Polarization Dependent Loss and All-Optical Modulation in Graphene on   Suspended Membrane Waveguides
  We observe a strong polarization dependent optical loss of in-plane light propagation in silicon waveguide due to the presence of graphene. Both transverse-electric (TE) and transverse-magnetic (TM) modes are efficiently (~3 dB) coupled to the graphene on suspended membrane waveguides using an apodized focusing subwavelength grating. The TE mode has 7.7 dB less excess optical loss than the TM mode at 1.5 {\mu}m for a 150 {\mu}m long waveguide in good agreement with a theoretical model. All-optical modulation of light is demonstrated. There is also a large thermally induced change in waveguide effective index because of optical absorption in graphene. 
Zhenzhou Cheng, Hon Ki Tsang, Xiaomu Wang, Chi Yan Wong, Xia Chen, Ke   Xu, Zerui Shi, Jian-Bin Xu
physics.optics