Applications of metamaterials in optical waveguide isolator

Abstract EN

Optical waveguide isolators are vital integrated optic modules in advanced optical fiber communication systems.

This study demonstrates an integrated optical isolator which has simple structure consisting of three layers.

A thin magnetic garnet film is sandwiched between linear dielectric cover and met material (MTM) substrate.

The effective refractive indexes for both forward and backward fields were analytically calculated by deriving the dispersion equation of the transverse magnetic fields (TM).

The difference (Δβ) between the phase constant for the forward and backward propagations was calculated numerically for different values of MTMs permittivity (εs) and permeability (μs).

Δβ is plotted as a function of the film thickness for different values of εs and μs.

Results show that the value of Δβ changes with the parameters of MTMs and decreases as the film thickness increases.

Results also show that Δβmax decreases with decreasing the step difference between the film and the substrate.

Moreover, the lowest value of Δβmax occurs at εs = -0.5.

The findings of this study help designers in selecting the optimal design for the isolator at which Δβ approaches zero.