The preparation, characterization and application of ultra-smooth, low-loss plasmonics noble metal films

Since its discovery, plasmonics has become one of the most popular topics in the field of nano-optics due to its unprecedented capability of harvesting and localizing electromagnetic fields down to diffraction-unlimited length scales. However, the application of plasmonic effects has long been hindered by the difficulties in controlling the surface morphology and reducing the optical loss of noble metal films, which not only hinders the progress of its experimental research, but also cast a shadow on its application prospects in many fields. With the fast development of nanofabrication technologies, the surface roughness and optical loss of noble metal films is getting closer the theoretical expectation, while the preparation technology is becoming precisely controllable, which lets it play an important role not only in the traditional field, but in may emerging fields as well. In this review, we systematically summarize the recent progress in preparation, characterization and application of ultra-smooth, low-loss noble metal films.