FDTD analysis of the optical properties of GaSb-based for 2μm long-wavelength laser application

The optical properties of the surface plasmons (SPs) in metal nanoarray on GaSb thin film have been studied using finite-difference time-domain (FDTD) method in the framework. A systematic investigation for the effects of the different geometry parameters on the surface plasmon resonance(SPR) wavelength was carried out, including radius (R), thickness (T) and the pitch between each Au nanodisk (P) in the periodic arrays. Calculations results indicated that the SPR wavelength of 2 μm can be acquired with the structure of R = 208 nm, H = 10 nm and P = 1011 nm, which mean that it could effectively enhance the luminescence of GaSb-based optoelectronic devices. Such a simple model of GaSb-based material has tremendous potential applications in the highly efficient solid state emitters.