Quasi normal mode perturbation theory to achieve Q factor optimization of resonances in disordered photonic systems

The optimization of the quality factor (Q) of photonic resonators is of great importance for applications exploiting both ordered and disordered systems. Here we propose a gradient-based automated optimization approach to maximize the Q of optical resonances in ordered and disordered dielectric slabs which uses first-order non-hermitian perturbation theory. By applying our method to optimize a selected Anderson mode in a random design exhibiting a Q-factor of 200, a new mode displaying Q = 105 is generated.