Dual photonic band gap and reversible tuning of 3D photonic crystal fabricated by multiphoton polymerization with photoresponsive polymer

A 3D woodpile photonic crystal (PhC) composed of two parts with different periodic parameters was fabricated with a novel photoresist containing photoresponsive azobenzene moieties by multiphoton polymerization. Dual photonic band gaps (PBGs) were experimentally measured, which were attributed to two independent parts of the 3D PhC with different periodicities. Under light irradiation, PBG tuning of 36 nm was obtained, and this tuning behavior showed good reversibility.