Strain sensitivity of a modified single-defect photonic crystal nanocavity for mechanical sensing

This paper reports the theoretical and experimental investigations of the strain sensitive effect of a 2D photonic crystal (PhC) nanocavity resonator for mechanical sensing applications. By using finite element method (FEM) using ANSYS software and finite different time domain (FDTD) simulation using CrystalWave software, the strain sensitivity of a high quality factor PhC nanocavity has been studied. Linear relationships between strain and shift of resonant wavelength of the cavity have been obtained. The sensitivities to longitudinal and transverse strains have been determined to be 1.9 nm/mε and 0.25 nm/mε, respectively. The sample structure were fabricated and characterized. The initial results show that the cavity peak with Q factor estimated to be 3800 had been obtained.