding new and improved optimization techniques to efficiently explore these complex design search spaces.

We invite researchers to contribute original papers that describe emerging optimization approaches that advance the start-of-the-art in electromagnetic (EM) and optical device design. The purpose of this special issue is to publish high-quality research papers addressing recent advances in optimization techniques used for synthesizing RF, microwave, mmWave, metamaterials, and optical devices. The scope of exploration within this special journal cluster encompasses a diverse spectrum of potential topics. These range from genetic algorithms (GAs), particle swarm optimization (PSO), covariance matrix adaptation evolution strategy (CMA-ES), derivative-free techniques, gradient-based methods, and beyond. These potential areas of investigation represent just a fraction of the expansive terrain this cluster aims to traverse, inviting contributions that shape the trajectory of powerful optimization algorithms used for synthesizing novel electromagnetic and optical devices.