Design of photonic crystal Fizeau interferometer using self-collimation effect

Abstract

A Fizeau interferometer based on the self-collimation effect of two-dimensional air-cylinder photonic crystal is discussed theoretically. The Fizeau interferometer includes one total reflection photonic crystal mirrors and two splitters. Compared with non-common optical path interferometer (e.g. Michelson and Sagnac), Fizeau is a type of common optical path interferometer, therefore the machining errors of optical paths lead to little influence on the interference signals. The equi-frequency contours are calculated by using the plane-wave expansion method, and interference properties are investigated by using the finite-difference time-domain method. The curves of the interference signals at output port are determined by the optical path difference of the interferometer. The peaks of the curves are sensitive to the refraction index changes in the optical path, which make it possible to be applied in future high-density photonic integrated circuits, such as air-sensors.