Enhancement of near-field radiation transfer using nano-scaled pillar-array structured surfaces

Abstract

Electromagnetic field and its energy density around a nano-sized gap between two pillar array structured surfaces were numerically calculated using a three-dimensional Finite Difference Time Domain (FDTD) method. The simulation results show that a normalized spectral radiation flux became significantly higher and the wavelength at the peak of normalized radiation flux was shifted from a short regime to a long regime with decreasing pillar width. In addition, the results also show that the near-field radiation transfer was limited and concentrated in a narrow area in the nano-sized gap with decreasing pillar width. As a result, the near-field radiation transfer was enhanced by decreasing width of pillar.