Nanostrain Sensing Based on Piezo-Optic Property of a Photonic Crystal Cavity

Abstract

This paper reports the theoretical and experimental investigations of the strain sensitive effect of a 2-D photonic crystal (PhC) cavity for strain sensing applications. Strain sensitivity of a high quality factor PhC cavity is studied based on finite element method (FEM) and finite difference time domain (FDTD) simulations. The results show that the resonant wavelength of cavity is proportional to the application of strain. Linear relationships between strain applied and shift of resonant wavelength were obtained. Thus, it is possible to detect the strain by determining resonant wavelength shift. The test device was fabricated using micromachining for experimental investigation. The sensitivity to longitudinal strains was determined to be 0. 95 pm/μ-strain.