Open AccessHigh Figure of Merit Fano Resonance in 2-D Defect-Free Pillar Array Photonic Crystal for Refractive Index Sensing
Author(s) -
Daquan Yang,
Changhong Li,
Chuan Wang,
Yuefeng Ji,
Qimin Quan
Publication year - 2016
Publication title -
ieee photonics journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 73
eISSN - 1943-0655
pISSN - 1943-0647
DOI - 10.1109/jphot.2016.2618851
Subject(s) - engineered materials, dielectrics and plasmas , photonics and electrooptics
We present a simple and robust structure to realize Fano resonance for refractive index sensing applications. The Fano resonance with ultrahigh Q factors (Q > 5.0 × 104) and high reflections (near 100%) is realized in a 2-D defect-free pillar array photonic crystal (PAPC) with optimized geometry (e.g., pillar array periodicity, height, and radius). We analyze its band structure, polarization, and transmission characteristics in detail with numerical methods (plane wave expansion and 3-D finite-difference time-domain (3-D-FDTD) simulations). The numerical results show that FOM ~6.85 × 103 (FOM being the figure of merit) can be achieved, which is an order of magnitude improved over the previous work. In addition, the unique simplicity of this system in which a long-lifetime delocalized electromagnetic field exists and interacts with the surrounding media permits new opportunities for point-of-care applications. Furthermore, the proposed architecture makes the implementation of lab-on-a-chip refractive index sensing possible, which is enabled by integrating PAPC on the tip of an optical fiber.