Design of Graphene Polarization Independent Electro-Optical Modulator Based on Inverted Ridge Structure

Based on the analysis of the principle of polarization independent modulation, a new type of inverted ridge polarization independent electro-optic modulator is proposed, which is inclined to place the graphene sheet in a silicon waveguide at a certain angle. At the wavelength of 1.55 μm, the effective mode parameters of TE and TM modes are the same, and the difference of absorption parameters is very small. In addition, the device can achieve extinction ratio higher than 18 dB for TE and TM modes at wavelengths from 1.5 μm to 1.6 μm, and the difference of extinction ratio is less than 4 dB. The 3 dB modulation bandwidth of the device can reach 123 GHz in ideal state.