Silicon photonic circuit with polarization diversity

TLDR

The authors designed a silicon photonic circuit with polarization diversity comprising splitters and rotators, and demonstrated its use in a polarization‑independent wavelength filter based on Si wire waveguides. The circuit uses a directional‑coupler splitter and an off‑axis double‑core rotator, both fabricated with planar technology, and incorporates these elements with a ring resonator to form the filter. The filter achieves only ~1 dB polarization‑dependent loss and supports 10‑Gbps data transmission with scrambled polarization.

Abstract

We devised a silicon photonic circuit with polarization diversity that consists of polarization splitters and polarization rotators. The splitter is based on a simple directional coupler and the rotator has an off-axis double-core structure. Both devices can be made by using planar fabrication technology and require no complex proceses for the fabrication of three-dimensional structures. We fabricated a polarization-independent wavelength filter based on Si wire waveguides as an application of the polarization diversity. The filter consists of the polarization splitters, the rotators, and a ring resonator. The polarization-dependent loss of the filter is about 1 dB. A 10-Gbps data transmission with scrambled polarization is demonstrated.