  Sufficient light-matter interactions are important for waveguide-coupled
graphene optoelectronic devices. Using a microfiber-based lab-on-a-rod
technique, we present a platform for ultra-long light-graphene interaction and
design graphene-integrated helical microfiber (MF) devices. Using this
approach, we experimentally demonstrate an in-line stereo polarizer by wrapping
an MF on a rod pretreated with a graphene sheet. The device operates as a
broadband (450 nm wavelength) polarizer capable of achieving an extinction
ratio (ER) as high as ~8 dB/coil in the telecommunication band. Furthermore, we
extend this approach to successfully demonstrate a high-Q graphene-based
single-polarization resonator, which operates with an ER of ~11 dB with
excellent suppression of polarization noise. The fiber-coil resonator shows
great potential for sensing applications and gyro-integration. By specializing
the rod surface and coil geometry, we believe the preliminary results reported
herein could contribute to advancing the research for lab-on-a-rod
graphene-MF-integrated devices.
