Polarization Engineering in Nanoscale Waveguides Using Lossless Media

Abstract

Abstract-A device that achieves controllable rotation of the state of polarization by rotating the orientation of the eigenmodes of a waveguide by 45• is introduced and analyzed. The device can be implemented using lossless materials on a nanoscale and helps circumvent the inherent polarization dependence of photonic devices realized within the silicon on insulator platform. We propose and evaluate two novel polarization rotator-based schemes to achieve polarization engineering functions: (1) A multi-purpose device, with dimensions on the order of a few wavelengths which can function as a polarization splitter or an arbitrary linear polarization state generator. (2) An energy efficient optical modulator that utilizes eigenmode rotation and epsilon near zero (ENZ) effects to achieve high extinction ratio, polarization insensitive amplitude modulation without the need to sweep the device geometry to match the TE and TM mode attributes. By using indium tin oxide (ITO) as an example for a tunable material, the proposed modulator provides polarization insensitive operation and can be realized with a modulation bandwidth of 112 GHz, a length of 1800 nm an energy per bit of 7.5 f J and an optical bandwidth of 210 nm.

Parallel directional coupler based dual-polarization electro-absorption modulator using epsilon near-zero material

“…This dependency on a single state of polarization increases system complexity in the hybrid PDM-WDM (wavelength-division-multiplexing) based data transmission. Though some initial studies have been proposed for TCO-based polarization-insensitive modulators [29][30][31][32], polarization beam splitter (PBS) is still necessary to split linearly polarized lightwave to transverse magnetic (TM) and transverse electric (TE) modes [24]. Qiu et al proposed an ITO-based dual-polarization intensity modulator [33], which finds a potential solution for omitting the PBS-element at the cost of a very large active length.…”

Magnetoplasmonic Faraday Rotators: Enabling Gigahertz Active Polarization Control for Integrated Plasmonics

“…Alternatively, waveguide-based designs are much more amenable for integrated operation and have been extensively examined for silicon photonics. , There have been several approaches to this class of plasmonic mode converting device, involving either mode evolution or mode interference. In a plasmonic mode evolution device, the structure is designed to have a gradually changing metal feature, such that the input mode couples to a plasmon on the metal and adiabatically evolves into the desired output polarization state.…”