The micro-cavity of the two dimensional plasmonic photonic crystal

College of Electrical Engineering, Yanshan University, West of Hebei Avenue 438, Qinhuangdao 066004, P.R. China

^a email: tongkai@ysu.edu.cn

Received: 15 April 2014
Revised: 22 July 2014
Accepted: 1 October 2014
Published online: 20 February 2015

Abstract

In this manuscript, we proposed a novel and effective two dimensional hybrid plasmonic photonic crystal micro-cavity structure to confine the surface plasmon to a sub-wavelength scale mode volume and obtain a relatively high quality factor. By introducing a single-cell defect at the two dimensional triangular lattice photonic crystal layer, the defect cavity has been established to provide sub-wavelength scale plasmonic mode localization within the hybrid plasmonic photonic crystal structure TM band gap. Comprehensive analysis methods of three-dimensional finite difference time domain method (3D-FDTD) have been used to analyze the characteristics of the micro-cavity of this hybrid structure, including the effects of the radius of the nearest neighbor air holes around the defect, the cavity length of the defect and the thickness of the gain medium on the features of the micro-cavity. By using a quantum dots (QDs)-polymer as a gain medium for the low index thin layer, a gain threshold as low as g_th = 534 cm⁻¹ can be achieved with such structures, and deep sub-wavelength mode volume of 0.00201 (λ/n)³ is also obtained.