Analysis of interference between two optical beams in a quasi-zero electric permittivity photonic crystal superlattice

A quasi-zero-average-index photonic crystal structure has been recently demonstrated by using the concept of complementary media. It consists of dielectric photonic crystal superlattices with alternating layers of negative index photonic crystals and positive index dielectric media. This photonic crystal structure has unique optical properties, such as phase-invariant field and self-collimation of light. In particular, the nanofabricated superlattices can be used in chip-scale optical interconnects and interferometers with quasi-zero-average phase difference. However, in potential interconnect applications, crosstalk between neighboring signals needs to be avoided. In this article, we study simulations of the interference of propagating electromagnetic waves in a quasi-zero electric permittivity photonic crystal superlattice. The simulations here are restricted to TM modes, with the main electric field along the vertical direction.