Ultimate electric field enhancement through terahertz nanocavity enabled by the inverse design method

This study proposes an inverse design method that combines an analytical solution for terahertz nanocavities with a double deep Q-learning algorithm. Through this approach, optimization was successfully achieved via the inverse design method, which was not possible with numerical simulation methods. The terahertz nanocavity consists of a loop nanogap array structure, and an ultimate electric field enhancement of more than 30,000 times was experimentally achieved.