  Integrated waveguide polarizers and polarization-selective micro-ring
resonators (MRRs) incorporated with graphene oxide (GO) films are
experimentally demonstrated. CMOS-compatible doped silica waveguides and MRRs
with both uniformly coated and patterned GO films are fabricated based on a
large-area, transfer-free, layer-by-layer GO coating method that yields precise
control of the film thickness. Photolithography and lift-off processes are used
to achieve photolithographic patterning of GO films with precise control of the
placement and coating length. Detailed measurements are performed to
characterize the performance of the devices versus GO film thickness and
coating length as a function of polarization, wavelength and power. A high
polarization dependent loss of ~53.8 dB is achieved for the waveguide coated
with 2-mm-long patterned GO films. It is found that intrinsic film material
loss anisotropy dominates the performance for less than 20 layers whereas
polarization dependent mode overlap dominates for thicker layers. For the MRRs,
the GO coating length is reduced to 50 microns, yielding a ~ 8.3-dB
polarization extinction ratio between TE and TM resonances. These results offer
interesting physical insights and trends of the layered GO films and
demonstrate the effectiveness of introducing GO films into photonic integrated
devices to realize high-performance polarization selective components.
