A technique to determine the strain field in one-dimensional (1D) photonic crystal (PC) involving high strain rate, high temperature around shock or ballistic impact is proposed. Transient strain sensing is important in aerospace and other structural health monitoring (SHM) applications. We consider a MEMS based smart sensor design with photonic crystal integrated on a silicon substrate for dynamic strain correlation. Deeply etched silicon rib waveguides with distributed Bragg reflectors are suitable candidates for miniaturization of sensing elements, replacing the conventional FBG. Main objective here is to investigate the effect of non-uniform strain localization on the sensor output. Computational analysis is done to determine the static and dynamic strain sensing characteristics of the 1D photonic crystal based sensor. The structure is designed and modeled using Finite Element Method. Dynamic localization of strain field is observed. The distributed strain field is used to calculated the PC waveguide response. The sensitivity of the proposed sensor is estimated to be 0.6 pm/με.

Date Published: 19 February 2014
PDF: 10 pages
Proc. SPIE 8994, Photonic and Phononic Properties of Engineered Nanostructures IV, 89940B (19 February 2014); doi: 10.1117/12.2042574

Published in SPIE Proceedings Vol. 8994:
Photonic and Phononic Properties of Engineered Nanostructures IV
Ali Adibi; Shawn-Yu Lin; Axel Scherer, Editor(s)