Highly sensitive sensors using in-fiber gratings fabricated in photonic crystal nanostructures

In this paper, an analysis of long period gratings in photonic nanostructured fibers and waveguides is presented. With the finite-difference time-domain (FDTD) method, a detailed quantitative study on the relationship between the spectral response shift of the gratings and the parameters of the photonic nanostructures is performed. It is found that the unique photonic nanostructures can substantially enhance the tuning capability of the spectral response of the gratings, which can lead to many practical applications in optical sensors and communications, such as optical sensors with ultra high sensitivity and wavelength filters with wide tuning range.