????????? ENZ ????????? ???????????? ??????

In this talk, we will discuss our recent work on natural ENZ materials. We have investigated various ENZ responses, using ultra-thin, doped semiconductors and conducting oxides: (i) Novel strong coupling between a planar metamaterial and an ENZ mode, (ii) Narrowband thermal emission from an ENZ material, (iii) Perfect absorption in an ENZ material. More recently, we could successfully prepare an ITO multilayer that exhibit broadband perfect absorption in the near-infrared frequency range. Similar ideas can be implemented in the visible region too. This could be interesting for many optical devices based on thin films