<p>Polarization selective devices, such as polarizers and polarization
selective resonant cavities (e.g., gratings and ring resonators), are core
components for polarization control in optical systems and find wide
applications in polarization-division-multiplexing, coherent optical detection,
photography, liquid crystal display, and optical sensing. In this paper, we
demonstrate integrated waveguide polarizers and polarization-selective
micro-ring resonators (MRRs) incorporated with graphene oxide (GO). We achieve
highly precise control of the placement, thickness, and length of the GO films
coated on integrated photonic devices by using a solution-based, transfer-free,
and layer-by-layer GO coating method followed by photolithography and lift-off
processes. The latter overcomes the layer transfer fabrication limitations of
2D materials and represent a significant advance towards manufacturing
integrated photonic devices incorporated with 2D materials. We measure the
performance of the waveguide polarizer for different GO film thicknesses and
lengths versus polarization, wavelength, and power, achieving a very high
polarization dependent loss (PDL) of ~ 53.8 dB. For GO-coated integrated MRRs,
we achieve an 8.3-dB polarization extinction ratio between the TE and TM
resonances, with the extracted propagation loss showing good agreement with the
waveguide results. Furthermore, we present layer-by-layer characterization of
the linear optical properties of 2D layered GO films, including detailed
measurements that conclusively determine the material loss anisotropy of the GO
films as well as the relative contribution of film loss anisotropy versus
polarization-dependent mode overlap, to the device performance. These results
offer interesting physical insights and trends of the layered GO films from
monolayer to quasi bulk like behavior and confirm the high-performance of
integrated polarization selective devices incorporated with GO films.</p>
Graphene oxide 2D films for integrated waveguide and ring resonator polarizers