Efficient third-harmonic generation based on Tamm plasmon polaritons.

We theoretically investigate efficient third-harmonic generation (THG) in the heterostructure with a one-dimensional photonic crystal (PC) and a thick metal film. There are both the fundamental Tamm plasmon mode and the high-order mode in the heterostructure. Commonly these two Tamm plasmon modes just satisfy single-resonance condition, but the double-resonance condition can be fulfilled by using a binary PC in the heterostructure. Taking advantage of the tunneling effect of Tamm plasmon modes, THG in the single-resonance heterostructure is enhanced over 3 orders of magnitude more than that in the single metal film, and that in the double-resonance one is further enhanced nearly 2 orders of magnitude.