Tunable Nano-Pattern Generation Based on Surface Plasmon Polaritons

We present a numerical observation of a tunable 1D and 2D nano-pattern generation and photolithography technique based on a surface plasmon resonant cavity formed by a metallic grating and a metallic thin-film layer separated by a photoresist layer. The tuning capability is implemented by varying the cavity length combined with the polarization of the incident light, from which different surface plasmon interferometric patterns can be generated in the cavity of photoresist layer with a fixed phase mask. The technique opens a new possibility to generate tunable ultra-deep subwavelength patterns by using a fixed diffraction-limited mask with capability of large area, deep exposure depth and flexibility of arbitrary 2D patterns.