Abstract
In this paper the finite-difference time-domain (FDTD) method is reviewed and then used to model and predict the geometric parameters used for the design of the device. The waveguide consists of a periodic array of air gap etched into a silicon (Si) strip on a silicon dioxide (SiO2) layer. The width and the depth of the grooves of the air gap (n = 1) as well as the length of the silicon layer (n = 3.4) are investigated. Using FDTD, the optical parameters are characterized. The effect of the air gap on the field profile distribution of the whole structure is calculated and performed in the range 0.09687 μm –1.55 μm. The field profile, and the response of the microcavity against frequency are calculated from sinusoidal sources. The spectral behavior of the structure is performed and its validity is verified by calculation of the reflectance spectra.