THz cavity based on confined Tamm modes

Resonators with high quality factor and small mode volume are very attractive for many applications in the THz frequency range. Here, we develop a novel THz cavity based on the Tamm modes that combines a distributed Bragg Reflector (DBR) and a metallic mirror. We demonstrate a quality factor higher than 100 at $\sim 1$ THz and good confinement properties. We show that the use of a metallic mirror enables the exploration of a wide range of original properties, among which and frequency tuning, over 30%, using sub-$\lambda$ periodic gold strip mirror.