Nonreciprocal Components for Optical Communication

Abstract

Optical isolators and circulators are needed to reduce feedback effects and noise in optical communication systems. These devides are based on the Faraday rotation or nonreciprocal phase shift in magnetooptic materials such as YIG, which is highly transparent for λ_o> 1 μm. Several versions of discrete microoptic devices provide ∼30 dB isolation independent of polarization. For integrated devices classical E/H/-mode converters, semileaky structures, cut-off isolators and differential phase shift components are investigated. Major progress has been made with respect to improved materials (θ_F >3000°/cm), analysis of optical waveguide modes in strips and multilayer structure and controlled phase match for coupling modes. Remaining problems include the combination of different subelements and integration on semiconductor substrates of integrated optics.

Indexing terms:

• Nonreciprocal components
• Optical isolators and circulators