Dependence of Q Factor on Surface Roughness in a Plasmonic Cavity

作者：Kim Yoon Ho; Kwon Soon Hong; Ee Ho Seok; Hwang Yongsop; No You Shin; Park Hong Gyu^*

来源：Journal of the Optical Society of Korea, 2016, 20(1): 188-191.

DOI：10.3807/JOSK.2016.20.1.188

• Surface plasmon polaritons
• Plasmonic cavities
• Surface roughness
• Finite-difference time-domain simulations

We investigated surface-roughness-dependent optical loss in a plasmonic cavity consisting of a semiconductor nanodisk/silver nanopan structure. Numerical simulations show that the quality factors of plasmonic resonant modes significantly depend on the surface roughness of the dielectric-metal interface in the cavity structure. In the transverse-magnetic-like whispering-gallery plasmonic mode excited in a structure with disk diameter of 1000 nm, the total quality factor decreased from 260 to 130 with increasing root-mean-square (rms) surface roughness from 0 to 5 nm. This quantitative theoretical study shows that the smooth metal surface plays a critical role in high-performance plasmonic devices.

• 出版日期2016-2