Passive optical switches based on endohedral fullerenes

Although there have been many attempts to find better nanomaterial-based optical limiters {\&} switches in recent years, currently there are only a few effective options for high-energy lasers. Reverse saturable absorption in fullerenes has been widely used to realize excellent passive optical limiters for the visible region up to 650 nm. The electronic structure of fullerenes can be modified by the encapsulation of endohedral clusters to achieve exotic quantum states of matter such as superconductivity. Building on this concept, in this talk, we show that three tri-metallic nitride endohedral fullerenes could alter the HOMO-LUMO gap and allow passive optical switching with a low limiting threshold (0.3 J/cm2) and a wider operation window up to 1064 nm (average pulse energy\textgreater 0.5 mJ in ns regime).