Analysis of a MZI based on a Triangular Lattice 2D Photonic Crystal Waveguide

Mach-Zehnder Interferometer (MZI) is an important component in integrated photonics for optical communication applications. Photonic Crystal (PhC), on the other hand, provides high degree of freedom in controlling light. Therefore, to access the merits both of these optical structures, this paper designs a MZI, based on a holes-in-slab triangular-lattice 2D PhC. Two Y junctions, one for splitting and the other for combining the optical waves, have been created by removing series of holes in 120° with almost 3dB power splitting ratio. The structure was optimized using its band-gap, calculated by the plane-wave expansion (PWE) method, and Finite Difference Time Domain (FDTD) simulations on the design. Diameter of only one hole at the corner of each 60° bend is optimized to obtain high transmittance compared to others optimization work in this context. The normalized transmission spectra for different radii of the corner air hole and the optimized MZI are obtained by using FDTD simulations. The proposed MZI design can be used to design small form-factor switches for integrated photonics by harnessing the slow-light phenomenon of the PhC.