Integrated nanophotonic polarizers in silicon waveguides and ring resonators using graphene oxide 2D films

TL;DR

This paper demonstrates integrated graphene oxide film-based polarizers in silicon photonic devices, achieving high polarization extinction ratios and broad bandwidth, with potential for advanced polarization control in integrated photonics.

Contribution

The work introduces on-chip integration of anisotropic graphene oxide films onto silicon photonic devices, enabling high-performance polarization filtering with tunable properties.

Findings

Maximum PDL of ~17 dB achieved

Maximum PER of ~10 dB achieved in MRRs

Broad operation bandwidth of over ~100 nm

Abstract

We experimentally demonstrate waveguide and microring resonator (MRR) polarizers by integrating 2D graphene oxide (GO) films onto silicon (Si) photonic devices. The 2D GO films with highly anisotropic light absorption are on-chip integrated with precise control over their thicknesses and sizes. Detailed measurements are performed for the fabricated devices with different GO film thicknesses, coating lengths, and Si waveguide widths. The results show that a maximum polarization-dependent loss (PDL) of ~17 dB is achieved for the hybrid waveguides, and the hybrid MRRs achieved a maximum polarization extinction ratio (PER) of ~10 dB. We also characterize the wavelength- and power-dependent response for these polarizers. The former demonstrates a broad operation bandwidth of over ~100 nm, and the latter verifies performance improvement enabled by photo-thermal changes in GO films. By fitting the experimental results with theoretical simulations, we find that the anisotropy in the loss of GO films dominates the polarization selectivity of these devices. These results highlight the strong potential of 2D GO films for realizing high-performance polarization selective devices in Si photonic platform.